Preface

Welcome to Clinical Anatomy by Systems by Richard S.

logic investigations. The anatomy of Common Medical

Snell, MD, PhD. This CD-ROM is designed for medical

Procedures has also been included, and the complications

students doing their clinical rotations, allied health stu-

caused by an ignorance of normal anatomy have been

dents, dental students, nurses, and residents.

emphasized.

The information provided is in the form of Clinical

Examples of clinical cases are given at the end of each

Notes, which are linked to the appropriate chapters of the

group of Clinical Notes. Each clinical vignette is followed

main text. This gives students ready access to the basic

by multiple choice questions. Answers and explanations for

anatomic and clinical material. Sections on Congenital

the problems are given at the end of the section in the CD-

Anomalies are also included.

ROM.

The clinical material provides the medical professional

*No part of this CD-ROM may be reproduced in any

with the practical application of anatomic facts that he or

form or by any means without written permission from the

she will require when examining patients. It will also be of

great assistance when interpreting the findings of techno-

iii

Chapter Outline

Skin

Blood Vessels

Lines of Cleavage

Diseases of Blood Vessels

Skin Infections

Lymphatic System

Sebaceous Cyst

Diseases of the Lymphatic System

Shock

Nervous System

Skin Burns

Segmental Innervation of Skin

Skin Grafting

Segmental Innervation of Muscle

Fasciae

Clinical Modification of the Activities of the

Fasciae and Infection

Autonomic Nervous Systems

Skeletal Muscle

Mucous and Serous Membranes

Muscle Attachments

Mucous and Serous Membranes and Inflammatory

Disease

Muscle Shape and Form

Bones

Cardiac Muscle

Bone Fractures

Necrosis of Cardiac Muscle

Rickets

Joints

Epiphyseal Plate Disorders

Examination of Joints

Clinical Significance of Sex, Race, and

Ligaments

Age on Structure

Damage to Ligaments

Clinical Problem Solving Questions

Bursae and Synovial Sheaths

Trauma and Infection of Bursae and Synovial Sheaths

Answers and Explanations

SKIN

Lines of Cleavage

In the dermis, the bundles of collagen fibers are mostly

arranged in parallel rows. A surgical incision through the

skin made along or between these rows causes the mini-

mum of disruption of collagen, and the wound heals with

minimal scar tissue. Conversely, an incision made across

the rows of collagen disrupts and disturbs it, resulting in the

massive production of fresh collagen and the formation of a

broad, ugly scar. The direction of the rows of collagen is

known as the lines of cleavage (Langer’s lines), and they

tend to run longitudinally in the limbs and circumferen-

tially in the neck and trunk (CD Fig. 1-1).

CD Figure 1-1

Cleavage lines of the skin.

Introduction to Clinical Anatomy

A general knowledge of the direction of the lines of

new circulation within it at the recipient site. The donor site

cleavage greatly assists the surgeon in making incisions that

is usually covered with a split-thickness graft. In certain cir-

result in cosmetically acceptable scars. This is particularly

cumstances the full-thickness graft is made in the form of a

important in those areas of the body not normally covered

pedicle graft, in which a flap of full-thickness skin is turned

by clothing. A salesperson, for example, may lose his or her

and stitched in position at the recipient site, leaving the base

job if an operation leaves a hideous facial scar.

of the flap with its blood supply intact at the donor site.

Later, when the new blood supply to the graft has been

established, the base of the graft is cut across.

Skin Infections

The nail folds, hair follicles, and sebaceous glands are

common sites for entrance into the underlying tissues of

FASCIAE

pathogenic organisms such as Staphylococcus aureus.

Infection occurring between the nail and the nail fold is

called a paronychia. Infection of the hair follicle and seba-

Fasciae and Infection

ceous gland is responsible for the common boil. A carbuncle

Knowledge of the arrangement of the deep fasciae often

is a staphylococcal infection of the superficial fascia. It fre-

helps explain the path taken by an infection when it spreads

quently occurs in the nape of the neck and usually starts as an

from its primary site. In the neck, for example, the various

infection of a hair follicle or a group of hair follicles.

fascial planes explain how infection can extend from the

region of the floor of the mouth to the larynx.

Sebaceous Cyst

A sebaceous cyst is caused by obstruction of the mouth of a

SKELETAL MUSCLE

sebaceous duct and may be caused by damage from a comb

or by infection. It occurs most frequently on the scalp.

Muscle Attachments

Shock

The importance of knowing the main attachments of all

A patient who is in a state of shock is pale and exhibits goose-

the major muscles of the body need not be emphasized.

flesh as a result of overactivity of the sympathetic system,

Only with such knowledge is it possible to understand the

which causes vasoconstriction of the dermal arterioles and

normal and abnormal actions of individual muscles or

contraction of the arrector pili muscles.

muscle groups. How can one even attempt to analyze,

for example, the abnormal gait of a patient without this

information?

Skin Burns

The depth of a burn determines the method and rate of

Muscle Shape and Form

healing. A partial-skin-thickness burn heals from the cells of

the hair follicles, sebaceous glands, and sweat glands as well

The general shape and form of muscles should also be

as from the cells at the edge of the burn. A burn that extends

noted, since a paralyzed muscle or one that is not used (such

deeper than the sweat glands heals slowly and from the

as occurs when a limb is immobilized in a splint) quickly

edges only, and considerable contracture will be caused by

atrophies and changes shape. In the case of the limbs, it is

fibrous tissue. To speed up healing and reduce the inci-

always worth remembering that a muscle on the opposite

dence of contracture, a deep burn should be grafted.

side of the body can be used for comparison.

Skin Grafting

CARDIAC MUSCLE

Skin grafting is of two main types: split-thickness grafting

and full-thickness grafting. In a split-thickness graft the

greater part of the epidermis, including the tips of the der-

Necrosis of Cardiac Muscle

mal papillae, are removed from the donor site and placed on

the recipient site. This leaves at the donor site for repair pur-

The cardiac muscle receives its blood supply from

poses the epidermal cells on the sides of the dermal papillae

the coronary arteries. A sudden block of one of the large

and the cells of the hair follicles and sweat glands.

branches of a coronary artery will inevitably lead to necro-

A full-thickness skin graft includes both the epidermis

sis of the cardiac muscle and often to the death of the

and dermis and, to survive, requires rapid establishment of a

patient.

Chapter 1

clot at the damaged site is invaded by blood vessels and

fibroblasts. The fibroblasts lay down new collagen and elas-

JOINTS

tic fibers, which become oriented along the lines of me-

chanical stress.

Examination of Joints

When examining a patient, the clinician should assess

the normal range of movement of all joints. When

BURSAE AND

the bones of a joint are no longer in their normal

anatomic relationship with one another, then the joint is

SYNOVIAL

said to be dislocated. Some joints are particularly suscep-

tible to dislocation because of lack of support by ligaments,

the poor shape of the articular surfaces, or the absence

SHEATHS

of adequate muscular support. The shoulder joint, tem-

poromandibular joint, and acromioclavicular joints are

Trauma and Infection of Bursae

good examples. Dislocation of the hip is usually congeni-

tal, being caused by inadequate development of the

and Synovial Sheaths

socket that normally holds the head of the femur firmly

in position.

Bursae and synovial sheaths are commonly the site of

The presence of cartilaginous discs within joints, espe-

traumatic or infectious disease. For example, the extensor

cially weightbearing joints, as in the case of the knee, makes

tendon sheaths of the hand may become inflamed after ex-

them particularly susceptible to injury in sports. During

cessive or unaccustomed use; an inflammation of the

a rapid movement the disc loses its normal relationship

prepatellar bursa may occur as the result of trauma from re-

to the bones and becomes crushed between the weight-

peated kneeling on a hard surface.

bearing surfaces.

In certain diseases of the nervous system (e.g., sy-

ringomyelia), the sensation of pain in a joint is lost. This

means that the warning sensations of pain felt when a joint

moves beyond the normal range of movement are not

BLOOD VESSELS

experienced. This phenomenon results in the destruction of

the joint.

Diseases of Blood Vessels

Knowledge of the classification of joints is of great value

because, for example, certain diseases affect only certain

Diseases of blood vessels are common. The surface anatomy

types of joints. Gonococcal arthritis affects large synovial

of the main arteries, especially those of the limbs, is dis-

joints such as the ankle, elbow, or wrist, whereas tubercu-

cussed in the appropriate sections of this book. The collat-

lous arthritis also affects synovial joints and may start in the

eral circulation of most large arteries should be understood,

synovial membrane or in the bone.

and a distinction should be made between anatomic end

Remember that more than one joint may receive the

arteries and functional end arteries.

same nerve supply. For example, the hip and knee joints

All large arteries that cross over a joint are liable to be

are both supplied by the obturator nerve. Thus, a patient

kinked during movements of the joint. However, the distal

with disease limited to one of these joints may experience

flow of blood is not interrupted because an adequate anas-

pain in both.

tomosis is usually between branches of the artery that arise

both proximal and distal to the joint. The alternative blood

channels, which dilate under these circumstances, form the

collateral circulation. Knowledge of the existence and posi-

LIGAMENTS

tion of such a circulation may be of vital importance should

it be necessary to tie off a large artery that has been damaged

by trauma or disease.

Damage to Ligaments

Coronary arteries are functional end arteries, and if

Joint ligaments are very prone to excessive stretching and

they become blocked by disease (coronary arterial occlusion

even tearing and rupture. If possible, the apposing damaged

is common), the cardiac muscle normally supplied by that

surfaces of the ligament are brought together by positioning

artery will receive insufficient blood and undergo necrosis.

and immobilizing the joint. In severe injuries, surgical

Blockage of a large coronary artery results in the death of the

approximation of the cut ends may be required. The blood

patient.

Introduction to Clinical Anatomy

Learning the segmental innervation of all the muscles

LYMPHATIC

of the body is an impossible task. Nevertheless, the segmen-

tal innervation of the following muscles should be known

because they can be tested by eliciting simple muscle

SYSTEM

reflexes in the patient (CD Fig. 1-4):

■ Biceps brachii tendon reflex: C5 and 6 (flexion of the

Diseases of the Lymphatic System

elbow joint by tapping the biceps tendon)

The lymphatic system is often de-emphasized by anatomists

■ Triceps tendon reflex: C6, 7, and 8 (extension of the

on the grounds that it is difficult to see on a cadaver. However,

elbow joint by tapping the triceps tendon)

it is of vital importance to medical personnel, since lymph

■ Brachioradialis tendon reflex: C5, 6, and 7 (supination

nodes may swell as the result of infection, metastases, or pri-

of the radioulnar joints by tapping the insertion of the

mary tumor. For this reason, the lymphatic drainage of all ma-

brachioradialis tendon)

jor organs of the body, including the skin, should be known.

■ Abdominal superficial reflexes (contraction of underly-

A patient may complain of a swelling produced by the

ing abdominal muscles by stroking the skin): Upper

enlargement of a lymph node. A physician must know the

abdominal skin T6-7, middle abdominal skin T8-9, and

areas of the body that drain lymph to a particular node if he

lower abdominal skin T10-12

or she is to be able to find the primary site of the disease. Of-

■ Patellar tendon reflex (knee jerk): L2, 3, and 4 (exten-

ten the patient ignores the primary disease, which may be a

sion of the knee joint on tapping the patellar tendon)

small, painless cancer of the skin.

■ Achilles tendon reflex (ankle jerk): S1 and S2 (plantar

Conversely, the patient may complain of a painful ulcer

flexion of the ankle joint on tapping the Achilles

of the tongue, for example, and the physician must know the

tendon)

lymph drainage of the tongue to be able to determine whether

the disease has spread beyond the limits of the tongue.

Clinical Modification of the

Activities of the Autonomic

NERVOUS SYSTEM

Nervous System

Many drugs and surgical procedures that can modify the

Segmental Innervation of the Skin

activity of the autonomic nervous system are available. For

example, drugs can be administered to lower the blood

The area of skin supplied by a single spinal nerve, and

pressure by blocking sympathetic nerve endings and causing

therefore a single segment of the spinal cord, is called a

vasodilatation of peripheral blood vessels. In patients with

dermatome. On the trunk, adjacent dermatomes overlap

severe arterial disease affecting the main arteries of the lower

considerably; to produce a region of complete anesthesia, at

limb, the limb can sometimes be saved by sectioning the

least three contiguous spinal nerves must be sectioned. Der-

sympathetic innervation to the blood vessels. This produces

matomal charts for the anterior and posterior surfaces of the

a vasodilatation and enables an adequate amount of blood to

body are shown in CD Figs. 1-2 and 1-3.

flow through the collateral circulation, thus bypassing the

In the limbs, arrangement of the dermatomes is more

obstruction.

complicated because of the embryologic changes that take

place as the limbs grow out from the body wall.

A physician should have a working knowledge of the

segmental (dermatomal) innervation of skin, because with

MUCOUS AND

the help of a pin or a piece of cotton he or she can determine

whether the sensory function of a particular spinal nerve or

SEROUS

segment of the spinal cord is functioning normally.

MEMBRANES

Segmental Innervation of Muscle

Skeletal muscle also receives a segmental innervation. Most

Mucous and Serous Membranes

of these muscles are innervated by two, three, or four spinal

nerves and therefore by the same number of segments of the

and Inflammatory Disease

spinal cord. To paralyze a muscle completely, it is thus nec-

essary to section several spinal nerves or to destroy several

Mucous and serous membranes are common sites for in-

segments of the spinal cord.

flammatory disease. For example, rhinitis, or the common

Chapter 1

transverse cutaneous nerve of neck

supraclavicular nerves

anterior cutaneous branch of second

intercostal nerve

upper lateral cutaneous nerve of arm

medial cutaneous nerve of arm

lower lateral cutaneous nerve of arm

medial cutaneous nerve of forearm

lateral cutaneous nerve of forearm

lateral cutaneous branch of

T10

subcostal nerve

T11

T12

femoral branch of genitofemoral

nerve

median nerve

ulnar nerve

ilioinguinal nerve

lateral cutaneous nerve of thigh

obturator nerve

medial cutaneous nerve of thigh

intermediate cutaneous nerve of thigh

infrapatellar branch of saphenous nerve

lateral sural cutaneous nerve

saphenous nerve

superficial peroneal nerve

deep peroneal nerve

CD Figure 1-2

Dermatomes and dis-

tribution of cutaneous nerves on the

anterior aspect of the body.

cold, is an inflammation of the nasal mucous membrane,

rections taken by the bony fragments depend not only on

and pleurisy is an inflammation of the visceral and parietal

the mechanism of injury, but also on the pull of the mus-

layers of the pleura.

cles attached to the fragments. Ligamentous attachments

also influence the deformity. In certain situations—for

example, the ileum—fractures result in no deformity be-

cause the inner and outer surfaces of the bone are splinted

BONES

by the extensive origins of muscles. In contrast, a fracture

of the neck of the femur produces considerable displace-

ment. The strong muscles of the thigh pull the distal frag-

Bone Fractures

ment upward so that the leg is shortened. The very strong

Immediately after a fracture, the patient suffers severe lo-

lateral rotators rotate the distal fragment laterally so that

cal pain and is not able to use the injured part. Deformity

the foot points laterally.

may be visible if the bone fragments have been displaced

Fracture of a bone is accompanied by a considerable

relative to each other. The degree of deformity and the di-

hemorrhage of blood between the bone ends and into the

Introduction to Clinical Anatomy

greater occipital nerve

third cervical nerve

great auricular nerve

fourth cervical nerve

lesser occipital nerve

supraclavicular nerve

first thoracic nerve

posterior cutaneous nerve of arm

medial cutaneous nerve of arm

posterior cutaneous nerve of forearm

medial cutaneous nerve of forearm

lateral cutaneous nerve of forearm

T10

T11

lateral cutaneous branch of T12

T12

posterior cutaneous branches of

L1, 2, and 3

radial nerve

ulnar nerve

posterior cutaneous branches of

S1, 2, and 3

branches of posterior cutaneous

nerve of thigh

posterior cutaneous nerve of thigh

obturator nerve

lateral cutaneous nerve

of calf

sural nerve

saphenous nerve

lateral plantar nerve

CD Figure 1-3

Dermatomes and distri-

medial plantar nerve

bution of cutaneous nerves on the pos-

terior aspect of the body.

surrounding soft tissue. The blood vessels and the fibroblasts

bossing of the frontal bones of the skull. Deformities of the

and osteoblasts from the periosteum and endosteum take

pelvis may also occur.

part in the repair process.

Epiphyseal Plate Disorders

Rickets

Epiphyseal plate disorders affect only children and adoles-

Rickets is a defective mineralization of the cartilage matrix

cents. The epiphyseal plate is the part of a growing bone con-

in growing bones. This produces a condition in which the

cerned primarily with growth in length. Trauma, infection,

cartilage cells continue to grow, resulting in excess cartilage

diet, exercise, and endocrine disorders can disturb the growth

and a widening of the epiphyseal plates. The poorly miner-

of the hyaline cartilaginous plate, leading to deformity and loss

alized cartilaginous matrix and the osteoid matrix are soft,

of function. In the femur, for example, the proximal epiphysis

and they bend under the stress of bearing weight. The

can slip because of mechanical stress or excessive loads. The

resulting deformities include enlarged costochondral junc-

length of the limbs can increase excessively because of in-

tions, bowing of the long bones of the lower limbs, and

creased vascularity in the region of the epiphyseal plate sec-

Introduction to Clinical Anatomy

ondary to infection or in the presence of tumors. Shortening

2. The liver is relatively much larger in the child than in

of a limb can follow trauma to the epiphyseal plate resulting

the adult. In the infant, the lower margin of the liver ex-

from a diminished blood supply to the cartilage.

tends inferiorly to a lower level than in the adult. This

is an important consideration when making a diagnosis

of hepatic enlargement.

CLINICAL

3. The urinary bladder in the child cannot be accommo-

dated entirely in the pelvis because of the small size of

SIGNIFICANCE OF

the pelvic cavity and thus is found in the lower part of

the abdominal cavity. As the child grows, the pelvis en-

SEX, RACE, AND

larges and the bladder sinks down to become a true

pelvic organ.

AGE ON STRUCTURE

4. At birth, all bone marrow is of the red variety. With

advancing age, the red marrow recedes up the

The fact that the structure and function of the human body

bones of the limbs so that in the adult it is largely

change with age may seem obvious, but it is often over-

confined to the bones of the head, thorax, and

looked; a child is just not a small adult. A few examples of

abdomen.

such changes are given here:

1. In the infant, the bones of the skull are more resilient

5. Lymphatic tissues reach their maximum degree of de-

than in the adult, and for this reason fractures of the

velopment at puberty and thereafter atrophy, so the vol-

skull are much more common in the adult than in the

ume of lymphatic tissue in older persons is considerably

young child.

reduced.

Clinical Problem Solving Questions

Read the following case histories/questions and give

examination, she has severe right lateral flexion defor-

the best answer for each.

mity of the vertebral column.

2. The following statement is correct about this case:

A 45-year-old patient has a small, firm, mobile tumor

A. The virus of poliomyelitis attacks and always destroys

on the dorsum of the right foot just proximal to

the motor anterior horn cells of the spinal cord.

the base of the big toe and superficial to the bones and

B. The disease resulted in the paralysis of the muscles

the long extensor tendon but deep to the superficial

that normally laterally flex the vertebral column on

fascia. The patient has a neurofibroma of a digital

the left side.

nerve.

C. The muscles on the right side of the vertebral col-

1. The following information concerning the tumor is

umn are hyperactive.

correct:

D. The right lateral flexion deformity is caused by the

A. It is situated on the lower surface of the foot close to

slow degeneration of the sensory nerve fibers origi-

the root of the big toe.

nating from the vertebral muscles on the right side.

B. It is attached to the first metatarsal bone.

C. On palpation, it moves more freely from medial to

A 20-year-old woman severely sprains her left ankle while

lateral than from proximal to distal.

playing tennis. When she tries to move the foot so that

D. It lies deep to the tendon of the extensor hallucis

the sole faces medially, she experiences severe pain.

longus muscle.

3. What is the correct anatomic term for the movement of

E. It is attached to the capsule of the metatarsopha-

the foot that produces the pain?

langeal joint of the big toe.

A. Pronation

A 31-year-old woman has a history of poliomyelitis af-

B. Inversion

fecting the anterior horn cells of the lower thoracic and

C. Supination

lumbar segments of the spinal cord on the left side. On

D. Eversion

Chapter 1

A 25-year-old man has a deep-seated abscess in the pos-

A woman recently took up employment in a factory.

terior part of the neck.

She is a machinist, and for 6 hours a day she has to

move a lever repeatedly, which requires that she extend

The following statement is correct concerning the

and flex her right wrist joint. At the end of the second

abscess:

week of her employment, she began to experience pain

A. The abscess probably lies superficial to the deep

over the posterior surface of her wrist and noticed a

fascia.

swelling in the area.

B. The deep fascia does not determine the direction of

spread of the abscess.

The following statements concerning this patient are

C. The abscess would be incised through a vertical skin

correct except which?

incision.

A. Extension of the wrist joint is brought about by

D. The lines of cleavage are not important when

several muscles that include the extensor digitorum

considering the direction of skin incisions.

muscle.

E. The abscess would be incised, if possible, through a

B. The wrist joint is diseased.

horizontal skin incision.

C. Repeated unaccustomed movements of tendons

through their synovial sheaths can produce trau-

A 40-year-old workman received a severe burn on

matic inflammation of the sheaths.

the anterior aspect of his right forearm. The area of the

D. The diagnosis is traumatic tenosynovitis of the long

burn exceeded 4 in.² (10 cm²). The greater part of

tendons of the extensor digitorum muscle.

the burn was superficial and extended only into the

superficial part of the dermis.

A 19-year-old boy was suspected of having leukemia. It

was decided to confirm the diagnosis by performing a

In the superficially burned area, the epidermis cells

bone marrow biopsy.

would regenerate from the following sites except which?

A. The hair follicles

The following statements concerning this procedure

B. The sebaceous glands

are correct except which?

C. The margins of the burn

A. The biopsy was taken from the lower end of the

D. The deepest ends of the sweat glands

tibia.

In a small area the burn penetrated as far as the superfi-

B. Red bone marrow specimens can be obtained from

cial fascia; in this region, the epidermal cells would

the sternum or the iliac crests.

regenerate from the following sites except which?

C. At birth, the marrow of all bones of the body is red

A. The ends of the sweat glands that lie in the superfi-

and hematopoietic.

cial fascia

D. The blood-forming activity of bone marrow in

B. The margins of the burn

many long bones gradually lessens with age, and

C. The sebaceous glands

the red marrow is gradually replaced by yellow

marrow.

In a 63-year-old man, a magnetic resonance imaging

scan of the lower thoracic region of the vertebral col-

A 22-year-old woman had a severe infection under the

umn reveals the presence of a tumor pressing on the

lateral edge of the nail of her right index finger. On ex-

lumbar segments of the spinal cord. He has a loss of

amination, a series of red lines were seen to extend up

sensation in the skin over the anterior surface of the left

the back of the hand and around to the front of the fore-

thigh and is unable to extend his left knee joint. Exam-

arm and arm, up to the armpit.

ination reveals that the muscles of the front of the left

10.

The following statements concerning this patient are

thigh have atrophied and have no tone and that the

probably correct except which?

left knee jerk is absent.

A. Palpation of the right armpit revealed the presence

The following statements concerning this patient are

of several tender enlarged lymph nodes

(lym-

correct except which?

phadenitis).

A. The tumor is interrupting the normal function of the

B. The red lines were caused by the superficial lym-

efferent motor fibers of the spinal cord on the left side.

phatic vessels in the arm, which were red and in-

B. The quadriceps femoris muscles on the front of the

flamed (lymphangitis) and could be seen through

left thigh are atrophied.

the skin.

C. The loss of skin sensation is confined to the der-

C. Lymph from the right arm entered the bloodstream

matomes L1, 2, 3, and 4.

through the thoracic duct.

D. The absence of the left knee jerk is because of

D. Infected lymph entered the lymphatic capillaries

involvement of the first lumbar spinal segment.

from the tissue spaces.

Introduction to Clinical Anatomy

Answers and Explanations

C is the correct answer. The tumor is a neurofibroma of

neck plays an important role in the direction of spread

a small digital nerve. This fact explains why the tumor

of a deep-seated abscess. C. The abscess would only be

is relatively superficial and moves with the digital nerve

incised through a vertical incision if a horizontal inci-

more freely from medial to lateral than from proximal

sion along a line of cleavage was not possible. A vertical

to distal. A. The tumor is situated on the dorsum or up-

incision in the neck would result in an unsightly scar.

per surface of the foot. B. The tumor is mobile and not

D. The lines of cleavage (see CD Fig. 1-1) are very im-

attached to the first metatarsal bone. D. The tumor lies

portant when considering the direction of skin inci-

superficial to the tendon of the extensor hallucis longus

sions. However, cosmetic concerns have to take second

muscle. E. The tumor is mobile and is not attached to

place in life-threatening situations.

the capsule of the metatarsophalangeal joint.

D is the correct answer. In a superficial burn, the epi-

B is the correct answer. The disease infected the ante-

dermal cells would regenerate from the hair follicles,

rior horn cells, whose axons supply the muscles that

the sebaceous glands, and the margins of the burn.

normally laterally flex the vertebral column on the left

C is the correct answer. The sebaceous glands are lo-

side. A. The virus of poliomyelitis attacks anterior horn

cated superficially (see text Fig. 1-4) and are destroyed

cells in the spinal cord. The result may be death of the

in deep burns.

cells and muscle paralysis or, depending on the severity

of the attack, the nerve cells may recover and the mus-

D is the correct answer. The patellar tendon reflex (knee

cle paralysis may also recover. C. The muscles on the

jerk) involves L2, 3, and 4 segments of the spinal cord.

right side of the vertebral column are contracting nor-

mally against the paralyzed left-sided vertebral muscles.

B is the correct answer. The wrist joint is not diseased

D. The sensory nerves of muscles are unaffected by the

in this patient. The swelling on the posterior surface of

polio virus.

the wrist region was caused by the excessive production

of fluid in the synovial sheaths of the extensor tendons

B is the correct answer. The movement of the foot so

secondary to repeated and excessive extensor move-

that the sole comes to face medially is called inversion

ments, a condition called traumatic tenosynovitis.

(see text Fig. 1-3). For a full discussion of the move-

ments of inversion and eversion of the foot at the subta-

A is the correct answer. In a 19-year-old boy, the bone

lar and transverse joints of the foot, see text.

marrow at the lower end of the tibia is yellow. A biopsy

specimen of red marrow in an adult, who is suspected

E is the correct answer. The abscess would be incised,

of suffering from leukemia, is easily obtained from the

if possible, through a horizontal skin incision along a

iliac crests or the sternum.

line of cleavage (see CD Fig. 1-1). A. A deep-seated

abscess in the neck usually lies deep to the superficial

10.

C is the correct answer. Lymph from the right upper

fascia and beneath the investing layer of deep cervical

limb enters the bloodstream through the right lym-

fascia. B. The arrangement of the deep fascia in the

phatic duct.

Chapter Outline

The Nose

Parotid Duct and Facial Injuries

Pupillodilatation

Submandibular Gland: Calculus Formation

Examination of the Nasal Cavity

Sublingual Gland and Cyst Formation

Infection of the Nasal Cavity

The Pharynx

Nasal Obstruction

Killian’s Dehiscence and Foreign Bodies

Trauma to the Nose

The Piriform Fossa and Foreign Bodies

Nasal Fractures

The Process of Swallowing (Deglutition)

Skin Lacerations

Swallowing in Unconscious Individuals

Congenital Anomalies of the Nose

Pharyngeal Obstruction of the Upper Airway

Median Nasal Furrow

Loss of the Gag Reflex

Lateral Proboscis

Palatine Tonsils

The Paranasal Sinuses

Examination of the Tonsils

Sinusitis and the Examination of the

Tonsillitis

Paranasal Sinuses

Quinsy

The Mouth

Adenoids

Examination of the Mouth

The Larynx

Lips and Vestibule and Facial Paralysis

The Cricoid Cartilage and the Sellick Maneuver

Ranula

Relationship between Vocal Folds and

The Tongue

Cricothyroid Ligament

Laceration of the Tongue

Larynx in Children

Tongue and Airway Obstruction

Epiglottitis

Anatomy of Procedures

Pulling the Tongue Forward in Airway

Foreign Bodies in the Airway

Obstruction

Anatomic Rationale for Differences in Procedures for

Oral Endotracheal Intubation

Removing Foreign Bodies in Adults and Children

Oral Endotracheal Intubation and the

Lesions of the Laryngeal Nerves

Incisor Teeth

Oral Endotracheal Intubation and the

Inspection of the Vocal Cords (Folds) with the

Small Mandible

Laryngeal Mirror and Laryngoscope

The Palate

Important Anatomic Axes for Endotracheal

Intubation

Angioedema of the Uvula (Quincke’s Uvula)

Anatomy of the Visualization of the Vocal Cords

Congenital Anomalies of the Palate

with the Laryngoscope

Cleft Palate

Reflex Activity Secondary to Endotracheal

The Salivary Glands

Intubation

Parotid Salivary Gland and Lesions of the

The Trachea

Facial Nerve

Palpation of the Trachea

Parotid Gland Infections

The Upper and Lower Airway and Associated Structures

Compromised Airway

The Bronchi

Anatomy of Cricothyroidotomy

Aspiration of Foreign Bodies and Stomach Contents

Complications

Anatomy of Tracheostomy

Suction Catheters, Endotracheal Tubes, and the

Complications

Bronchi

Some Important Airway Distances

Bronchopulmonary Segments

Changes in the Tracheal Length with

Clinical Problem Solving Questions

Respiration and Position of the Head

and Neck

Answers and Explanations

Infection of the Nasal Cavity

THE NOSE

Infection of the nasal cavity can spread in a variety of

directions. The paranasal sinuses are especially prone to

Pupillodilatation

infection. Organisms may spread via the nasal part of the

pharynx and the auditory tube to the middle ear. It is pos-

A vasoconstrictor sprayed into the nasal vestibule can ascend

sible for organisms to ascend to the meninges of the ante-

in the nasolacrimal duct to the conjunctival sac, where it is

rior cranial fossa, along the sheaths of the olfactory nerves

absorbed, and may produce pupillodilatation.

through the cribriform plate, and produce meningitis.

Epistaxis, or bleeding from the nose, is a frequent con-

dition. The most common cause is nose picking. The

Examination of the Nasal Cavity

bleeding may be arterial or venous, and most episodes oc-

Examination of the nasal cavity may be carried out by insert-

cur on the anteroinferior portion of the septum and in-

ing a speculum through the external nares or by means of a

volve the septal branches of the sphenopalatine and facial

mirror in the pharynx. In the latter case, the choanae and the

vessels.

posterior border of the septum can be visualized (CD Fig. 2-

Beware of bilateral cauterization of the septal mucous

1). It should be remembered that the nasal septum is rarely

membrane. It could compromise the blood supply to the

situated in the midline. A severely deviated septum may

perichondrium and cause necrosis of the cartilaginous part

interfere with drainage of the nose and the paranasal sinuses.

of the septum.

nasal septum

superior concha

middle concha

tubal elevation

inferior concha

soft palate

uvula

CD Figure 2-1

A. Position of the mirror in posterior rhinoscopy. B. Structures seen in

posterior rhinoscopy.

Chapter 2

lip, or across the lower eyelid, since future scars tend to con-

Nasal Obstruction

tract and distort the depression.

Nasal obstruction can be caused by edema of the mucous

membrane secondary to infection, or by foreign bodies

lodged between the conchae. The shelf-like conchae make

CONGENITAL

impaction and retention of balloons, peas, and small toys

relatively easy in children. Other causes include tumors,

ANOMALIES OF

polyps, and septal abscesses.

Deflection of the nasal septum is common. It is be-

THE NOSE

lieved to occur most commonly in males because of trauma

in childhood.

The most voluminous part of the nasal cavity is close to

Median Nasal Furrow

the floor, and it is usually possible to pass a well-lubricated

tube through the nostril along the inferior meatus into the

In median nasal furrow, the nasal septum is split, separating

nasopharynx.

the two halves of the nose (CD Fig. 2-2A).

Trauma to the Nose

Lateral Proboscis

In lateral proboscis, a skin-covered process develops, usually

Nasal Fractures

with a dimple at its lower end (CD Fig. 2-2B).

Fractures involving the nasal bones are common. Blows di-

rected from the front may cause one or both nasal bones to

be displaced downward and inward.

THE PARANASAL

Lateral fractures also occur in which one nasal bone is

driven inward and the other outward; the nasal septum is

usually involved.

SINUSES

Skin Lacerations

Sinusitis and the Examination of

Lacerations are sutured in the usual way. Remember, how-

ever, that there is very little excess of skin so that the vascu-

the Paranasal Sinuses

larity may be compromised if too much tension is placed on

the sutures. Avoid making incisions across depressed areas

Infection of the paranasal sinuses is a common complication

on the side of the nose or at the junction of the nose and the

of nasal infections. Rarely, the cause of maxillary sinusitis is

CD Figure 2-2

A. Median nasal furrow in which the nasal septum has completely split,

separating the two halves of the nose. Note that the external nares are separated by a wide

furrow. (Courtesy of L Thompson.) B. Lateral proboscis.

The Upper and Lower Airway and Associated Structures

frontal sinus

maxillary sinus

sphenoethmoidal recess

superior concha

frontal sinus

superior meatus

ethmoidal sinuses

middle meatus

middle concha

bulla ethmoidalis

hiatus semilunaris

maxillary sinus

inferior meatus

inferior concha

CD Figure 2-3

A. Bones of the face showing the po-

sitions of the frontal and maxillary sinuses. B. Regions

where pain is experienced in sinusitis (lightly dotted

palate

nasal septum

area in frontal sinusitis; solid area in sphenoethmoidal

sinusitis; and heavily dotted area in maxillary sinusi-

tis). C. Coronal section through the nasal cavity show-

ing the frontal, ethmoidal, and maxillary sinuses.

extension from an apical dental abscess. The extreme thin-

have pain referred over this area (see CD Fig. 2-3). The

ness of the medial wall of the orbit relative to the ethmoidal

maxillary sinus is innervated by the infraorbital nerve and,

air cells must be emphasized. Ethmoidal sinusitis is the most

in this case, pain is referred to the upper jaw, including the

common cause of orbital cellulitis. The infection can easily

teeth (see CD Fig. 2-3).

spread through the paper-thin bone.

The frontal, ethmoidal, and maxillary sinuses can be

palpated clinically for areas of tenderness (CD Fig. 2-3).

THE MOUTH

The frontal sinus can be examined by pressing the finger up-

ward beneath the medial end of the superior orbital margin.

Here the floor of the frontal sinus is closest to the surface.

Examination of the Mouth

The ethmoidal sinuses can be palpated by pressing the

finger medially against the medial wall of the orbit. The

The mouth is one of the most important areas of the body

maxillary sinus can be examined for tenderness by pressing

that the medical professional is called on to examine. Need-

the finger against the anterior wall of the maxilla below the

less to say, the health professional must be able to recognize

inferior orbital margin; pressure over the infraorbital nerve

all the structures visible in the mouth and be familiar with

may reveal increased sensitivity.

the normal variations in the color of the mucous membrane

The frontal sinus is supplied by the supraorbital nerve,

covering the underlying structures. The sensory nerve sup-

which also supplies the skin of the forehead and scalp. It is

ply and lymph drainage of the mouth cavity should be

not surprising, therefore, that patients with frontal sinusitis

known. The close relation of the lingual nerve to the lower

Chapter 2

third molar tooth should be remembered. The close rela-

Sometimes this is inadequate to relieve the obstruction and

tion of the submandibular duct to the floor of the mouth

should be supplemented by placing the fingers behind the

may enable one to palpate a calculus in cases of periodic

angles of the mandible and exerting forward pressure. This

swelling of the submandibular salivary gland.

moves the mandible forward, causing displacement of the

tongue away from the laryngeal opening, since the mandible

is attached to the tongue by the genioglossus muscles.

Lips and Vestibule and Facial

Oral Endotracheal Intubation

Paralysis

Total visualization of the glottis with a laryngoscope is not

Asymmetry of the lips and paralysis of the buccinator with a

necessary for endotracheal intubation. If the epiglottis is vis-

tendency to accumulate saliva and food in the vestibule in-

ible, the tube is laid on the laryngeal side of the epiglottis

dicate a lesion of the facial nerve on that side.

and advanced along its surface. Often this procedure alone

will allow the tube to go into the trachea. If only the esoph-

Ranula

agus is visible and not the vocal cords, the endotracheal tube

can be placed “blindly” just anterior to the esophageal open-

Ranula is a cystic swelling arising in a distended mucous

ing. Occasionally when the tube is caught at the anterior

gland of the mucous membrane. It commonly occurs in the

glottic constriction, the head should be flexed slightly, al-

floor of the mouth, and because of its transparent covering,

lowing the pressure of the tongue to displace the endotra-

it resembles frog skin.

cheal tube posteriorly and hence move it into the opening

of the glottis. Frequently this maneuver has to be supple-

mented by turning the head slightly to one side or another.

THE TONGUE

The use of styleted endotracheal tubes also may help in this

situation. “Trigger tubes” may be used, which allow the tip

to be manipulated from above.

Laceration of the Tongue

When oral endotracheal intubation is impossible in the

above situations, nasotracheal intubation may be successful,

A wound of the tongue is often caused by the patient’s teeth

since the tube approaches the glottis slightly more posteri-

following a blow on the chin when the tongue is partly pro-

orly and is directed more toward it.

truded from the mouth. It can also occur when a patient ac-

cidentally bites the tongue while eating, during recovery

Oral Endotracheal Intubation and the Incisor Teeth

from an anesthetic, or during an epileptic attack. Bleeding

Interference with endotracheal intubation may be caused

is halted by grasping the tongue between the finger and

by the presence of protruding incisor teeth, often making it

thumb posterior to the laceration, thus occluding the

necessary to put the endotracheal tube in an extreme lateral

branches of the lingual artery.

position to approach the glottis.

Oral Endotracheal Intubation and the Small Mandible

Tongue and Airway Obstruction

Patients with receding jaws, secondary to a small mandible,

In an unconscious patient, there is a tendency for the

often make intubation difficult, and in some cases the nasal

tongue to fall backward and obstruct the laryngeal opening.

route or a lighted stylet or digital intubation must be used.

This is caused by the loss of tone of the extrinsic muscles

However, since this anatomic configuration approaches the

and, unless quickly corrected “with a jaw thrust or chin lift

picture seen in younger children, many times a small

maneuver,” will lead to all of the signs and symptoms of air-

straight blade such as a Miller no. 2 or Miller no. 3 can over-

way obstruction.

come the visual difficulties noted when a curved blade of

the Macintosh type is used.

Anatomy of Procedures

Pulling the Tongue Forward in Airway

THE PALATE

Obstruction

The head should be extended at the atlantooccipital joint

Angioedema of the Uvula (Quincke’s

and the neck flexed at the C4 to C7 joints. The extended

head stretches the fascia and muscles of the front of the neck

Uvula)

and causes a forward and downward movement of the

mandible that is correctable by placing a finger below the

The uvula has a core of voluntary muscle, the musculus

symphysis menti and pulling the mandible forward and up.

uvulae, that is attached to the posterior border of the hard

The Upper and Lower Airway and Associated Structures

palate. Surrounding the muscle is the loose connective tis-

sue of the submucosa that is responsible for the great

swelling of this structure secondary to angioedema.

CONGENITAL

ANOMALIES OF

THE PALATE

Cleft Palate

Cleft palate is commonly associated with cleft upper lip.

All degrees of cleft palate occur and are caused by failure

of the palatal processes of the maxilla to fuse with each

other in the midline; in severe cases, these processes also

fail to fuse with the primary palate (premaxilla) (CD Figs.

2-4 and 2-5). The first degree of severity is cleft uvula, and

the second degree is ununited palatal processes. The third

degree is ununited palatal processes and a cleft on one side

of the primary palate. This type is usually associated with

unilateral cleft lip. The fourth degree of severity, which is

rare, consists of ununited palatal processes and a cleft on

both sides of the primary palate. This type is usually asso-

ciated with bilateral cleft lip. A rare form may occur in

which a bilateral cleft lip and failure of the primary palate

CD Figure 2-5

Different forms of cleft palate: cleft uvula (A),

cleft soft and hard palate (B), total unilateral cleft palate and

to fuse with the palatal processes of the maxilla on each

cleft lip (C), total bilateral cleft palate and cleft lip (D), and

side are present.

bilateral cleft lip and jaw (E).

A baby born with a severe cleft palate presents a difficult

feeding problem, since he or she is unable to suck effi-

ciently. Such a baby often receives in the mouth some milk,

which then is regurgitated through the nose or aspirated into

THE SALIVARY

the lungs, leading to respiratory infection. For this reason,

careful artificial feeding is required until the baby is strong

enough to undergo surgery. Plastic surgery is recommended

GLANDS

usually between 1 and 2 years of age, before improper

speech habits have been acquired.

Parotid Salivary Gland and Lesions

of the Facial Nerve

The facial nerve lies in the interval between the superficial

and deep parts of the gland. A benign parotid tumor rarely,

if ever, causes facial palsy. A malignant tumor of the parotid

is usually highly invasive and quickly involves the facial

nerve, causing unilateral facial paralysis.

Parotid Gland Infections

The parotid gland may become acutely inflamed as a result

of retrograde bacterial infection from the mouth via the

parotid duct. The gland may also become infected via the

CD Figure 2-4

Cleft hard and soft palate.

bloodstream, as in mumps.

Chapter 2

Parotid Duct and Facial Injuries

THE PROCESS OF

The parotid duct, which is a comparatively superficial struc-

ture on the face, runs forward from the parotid gland one

SWALLOWING

fingerbreadth below the zygomatic arch (see text Fig. 2-18).

It is about 2 in. (5 cm) long and can be rolled beneath the

(DEGLUTITION)

examining finger at the anterior border of the masseter as it

turns medially and pierces the buccinator muscle; it then

opens into the mouth opposite the upper second molar

Swallowing in Unconscious

tooth (see text Fig. 2-8).

The parotid duct may be damaged in injuries to the

Individuals

face or may be inadvertently cut during surgical operations

on the face. The integrity of the parotid duct can be estab-

During swallowing in conscious individuals, food and

lished by wiping the inside of the cheek dry and then press-

fluid cross naturally from the mouth to the esophagus,

ing on the parotid gland. Look for a drop of viscid saliva to

and movements of air from the nose to the larynx is

appear on the tip of the papilla in the mouth.

momentarily stopped. In unconscious individuals, when

the reflex mechanisms are not functioning, it is possible

for food and fluid to enter the bronchial tree or air to enter

Submandibular Gland: Calculus

the stomach. Moreover, should vomiting occur, the regur-

gitated gastric contents may be inhaled into the lungs

Formation

(see below).

The submandibular salivary gland is a common site of cal-

culus formation. The presence of a tense swelling below the

body of the mandible, which is greatest before or during a

Pharyngeal Obstruction of the

meal and is reduced in size or absent between meals, is di-

agnostic of the condition. Examination of the floor of the

Upper Airway

mouth will reveal absence of ejection of saliva from the ori-

fice of the duct of the affected gland. Frequently, the stone

This condition frequently occurs in patients during

can be palpated in the duct, which lies below the mucous

cardiopulmonary arrest or in the decreased level of con-

membrane of the floor of the mouth.

sciousness that accompanies a major cerebrovascular acci-

dent or drug overdose. The obstruction is caused when the

Sublingual Gland and Cyst

atonic tongue falls back and the pharyngeal wall caves in

due to loss of tone of the pharyngeal muscles. The obstruc-

Formation

tion may clear if the patient is placed in the lateral decubi-

tus position, with the neck extended and the jaw pulled

Blockage of one of the ducts of the sublingual gland may

forward (which pulls the tongue forward). If the patient

cause cysts under the tongue.

must lie in a supine position, an oropharyngeal or nasopha-

ryngeal airway may have to be inserted to counteract the

flaccid pharyngeal walls.

THE PHARYNX

The Killian’s Dehiscence and

Loss of the Gag Reflex

In conscious patients the airway is protected by a number of

Foreign Bodies

important reflexes, including the gag reflex, the laryngeal

Inverted foreign bodies tend to get snared in the region of

reflex, and the cough reflex. The gag or swallowing reflex

Killian’s dehiscence.

occurs in response to stimulation of the pharyngeal mucous

membrane, which is innervated by the glossopharyngeal

nerve. The laryngeal and cough reflexes (trachea and

The Piriform Fossa and Foreign

bronchi) are mediated by the vagus nerve. These protective

reflexes are lost in descending order as the patient becomes

Bodies

less and less responsive. In these circumstances the airway

The piriform fossa is a common site for fish bones or other

may be blocked by aspiration of vomit and gastric and pha-

foreign bodies to become lodged.

ryngeal secretions.

The Upper and Lower Airway and Associated Structures

Relationship between Vocal Folds

PALATINE TONSILS

and Cricothyroid Ligament

Text Fig. 2-27 shows the relationship between the vocal folds

Examination of the Tonsils

and the cricothyroid ligament. It is clear that the folds may

With the mouth wide open and with a good light shining into

be damaged in puncture wounds in the front of the larynx.

the mouth, the tongue is depressed with a spatula. The ton-

sils can be clearly seen on each side of the oral pharynx in the

Larynx in Children

depression between the palatoglossal and palatopharyngeal

folds. Note the size and color of the tonsil; a reddened tonsil

In children the neck is shorter and the larynx is more cepha-

covered with mucus or pus is a clear indication of tonsillitis.

lad than in adults (CD Fig. 2-6). At birth the cricoid cartilage

lies at the level of the fourth cervical vertebra, and only at the

age of 6 years does it lie opposite the sixth cervical vertebra.

Tonsillitis

The glottis at birth lies opposite the second cervical vertebra.

The palatine tonsils reach their maximum normal size in

The epiglottis is U-shaped and less flexible in children,

early childhood. After puberty, together with other lym-

which sometimes makes it difficult to line up the oral, pha-

phoid tissues in the body, they gradually atrophy. The pala-

ryngeal, and tracheal axes when passing a laryngoscope.

tine tonsils are a common site of infection, producing the

The rima glottidis tends to be more anterior in children

characteristic sore throat and pyrexia. The deep cervical

than in adults. The vocal folds in children have thicker sub-

lymph node situated below and behind the angle of the

mucosa, so that edema of the folds is more likely to occlude

mandible, which drains lymph from this organ, is usually

the glottis.

enlarged and tender.

As mentioned previously, the cavity of the larynx is nar-

Tonsillectomy, which is often the treatment for recur-

rowest within the cricoid ring in children, whereas the glot-

rent episodes of tonsillitis, is sometimes accompanied by

tis is the narrowest part of the cavity in adults.

troublesome postoperative bleeding from the external pala-

tine vein.

Epiglottitis

An acute inflammatory swelling of the mucous membrane of

Quinsy

the epiglottis can compromise the upper airway. The inflam-

A peritonsillar abscess, or quinsy, is caused by spread of in-

mation may spread rapidly in the loosely arranged submucosa

fection from the palatine tonsil to the loose connective tis-

down to the vocal cords. Here the spreading stops because the

sue outside the capsule (see text Fig. 2-24).

mucosa is tightly adherent to the underlying vocal ligaments.

The condition is most often seen in children where the nar-

row passageway quickly leads to upper airway obstruction.

Adenoids

Adenoids are enlarged nasopharyngeal tonsils usually associ-

Foreign Bodies in the Airway

ated with infection. Excessive enlargement blocks the poste-

The laryngeal and cough reflexes mediated through the va-

rior nasal openings and causes the patient to snore loudly at

gus nerves are the natural defense mechanisms for expelling

night and to breathe through the open mouth. The close re-

foreign bodies from the airway at all ages. If coughing is suc-

lationship of the infected lymphoid tissue to the auditory

cessfully freeing the obstruction, it should be encouraged to

tube may be the cause of deafness and recurrent otitis media.

continue. If intervention is necessary, anatomic and physio-

logic age differences dictate treatment.

THE LARYNX

Anatomic Rationale for

The Cricoid Cartilage and the

Differences in Procedures for

Sellick Maneuver

Removing Foreign Bodies in

The continuous ring structure of the cricoid cartilage is uti-

Adults and Children

lized when applying pressure on the cricoid to control re-

gurgitation of stomach contents during the induction of

It is generally agreed that all maneuvers are directed toward

anesthesia.

the increase in intrathoracic pressure by compressing the

Chapter 2

mandible

hyoid cartilage

mandible

thyroid cartilage

body of

cricoid cartilage

hyoid bone

manubrium sterni

thyroid cartilage

cricoid cartilage

CD Figure 2-6

Sagittal sections of the neck of an adult (A) and an infant (B) shortly after

birth. Different vertebral levels in these age groups are shown.

intrathoracic gas volume to expel the foreign body from

may be involved in a bronchial or esophageal carcinoma or

the airway. For children older than 1 year and for adults,

in secondary metastatic deposits in the mediastinal lymph

the abdominal thrust (Heimlich maneuver) should be used.

nodes. The right and left recurrent laryngeal nerves may be

The rapid compression of the abdominal viscera suddenly

damaged by malignant involvement of the deep cervical

forces the diaphragm into the thoracic cavity. In infants, the

lymph nodes.

relatively large size of the liver and the delicate structure of

Section of the external laryngeal nerve produces weak-

the abdominal viscera generally preclude its use. Children

ness of the voice because the vocal fold cannot be tensed.

younger than 1 year should be placed face down over the

The cricothyroid muscle is paralyzed (CD Fig. 2-7).

rescuer’s arm, with the head lower than the trunk, and mea-

Unilateral complete section of the recurrent laryn-

sured back blows should be delivered between the scapulae.

geal nerve results in the vocal fold on the affected side

If this fails to open the airway, they should be rolled over,

assuming the position midway between abduction and

and four rapid sternal compressions should be administered.

adduction. It lies just lateral to the midline. Speech is not

It is now accepted that sudden blows to the back in the

greatly affected because the other vocal fold compensates to

older age groups, especially in the standing or sitting

some extent and moves toward the affected vocal fold (CD

position, extends the thoracic part of the vertebral column

Fig. 2-7).

and may displace the foreign body further down the airway,

Bilateral complete section of the recurrent laryngeal

leading to impaction or complete obstruction.

nerve results in both vocal folds assuming the position

midway between abduction and adduction. Breathing is

impaired because the rima glottidis is partially closed, and

Lesions of the Laryngeal Nerves

speech is lost (CD Fig. 2-7).

The muscles of the larynx are innervated by the recurrent la-

Unilateral partial section of the recurrent laryngeal

ryngeal nerves, with the exception of the cricothyroid mus-

nerve results in a greater degree of paralysis of the abductor

cle, which is supplied by the external laryngeal nerve. Both

muscles than of the adductor muscles. The affected vocal

these nerves are vulnerable during operations on the thyroid

fold assumes the adducted midline position (CD Fig. 2-7).

gland because of the close relationship between them and

This phenomenon has not been explained satisfactorily.

the arteries of the gland. The left recurrent laryngeal nerve

It must be assumed that the abductor muscles receive a

The Upper and Lower Airway and Associated Structures

epiglottis

rima

right vocal fold (cord)

glottidis

A. Bilateral

external laryngeal

nerve palsy

aryepiglottic fold

corniculate cartilage

inspiration

B. Unilateral

complete section

of right recurrent

laryngeal nerve

inspiration

phonation

C. Bilateral

complete section

of recurrent laryngeal

nerves

inspiration

D. Unilateral partial section

of right recurrent

laryngeal nerve

inspiration

E. Bilateral partial section

of recurrent laryngeal

CD Figure 2-7

The position of the

nerves

vocal folds (cords) after damage to

the external and recurrent laryngeal

inspiration

nerves.

greater number of nerves than the adductor muscles, and

thus partial damage of the recurrent laryngeal nerve results

Inspection of the Vocal Cords

in damage to relatively more nerve fibers to the abductor

muscles. Another possibility is that the nerve fibers to the ab-

(Folds) with the Laryngeal Mirror

ductor muscles are traveling in a more exposed position in

the recurrent laryngeal nerve and are therefore more prone

and Laryngoscope

to be damaged.

The interior of the larynx can be inspected indirectly

Bilateral partial section of the recurrent laryngeal

through a laryngeal mirror passed through the open mouth

nerve results in bilateral paralysis of the abductor muscles

into the oral pharynx (CD Fig. 2-8). A more satisfactory

and the drawing together of the vocal folds (CD Fig. 2-7).

method is the direct method using the laryngoscope. The

Acute breathlessness (dyspnea) and stridor follow, and

neck is brought forward on a pillow and the head is fully

cricothyroidotomy or tracheostomy is necessary.

extended at the atlantooccipital joints. The illuminated

Chapter 2

orientation of

laryngeal inlet

vocal fold

epiglottis

hard palate

(cord)

vestibular fold

rima glottidis

examiner's

eye

cuneiform

cartilage

tongue

corniculate

cartilage

entrance into larynx

laryngoscope

examiner's

eye

tongue

entrance

into larynx

CD Figure 2-8

Inspection of the vocal folds (cords) indirectly through a laryngeal mirror

(A) and through a laryngoscope (B). Note the orientation of the structures forming the

laryngeal inlet.

instrument can then be introduced into the larynx over the

If the patient is asked to breathe deeply, the vocal folds

back of the tongue (CD Fig. 2-8). The valleculae, the piri-

become widely abducted, and the inside of the trachea can

form fossae, the epiglottis, and the aryepiglottic folds are

be seen.

clearly seen. The two elevations produced by the corniculate

and cuneiform cartilages can be recognized. Within the lar-

Important Anatomic Axes for

ynx, the vestibular folds and the vocal folds can be seen. The

former are fixed, widely separated, and reddish in color; the

Endotracheal Intubation

latter move with respiration and are white in color. With

quiet breathing, the rima glottidis is triangular, with the apex

The upper airway has three axes that have to be brought into

in front. With deep inspiration, the rima glottidis assumes a

alignment if the glottis is to be viewed adequately through a

diamond shape because of the lateral rotation of the ary-

laryngoscope—the axis of the mouth, the axis of the phar-

tenoid cartilages.

ynx, and the axis of the trachea (CD Fig. 2-9).

The Upper and Lower Airway and Associated Structures

CD Figure 2-9

Anatomic axes for endo-

tracheal intubation. A. With the head in

the neutral position, the axis of the mouth

(M), the axis of the trachea (T), and the

axis of the pharynx (P) are not aligned

with one another. B. If the head is ex-

tended at the atlantooccipital joints, the

axis of the mouth is correctly placed. If

the back of the head is raised off the table

with a pillow, thus flexing the cervical

vertebral column, the axes of the trachea

and pharynx are brought in line with the

axis of the mouth.

The following procedures are necessary: First the head

2. The vocal cords (ligaments) are attached at their ante-

is extended at the atlantooccipital joints. This brings the axis

rior ends to the thyroid cartilage just below the attach-

of the mouth into the correct position. Then the neck is

ment of the epiglottis (see text Fig. 2-26).

flexed at cervical vertebrae C4 to C7 by elevating the back

3. Because of the above two facts, it follows that manipu-

of the head off the table, often with the help of a pillow. This

lation of the epiglottis and possibly the thyroid cartilage

brings the axes of the pharynx and the trachea in line with

will greatly assist the operator in visualizing the cords

the axis of the mouth.

and the glottis.

Anatomy of the Visualization of the

The patient’s head and neck are correctly positioned so

that the three axes of the airway (noted above) have been es-

Vocal Cords with the Laryngoscope

tablished and the patient has assumed the “sniffing” posi-

tion. The laryngoscope is inserted into the patient’s mouth,

1. The pear-shaped epiglottis is attached by its stalk at its

and the blade is correctly placed alongside the right

lower end to the interior of the thyroid cartilage (see text

mandibular molar teeth. The blade can then be passed over

Fig. 2-26).

the tongue and down into the esophagus. The tip of the

Chapter 2

median

tongue

glossoepi-

glottic fold

epiglottis

vallecula

tubercle of

epiglottis

vestibular fold

lateral

glossoepi-

glottic fold

vocal fold

aryepiglottic fold

piriform fossa

cuneiform cartilage

rima glottidis

CD Figure 2-10

The laryngeal inlet as seen

corniculate cartilage

from above.

blade must be fully inserted into the esophagus (so that you

changes are largely mediated through the branches of the

know where it is anatomically). The blade should by now

vagus nerves.

have moved toward the midline and followed the anatomic

curvature on the posterior surface of the tongue.

The laryngoscopic blade is then gently and slowly with-

THE TRACHEA

drawn. The tip of the blade is kept under direct vision at all

times and is permitted to rise up out of the esophagus. Re-

member that the tip of the blade is at first in the esophagus

Palpation of the Trachea

and therefore distal to the level of the vocal cords. Once the

blade tip has left the esophagus, it is in the laryngeal part of

The trachea can be readily felt below the larynx. As it

the pharynx, and a view of the glottis should immediately be

descends, it becomes deeply placed and may lie as much as

apparent (CD Fig. 2-10). This is the critical stage. If the glot-

1.5 in. (4 cm) from the surface at the suprasternal notch.

tis is not visualized, then the operator is viewing the poste-

Remember that in the adult it may measure as much as 1 in.

rior surface of the epiglottis. Now use your anatomic

(2.5 cm) in diameter, but in a 3-year-old child it may

knowledge.

measure only 0.5 in. in diameter. The trachea is a mobile

With the tip of the blade of the laryngoscope applied to

elastic tube and is easily displaced by the enlargement of

the posterior surface of the epiglottis, gently lift up and

adjacent organs or the presence of tumors. Remember also

elevate the epiglottis to expose the glottis. If the glottis is still

that lateral displacement of the cervical part of the trachea

not in view, do not panic! Again use your knowledge of

may be caused by a pathologic lesion in the thorax.

anatomy. With the right free hand grasp the thyroid carti-

lage (to which the cords and the epiglottis are attached) be-

Compromised Airway

tween your finger and thumb and apply firm backward,

upward, rightward pressure (BURP). This maneuver re-

In a medical emergency immediate treatment is necessary.

aligns the box of the larynx relative to the laryngoscopic

Anatomy of Cricothyroidotomy

blade, and the visual axis of the operator and the glottis

should immediately be seen.

In cricothyroidotomy, a tube is inserted in the interval be-

tween the cricoid cartilage and the thyroid cartilage. The

trachea and larynx are steadied by extending the neck over a

Reflex Activity Secondary to

sandbag.

A vertical or transverse incision is made in the skin in

Endotracheal Intubation

the interval between the cartilages (CD Fig. 2-11). The

Stimulation of the mucous membrane of the upper airway

incision is made through the following structures: the skin,

during the process of intubation may produce cardiovascu-

the superficial fascia (beware of the anterior jugular veins,

lar changes such as bradycardia and hypertension. These

which lie close together on either side of the midline), the

The Upper and Lower Airway and Associated Structures

body of hyoid

thyrohyoid

bone

membrane

(ligament)

sternohyoid

muscle

superior belly of

thyroid cartilage

omohyoid muscle

site of skin

cricothyroid membrane

incision

(ligament)

cricothyroid

cricoid

muscle

cartilage

anterior jugular

vein

isthmus

first tracheal ring

of thyroid

gland

fascia

thyroid

thyroid cartilage

skin

cartilage

edge

cricothyroid

membrane

small

(ligament)

cricothyroid

artery

cricothyroid

membrane

cricoid

(ligament)

cartilage

CD Figure 2-11

The anatomy of cricothyroidotomy. A. A vertical incision is made through

the skin and superficial and deep cervical fasciae. B. The cricothyroid membrane (ligament)

is incised through a horizontal incision close to the upper border of the cricoid cartilage.

C. Insertion of the tube.

investing layer of deep cervical fascia, the pretracheal fascia

2. Hemorrhage: The small branches of the superior

(separate the sternohyoid muscles and incise the fascia), and

thyroid artery that occasionally cross the front of the

the larynx. The larynx is incised through a horizontal inci-

cricothyroid membrane to anastomose with one an-

sion through the cricothyroid ligament and the tube in-

other should be avoided.

serted (CD Fig. 2-12).

Anatomy of Tracheostomy

Complications

Tracheostomy is rarely performed and is limited to patients

1. Esophageal perforation: Because the lower end of the

with extensive laryngeal damage and infants with severe air-

pharynx and the beginning of the esophagus lie directly

way obstruction. Because of the presence of major vascular

behind the cricoid cartilage, it is imperative that the

structures (carotid arteries and internal jugular vein), the

scalpel incision through the cricothyroid membrane

thyroid gland, nerves (recurrent laryngeal branch of vagus

not be carried too far posteriorly. This is particularly im-

and vagus nerve), the pleural cavities, and esophagus, metic-

portant in young children, in whom the cross diameter

ulous attention to anatomic detail has to be observed (CD

of the larynx is so small.

Fig. 2-13).

The Upper and Lower Airway and Associated Structures

The procedure is as follows:

3. Pneumothorax: The cervical dome of the pleura may

be pierced. This is especially common in children be-

1. The thyroid and cricoid cartilages are identified and the

cause of the high level of the pleura in the neck.

neck is extended to bring the tracheal forward.

4. Esophageal injury: Damage to the esophagus, which is

2. A vertical midline skin incision is made from the region

located immediately posterior to the trachea, occurs

of the cricothyroid membrane inferiorly toward the

most commonly in infants; it follows penetration of the

suprasternal notch.

small-diameter trachea by the point of the scalpel blade.

3. The incision is carried through the superficial fascia

and the fibers of the platysma muscle. The anterior

jugular veins in the superficial fascia are avoided by

SOME IMPORTANT

maintaining a midline position.

AIRWAY DISTANCES

4. The investing layer of deep cervical fascia is incised.

CD Table 2-1 shows some important distances between

5. The pretracheal muscles embedded in the pretracheal

the incisor teeth or nostrils to anatomic landmarks in

fascia are split in the midline two fingerbreadths supe-

the airway in the adult. These approximate figures are

rior to the sternal notch.

helpful in determining the correct placement of an endo-

6. The tracheal rings are then palpable in the midline, or

tracheal tube.

the isthmus of the thyroid gland is visible. If a hook is

placed under the lower border of the cricoid cartilage

and traction is applied upward, the slack is taken out of

CHANGES IN THE

the elastic trachea; this stops it from slipping from side

to side.

TRACHEAL LENGTH

7. A decision is then made as to whether to enter the tra-

chea through the second ring above the isthmus of the

WITH RESPIRATION

thyroid gland; through the third, fourth, or fifth ring by

first dividing the vascular isthmus of the thyroid gland;

AND POSITION OF

or through the lower tracheal rings below the thyroid

isthmus. At the latter site, the trachea is receding from

the surface of the neck, and the pretracheal fascia

THE HEAD AND

contains the inferior thyroid veins and possibly the

thryoidea ima artery.

NECK

8. The preferred site is through the second ring of the tra-

On deep inspiration the carina may descend by as much as

chea in the midline, with the thyroid isthmus retracted

3 cm. Extension of the head and neck, as when maintaining

inferiorly. A vertical tracheal incision is made, and the

an airway in an anesthetized patient, may stretch the trachea

tracheostomy tube is inserted.

and increase its length by 25%.

Complications

Most complications result from not adequately palpating

and recognizing the thyroid, cricoid, and tracheal cartilages

Important Airway

CD Table 2-1

and not confining the incision strictly to the midline.

Distances (Adult)^a

1. Hemorrhage: The anterior jugular veins located in the

Distances

superficial fascia close to the midline should be

Airway

(approximate)

avoided. If the isthmus of the thyroid gland is tran-

sected, secure the anastomosing branches of the supe-

Incisor teeth to the vocal cords

5.9 in. (15 cm)

rior and inferior thyroid arteries that cross the midline

Incisor teeth to the carina

7.9 in. (20 cm)

on the isthmus.

External nares to the carina

11.8 in. (30 cm)

2. Nerve paralysis: The recurrent laryngeal nerves may be

^aAverage figures given

1-2 cm.

damaged as they ascend the neck in the groove between

the trachea and the esophagus.

Chapter 2

Suction Catheters, Endotracheal

THE BRONCHI

Tubes, and the Bronchi

Suction catheters and endotracheal tubes are more likely to

Aspiration of Foreign Bodies and

enter the right more vertical principal bronchus than the

obliquely positioned left principal bronchus in adults and

Stomach Contents

older children.

In adults, foreign bodies and stomach contents tend to be

aspirated into the right principal bronchus, since this is

more in line with the trachea than the left bronchus.

BRONCHOPULMO-

In young babies, since both bronchi arise from the trachea

at equal angles, no predilection for the right bronchus

NARY SEGMENTS

exists.

See CD-ROM Chapter 3.

Clinical Problem Solving Questions

Read the following case histories/questions and give

a hoarse cry. The cough then became croupy, and

the best answer for each.

aphonia occurred. The mother, hearing the commo-

tion, rushed into the room and quickly realized what

A 36-year-old man was taken to the emergency depart-

had happened. She turned the child upside down and

ment after having been found lying unresponsive in a

hit his back several times, but with no effect. The child,

local park with an empty whisky bottle nearby. He was

now in obvious respiratory distress, was rushed to the

given oxygen by an open face mask during the 15-

local emergency department. On examination, he was

minute ride in the ambulance. The paramedic decided

tachypneic, with suprasternal retractions. He was not

to improve the airway by passing a soft nasal tube. On

coughing, and although he attempted to cry, there was

attempting to pass the well-lubricated tube into the

no sound. He would not tolerate being laid down. On

patient’s nose, the paramedic found it impossible to

the basis of your knowledge of the anatomy of the air-

push it much beyond the nasal vestibule on either side.

way, where do you think the foreign body was lodged?

What are the common anatomic causes of obstruction

Describe the normal protective reflexes that exist in the

of the nasal airway?

airway to prevent the inhalation of a foreign body. What

is the anatomic and physiologic rationale behind the

A 12-year-old girl was brought to the hospital with a his-

use of back blows, chest thrusts, and abdominal thrusts

tory of fever, malaise, anorexia, and a sore throat. She

(Heimlich procedure) in the management of upper

also had hoarseness, a cough, and rhinitis. On exami-

airway obstruction? Which of these procedures is most

nation there was erythema of the posterior pharyngeal

appropriate for a 3-year-old child?

wall, with small ulcers on the palatoglossal folds and

soft palate. The tonsils were seen to be red and en-

A 17-year-old boy was driving his minibike at high

larged, and an obvious white-yellow exudate was seen

speed along a country lane, when he suddenly saw what

on the surface of the left tonsil. Examination of the

he thought was a shortcut through a gap in a hedge. He

deep cervical lymph nodes showed enlargement and

did not see that the gap was closed by a strand of barbed

tenderness of the node below and behind the angle of

wire. He struck the wire with his neck and was thrown

the mandible; the enlargement was greatest on the left

from the bicycle. On arrival at the emergency depart-

side. A diagnosis of viral pharyngitis was made. List the

ment, he had all the signs and symptoms of upper air-

various lymphoid organs found in the nasal and oral

way obstruction. Using your knowledge of the anatomy

parts of the pharynx. Explain Waldeyer’s ring.

of the neck, explain the type of injury that could have

A 3-year-old boy was playing with his toys on the floor

occurred in this case. Does the position of the vocal

when his sister decided to share some peanuts with

cords at the time of impact influence the type of injury

him. A few minutes later he started to cough and gave

that occurs? What anatomic factors normally protect

The Upper and Lower Airway and Associated Structures

the upper airway from serious blunt injuries? Does age

rior pharyngeal wall. At times, why is it not possible to

play a role in the severity of the injury?

pull the tongue forward in the presence of a fractured

mandible?

5. A 39-year-old man with extensive maxillofacial injuries

following an automobile accident was brought to the

6. When a laryngoscope is passed it is important to align

hospital. Evaluation of the airway revealed partial

the mouth, the oropharynx, and the larynx into one

obstruction. Despite an obvious fractured mandible, an

plane. How do you bring the axes of the oropharynx

attempt was made to move the tongue forward from the

and the larynx in line? How do you bring the axis of

posterior pharyngeal wall by pushing the angles of

the mouth in line with the other axes? Describe the

the mandible forward. This maneuver failed to move

structures in the order that you can view them through

the tongue, and it became necessary to hold the tongue

a laryngoscope from the base of the tongue down to

forward directly in order to pull it away from the poste-

the trachea.

Answers and Explanations

The most common cause for difficulty in passing a

The impact of the wire to the front of the neck caused

nasal tube is a deflected nasal septum. This occurs

hyperextension of the cervical part of the vertebral col-

more commonly in the male, and is thought to be due

umn with stretching of the larynx and trachea. This ef-

to previous trauma to the septum during the period of

fectively fixed the airway structures in the midline so

active growth. Nasal spurs and polyps may cause diffi-

that they were not deflected laterally at the moment of

culty and swelling of the mucous membrane secondary

impact. Under these circumstances the cartilages of the

to infection or chemical irritation, and can also cause

larynx are fractured or crushed. Depending on the

blockage. The widest part of the nasal cavity is near

speed of the impact, the larynx could be completely

the floor.

avulsed from the trachea. In this situation the tone of

the suprahyoid muscles would cause the larynx to be re-

The lymphoid tissue around the openings of the mouth

tracted superiorly and the elasticity of the trachea

and nasal cavities into the pharynx include (1) the pala-

would cause it to retract inferiorly to the root of the neck

tine tonsil, (2) the lingual tonsil, (3) the tubal tonsils,

or behind the sternum.

and (4) the pharyngeal tonsil. For details of Waldeyer’s

ring, see text Chapter 2.

If the glottis were closed at the time of impact,

the raised intraluminal pressure within the upper

The presence of severe respiratory distress with supraster-

airway may contribute to the severity of the injury.

nal retractions and aphonia indicates the presence of up-

The upper airway receives a considerable amount of

per airway obstruction, probably located within the

protection from blows to the front of the neck and

larynx. The airway is protected by a number of important

chest because of the presence of the mandible and

reflexes, including the gag reflex, the laryngeal reflex,

manubrium sterni. With the head and neck in the

and the cough reflex. The gag reflex occurs in response

flexed position, the larynx and trachea are remarkably

to stimulation of the pharyngeal mucous membrane in-

mobile and often deflected laterally by an anterior

nervated by the glossopharyngeal nerve. The laryngeal

blow to the neck.

and the cough reflexes are mediated via the vagus nerve.

These protective reflexes are lost in descending order as

In children, the very flexible nature of the laryngeal and

a patient loses consciousness.

tracheal cartilages and looseness of the supporting con-

nective tissue reduce the likelihood of severe damage to

All maneuvers that are directed toward freeing an ob-

these structures.

struction of the airway by an inhaled foreign body are

based on an attempt to increase the intrathoracic pres-

The root of the tongue is attached anteriorly to the

sure by compressing the intrathoracic gas volume, so

mental spines on the posterior surface of the symph-

that the foreign body is expressed from the mouth. The

ysis menti of the mandible by the right and left

underlying mechanisms involved in the use of back

genioglossus muscles. If this bony origin were floating

blows, chest thrusts, and abdominal thrusts are dis-

because of fractures on both sides of the body of

cussed in this CD chapter. It is now generally agreed

the mandible, pulling the angles of the mandible for-

that the best and safest method to use on a 3-year-old

ward would have no effect on the position of the

child is the abdominal thrust.

tongue.

Chapter Outline

The Chest Wall

Lymph Drainage of the Thoracic Wall

Sternum and Marrow Biopsy

The Breasts

The Ribs

Witch’s Milk in the Newborn

Cervical Rib

Breast Examination

Rib Excision

Mammography

The Intercostal Nerves

Supernumerary and Retracted Nipples

Skin Innervation of the Chest Wall and

The Importance of Fibrous Septa

Referred Pain

Lymph Drainage and Carcinoma of the Breast

Herpes Zoster

Congenital Anomalies of the Breast

Anatomy of Intercostal Nerve Block

Polythelia

Area of Anesthesia

Retracted Nipple or Inverted Nipple

Indications

Procedure

Micromastia

Anatomy of Complications

Macromastia

The Sternum, Ribs, and Costal Cartilages

Gynecomastia

Chest Cage Distortion

The Mediastinum

Chest Trauma

Deflection of Mediastinum

Mechanics of Chest Trauma

Mediastinitis

Rib Contusion

Rib Fractures

Mediastinal Tumors or Cysts

Flail Chest

Mediastinoscopy

Fractured Sternum

Traumatic Injury to the Back of the Chest

The Pleura

Traumatic Injury to the Chest and Abdominal

Pleural Fluid

Viscera

Pleurisy

The Diaphragm

Pneumothorax

Hiccup

Spontaneous Pneumothorax

Paralysis of the Diaphragm

Open Pneumothorax

Tension Pneumothorax

Penetrating Injuries of the Diaphragm

Fluid in the Pleural Cavity

Rupture of the Diaphragm

Pleural Effusion

Congenital Anomalies of the Diaphragm

Hydropneumothorax

Pyopneumothorax

Congenital Herniae

Hemopneumothorax

Acquired Herniae

Empyema

Internal Thoracic Artery in the Treatment

Position of Thoracic and Upper

of Coronary Artery Disease

Abdominal Viscera during Different

Phases of Respiration

The Clavicle and Its Relationship with the

Thoracic Outlet

Root of the Neck Injuries

The Thoracic Outlet Syndromes

Traumatic Asphyxia

The Adson Maneuver

Cardiopulmonary Resuscitation

The Chest Wall, Chest Cavity, Lungs, and Pleural Cavities

The Chest Wall

Segmental Resection of the Lung

Thoracocentesis

Pulmonary Contusion

Needle Thoracostomy

Tracheobronchial Injury

Anterior Approach

Bronchogenic Carcinoma

Lateral Approach

Conditions That Decrease Respiratory Efficiency

Tube Thoracostomy

Constriction of the Bronchi (Bronchial Asthma)

Thoracotomy

Loss of Lung Elasticity

Loss of Lung Distensibility

The Trachea and Principal Bronchi

Postural Drainage

Compression of the Trachea

Tracheitis or Bronchitis

Congenital Anomalies of the Trachea

and Lungs

Inhaled Foreign Bodies

Esophageal Atresia and Tracheoesophageal Fistula

Bronchoscopy

Neonatal Lobar Emphysema

The Lungs

Congenital Cysts of the Lung

Clinical Examination of the Chest

Trauma to the Lungs

Clinical Problem Solving Questions

Fractured Ribs and the Lungs

Answers and Explanations

Pain and Lung Disease

Surgical Access to the Lungs

also exert pressure on the overlying subclavian artery and

THE CHEST WALL

interfere with the circulation of the upper limb.

Rib Excision

Sternum and Marrow Biopsy

Rib excision is commonly performed by thoracic surgeons

Since the sternum possesses red hematopoietic marrow

wishing to gain entrance to the thoracic cavity. A longitudi-

throughout life, it is a common site for marrow biopsy.

nal incision is made through the periosteum on the outer

Under a local anesthetic, a wide-bore needle is introduced

surface of the rib and a segment of the rib is removed. A sec-

into the marrow cavity through the anterior surface of the

ond longitudinal incision is then made through the bed of

bone. The sternum may also be split at operation to allow

the rib, which is the inner covering of periosteum. After the

the surgeon to gain easy access to the heart, great vessels,

operation, the rib regenerates from the osteogenetic layer of

and thymus.

the periosteum.

THE RIBS

THE INTERCOSTAL

Cervical Rib

NERVES

A cervical rib (i.e., a rib arising from the anterior tubercle of

the transverse process of the seventh cervical vertebra)

Skin Innervation of the Chest

occurs in about 0.5% of humans (CD Fig. 3-1). It may have

a free anterior end, may be connected to the first rib by a

Wall and Referred Pain

fibrous band, or may articulate with the first rib. The

importance of a cervical rib is that it can cause pressure on

Above the level of the sternal angle, the cutaneous innerva-

the lower trunk of the brachial plexus in some patients,

tion of the anterior chest wall is derived from the supraclav-

producing pain down the medial side of the forearm and

icular nerves (C3 and 4). Below this level, the anterior and

hand and wasting of the small muscles of the hand. It can

lateral cutaneous branches of the intercostal nerves supply

Chapter 3

scalenus medius

brachial plexus

cervical rib

CD Figure 3-1

Thoracic outlet as

seen from above. Note the pres-

ence of the cervical ribs (black) on

scalenus anterior

lower trunk of plexus

both sides. On the right side of the

thorax, the rib is almost complete

and articulates anteriorly with the

first rib. On the left side of the tho-

rax, the rib is rudimentary but is

subclavian artery

continued forward as a fibrous

band that is attached to the first

cervical rib

costal cartilage. Note that the cervi-

fibrous band

cal rib may exert pressure on the

lower trunk of the brachial plexus

and may kink the subclavian artery.

oblique bands of skin in regular sequence. The skin on the

the distribution of the sensory neuron in a thoracic spinal

posterior surface of the chest wall is supplied by the posterior

nerve, followed in a few days by a skin eruption. The

rami of the spinal nerves. The arrangement of the der-

condition occurs most frequently in patients older than

matomes is shown in CD Figures 1-2 and 1-3.

50 years.

An intercostal nerve supplies not only areas of skin but

also the ribs, costal cartilages, intercostal muscles, and the

Anatomy of Intercostal Nerve Block

parietal pleura lining the intercostal space. Furthermore,

the seventh to eleventh intercostal nerves leave the thoracic

Area of Anesthesia

wall and enter the anterior abdominal wall so that they, in

addition, supply dermatomes on the anterior abdominal

The skin and the parietal pleura cover the outer and inner

wall, muscles of the anterior abdominal wall, and parietal

surfaces of each intercostal space, respectively; the seventh

peritoneum. This latter fact is of great clinical importance

to eleventh intercostal nerves supply the skin and the pari-

because it means that disease in the thoracic wall may be re-

etal peritoneum covering the outer and inner surfaces of the

vealed as pain in a dermatome that extends across the costal

abdominal wall, respectively. Therefore, an intercostal

margin into the anterior abdominal wall. For example, a

nerve block will also anesthetize these areas. In addition, the

pulmonary thromboembolism or pneumonia with pleurisy

periosteum of the adjacent ribs is anesthetized.

involving the costal parietal pleura could give rise to ab-

Indications

dominal pain and tenderness and rigidity of the abdominal

musculature. The abdominal pain in these instances is

Intercostal nerve block is indicated for repair of lacerations

called referred pain.

of the thoracic and abdominal walls, for relief of pain in rib

fractures, and to allow pain-free respiratory movements.

Herpes Zoster

Procedure

Herpes zoster, or shingles, is a relatively common condi-

tion caused by the reactivation of the latent varicella-zoster

To produce analgesia of the anterior and lateral thoracic

virus in a patient who has previously had chickenpox. The

and abdominal walls, the intercostal nerve should be

lesion is seen as an inflammation and degeneration of

blocked before the lateral cutaneous branch arises at the

the sensory neuron in a cranial or spinal nerve with the for-

midaxillary line. The ribs may be identified by counting

mation of vesicles and inflammation of the skin. In the

down from the second (opposite sternal angle) or up

thorax, the first symptom is a band of dermatomal pain in

from the twelfth. The needle is directed toward the rib

The Chest Wall, Chest Cavity, Lungs, and Pleural Cavities

near the lower border (Text Fig. 3-4) and the tip comes to

Rib Contusion

rest near the subcostal groove, where the local anesthetic is

Bruising of a rib, secondary to trauma, is the most common

infiltrated around the nerve. Remember that the order of

rib injury. In this painful condition, a small hemorrhage

structures lying in the neurovascular bundle from above

occurs beneath the periosteum.

downward is intercostal vein, artery, and nerve and that

these structures are situated between the posterior inter-

costal membrane of the internal intercostal muscle and

Rib Fractures

the parietal pleura. Furthermore, laterally the nerve lies

Fractures of the ribs are common chest injuries. In chil-

between the internal intercostal muscle and the innermost

dren, the ribs are highly elastic, and fractures in this age

intercostal muscle.

group are therefore rare. Unfortunately, the pliable chest

wall in the young can be easily compressed so that the un-

Anatomy of Complications

derlying lungs and heart may be injured. With increasing

Complications include pneumothorax and hemorrhage.

age, the rib cage becomes more rigid, owing to the deposit

Pneumothorax can occur if the needle point misses

of calcium in the costal cartilages, and the ribs become

the subcostal groove and penetrates too deeply through the

brittle. The ribs then tend to break at their weakest part,

parietal pleura.

their angles.

Hemorrhage is caused by the puncture of the intercostal

The ribs prone to fracture are those that are exposed or

blood vessels. This is a common complication, so aspiration

relatively fixed. Ribs five through 10 are the most commonly

should always be performed before injecting the anesthetic.

fractured ribs. The first four ribs are protected by the clavi-

A small hematoma may result.

cle and pectoral muscles anteriorly and by the scapula and

its associated muscles posteriorly. The eleventh and twelfth

ribs float and move with the force of impact.

Because the rib is sandwiched between the skin exter-

THE STERNUM,

nally and the delicate pleura internally, it is not surprising

that the jagged ends of a fractured rib may penetrate the

lungs and present as a pneumothorax.

RIBS, AND COSTAL

Severe localized pain is usually the most important

symptom of a fractured rib. The periosteum of each rib is in-

CARTILAGES

nervated by the intercostal nerves above and below the rib.

To encourage the patient to breathe adequately, it may be

necessary to relieve the pain by performing an intercostal

Chest Cage Distortion

nerve block.

The shape of the thorax can be distorted by congenital

anomalies of the vertebral column or by the ribs. Destruc-

Flail Chest

tive disease of the vertebral column that produces lateral

In severe crush injuries, a number of ribs may break. If lim-

flexion or scoliosis results in marked distortion of the tho-

ited to one side, the fractures may occur near the rib angles

racic cage.

and anteriorly near the costochondral junctions. This

causes flail chest, in which a section of the chest wall is

Chest Trauma

disconnected to the rest of the thoracic wall. If the fractures

occur on either side of the sternum, the sternum may be

Traumatic injury to the thorax is common, especially as a re-

flail. In either case, the stability of the chest wall is lost, and

sult of automobile accidents.

the flail segment is sucked in during inspiration and driven

out during expiration, producing paradoxic and ineffective

Mechanics of Chest Trauma

respiratory movements (CD Fig. 3-2).

Chest organ injuries from blunt trauma occur as the result

of rapid acceleration or deceleration, by compression, or

Fractured Sternum

by a sudden increase in intrathoracic or intraabdominal

pressure. A knife wound piercing the chest wall injures the

The sternum is a resilient structure that is held in position

organs along its path. A bullet wound does not follow a

by relatively pliable costal cartilages and bendable ribs. For

straight path but yaws, tumbles, and may fragment, causing

these reasons, fracture of the sternum is not common; how-

widespread tissue damage. In addition, the kinetic energy

ever, it does occur in high-speed motor vehicle accidents.

generated by a speeding bullet may damage tissue that is

Remember that the heart lies posterior to the sternum and

distant from the actual path of the bullet.

may be severely contused by the sternum on impact.

Chapter 3

spinal cord should be considered. Remember also the pres-

ence of the scapula, which overlies the upper seven ribs.

This bone is covered with muscles and is fractured only in

cases of severe trauma.

Traumatic Injury to the Chest and

Abdominal Viscera

When the anatomy of the thorax is reviewed, it is important

to remember that the upper abdominal organs—namely,

the liver, stomach, and spleen—may be injured by trauma

to the rib cage. In fact, any injury to the chest below the level

of the nipple line may involve abdominal organs as well as

chest organs.

inspiration

THE DIAPHRAGM

Hiccup

Hiccup is the involuntary spasmodic contraction of the di-

aphragm accompanied by the approximation of the vocal

folds and closure of the glottis of the larynx. It is a common

condition in normal individuals and occurs after eating or

drinking as a result of gastric irritation of the vagus nerve

endings. It may, however, be a symptom of disease such as

pleurisy, peritonitis, pericarditis, or uremia.

Paralysis of the Diaphragm

A single dome of the diaphragm may be paralyzed by

crushing or sectioning of the phrenic nerve in the neck.

This may be necessary in the treatment of certain forms of

expiration

lung tuberculosis, when the physician wishes to rest the

lower lobe of the lung on one side. Occasionally, the con-

tribution from the fifth cervical spinal nerve joins the

phrenic nerve late as a branch from the nerve to the sub-

CD Figure 3-2

Flail chest is a condition in which a portion of

clavius muscle. This is known as the accessory phrenic

the chest wall is drawn inward during inspiration and bulges

outward during expiration; it occurs when several ribs are

nerve. To obtain complete paralysis under these circum-

fractured in two or more places. A. On inspiration the frac-

stances, the nerve to the subclavius muscle must also be

tured ribs are pulled inward as the pressure within the chest

sectioned.

decreases. The inspired air passing down the trachea tends

to be drawn into the lung on the unaffected side. B. On expi-

ration the fractured ribs are pushed outward as the pressure

Penetrating Injuries of

within the chest rises. Note that some of the air in the bronchi

tends to enter the lung on the affected side as well as passing

up the trachea.

the Diaphragm

Penetrating injuries can result from stab or bullet wounds

to the chest or abdomen. Any penetrating wound to the

Traumatic Injury to the Back of the

chest below the level of the nipples should be suspected

Chest

of causing damage to the diaphragm until proved other-

The posterior wall of the chest in the midline is formed by

wise. The arching domes of the diaphragm can reach

the vertebral column. In severe posterior chest injuries, the

the level of the fifth rib (the right dome can reach a

possibility of a vertebral fracture with associated injury to the

higher level).

The Chest Wall, Chest Cavity, Lungs, and Pleural Cavities

Rupture of the Diaphragm

INTERNAL THOR-

In severe crushing injuries to the chest or abdomen, the di-

aphragm may rupture, usually through the central tendon.

ACIC ARTERY IN

Herniation of abdominal viscera into the thorax may occur,

especially if the left dome of the diaphragm is the site of the

THE TREATMENT

rupture. The rupture of the right dome or the central tendon

is usually plugged by the large right lobe of the liver, unless

OF CORONARY

the opening is very great. A ruptured diaphragm, if not re-

paired, may result in a delayed herniation of abdominal

contents.

ARTERY DISEASE

In patients with occlusive coronary disease caused by ather-

osclerosis, the diseased arterial segment can be bypassed by

CONGENITAL

inserting a graft. The graft most commonly used is the great

saphenous vein of the leg. In some patients, the my-

ANOMALIES OF

ocardium can be revascularized by surgically mobilizing

one of the internal thoracic arteries and joining its distal cut

end to a coronary artery.

THE DIAPHRAGM

THE CLAVICLE

Congenital Herniae

Congenital herniae may occur as the result of incomplete

AND ITS

fusion of the septum transversum, the dorsal mesentery, and

the pleuroperitoneal membranes from the body wall. The

herniae occur at the following sites: (1) the pleuroperitoneal

RELATIONSHIP

canal (more common on the left side; caused by failure of

fusion of the septum transversum with the pleuroperitoneal

WITH THE

membrane), (2) the opening between the xiphoid and costal

origins of the diaphragm, and (3) the esophageal hiatus.

THORACIC OUTLET

Acquired Herniae

The Thoracic Outlet Syndromes

Acquired herniae may occur in middle-aged people with

The brachial plexus of nerves (C5, 6, 7, and 8 and T1) and

weak musculature around the esophageal opening in the

the subclavian artery and vein are closely related to the

diaphragm. These herniae may be either sliding or parae-

upper surface of the first rib and the clavicle as they enter

sophageal (CD Fig. 3-3).

the upper limb see (see CD Fig. 3-4). It is here that the

esophagus

diaphragm

stomach

peritoneum

CD Figure 3-3

A. Sliding esophageal hernia. B. Parae-

sophageal hernia.

Chapter 3

brachial plexus

subclavian artery

first rib

clavicle

axillary artery

first rib

part of

brachial plexus

subclavian artery

axillary artery

axillary

artery

pectoralis

minor

CD Figure 3-4

Examples of thoracic outlet syndrome. A. The relationship between the

brachial plexus, the subclavian and axillary arteries, the clavicle, the first rib, and the pec-

toralis minor tendon. B. How the cords of the brachial plexus and the subclavian artery can

be squeezed between the clavicle and the first rib in some individuals. C. How the axillary

artery and the branches of the brachial plexus might be pressed upon by the pectoralis

minor tendon when the arm is abducted at the shoulder joint.

nerves or blood vessels may be compressed between

The Adson Maneuver

the bones. Most of the symptoms are caused by pressure on

the lower trunk of the plexus producing pain down the me-

This maneuver was commonly used in making the diagno-

dial side of the forearm and hand and wasting of the small

sis of thoracic outlet syndrome; recently the reliability of the

muscles of the hand. Pressure on the blood vessels may

test has been questioned. The patient takes a deep breath

compromise the circulation of the upper limb. Examples of

(raises the first rib), extends the neck (takes up the slack of

the thoracic outlet syndromes are shown in CD Fig. 3-4.

the brachial nerve plexus and subclavian vessels), and turns

The Chest Wall, Chest Cavity, Lungs, and Pleural Cavities

his or her chin to the side being examined (narrows the in-

of the duct epithelium and the surrounding connective tis-

terval between the scalene muscles); at the same time the

sue. This proliferation may cause swelling of the mammary

pulse of the radial artery is palpated. Disappearance or re-

glands in both sexes during the first week of life; in some

duction of the pulse, and possibly coldness and paleness of

cases a milky fluid, called witch’s milk, may be expressed

the hand, would indicate that the subclavian artery is being

from the nipples. The condition is resolved spontaneously as

compressed by the scalene muscles and/or the first (or cer-

the maternal hormone levels in the child fall.

vical) rib. In addition to looking for vascular compromise,

the physician should also look for replication of the nerve

Breast Examination

symptoms down the arm.

The breast is one of the common sites of cancer in women.

It is also the site of different types of benign tumors and may

LYMPH DRAINAGE

be subject to acute inflammation and abscess formation.

For these reasons, clinical personnel must be familiar

with the development, structure, and lymph drainage of

OF THE THORACIC

this organ.

With the patient undressed to the waist and sitting up-

WALL

right, the breasts are first inspected for symmetry. Some de-

gree of asymmetry is common and is the result of unequal

The lymph drainage of the skin of the anterior chest wall

breast development. Any swelling should be noted. A

passes to the anterior axillary lymph nodes; that from the

swelling can be caused by an underlying tumor, cyst, or ab-

posterior chest wall passes to the posterior axillary nodes

scess formation. The nipples should be carefully examined

(CD Fig. 3-5). The lymph drainage of the intercostal spaces

for evidence of retraction. A carcinoma within the breast

passes forward to the internal thoracic nodes, situated along

substance can cause retraction of the nipple by pulling on

the internal thoracic artery, and posteriorly to the posterior

the lactiferous ducts. The patient is then asked to lie down

intercostal nodes and the paraaortic nodes in the posterior

so that the breasts can be palpated against the underlying

mediastinum. The lymphatic drainage of the breast is

thoracic wall. Finally, the patient is asked to sit up again and

described in the next section.

raise both arms above her head. With this maneuver, a car-

cinoma tethered to the skin, the suspensory ligaments, or

the lactiferous ducts produces dimpling of the skin or re-

traction of the nipple.

THE BREASTS

Mammography

Witch’s Milk in the Newborn

Mammography is a radiographic examination of the breast

While the fetus is in the uterus, the maternal and placental

(CD Fig. 3-6). This technique is extensively used for screen-

hormones cross the placental barrier and cause proliferation

ing the breasts for benign and malignant tumors and cysts.

posterior

anterior axillary

axillary

nodes

lymph

nodes

watershed

superficial

CD Figure 3-5

Lymph drainage of the skin of the

inguinal

thorax and abdomen. Note that levels of the umbili-

lymph

cus anteriorly and iliac crests posteriorly may be

nodes

regarded as watersheds for lymph flow.

Chapter 3

skin

dense

fibrous

septa

nipple

CD Figure 3-6

Mediolateral

mammogram showing the glan-

glandular tissue supported

dular tissue supported by the

by connective tissue

connective tissue septa.

Extremely low doses of x-rays are used so that the dangers are

may result in a mistaken diagnosis of warts or moles. A long-

minimal and the examination can be repeated often. Its suc-

standing retracted nipple is a congenital deformity caused by

cess is based on the fact that a lesion measuring only a few

a failure in the complete development of the nipple. A re-

millimeters in diameter can be detected long before it is felt

tracted nipple of recent occurrence is usually caused by an

by clinical examination.

underlying carcinoma pulling on the lactiferous ducts.

Supernumerary and

The Importance of Fibrous Septa

The interior of the breast is divided into 15 to 20 compart-

Retracted Nipples

ments that radiate from the nipple by fibrous septa that ex-

Supernumerary nipples occasionally occur along a line ex-

tend from the deep surface of the skin. Each compartment

tending from the axilla to the groin; they may or may not be

contains a lobe of the gland. Normally, the skin feels

associated with breast tissue. This minor congenital anomaly

completely mobile over the breast substance. However,

The Chest Wall, Chest Cavity, Lungs, and Pleural Cavities

should the fibrous septa become involved in a scirrhous car-

This means that the breast and the associated structures con-

cinoma or in a disease such as a breast abscess, which results

taining the lymph vessels and nodes must be removed en

in the production of contracting fibrous tissue, the septa will

bloc. The excised mass is therefore made up of the follow-

be pulled on, causing dimpling of the skin. The fibrous

ing: a large area of skin overlying the tumor and including

septa are sometimes referred to as the suspensory ligaments

the nipple; all the breast tissue; the pectoralis major and

of the mammary gland.

associated fascia through which the lymph vessels pass to the

An acute infection of the mammary gland may occur

internal thoracic nodes; the pectoralis minor and associated

during lactation. Pathogenic bacteria gain entrance to the

fascia related to the lymph vessels passing to the axilla; all

breast tissue through a crack in the nipple. Because of

the fat, fascia, and lymph nodes in the axilla; and the fascia

the presence of the fibrous septa, the infection remains

covering the upper part of the rectus sheath, the serratus

localized to one compartment or lobe in the beginning.

anterior, the subscapularis, and the latissimus dorsi muscles.

Abscesses should be drained through a radial incision to

The axillary blood vessels, the brachial plexus, and the

avoid spreading of the infection into neighboring compart-

nerves to the serratus anterior and the latissimus dorsi are

ments; a radial incision also minimizes the damage to the

preserved. Some degree of postoperative edema of the arm

radially arranged ducts.

is likely to follow such a radical removal of the lymph vessels

draining the upper limb.

A modified form of radical mastectomy for patients with

Lymph Drainage and Carcinoma

clinically localized cancer is also a common procedure and

consists of a simple mastectomy in which the pectoral mus-

of the Breast

cles are left intact. The axillary lymph nodes, fat, and fascia

The importance of knowing the lymph drainage of the

are removed. This procedure removes the primary tumor

breast in relation to the spread of cancer from that organ

and permits pathologic examination of the lymph nodes for

cannot be overemphasized. The lymph vessels from the

possible metastases.

medial quadrants of the breast pierce the second, third,

and fourth intercostal spaces and enter the thorax to drain

into the lymph nodes alongside the internal thoracic

CONGENITAL

artery. The lymph vessels from the lateral quadrants of the

breast drain into the anterior or pectoral group of axillary

nodes. It follows, therefore, that a cancer occurring in the

ANOMALIES OF

lateral quadrants of the breast tends to spread to the axillary

nodes. Thoracic metastases are difficult or impossible to

THE BREAST

treat, but the lymph nodes of the axilla can be removed

surgically.

Approximately 60% of carcinomas of the breast occur

Polythelia

in the upper lateral quadrant. The lymphatic spread of

Supernumerary nipples occasionally occur along a line cor-

cancer to the opposite breast, to the abdominal cavity, or

responding to the position of the milk ridge. They are liable

into lymph nodes in the root of the neck is caused by

to be mistaken for moles.

obstruction of the normal lymphatic pathways by malig-

nant cells or destruction of lymph vessels by surgery or

radiotherapy. The cancer cells are swept along the lymph

Retracted Nipple or Inverted Nipple

vessels and follow the lymph stream. The entrance of can-

cer cells into the blood vessels accounts for the metastases

Retracted nipple is a failure in the development of the nip-

in distant bones.

ple during its later stages. It is important clinically, because

In patients with localized cancer of the breast, most sur-

normal suckling of an infant cannot take place, and the nip-

geons do a simple mastectomy or a lumpectomy, followed

ple is prone to infection.

by radiotherapy to the axillary lymph nodes and/or hormone

therapy. In patients with localized cancer of the breast with

Micromastia

early metastases in the axillary lymph nodes, most authori-

ties agree that radical mastectomy offers the best chance of

An excessively small breast on one side occasionally occurs,

cure. In patients in whom the disease has already spread be-

resulting from lack of development.

yond these areas (e.g., into the thorax), simple mastectomy,

followed by radiotherapy or hormone therapy, is the treat-

Macromastia

ment of choice.

Radical mastectomy is designed to remove the primary

Diffuse hypertrophy of one or both breasts occasionally oc-

tumor and the lymph vessels and nodes that drain the area.

curs at puberty in otherwise normal girls.

Chapter 3

opening the pleural cavities. A small incision is made in the

Gynecomastia

midline in the neck just above the suprasternal notch, and

the superior mediastinum is explored down to the region of

Unilateral or bilateral enlargement of the male breast occa-

the bifurcation of the trachea. The procedure can be used to

sionally occurs, usually at puberty. The cause is unknown,

determine the diagnosis and degree of spread of carcinoma

but the condition is probably related to some form of hor-

of the bronchus.

monal imbalance.

THE PLEURA

THE MEDIASTINUM

Pleural Fluid

Deflection of Mediastinum

The pleural space normally contains 5 to 10 mL of clear

In the cadaver, the mediastinum, as the result of the hard-

fluid, which lubricates the apposing surfaces of the visceral

ening effect of the preserving fluids, is an inflexible, fixed

and parietal pleurae during respiratory movements. The

structure. In the living, it is very mobile; the lungs, heart,

formation of the fluid results from hydrostatic and osmotic

and large arteries are in rhythmic pulsation, and the esoph-

pressures. Since the hydrostatic pressures are greater in the

agus distends as each bolus of food passes through it.

capillaries of the parietal pleura than in the capillaries of

If air enters the pleural cavity (a condition called pneu-

the visceral pleura (pulmonary circulation), the pleural

mothorax), the lung on that side immediately collapses and

fluid is normally absorbed into the capillaries of the vis-

the mediastinum is displaced to the opposite side. This con-

ceral pleura. Any condition that increases the production

dition reveals itself by the patient’s being breathless and in a

of the fluid

(e.g., inflammation, malignancy, congestive

state of shock; on examination, the trachea and the heart are

heart disease) or impairs the drainage of the fluid (e.g., col-

found to be displaced to the opposite side.

lapsed lung) results in the abnormal accumulation of fluid,

called a pleural effusion. The presence of 300 mL of fluid

Mediastinitis

in the costodiaphragmatic recess in an adult is sufficient to

enable its clinical detection. The clinical signs include de-

The structures that make up the mediastinum are embed-

creased lung expansion on the side of the effusion, with

ded in loose connective tissue that is continuous with that of

decreased breath sounds and dullness on percussion over

the root of the neck. Thus, it is possible for a deep infection

the effusion.

of the neck to spread readily into the thorax, producing a

mediastinitis. Penetrating wounds of the chest involving the

Pleurisy

esophagus may produce a mediastinitis. In esophageal per-

forations, air escapes into the connective tissue spaces and

Inflammation of the pleura (pleuritis or pleurisy), sec-

ascends beneath the fascia to the root of the neck, produc-

ondary to inflammation of the lung (e.g., pneumonia),

ing subcutaneous emphysema.

results in the pleural surfaces becoming coated with inflam-

matory exudate, causing the surfaces to be roughened. This

Mediastinal Tumors or Cysts

roughening produces friction, and a pleural rub can be

heard with the stethoscope on inspiration and expiration.

Because many vital structures are crowded together within

Often the exudate becomes invaded by fibroblasts, which

the mediastinum, their functions can be interfered with by

lay down collagen and bind the visceral pleura to the pari-

an enlarging tumor or organ. A tumor of the left lung can

etal pleura, forming pleural adhesions.

rapidly spread to involve the mediastinal lymph nodes,

which on enlargement may compress the left recurrent la-

Pneumothorax

ryngeal nerve, producing paralysis of the left vocal fold. An

expanding cyst or tumor can partially occlude the superior

As a result of disease or injury (stab or gunshot wounds), air

vena cava, causing severe congestion of the veins of the up-

can enter the pleural cavity from the lungs or through the

per part of the body. Other pressure effects can be seen on

chest wall (pneumothorax).

the sympathetic trunks, phrenic nerves, and sometimes the

trachea, main bronchi, and esophagus.

Spontaneous Pneumothorax

A spontaneous pneumothorax is a condition in which air

Mediastinoscopy

enters the pleural cavity suddenly without its cause being

Mediastinoscopy is a diagnostic procedure whereby speci-

immediately apparent. After investigation, it is usually found

mens of tracheobronchial lymph nodes are obtained without

that air has entered from a diseased lung and a bulla (bleb)

The Chest Wall, Chest Cavity, Lungs, and Pleural Cavities

has ruptured. The resulting signs of pneumothorax are ab-

sent or diminished breath sounds over the affected lung and

deflection of the trachea to the opposite side.

Open Pneumothorax

Open pneumothorax occurs when the air enters the pleural

cavity through an opening in the chest wall and may result

from stab or bullet wounds (CD Fig. 3-7). Sucking pneu-

mothorax occurs when the hole in the chest wall is larger

than the glottis. With each inspiration the negative pressure

created is more effective at sucking air in through the chest

wound than air entering through the glottis; this produces a

sucking sound. The lung cannot be expanded, and respira-

tion is compromised.

Tension Pneumothorax

inspiration

Tension pneumothorax occurs when air is sucked into the

pleural cavity through a chest wound with each inspiration

but does not escape (CD Fig. 3-8). This can occur as the

result of clothing and/or the layers of the chest wall com-

bining to form a valve so that air enters on inspiration but

cannot exit through the wound. In these circumstances,

the air pressure builds up on the wounded side and pushes

the mediastinum progressively over to the opposite side.

Because of the anatomic thin walls of the great veins (vena

cavae) and the atria of the heart, the increase in air pres-

sure within the chest cavity interferes with blood return

to the heart; the patient may die because of lack of venous

return. The clinical signs are hypertension, hyperreso-

nance to percussion on the affected side, the engorgement

of the neck veins, and the evidence of mediastinal deflec-

tion. Eventually, hypotension (secondary to lack of venous

return) results. The treatment is immediate decompres-

expiration

sion of the affected side by the insertion of a needle thora-

costomy.

Fluid in the Pleural Cavity

CD Figure 3-7

Open pneumothorax without tension. A. On

inspiration air is drawn in through the wound in the chest

wall at atmospheric pressure, and the lung partially or com-

Pleural Effusion

pletely collapses (depending on the size of the hole in the

chest wall) from its own inherent elasticity; the mediastinum

The presence of fluid in the cavity is referred to as a pleural

is deflected to the opposite side. B. On expiration air passes

effusion. Fluid (serous, blood, or pus) can be drained from

out of the chest wound as the diaphragm rises and the

the pleural cavity through a wide-bore needle, as described

mediastinum is deflected to the same side. With large chest

later in this section.

openings (larger than the cross-sectional area of trachea), air

will preferentially use the hole in the chest wall rather than

passing up and down the trachea, and respiratory ventilation

Hydropneumothorax

will cease.

Air in the pleural cavity associated with serous fluid is

known as hydropneumothorax.

Pyopneumothorax

Air in the pleural cavity associated with pus is known as

pyopneumothorax.

The Chest Wall, Chest Cavity, Lungs, and Pleural Cavities

POSITION OF

CARDIOPULMONARY

THORACIC AND

RESUSCITATION

Cardiopulmonary resuscitation (CPR), achieved by compres-

UPPER ABDOMINAL

sion of the chest, was originally believed to succeed because

of the compression of the heart between the sternum and the

VISCERA DURING

vertebral column. Now it is recognized that the blood flows in

CPR because the whole thoracic cage is the pump; the heart

DIFFERENT PHASES

functions merely as a conduit for blood. An extrathoracic

pressure gradient is created by external chest compressions.

The pressure in all chambers and locations within the chest

OF RESPIRATION

cavity is the same. With compression, blood is forced out of

the thoracic cage. The blood preferentially flows out the arte-

It is important to remember that the pleura, lungs, and heart

rial side of the circulation and back down the venous side be-

in the chest cavity, and the upper abdominal viscera in the

cause the venous valves in the internal jugular system prevent

abdominal cavity, move extensively during the different

a useless oscillatory movement. With the release of compres-

phases of respiration. This movement largely results from

sion, blood enters the thoracic cage, preferentially down the

the rising and falling of the diaphragm. It is particularly

venous side of the systemic circulation.

important when trying to work out the path taken by a sharp

instrument or bullet following penetrating wounds to the

lower chest.

THE CHEST WALL

ROOT OF THE NECK

Thoracocentesis

INJURIES

Needle Thoracostomy

A needle thoracostomy is necessary in patients with tension

The cervical dome of the parietal pleura and the apex of the

pneumothorax (air in the pleural cavity under pressure) or to

lungs extend into the neck so that at their highest point

drain fluid (blood or pus) away from the pleural cavity to al-

they lie about 1 in. (2.5 cm) above the clavicles (see text

low the lung to reexpand. It may also be necessary to withdraw

Fig.

3-51). Consequently, they are vulnerable to stab

a sample of pleural fluid for microbiologic examination.

wounds in the root of the neck.

Anterior Approach

For the anterior approach, the patient is in the supine posi-

TRAUMATIC

tion. The sternal angle is identified, and then the second

costal cartilage, the second rib, and the second intercostal

space are found in the midclavicular line.

ASPHYXIA

Lateral Approach

The sudden caving in of the anterior chest wall associated

with fractures of the sternum and ribs causes a dramatic rise

For the lateral approach, the patient is lying on the lateral

in intrathoracic pressure. Apart from the immediate evi-

side. The second intercostal space is identified as above, but

dence of respiratory distress, the anatomy of the venous

the anterior axillary line is used.

system plays a significant role in the production of the char-

The skin is prepared in the usual way, and a local anes-

acteristic vascular signs of traumatic asphyxia. The thinness

thetic is introduced along the course of the needle above the

of the walls of the thoracic veins and the right atrium of the

upper border of the third rib. The thoracostomy needle will

heart causes their collapse under the raised intrathoracic

pierce the following structures as it passes through the chest

pressure, and venous blood is dammed back in the veins of

wall (see text Fig. 3-4): (a) skin, (b) superficial fascia (in the

the neck and head. This produces venous congestion;

anterior approach the pectoral muscles are then penetrated),

bulging of the eyes, which become injected; and swelling of

the lips and tongue, which become cyanotic. The skin of the

(e) internal intercostal muscle, (f) innermost intercostal mus-

face, neck, and shoulders becomes purple.

cle, (g) endothoracic fascia, and (h) parietal pleura.

Chapter 3

The needle should be kept close to the upper border of

of the rib above and maintains that position as it courses

the third rib to avoid injuring the intercostal vessels and

forward.

nerve in the subcostal groove.

The introduction of a thoracostomy tube or needle

through the lower intercostal spaces is possible provided that

the presence of the domes of the diaphragm is remembered

Tube Thoracostomy

as they curve upward into the rib cage as far as the fifth rib

The preferred insertion site for a tube thoracostomy is the

(higher on the right). Avoid damaging the diaphragm and

fourth or fifth intercostal space at the anterior axillary line

entering the peritoneal cavity and injuring the liver, spleen,

(CD Fig. 3-9). The tube is introduced through a small inci-

or stomach.

sion. The neurovascular bundle changes its relationship to

the ribs as it passes forward in the intercostal space. In the

Thoracotomy

most posterior part of the space, the bundle lies in the mid-

dle of the intercostal space. As the bundle passes forward to

In patients with penetrating chest wounds with uncon-

the rib angle, it becomes closely related to the lower border

trolled intrathoracic hemorrhage, thoracotomy may be a

intercostal vein

intercostal artery

intercostal nerve

tube

lung

visceral pleura

pleural cavity (space)

parietal pleura

innermost intercostal

skin

internal intercostal

superficial fascia

external

serratus anterior

intercostal

CD Figure 3-9

Tube thoracostomy. A. The site for insertion of the tube at the anterior ax-

illary line. The skin incision is usually made over the intercostal space one below the space

to be pierced. B. The various layers of tissue penetrated by the scalpel and later the tube as

they pass through the chest wall to enter the pleural cavity (space). The incision through the

intercostal space is kept close to the upper border of the rib to avoid injuring the intercostal

vessels and nerve. C. The tube advancing superiorly and posteriorly in the pleural space.

The Chest Wall, Chest Cavity, Lungs, and Pleural Cavities

life-saving procedure. After preparing the skin in the usual

peanuts, and parts of chicken bones and toys have all found

way, the physician makes an incision over the fourth or fifth

their way into the bronchi. Parts of teeth may be inhaled

intercostal space, extending from the lateral margin of the

while a patient is under anesthesia during a difficult dental

sternum to the anterior axillary line

(CD Fig. 3-10).

extraction. Because the right bronchus is the wider and

Whether to make a right or left incision depends on the site

more direct continuation of the trachea (see text Fig. 3-22),

of the injury. For access to the heart and aorta, the chest

foreign bodies tend to enter the right instead of the left

should be entered from the left side. The following tissues

bronchus. From there, they usually pass into the middle or

will be incised (see CD Fig. 3-9): (a) skin, (b) subcutaneous

lower lobe bronchi.

tissue, (c) serratus anterior and pectoral muscles, (d) exter-

nal intercostal muscle and anterior intercostal membrane,

Bronchoscopy

(e) internal intercostal muscle, (f) innermost intercostal

muscle, (g) endothoracic fascia, and (h) parietal pleura.

Bronchoscopy enables a physician to examine the interior of

Avoid the internal thoracic artery, which runs vertically

the trachea; its bifurcation, called the carina; and the main

downward behind the costal cartilages about a fingerbreadth

bronchi (CD Figs. 3-11 and 3-12). With experience, it is

lateral to the margin of the sternum, and the intercostal ves-

possible to examine the interior of the lobar bronchi and the

sels and nerve, which extend forward in the subcostal groove

beginning of the first segmental bronchi. By means of this

in the upper part of the intercostal space (see CD Fig. 3-9).

procedure, it is also possible to obtain biopsy specimens of

mucous membranes and to remove inhaled foreign bodies

(even an open safety pin).

THE TRACHEA AND

PRINCIPAL

THE LUNGS

BRONCHI

Clinical Examination of the Chest

As medical personnel, you will be examining the chest to

Compression of the Trachea

detect evidence of disease. Your examination consists of in-

The trachea is a membranous tube kept patent under normal

spection, palpation, percussion, and auscultation.

conditions by U-shaped bars of cartilage. In the neck, a uni-

Inspection shows the configuration of the chest,

lateral or bilateral enlargement of the thyroid gland can cause

the range of respiratory movement, and any inequalities on

gross displacement or compression of the trachea. A dilatation

the two sides. The type and rate of respiration are also

of the aortic arch (aneurysm) can compress the trachea. With

noted.

each cardiac systole the pulsating aneurysm may tug at the

Palpation enables the physician to confirm the impres-

trachea and left bronchus, a clinical sign that can be felt by

sions gained by inspection, especially of the respiratory

palpating the trachea in the suprasternal notch.

movements of the chest wall. Abnormal protuberances or re-

cession of part of the chest wall is noted. Abnormal pulsa-

tions are felt and tender areas detected.

Tracheitis or Bronchitis

Percussion is a sharp tapping of the chest wall with

The mucosa lining the trachea is innervated by the recur-

the fingers. This produces vibrations that extend through

rent laryngeal nerve and, in the region of its bifurcation, by

the tissues of the thorax. Air-containing organs such as the

the pulmonary plexus. A tracheitis or bronchitis gives rise to

lungs produce a resonant note; conversely, a more solid

a raw, burning sensation felt deep to the sternum instead of

viscus such as the heart produces a dull note. With prac-

actual pain. Many thoracic and abdominal viscera, when

tice, it is possible to distinguish the lungs from the heart or

diseased, give rise to discomfort that is felt in the midline. It

liver by percussion.

seems that organs possessing a sensory innervation that is not

Auscultation enables the physician to listen to the

under normal conditions directly relayed to consciousness

breath sounds as the air enters and leaves the respiratory

display this phenomenon. The afferent fibers from these or-

passages. Should the alveoli or bronchi be diseased and

gans traveling to the central nervous system accompany au-

filled with fluid, the nature of the breath sounds will be al-

tonomic nerves.

tered. The rate and rhythm of the heart can be confirmed

by auscultation, and the various sounds produced by the

heart and its valves during the different phases of the car-

Inhaled Foreign Bodies

diac cycle can be heard. It may be possible to detect fric-

Inhalation of foreign bodies into the lower respiratory tract

tion sounds produced by the rubbing together of diseased

is common, especially in children. Pins, screws, nuts, bolts,

layers of pleura or pericardium.

The Chest Wall, Chest Cavity, Lungs, and Pleural Cavities

To make these examinations, the physician must be

familiar with the normal structure of the thorax and must

have a mental image of the normal position of the lungs and

heart in relation to identifiable surface landmarks. Further-

more, it is essential that the physician be able to relate any

abnormal findings to easily identifiable bony landmarks so

that he or she can accurately record and communicate them

to colleagues.

Since the thoracic wall actively participates in the

movements of respiration, many bony landmarks change

their levels with each phase of respiration. In practice, to sim-

plify matters, the levels given are those usually found at about

midway between full inspiration and full expiration.

For physical examination of the patient, it is good to

remember that the upper lobe of the lungs is most easily

examined from the front of the chest and the lower lobe

from the back. In the axilla, areas of all three lobes can be

examined (see text Fig. 3-53).

Trauma to the Lungs

A physician must always remember that the apex of the lung

projects up into the neck (1 in. [2.5 cm] above the clavicle)

and can be damaged by stab or bullet wounds in this area.

CD Figure 3-11

The bifurcation of the trachea as seen

through an operating bronchoscope. Note the ridge of the ca-

rina seen in the center and the opening into the right main

Fractured Ribs and the Lungs

bronchus on the right, which is a more direct continuation of

the trachea. (Courtesy of E.D. Andersen.)

Although the lungs are well protected by the bony thoracic

cage, a splinter from a fractured rib can nevertheless pene-

trate the lung, and air can escape into the pleural cavity,

causing a pneumothorax and collapse of the lung. It can also

find its way into the lung connective tissue. From there, the

air moves under the visceral pleura until it reaches the lung

root. It then passes into the mediastinum and up to the neck.

Here, it may distend the subcutaneous tissue, a condition

known as subcutaneous emphysema.

The changes in the position of the thoracic and upper

abdominal viscera and the level of the diaphragm during

different phases of respiration relative to the chest wall are of

considerable clinical importance. A penetrating wound in

the lower part of the chest may or may not damage abdomi-

nal viscera, depending on the phase of respiration at the

time of injury.

Pain and Lung Disease

Lung tissue and the visceral pleura are devoid of pain-

sensitive nerve endings, so that pain in the chest is always

the result of conditions affecting the surrounding struc-

tures. In tuberculosis or pneumonia, for example, pain

may never be experienced.

Once lung disease crosses the visceral pleura and the

pleural cavity to involve the parietal pleura, pain becomes a

CD Figure 3-12

The interior of the left main bronchus as

prominent feature. Lobar pneumonia with pleurisy, for

seen through an operating bronchoscope. The openings into

the left upper lobe bronchus and its division and the left lower

example, produces a severe tearing pain, accentuated by

lobe bronchus are indicated. (Courtesy of E. D. Andersen.)

inspiring deeply or coughing. Because the lower part of the

Chapter 3

costal parietal pleura receives its sensory innervation from

Bronchogenic Carcinoma

the lower five intercostal nerves, which also innervate the

skin of the anterior abdominal wall, pleurisy in this area

Bronchogenic carcinoma accounts for about one third of all

commonly produces pain that is referred to the abdomen.

cancer deaths in men and is becoming increasingly common

This has sometimes resulted in a mistaken diagnosis of an

in women. It commences in most patients in the mucous

acute abdominal lesion.

membrane lining the larger bronchi and is therefore situated

In a similar manner, pleurisy of the central part of the

close to the hilum of the lung. The neoplasm rapidly spreads

diaphragmatic pleura, which receives sensory innervation

to the tracheobronchial and bronchomediastinal nodes and

from the phrenic nerve (C3, 4, and 5), can lead to referred

may involve the recurrent laryngeal nerves, leading to hoarse-

pain over the shoulder because the skin of this region is sup-

ness of the voice. Lymphatic spread via the bronchomediasti-

plied by the supraclavicular nerves (C3 and 4).

nal trunks may result in early involvement in the lower deep

cervical nodes just above the level of the clavicle. Hematoge-

Surgical Access to the Lungs

nous spread to bones and the brain commonly occurs.

Surgical access to the lungs or mediastinum is commonly

Conditions That Decrease

undertaken through an intercostal space. Special rib retrac-

tors that allow the ribs to be widely separated are used. The

Respiratory Efficiency

costal cartilages are sufficiently elastic to permit consider-

able bending. Good exposure of the lungs is obtained by this

method.

Constriction of the Bronchi (Bronchial

Asthma)

Segmental Resection of the Lung

One of the problems associated with bronchial asthma is the

A localized chronic lesion such as that of tuberculosis or a

spasm of the smooth muscle in the wall of the bronchioles.

benign neoplasm may require surgical removal. If it is re-

This particularly reduces the diameter of the bronchioles

stricted to a bronchopulmonary segment, it is possible to

during expiration, usually causing the asthmatic patient to

carefully dissect out a particular segment and remove it,

experience great difficulty in expiring, although inspiration is

leaving the surrounding lung intact. Segmental resection re-

accomplished normally. The lungs consequently become

quires that the radiologist and thoracic surgeon have a

greatly distended and the thoracic cage becomes perma-

sound knowledge of the bronchopulmonary segments and

nently enlarged, forming the so-called barrel chest. In addi-

that they cooperate fully to localize the lesion accurately be-

tion, the air flow through the bronchioles is further impeded

fore operation.

by the presence of excess mucus, which the patient is unable

to clear because an effective cough cannot be produced.

Pulmonary Contusion

Loss of Lung Elasticity

This condition is caused by a sudden rapid compression of

the chest wall and underlying lung. It may be produced by

Many diseases of the lungs, such as emphysema and pul-

blunt trauma or gunshot wounds. Because of the pliability

monary fibrosis, destroy the elasticity of the lungs, and thus

of the chest wall in children, lung contusion is often

the lungs are unable to recoil adequately, causing incom-

present in the absence of rib fractures. The localized

plete expiration. The respiratory muscles in these patients

endothelial damage to the capillaries results in the transu-

have to assist in expiration, which no longer is a passive

dation of fluid into the lung parenchyma, thus compro-

phenomenon.

mising lung function. In cases of blunt trauma, the area of

Loss of Lung Distensibility

damage to the lung will depend on the site of impact

and will not be determined by anatomic subdivisions of

Diseases such as silicosis, asbestosis, cancer, and pneumo-

the lung.

nia interfere with the process of expanding the lung in

inspiration. A decrease in the compliance of the lungs

Tracheobronchial Injury

and the chest wall then occurs, and a greater effort has to

be undertaken by the inspiratory muscles to inflate the lungs.

The lung root is the site where the mobile lung is connected

by the main bronchi to the relatively fixed lower end of the

trachea. It is not surprising, therefore, to find that when a

Postural Drainage

rapid deceleration or shearing force is applied to the lungs,

injuries occur to the bronchi. In the majority of patients, the

Excessive accumulation of bronchial secretions in a lobe or

tear occurs within 1 in. of the carina.

segment of a lung can seriously interfere with the normal

The Chest Wall, Chest Cavity, Lungs, and Pleural Cavities

esophagus

trachea

fistula

CD Figure 3-13

Different types

of esophageal atresia and tra-

cheoesophageal fistula. A. Com-

plete blockage of the esophagus

with a tracheoesophageal fistula.

B. Similar to type A, but the two

parts of the esophagus are joined

diaphragm

together by fibrous tissue.

C. Complete blockage of the

esophagus; the distal end is

rudimentary. D. A tracheoe-

sophageal fistula with narrowing

of the esophagus. E. An

esophagotracheal fistula; the

esophagus is not connected with

the distal end, which is rudimen-

tary. F. Separate esophagotra-

cheal and tracheoesophageal

fistulas. G. Narrowing of the

esophagus without a fistula.

In most cases, the lower

esophageal segment communi-

cates with the trachea, and types

A and B occur more commonly.

flow of air into the alveoli. Furthermore, the stagnation of

septum formed by the fusion of the margins of the laryngotra-

such secretions is often quickly followed by infection. To aid

cheal groove should be deviated posteriorly, the lumen of the

in the normal drainage of a bronchial segment, a physio-

esophagus would be much reduced in diameter. The differ-

therapist often alters the position of the patient so that grav-

ent types of atresia, with and without fistula, are shown in CD

ity assists in the process of drainage. Sound knowledge of the

Fig. 3-13). Obstruction of the esophagus prevents the child

bronchial tree is necessary to determine the optimum posi-

from swallowing saliva and milk, and this leads to aspiration

tion of the patient for good postural drainage.

into the larynx and trachea, which usually results in pneu-

monia. With early diagnosis, it is often possible to correct this

serious anomaly surgically.

CONGENITAL

Neonatal Lobar Emphysema

ANOMALIES OF

This condition occurs shortly after birth and is an overdisten-

tion of one or more lobes of the lung. It is a result, in many

THE TRACHEA AND

cases, of a failure of development of bronchial cartilage,

which causes the bronchi to collapse. Air is inspired through

the collapsed bronchi, but it is trapped during expiration.

LUNGS

Congenital Cysts of the Lung

Esophageal Atresia and Tracheo-

Lung cysts may be solitary or may form multiple honey-

comb-like masses. They are believed to be caused by sepa-

esophageal Fistula

ration of lung tissue occurring during development. Prompt

If the margins of the laryngotracheal groove fail to fuse ade-

surgical removal of the cysts is necessary to prevent com-

quately, an abnormal opening may be left between the laryn-

pression and collapse of surrounding lung and infectious

gotracheal tube and the esophagus. If the tracheoesophageal

complications.

Chapter 3

Clinical Problem Solving Questions

Read the following case histories/questions and give

A 65-year-old man and a 10-year-old boy were involved

the best answer for each.

in a severe automobile accident. In both patients the

thorax had been badly crushed. Radiographic examina-

A 31-year-old soldier received a shrapnel wound in the

tion revealed that the man had five fractured ribs but

neck during the Persian Gulf War. Recently, during a

the boy had no fractures.

physical examination, it was noticed that when he blew

What is the most likely explanation for this difference in

his nose or sneezed, the skin above the right clavicle

medical findings?

bulged upward.

A. The patients were in different seats in the vehicle.

The upward bulging of the skin could be explained by

B. The boy was wearing his seat belt and the man was

A. injury to the cervical pleura.

not.

B. damage to the suprapleural membrane.

C. The chest wall of a child is very elastic, and fractures

C. damage to the deep fascia in the root of the neck.

of ribs in children are rare.

D. ununited fracture of the first rib.

D. The man anticipated the impact and tensed his

muscles, including those of the shoulder girdle and

A 52-year-old woman was admitted to the hospital with

abdomen.

a diagnosis of right-sided pleurisy with pneumonia. It

was decided to remove a sample of pleural fluid from

On examination of a posteroanterior chest radiograph

her pleural cavity. The resident inserted the needle

of an 18-year-old woman, it was seen that the left dome

close to the lower border of the eighth rib in the ante-

of the diaphragm was higher than the right dome and

rior axillary line. The next morning he was surprised to

reached to the upper border of the fourth rib.

hear that the patient had complained of altered skin

The position of the left dome of the diaphragm could

sensation extending from the point where the needle

be explained by the following conditions except which?

was inserted downward and forward to the midline of

A. The left lung could be collapsed.

the abdominal wall above the umbilicus.

B. There is a collection of blood under the diaphragm

The altered skin sensation in this patient after the nee-

on the left side.

dle thoracostomy could be explained by which of the

C. There is an amoebic abscess in the left lobe of the

following?

liver.

A. The needle was inserted too low down in the inter-

D. The left dome of the diaphragm is normally higher

costal space.

than the right dome.

B. The needle was inserted too close to the lower bor-

E. There is a peritoneal abscess beneath the diaphragm

der of the eighth rib and damaged the eighth inter-

on the left side.

costal nerve.

A 43-year-old man was involved in a violent quarrel

C. The needle had impaled the eighth rib.

with his wife over another woman. In a fit of rage, the

D. The needle had penetrated too deeply and pierced

wife picked up a carving knife and lunged forward at

the lung.

her husband, striking his anterior neck over the left

A 68-year-old man complained of a swelling in the skin

clavicle. The husband collapsed on the kitchen floor,

on the back of the chest. He had noticed it for the last 3

bleeding profusely from the wound. The distraught

years and was concerned because it was rapidly enlarg-

wife called for an ambulance.

ing. On examination, a hard lump was found in the skin

On examination in the emergency department of the

in the right scapula line opposite the seventh thoracic

hospital the following conditions were found except

vertebra. A biopsy revealed that the lump was malignant.

which?

Because of the rapid increase in the size of the tumor,

A. A wound was seen about 1 in. (2.5 cm) wide over the

the following lymph nodes were examined for metas-

left clavicle.

tases:

B. Auscultation revealed diminished breath sounds

A. Superficial inguinal nodes

over the left hemithorax.

B. Anterior axillary nodes

C. The trachea was deflected to the left.

C. Posterior axillary nodes

D. The left upper limb was lying stationary on the table,

D. External iliac nodes

and active movement of the small muscles of the left

E. Deep cervical nodes

hand was absent.

The Chest Wall, Chest Cavity, Lungs, and Pleural Cavities

E. The patient was insensitive to pin prick along the lat-

B. The carcinoma had metastasized to the broncho-

eral side of the left arm, forearm, and hand.

mediastinal lymph nodes, causing their enlarge-

ment and producing a widening of the mediastinal

A 72-year-old man complaining of burning pain on the

shadow seen on the chest radiograph.

right side of his chest was seen by his physician. On ex-

C. The enlarged lymph nodes had pressed on the left

amination the patient indicated that the pain passed

recurrent laryngeal nerve.

forward over the right sixth intercostal space from the

D. Partial injury to the recurrent laryngeal nerve re-

posterior axillary line forward as far as the midline over

sulted in paralysis of the abductor muscles of the vo-

the sternum. The physician noted that there were sev-

cal cords, leaving the adductor muscles unopposed.

eral watery blebs on the skin in the painful area.

E. The enlarged lymph nodes pressed on the left re-

The following statements are correct except which?

current nerve as it ascended to the neck anterior to

A. This patient has herpes zoster.

the arch of the aorta.

B. A virus descends along the cutaneous nerves, caus-

A 35-year-old woman had difficulty breathing and

ing dermatomal pain and the eruption of vesicles.

sleeping at night. She says she falls asleep only to wake

C. The sixth right intercostal nerve was involved.

up with a choking sensation. She finds that she has to

D. The condition was confined to the anterior cuta-

sleep propped up in bed on pillows with her neck flexed

neous branch of the sixth intercostal nerve.

to the right.

An 18-year-old woman was thrown from a horse while

10.

The following statements concerning this case are

attempting to jump a fence. She landed heavily on the

correct except which?

ground, striking the lower part of her chest on the left

A. Veins in the skin at the root of the neck are

side. On examination in the emergency department she

congested.

was conscious but breathless. The lower left side of her

B. The U-shaped cartilaginous rings in the wall of the

chest was badly bruised, and the ninth and tenth ribs

trachea prevent it from being kinked or compressed.

were extremely tender to touch. She had severe tachy-

C. The left lobe of the thyroid gland is larger than the

cardia, and her systolic blood pressure was low.

right lobe.

The following statements are possibly correct except

D. On falling asleep, the patient tends to flex her neck

which?

laterally over the enlarged left thyroid lobe.

A. There was evidence of tenderness and muscle spasm

E. The enlarged thyroid gland extends down the neck

in the left upper quadrant of the anterior abdominal

into the superior mediastinum.

wall.

F. The brachiocephalic veins in the superior medi-

B. A posteroanterior radiograph of the chest revealed

astinum were partially obstructed by the enlarged

fractures of the left ninth and tenth ribs near their

thyroid gland.

angles.

A 15-year-old boy was rescued from a lake after falling

C. The blunt trauma to the ribs had resulted in a tear of

through thin ice. The next day, he developed a severe

the underlying spleen.

cold, and 3 days later his general condition deterio-

D. The presence of blood in the peritoneal cavity had

rated. He became febrile and started to cough up blood-

irritated the parietal peritoneum, producing reflex

stained sputum. At first, he had no chest pain, but later,

spasm of the upper abdominal muscles.

when he coughed, he experienced severe pain over the

E. The muscles of the anterior abdominal wall are not

right fifth intercostal space in the midclavicular line.

supplied by thoracic spinal nerves.

11.

The following statements would explain the patient’s

A 55-year-old man states that he has noticed an alter-

signs and symptoms except which?

ation in his voice. He has lost 40 lb (18 kg) and has a

A. The patient had developed lobar pneumonia and

persistent cough with blood-stained sputum. He

pleurisy in the right lung.

smokes 50 cigarettes a day. On examination, the left vo-

B. Disease of the lung does not cause pain until the

cal fold is immobile and lies in the adducted position.

parietal pleura is involved.

A posteroanterior chest radiograph reveals a large mass

C. The pneumonia was located in the right middle

in the upper lobe of the left lung with an increase in

lobe.

width of the mediastinal shadow on the left side.

D. The visceral pleura is innervated by autonomic

The symptoms and signs displayed by this patient can

nerves that contain pain fibers.

be explained by the following statements except which?

E. Pain associated with the pleurisy was accentuated

A. This patient has advanced carcinoma of the

when movement of the visceral and parietal pleurae

bronchus in the upper lobe of the left lung, which

occurred, for example, on deep inspiration or

was seen as a mass on the chest radiograph.

coughing.

Chapter 3

A 2-year-old boy was playing with his toy car when his

C. The costodiaphragmatic recess is situated between

baby-sitter noticed that a small metal nut was missing

the lower border of the lung and the parietal

from the car. Two days later the child developed a

pleura.

cough and became febrile.

D. The lung on extreme inspiration could descend in

the costodiaphragmatic recess only as far as the

12.

This child’s illness could be explained by the following

eighth rib.

statements except which?

E. No breath sounds were heard because the stetho-

A. The child had inhaled the nut.

scope was located over the liver.

B. The metal nut could easily be seen on posteroante-

rior and right oblique radiographs.

A 36-year-old woman with a known history of emphy-

C. The left principal bronchus is the more vertical and

sema (dilatation of alveoli and destruction of alveolar

wider of the two principal bronchi, and inhaled for-

walls with a tendency to form cystic spaces) suddenly

eign bodies tend to become lodged in it.

experiences a severe pain in the left side of her

D. The nut was successfully removed through a bron-

chest, is breathless, and is obviously in a state of

choscope.

shock.

E. Children who are teething tend to suck on hard toys.

14.

Examination of this patient reveals the following

A 23-year-old woman was examined in the emergency

findings except which?

department because of the sudden onset of respiratory

A. The trachea is displaced to the right in the supraster-

distress. The physician was listening to breath sounds

nal notch.

over the right hemithorax and was concerned when no

B. The apex beat of the heart can be felt in the fifth left

sounds were heard on the front of the chest at the level

intercostal space just lateral to the sternum.

of the tenth rib in the midclavicular line.

C. The right lung is collapsed.

13.

The following comments concerning this patient are

D. The air pressure in the left pleural cavity is at

correct except which?

atmospheric pressure.

A. In a healthy individual, the lower border of the right

E. The air has entered the left pleural cavity as the

lung in the midclavicular line in the midrespiratory

result of rupture of one of the emphysematous cysts

position is at the level of the sixth rib.

of the left lung (left-sided pneumothorax).

B. The parietal pleura in the midclavicular line crosses

F. The elastic recoil of the lung tissue caused the lung

the tenth rib.

to collapse.

Answers and Explanations

1. B is the correct answer. The shrapnel had torn the

6. E is the correct answer. The lower trunk of the brachial

suprapleural membrane, which normally prevents

plexus was cut by the knife. This would explain the loss

the cervical dome of the pleura from bulging up into

of movement of the small muscles of the left hand. It

the neck.

would also explain the loss of skin sensation that oc-

curred in the C8 and T1 dermatomes on the medial,

2. B is the correct answer. The intercostal nerve is located

not on the lateral, side of the left forearm and hand. The

in the subcostal groove on the lower border of the rib

knife had also pierced the left dome of the cervical

(see text Fig. 3-4).

pleura, causing a left pneumothorax with left-sided

3. C is the correct answer. The lymphatic drainage of the

diminished breath sounds and a deflection of the tra-

skin of the back above the level of the iliac crests is

chea to the left.

upward and forward into the posterior axillary lymph

7. D is the correct answer. The skin over the sixth inter-

nodes.

costal space is innervated by the lateral cutaneous

4. C is the correct answer. The chest wall of a child is very

branch as well as the anterior cutaneous branch of the

elastic, and fractures of ribs in children are rare.

sixth intercostal nerve.

5. D is the correct answer. The right dome of the di-

8. E is the correct answer. The seventh to the eleventh in-

aphragm is normally higher than the left dome due to

tercostal nerves supply the muscles of the anterior ab-

the large size of the right lobe of the underlying liver.

dominal wall.

The Chest Wall, Chest Cavity, Lungs, and Pleural Cavities

9. E is the correct answer. The left recurrent laryngeal

12. C is the correct answer. The right principal (main)

nerve ascends to the neck by passing under the arch of

bronchus is the more vertical and wider of the two prin-

the aorta; it ascends in the groove between the trachea

cipal bronchi, and for this reason an inhaled foreign

and the esophagus.

body passes down the trachea and tends to enter the right

main bronchus, where it was lodged in this patient.

10. B is the correct answer. The trachea is a mobile, fibro-

13. B is the correct answer. The parietal pleura in the mid-

elastic tube that can be kinked or compressed despite

clavicular line only extends down as far as the eighth rib

the presence of the cartilaginous rings.

(see text Fig. 3-51).

11. D is the correct answer. Lung tissue and the visceral

14. C is the correct answer. The left lung collapsed imme-

pleura are not innervated with pain fibers. The costal

diately when air entered the left pleural cavity because

parietal pleura is innervated by the intercostal nerves,

the air pressures within the bronchial tree and in the

which have pain endings in the pleura.

pleural cavity were then equal.

Chapter Outline

The Heart

Cardiac Injuries

Cardiac Contusion

Chordae Tendineae and Papillary Muscle Rupture

Valve and Septal Injuries

Mitral Valve Prolapse

Penetrating Injuries to the Heart

Accessory Atrioventricular Bundles

Congenital Anomalies

Atrial Septal Defects

Circus Movement

Ventricular Septal Defects

Failure of Conduction System

Tetralogy of Fallot

Coronary Angiography

Mitral Valve Prolapse

Bicuspid Aortic Valve

Coronary Artery Disease

Persistent Truncus Arteriosus

Myocardial Infarction and Papillary Muscle Rupture

Patent Ductus Arteriosus

Chest Pain

The Pericardium

Somatic Pain

Visceral Pain

Traumatic Injury to the Pericardium

Referred Pain

Pericardial Disruption

Hemopericardium

Clinical Significance of Thoracic Dermatomes

Pericardiocentesis

Relative to Chest Pain

Anatomy of Complications

Cardiac Pain

Auscultation of Heart Valves

Clinical Problem Solving Questions

Valvular Disease of the Heart

Answers and Explanations

Valvular Heart Murmurs

Accessory Atrioventricular Bundles

THE HEART

Accessory atrioventricular bundles are thought to exist. They

are believed to be slender and normally have no functional

Chordae Tendineae and Papillary

significance. However, in the condition of accelerated atri-

oventricular conduction, the aberrant connection (bundle of

Muscle Rupture

Kent) permits one ventricle to be excited early. In this condi-

tion the PR interval is shortened and a delta wave appears on

Rupture of the chordae tendineae by disease, such as acute

the initial part of the QRS complex. Another aberrant con-

bacterial endocarditis, may cause sudden valvular insuffi-

nection (bundle of Mahaim) bypasses the atrioventricular

ciency and cardiac decompensation. Rupture of a papillary

node and inserts just distal to the node. In this condition,

muscle, since each has many chordae attached to its apex, is

known as the Lown-Ganong-Levine syndrome, the PR inter-

much more serious. Rupture of a papillary muscle may oc-

val is short but the QRS complex is normal.

cur in penetrating wounds of the heart.

Mitral Valve Prolapse

Circus Movement

In this condition, one or both mitral valve cusps balloon up

This abnormal form of conduction allows a wave of excita-

into the left atrium during ventricular systole. The valve

tion to travel continuously in a circle. This ring may occur

cusps are larger than normal and the chordae tendineae

in the atrioventricular node, causing abnormal atrial con-

may be excessively long. The posterior cusp is always in-

tractions and paroxysmal nodal tachycardia. If the individ-

volved; the anterior cusp is involved less frequently.

ual has an accessory atrioventricular bundle, the circus

The Heart, Coronary Vessels, and Pericardium

movement may pass in one direction through the atrioven-

scopic control, a long narrow catheter is passed into the as-

tricular node and in the opposite direction through the

cending aorta via the femoral artery in the leg. The tip of the

bundle of Kent.

catheter is carefully guided into the orifice of a coronary

artery and a small amount of radiopaque material is injected

to reveal the lumen of the artery and its branches. The in-

Failure of Conduction System

formation can be recorded on radiographs (CD Fig. 4-1) or

The sinuatrial node is the spontaneous source of the cardiac

by cineradiography. Using this technique, pathologic nar-

impulse. The atrioventricular node is responsible for picking

rowing or blockage of a coronary artery can be identified.

up the cardiac impulse from the atria. The atrioventricular

bundle is the only route by which the cardiac impulse can

Coronary Artery Disease

spread from the atria to the ventricles. Failure of the bundle

to conduct the normal impulses results in alteration in the

The myocardium receives its blood supply through the right

rhythmic contraction of the ventricles (arrhythmias) or, if

and left coronary arteries. Although the coronary arteries

complete bundle block occurs, complete dissociation be-

have numerous anastomoses at the arteriolar level, they are

tween the atria and ventricular rates of contraction. The com-

essentially functional end arteries. A sudden block of one of

mon cause of defective conduction through the bundle or its

the large branches of either coronary artery will usually lead

branches is atherosclerosis of the coronary arteries, which re-

to necrosis of the cardiac muscle (myocardial infarction) in

sults in a diminished blood supply to the conducting system.

that vascular area, and often the patient dies. Most cases of

coronary artery blockage are caused by an acute thrombosis

on top of a chronic atherosclerotic narrowing of the lumen.

Coronary Angiography

Arteriosclerotic disease of the coronary arteries may pre-

The coronary arteries can be visualized by the introduction

sent in three ways, depending on the rate of narrowing of the

of radiopaque material into their lumen. Under fluoro-

lumina of the arteries: (1) General degeneration and fibrosis

CD Figure 4-1

Coronary angiograms. A. An area of extreme narrowing of the circumflex

branch of the left coronary artery (white arrow). B. The same artery after percutaneous

transluminal coronary angioplasty. Inflation of the luminal balloon has dramatically im-

proved the area of stenosis (white arrow).

Chapter 4

CD Table 4-1

Coronary Artery Lesions, Infarct Location, and ECG Signature

Coronary Artery

Infarct Location

ECG Signature

Proximal LAD

Large anterior wall

ST elevation: I, L, V1-V6

More distal LAD

Anteroapical

ST elevation: V2-V4

Inferior wall if

ST elevation: II, III, F

wraparound LAD

Distal LAD

Anteroseptal

ST elevation: V1-V3

Early obtuse, marginal

High lateral wall

ST elevation: I, L, V4-V6

More distal marginal

Small lateral wall

ST elevation: I, L, or V4-V6, or no abnormality

branch, circumflex

Circumflex

Posterolateral

ST elevation: V4-V6; ST depression: V1-V2

Distal RCA

Small inferior wall

ST elevation: II, III, F; ST depression: I, L

Proximal RCA

Large inferior wall and

ST elevation: II, III, F;

posterior wall

ST depression: I, L, V1-V3

Some lateral wall

ST elevation: V5-V6

RCA

Right ventricular

ST elevation: V2R-V4R; some

ST elevation: V1, or ST depression: V2-V3

Usually inferior

ST elevation: II, III, F

ECG, electrocardiographic; LAD, left anterior descending (interventricular); RCA, right coronary artery.

of the myocardium occur over many years and are caused by

supplied by a single artery, the right coronary artery. The an-

a gradual narrowing of the coronary arteries. (2) Angina pec-

terolateral papillary muscle is less likely to rupture since it

toris is cardiac pain that occurs on exertion and is relieved

has a dual blood supply from the anterior interventricular

by rest. In this condition, the coronary arteries are so nar-

and circumflex branches of the left coronary artery.

rowed that myocardial ischemia occurs on exertion but not

at rest. (3) Myocardial infarction occurs when coronary flow

Chest Pain

is suddenly reduced or stopped and the cardiac muscle un-

dergoes necrosis. Myocardial infarction is the major cause

The presenting symptom of chest pain is a common and

of death in industrialized nations.

classic problem in medicine. Unfortunately, chest pain is a

CD Table 4-1 shows the different coronary arteries that

symptom common to a large number of conditions and may

supply the different areas of the myocardium. This informa-

be caused by disease in the thoracic and abdominal walls or

tion can be helpful when attempting to correlate the site of

in many different chest or abdominal viscera. The severity of

myocardial infarction, the artery involved, and the electro-

the pain is often unrelated to the seriousness of the cause.

cardiographic signature.

Myocardial pain may mimic esophagitis, musculoskeletal

Because coronary bypass surgery, coronary angioplasty,

chest wall pain, and other non-life-threatening causes. Un-

and coronary artery stenting are now commonly accepted

less medical personnel are astute, a patient may be dis-

methods of treating coronary artery disease, it is incumbent on

charged from the hospital with a more serious condition

the student to be prepared to interpret still- and motion-picture

than the symptoms indicate. It is not good enough to have a

angiograms that have been carried out before treatment. For

correct diagnosis only 99% of the time with chest pain. An

this reason, a working knowledge of the origin, course, and dis-

understanding of the anatomy of chest pain will help the

tribution of the coronary arteries should be memorized.

physician in the systematic consideration of the differential

diagnosis.

Myocardial Infarction and

Somatic Pain

Papillary Muscle Rupture

Pain arising from the chest or abdominal walls is intense and

Rarely, in acute myocardial infarction involving the left ven-

discretely localized. Somatic pain arises in sensory nerve

tricle, a papillary muscle may rupture. Rupture of the pos-

endings in these structures and is conducted to the central

teromedial papillary muscle is more common since it is

nervous system by somatic segmental spinal nerves.

The Heart, Coronary Vessels, and Pericardium

Visceral Pain

disease of neighboring viscera, such as the gallbladder, liver,

or stomach, could send afferent impulses up to the central

Visceral pain is diffuse and poorly localized. It is conducted

nervous system. Because of the phenomenon of referred

to the central nervous system along afferent autonomic

pain, the patient would presume that the cause of the pain

nerves. Most visceral pain fibers ascend to the spinal cord

was located over the upper part of the chest wall or shoulder.

along sympathetic nerves and enter the cord through the

Below the level of the sternal angle and the spine of the

posterior nerve roots of segmental spinal nerves. Some pain

scapula, the chest skin is innervated by the thoracic segments

fibers from the pharynx and upper part of the esophagus and

of the spinal cord. The anterior chest wall is supplied by the

the trachea enter the central nervous system through the

intercostal nerves T2 through T6; the seventh intercostal

parasympathetic nerves via the glossopharyngeal and vagus

nerve enters the anterior abdominal wall to supply the skin

nerves. The descending colon, the pelvic colon and rectum,

in the xiphoid area. The posterior chest wall is supplied by

and the bladder reach the sacral spinal cord through the

the posterior primary rami of the thoracic spinal nerves T2

parasympathetic nerves.

through T11. Remember that the seventh to the eleventh in-

tercostal nerves cross the costal margin and innervate the full

Referred Pain

thickness of the anterior abdominal wall including the pari-

Visceral pain frequently is referred to skin areas that are in-

etal peritoneum. This would explain how irritation of the

nervated by the same segment of the spinal cord as is the

parietal peritoneum caused by disease of abdominal viscera

painful viscus. The explanation for referred pain is not

could give rise to pain referred to the chest wall.

known. One theory is that the nerve fibers from the viscus

Note also the distribution of the T1 and T2 der-

and the dermatome ascend in the central nervous system

matomes; they extend down the medial side of the upper

along a common pathway and the cerebral cortex is inca-

limbs. The second thoracic nerve reaches the skin of the ax-

pable of distinguishing between the sites of origin. Another

illa and the medial (ulnar) side of the arm via the intercos-

theory is that under normal conditions the viscus does not

tobrachial nerve (a branch of the second intercostal nerves).

give rise to painful stimuli, whereas the skin area repeatedly

T1 reaches the ulnar side of the forearm via the medial cu-

receives noxious stimuli. Because both afferent fibers enter

taneous nerve of the forearm from the brachial plexus.

the spinal cord at the same segment, the brain interprets the

information as coming from the skin rather than the viscus.

Cardiac Pain

Pain arising from the gastrointestinal tract is referred to the

midline. This can probably be explained since the tract

Pain originating in the heart as the result of acute myocardial

arises embryologically as a midline structure and receives a

ischemia is assumed to be caused by oxygen deficiency and

bilateral nerve supply.

the accumulation of metabolites, which stimulate the sen-

sory nerve endings in the myocardium. The afferent nerve

fibers ascend to the central nervous system through the car-

Clinical Significance of Thoracic

diac branches of the sympathetic trunk and enter the spinal

cord through the posterior roots of the upper four thoracic

Dermatomes Relative to Chest Pain

nerves. The nature of the pain varies considerably, from a se-

The dermatomes on the anterior and posterior chest walls

vere crushing pain to nothing more than mild discomfort.

are shown in CD Figs. 1-2 and 1-3. A dermatome is an area

The pain is not felt in the heart, but is referred to the

of skin supplied by a single spinal nerve and, therefore, a

skin areas supplied by the corresponding spinal nerves. The

single segment of the spinal cord. On the trunk, adjacent

skin areas supplied by the upper four intercostal nerves and

dermatomes overlap considerably and a given area of skin is

by the intercostobrachial nerve (T2) are therefore affected.

innervated by three adjacent spinal nerves.

The intercostobrachial nerve communicates with the me-

Each thoracic spinal nerve innervates a large number of

dial cutaneous nerve of the arm and is distributed to skin on

structures, including the vertebrae; the ribs and costal carti-

the medial side of the upper part of the arm. A certain

lages and their joints; the postvertebral, intercostal, and ab-

amount of spread of nervous information must occur within

dominal muscles; and the costal parietal pleura and parietal

the central nervous system, for the pain is sometimes felt in

peritoneum. Any one of these structures could be the source

the neck and the jaw.

of chest pain.

Myocardial infarction involving the inferior wall or di-

The skin of the anterior and posterior chest walls, down

aphragmatic surface of the heart often gives rise to discom-

as far as the sternal angle in front and the spine of the

fort in the epigastrium. One must assume that the afferent

scapula behind, is supplied by the supraclavicular nerves

pain fibers from the heart ascend in the sympathetic nerves

(C3 and C4). The phrenic nerves (C3, C4, and C5) supply

and enter the spinal cord in the posterior roots of the sev-

the parietal pleura over the central part of the diaphragm

enth, eighth, and ninth thoracic spinal nerves and give rise

and a corresponding area of parietal peritoneum over the

to referred pain in the T7, T8, and T9 thoracic dermatomes

lower surface of the diaphragm. Irritation of these areas by

in the epigastrium.

Chapter 4

Because the heart and the thoracic part of the esopha-

Valvular Disease of the Heart

gus probably have similar afferent pain pathways, it is not

surprising that painful acute esophagitis can mimic the pain

Inflammation of a valve can cause the edges of the valve cusps

of myocardial infarction.

to stick together. Later, fibrous thickening occurs, followed by

loss of flexibility and shrinkage. Narrowing (stenosis) and

Auscultation of Heart Valves

valvular incompetence (regurgitation) result, and the heart

ceases to function as an efficient pump. In rheumatic disease

On listening to the heart with a stethoscope, one can hear

of the mitral valve, for example, not only do the cusps undergo

two sounds: l

¯ b-du˘ p. The first sound is produced by the con-

fibrosis and shrink, but also the chordae tendineae shorten,

traction of the ventricles and the closure of the tricuspid and

preventing closure of the cusps during ventricular systole.

mitral valves. The second sound is produced by the sharp

closure of the aortic and pulmonary valves. It is important

Valvular Heart Murmurs

for a physician to know where to place the stethoscope on

the chest wall so that he or she will be able to hear sounds

Apart from the sounds of the valves closing, l

¯b-du˘p, the

produced at each valve with the minimal distraction or in-

blood passes through the normal heart silently. Should the

terference (CD Fig. 4-2).

valve orifices become narrowed or the valve cusps distorted

■ The tricuspid valve is best heard over the right half of the

and shrunken by disease, however, a rippling effect would

lower end of the body of the sternum.

be set up, leading to turbulence and vibrations that are

■ The mitral valve is best heard over the apex beat, that is,

heard as heart murmurs.

at the level of the fifth left intercostal space, 3.5 in. (9 cm)

from the midline.

Cardiac Injuries

■ The pulmonary valve is heard with least interference

over the medial end of the second left intercostal

Cardiac Contusion

space.

■ The aortic valve is best heard over the medial end of the

The heart, although protected by the thoracic cage, can be

second right intercostal space.

squeezed between the sternum and the vertebral column

pulmonary valve

aortic valve

right atrium

left ventricle

mitral valve

tricuspid

CD Figure 4-2

Surface

valve

anatomy of the heart and great

right ventricle

blood vessels. Note the position

of the heart valves relative to

the chest wall. The bold letters

indicate positions where valves

may be heard with least interfer-

apex

ence. A aortic valve, M mi-

tral valve, P pulmonary valve,

T tricuspid valve.

The Heart, Coronary Vessels, and Pericardium

(see text Fig. 4-8) when the thorax is subjected to a severe

and results in oxygenated blood from the left atrium passing

frontal impact. Moreover, if the force is also applied to the

over into the right atrium (CD Fig. 4-3).

anterior abdominal wall, the diaphragm is thrust upward,

impinging on the heart from below. The highly flexible rib

Ventricular Septal Defects

cage present in children makes myocardial contusion a

The ventricular septum is formed in a complicated manner

common occurrence in this age group. The result of heart

and is complete only when the membranous part fuses with

muscle damage is precordial pain, similar in nature to a my-

the muscular part. Ventricular septal defects are less fre-

ocardial infarction. Tachycardia often occurs and, if enough

quent than atrial septal defects. They are found in the

cardiac muscle is contused, cardiac output may decrease.

membranous part of the septum and can measure 1 to 2 cm

Depending on the severity of the injury, there may be ar-

in diameter. Blood under high pressure passes through the

rhythmias and evidence of heart block.

defect from left to right, causing enlargement of the right

ventricle. Large defects are serious and can shorten life if

Valve and Septal Injuries

surgery is not performed.

In both blunt and penetrating injuries to the heart, the valve

cusps, the papillary muscles, and the chordae tendineae can

Tetralogy of Fallot

be damaged. The incidence of valve involvement is in the

Normally, the bulbus cordis becomes divided into the aorta

following order: aortic, mitral, and pulmonary. Acute valvu-

and pulmonary trunk by the formation of the spiral aorti-

lar insufficiency can be diagnosed clinically, but it should

copulmonary septum. This septum is formed by the fusion

be confirmed by cardiac catheterization. In severe cases

of the bulbar ridges. If the bulbar ridges fail to fuse correctly,

prompt surgical repair may be necessary.

unequal division of the bulbus cordis may occur, with con-

sequent narrowing of the pulmonary trunk and resulting in

Penetrating Injuries to the Heart

interference with the right ventricular outflow.

The anatomy of the heart relative to the front of the thoracic

This congenital anomaly is responsible for about 9% of

cage determines the common sites of injury. The anterior sur-

all congenital heart disease (see CD Fig. 4-3). The anatomic

face of the heart is formed largely by the right ventricle; the

abnormalities include large ventricular septal defect; steno-

left border is formed by the left ventricle and the right border

sis of the pulmonary trunk, which can occur at the in-

is formed by the right atrium. The right ventricle is most com-

fundibulum of the right ventricle or at the pulmonary valve;

monly injured, followed by the left ventricle and the right

exit of the aorta immediately above the ventricular septal de-

atrium. The anterior interventricular branch of the left coro-

fect (instead of from the left ventricular cavity only); and se-

nary artery is the most common artery to be damaged.

vere hypertrophy of the right ventricle, because of the high

Since the pericardium has to be penetrated for the

blood pressure in the right ventricle. The defects cause con-

heart to be injured, cardiac tamponade is often present. The

genital cyanosis and considerably limit activity; patients

hemopericardium quickly presses on the thin-walled atria

with severe untreated abnormalities die. Once the diagnosis

and large veins and compromises the venous return. The

has been made, most children can be successfully treated

classic triad of (1) distension of the jugular veins of the neck,

surgically.

(2) faint heart sounds (damped down by blood in the peri-

Most children find that assuming the squatting position

cardial sac), and (3) hypotension may all be present. If there

after physical activity relieves their breathlessness. This

is substantial concomitant blood loss or volume depletion,

happens because squatting reduces the venous return by

the jugular veins may not be enlarged. Do not expect to see

compressing the abdominal veins and increasing the sys-

a greatly enlarged heart shadow on a chest radiograph. Even

temic arterial resistance by kinking the femoral and

though the blood in the pericardial sac may be under high

popliteal arteries in the legs; both these mechanisms tend to

pressure caused by a ventricular leak, the tough fibrous tis-

decrease the right-to-left shunt through the ventricular sep-

sue in the wall of the fibrous pericardium prevents its undue

tal defect and improve the pulmonary circulation.

distension. Hemopericardium must be relieved surgically.

Mitral Valve Prolapse

Congenital Anomalies

In this condition, one or both mitral valve cusps balloon up

into the left atrium during ventricular systole. The valve

Atrial Septal Defects

cusps are larger than normal and the chordae tendineae

After birth, the foramen ovale becomes completely closed as

may be excessively long. The posterior cusp is always in-

the result of the fusion of the septum primum with the sep-

volved; the anterior cusp is involved less frequently. The ma-

tum secundum. In 25% of hearts, a small opening persists,

jority of the patients are female, and there may be a familial

but this is usually of such a minor nature that it has no clin-

incidence of the syndrome. The typical symptoms are chest

ical significance. Occasionally, the opening is much larger

pain and palpitations, and dysrhythmias may occur.

The Heart, Coronary Vessels, and Pericardium

establishment of a separate pulmonary and aortic outflow

Hemopericardium

are necessary.

With blunt or penetrating injuries to the heart, blood can es-

Patent Ductus Arteriosus

cape into the pericardial cavity. The normal volume of peri-

cardial fluid, about 50 mL, is used to lubricate the apposing

The ductus arteriosus represents the distal portion of the

surfaces of the serous pericardium during heart movements.

sixth left aortic arch and connects the left pulmonary artery

Once the fluid in the cavity exceeds about 250 mL, the dias-

to the beginning of the descending aorta (see CD Fig. 4-3).

tolic filling is compromised, a condition known as cardiac

During fetal life, blood passes through it from the pul-

tamponade.

monary artery to the aorta, thus bypassing the lungs. After

birth, it normally constricts, later closes, and becomes the

ligamentum arteriosum.

Pericardiocentesis

Failure of the ductus arteriosus to close may occur as an

This procedure is used in the treatment of cardiac

isolated congenital abnormality or may be associated with

tamponade.

congenital heart disease. A persistent patent ductus arterio-

The patient is placed in a supine position with the

sus results in high-pressure aortic blood passing into the pul-

shoulders raised 60° from the horizontal position. The

monary artery, which raises the pressure in the pulmonary

usual skin preparation is now completed. The needle is in-

circulation. A patent ductus arteriosus is life threatening and

serted in the angle between the xiphoid process and the

should be ligated and divided surgically.

left costal margin. With the positions of the cardiac

notches of the lungs and pleura in mind (CD Fig. 4-5), the

tip of the needle is directed upward, backward, and to the

left in the left xiphocostal angle, that is, toward the left

THE PERICARDIUM

shoulder. The following structures will be penetrated by

the needle:

Traumatic Injury to the Pericardium

1. Skin

Pericardial Disruption

2. Subcutaneous tissue

This may occur from blunt trauma from a puncture following

3. Aponeurosis of the external oblique muscle of the

penetration by a fractured rib and rupture from a sudden in-

abdomen

crease in pressure. The most common location of rupture is

4. Anterior lamina of the aponeurosis of the internal

along the lateral margins, especially on the left side. The

oblique muscle of the abdomen

phrenic nerve may be involved, as it is situated between the

mediastinal parietal pleura and the pericardium (CD Fig. 4-4)

5. Rectus abdominis muscle

left phrenic

right phrenic

nerve

rupture of

left ventricle

right atrium

CD Figure 4-4

Anterior view of

the heart showing common sites

for rupture of the pericardium on

the anterior surface. Note the po-

sition of the right and left phrenic

nerves.

Chapter 4

pleural reflection

internal thoracic

artery

pericardium

cardiac notch

xiphoid

pericardial cavity

process

heart

lower border

of lung

liver

diaphragm

liver

xiphoid

pleural

process

reflection

CD Figure 4-5

A and B. The xiphisternal approach for pericardiocentesis. Note that the

needle is aimed upward and backward in the direction of the left shoulder.

Anatomy of Complications

6. Posterior lamina of the aponeurosis of the internal

oblique and the transversus abdominis muscles

1. The needle is advanced too far and enters the my-

7. Extraperitoneal fat; avoid entering the peritoneal cavity

ocardium of the right ventricle.

8. Diaphragm

2. The needle pierces the anterior descending branch of

9. Pericardium (fibrous pericardium and parietal serous

the left coronary artery.

pericardium)

3. The needle enters the pleural cavity, producing a pneu-

The long large-bore needle is advanced through

mothorax or a hydropneumothorax.

the above structures and when pericardial penetration is

4. The needle pierces the liver.

achieved there is a sudden “give.” The needle is connected

to a 20-mL syringe with a three-way stopcock to permit

aspiration of the fluid.

Clinical Problem Solving Questions

Read the following case histories/questions and give

the discomfort disappeared with rest after about 5 min-

the best answer for each.

utes. The reason he came to the emergency department

was that the chest discomfort had occurred with much

A 61-year-old man was seen in the emergency depart-

less exertion.

ment complaining of a feeling of pressure within his

chest. On questioning, he said that he had several attacks

1. The following comments concerning this case are cor-

before and that they had always occurred when he was

rect except which?

climbing stairs or digging in the garden. He found that

A. The diagnosis is a classic case of angina pectoris.

The Heart, Coronary Vessels, and Pericardium

B. The sudden change in history, that is, pain caused

A 38-year-old woman was taken from the scene of an au-

by less exertion, should cause the physician concern

tomobile accident to the local hospital. She had been

that the patient now has unstable angina or an actual

driving her car without a seat belt on and had hit a util-

myocardial infarction.

ity pole head on. On examination she was conscious and

C. The afferent pain fibers from the heart ascend to the

alert but had sustained severe facial and chest injuries.

central nervous system through the cardiac branches

A careful examination of the chest cage revealed the

of the sympathetic trunk to enter the spinal cord.

presence of a sternal fracture (middle of the body) and

D. The afferent pain fibers enter the spinal cord via the

fractures of the third and fourth left ribs near their cos-

posterior roots of the tenth to the twelfth thoracic

tochondral junctions. After an extensive workup it was

nerves.

decided that the patient had a ruptured pericardium.

E. Pain is referred to dermatomes supplied by the up-

The following observations are in agreement with the

per four intercostal nerves and the intercostal

diagnosis except which?

brachial nerve.

A. Blunt trauma had been applied to the anterior chest

A 55-year-old woman has severe aortic incompetence,

wall.

with the blood returning to the cavity of the left ventri-

B. The fractures of the third and fourth left ribs were

cle during ventricular diastole.

situated over the anterior surface of the heart.

C. The left dome of the diaphragm was paralyzed.

To hear the aortic valve with the least interference from

D. The patient had tachycardia.

the other heart sounds, the best place to place your

E. The right lateral margin of the pericardium was the

stethoscope on the chest wall is

site of the rupture.

A. the right half of the lower end of the body of the

F. There were diminished breath sounds over the

sternum.

lower lobe of the left lung.

B. the medial end of the second right intercostal space.

C. the medial end of the second left intercostal space.

A 21-year-old man was walking along a city street when

D. the apex of the heart.

suddenly a burst of automatic gunfire came from a pass-

E. the fifth left intercostal space 3.5 in. (9 cm) from the

ing car. The man, who was an innocent bystander, was

midline.

struck in the front of the chest by a stray bullet. He was

rushed to the emergency department by an ambulance.

A 33-year-old woman was jogging across the park at 11

The position of the entry wound was the fourth left

PM when she was attacked by a gang of youths. After she

intercostal space about 3 in. from the midline.

was brutally mugged and raped, one of the youths de-

cided to stab her in the heart to keep her silent. Later in

The following observations are in agreement with the

the emergency department she was unconscious and in

findings in this patient except which?

extremely poor shape. A small wound about 0.5 in. in di-

A. The right ventricle is the most likely chamber of the

ameter was present in the left fifth intercostal space

heart to be injured should a bullet enter the frontal

about 0.5 in. from the lateral sternal margin. Her carotid

surface of the chest.

pulse was rapid and weak, and her neck veins were dis-

B. If the bullet continues on its path, the left ventricle

tended. No evidence of a left-sided pneumothorax ex-

is also damaged, since the left ventricle lies posterior

isted. A diagnosis of cardiac tamponade was made.

to the right ventricle.

C. The circumflex branch of the left coronary artery

The following observations are in agreement with the

may be damaged by the bullet as it runs down the

diagnosis except which?

anterior surface of the heart.

A. The tip of the knife had pierced the pericardium.

D. The chordae tendineae of the anterior cusp of the

B. The knife had pierced the anterior wall of the left

tricuspid valve could be injured.

ventricle.

C. The blood in the pericardial cavity was under right

A 5-year-old boy was seen in the emergency room fol-

ventricular pressure.

lowing an attack of breathlessness during which he had

D. The blood in the pericardial cavity pressed on the

lost consciousness. The mother, on questioning, said

thin-walled atria and large veins as they traversed the

that her child had had several such attacks before and

pericardium to enter the heart.

sometimes his skin had become bluish. Recently she

E. The backed-up venous blood caused congestion of

had noticed that he breathed more easily when he was

the veins seen in the neck.

playing in a squatting position; he also seemed to sleep

F. The poor venous return severely compromised the

more easily with his knees drawn up. On physical ex-

cardiac output.

amination, the child was found to be thinner and

G. A left-sided pneumothorax did not occur because

shorter than normal. His lips were cyanotic, and his fin-

the knife passed through the cardiac notch.

gers and toes were clubbed. A systolic murmur was

Chapter 4

present along the left border of the sternum, and the

husband the previous day and that they had been

heart was considerably enlarged to the right. An exten-

caught in a storm. She described the pain as a continu-

sive workup, including angiography, demonstrated

ous dull ache that was made worse by taking deep

tetralogy of Fallot.

breaths and using the left arm. She indicated that the

pain was localized over the sixth left costal cartilage

Using your knowledge of cardiac development, criti-

about 2 in. to the left of the sternum, which corre-

cally read the following observations made in this case

sponded to an area of tenderness over the sixth left cos-

and determine the one that is incorrect.

tochondral junction.

A. The systolic murmur heard along the left border of

the sternum was caused by the pulmonary stenosis.

The following possible conditions could explain the se-

B. A right-to-left shunt of blood occurs through the

vere chest pain. Choose the most likely diagnosis based

large ventricular septal defect.

on your knowledge of anatomy.

C. The aortic blood is poorly oxygenated resulting in

A. Myocardial infarction

the impaired growth of the child, the cyanosis of the

B. Lobar pneumonia of the left lung

lips, and the clubbing of the fingers and toes

C. Tearing of muscle fibers in the chest wall, possibly

D. Maintaining the squatting position during play and

the serratus anterior muscle

sleeping with the knees drawn up increases the pe-

D. Separation of the sixth left costochondral joint or an

ripheral resistance in the systemic circulation and

acute costochondritis

decreases the right-to-left shunt through the ventric-

E. Left-sided pleurisy

ular septum.

The following anatomic structures are penetrated by a

E. If the patient had a large ductus arteriosus as well as the

needle when performing a pericardiocentesis except

tetralogy of Fallot, the cyanosis would be much worse.

which?

A 43-year-old woman was seen in the emergency de-

A. Skin and subcutaneous tissue

partment complaining of a severe localized pain over

B. The aponeuroses of the external and internal

the left side of the chest. She stated that the pain started

oblique muscles

quite suddenly, about 1 hour previously, when she was

C. The left parietal and visceral layers of pleura

reaching for a book on a high shelf. On further ques-

D. The rectus abdominis muscle

tioning she disclosed that she had been sailing with her

E. The diaphragm and fibrous pericardium

Answers and Explanations

1. D is the correct answer. The afferent pain fibers from

6. E is the correct answer. The tetralogy of Fallot consists

the heart enter the spinal cord via the posterior nerve

of the following: (1) a large ventricular septal defect, (2)

roots of the upper four thoracic spinal nerves.

a stenosis of the pulmonary trunk or the pulmonary

valve, (3) an exit of the aorta that lies immediately above

2. B is the correct answer. The best location to place your

the ventricular septal defect and thus communicates

stethoscope on the chest wall to hear the aortic valve is

with both ventricles, and (4) a right ventricular hyper-

the medial end of the second right intercostal space (see

trophy secondary to the ventricular septal defect and

CD Fig. 4-2).

pulmonary stenosis. Should the child have a large

3. B is the correct answer. The knife had pierced the an-

patent ductus arteriosus, cyanosis is reduced to a mini-

terior wall of the right ventricle.

mum. This is because a large patent ductus allows aor-

4. E is the correct answer. The left lateral margin of the

tic blood to enter the pulmonary trunk distal to the

pericardium had ruptured, injuring the left phrenic

stenosis of the pulmonary artery or valve and, in this

nerve; this resulted in the paralysis of the left dome of

way, enables the blood to enter the pulmonary circula-

the diaphragm and the diminished breathing heard

tion for oxygenation.

over the lower lobe of the left lung.

7. D is the correct answer. Separation of the sixth left

5. C is the correct answer. The anterior interventricular

costochondral joint or an acute costochondritis can be

(descending) branch of the left coronary artery is the

extremely painful conditions. The injury must have oc-

most likely artery to be damaged in such a wound

curred when the patient was pulling on the ropes of the

through the frontal surface of the chest.

sailing boat during the storm on the previous day. The

Chapter Outline

Large Arteries of the Thorax

Coarctation of the Aorta

Double Aorta and Right Aortic Arch

The Aorta

Ascending Aorta and the Pericardium

Large Veins of the Thorax

Aneurysm of the Arch of the Aorta

Penetrating Injuries

Coarctation of the Aorta

Migrating Bullets

Trauma to the Aorta in the Thorax

Deceleration Injuries

Superior Vena Cava or Brachiocephalic Vein

Penetrating Injuries of the Aorta

Thrombosis

The Descending Thoracic Aorta and the

Important Connections between the Superior and

Esophagus in Posterior Thoracotomy

Inferior Venae Cavae

The Descending Thoracic Aorta and Left

Embryologic Note: Fetal Circulation and

Hemothorax

Aortic Dissection

Changes in Fetal Circulation at Birth

Fetal Circulation

The Pulmonary Trunk

Penetrating Injuries of the Pulmonary Trunk

Changes in the Fetal Circulation at Birth

Pulmonary Artery (Swan-Ganz) Catheterization

Physiologic Note: Blood Flow in the

Pulmonary Embolism

Umbilical Cord after Delivery

Embryologic Note: Detailed Development

Physiologic Note: The Heart in

of the Large Arteries of the Thorax and

the Newborn

the Ductus Arteriosus

Clinical Problem Solving Questions

Congenital Anomalies

Patent Ductus Arteriosus

Answers and Explanations

Coarctation of the Aorta

LARGE ARTERIES

Coarctation of the aorta is a congenital narrowing of the aorta

just proximal, opposite, or distal to the site of attachment of

OF THE THORAX

the ligamentum arteriosum (CD Fig. 5-1). Clinically, the

cardinal sign of aortic coarctation is absent or diminished

pulses in the femoral arteries of both lower limbs. To com-

The Aorta

pensate for the diminished volume of blood reaching the

lower part of the body, an enormous collateral circulation

Ascending Aorta and the Pericardium

develops, with dilatation of the internal thoracic, subclavian,

and posterior intercostal arteries. The dilated intercostal

The entire ascending aorta lies within the pericardial sac.

arteries erode the lower borders of the ribs, producing char-

Consequently, tear or rupture of this part of the aorta results

acteristic notching, which is seen on radiographic examina-

in a massive outpouring of blood into the pericardial cavity,

tion. The condition should be treated surgically.

producing cardiac tamponade.

Trauma to the Aorta in the Thorax

Aneurysm of the Arch of the Aorta

Deceleration Injuries

The arch of the aorta lies behind the manubrium sterni. A

gross dilatation of the aorta (aneurysm) may show itself as a

The heart is suspended from the aorta much like a weight

pulsatile swelling in the suprasternal notch.

attached to the end of a curved piece of flexible tubing.

The Blood Vessels of the Thorax

left subclavian

The Descending Thoracic Aorta and the

artery

Esophagus in Posterior Thoracotomy

arch of aorta

The relationship of the aorta and the esophagus in the pos-

terior mediastinum is important when distinguishing

descending aorta

between these structures when performing an emergency

thoracotomy.

coarctation of

aorta

The Descending Thoracic Aorta and

ligamentum

arteriosum

Left Hemothorax

The close relationship of the descending thoracic aorta to

the left pleura and lung means that rupture of the aorta may

occur into the left pleural cavity, producing a massive

hemothorax.

Aortic Dissection

CD Figure 5-1

Coarctation of the aorta.

This is the most serious and difficult form of aortic disease

to treat (CD Fig. 5-2). Degeneration of the tunica media

of the aortic wall is believed to be the basic cause, and the

In horizontal deceleration injuries the movement of

condition is associated with a history of hypertension in the

the body is suddenly stopped and the heart continues to

majority of patients. Marfan’s disease can also be responsi-

move forward within the pericardial sac. The descending

ble for the degeneration. Hemorrhage occurs through the

thoracic aorta from the point of origin of the left subclavian

tunical intima and extends as an expanding hematoma

artery onward is firmly attached to the vertebral column by

between the middle and outer thirds of the tunica media.

connective tissue and pleura. As the heart continues to

The initial tear may occur anywhere along the thoracic

move forward on body impact, the curve of the arch of the

aorta. Type A (proximal dissection) involves the ascend-

aorta is slightly straightened and the vessel shears just distal

ing aorta or ascending and descending aorta (see CD Fig.

to the origin of the left subclavian artery. The aorta may be

5-2). Type B (distal dissection) does not involve the

completely transected and be accompanied by a massive

ascending aorta and usually begins distal to the left subcla-

hemorrhage. If the trauma to the aorta is less, a tear may

vian artery. The clinical signs and symptoms will depend

occur in the aortic wall, leaving the more resilient outer

on the type of aneurysm present and the extent of distal

connective tissue coat intact. Blood then dissects between

propagation.

the layers of the aortic wall, producing a false aneurysm.

The sudden onset of excruciating, sharp, tearing pain

In vertical deceleration injuries, as in falls from a

localized to the front or the back of the chest and back is a

height, the violent pull of the heart on the end of the aortic

typical presenting symptom. It must be assumed that the

arch causes a tear in the inner coat of the aortic wall at the

pain impulses originate in the aortic wall, ascend to the

root of the ascending aorta. If rupture of the ascending aorta

central nervous system along with the sympathetic nerves,

should ensue, the aortic blood would burst into the pericar-

and enter the spinal cord through the posterior roots of the

dial sac, causing immediate cardiac tamponade. The

segmental spinal nerves. The pain is then referred along

ascending aorta together with the pulmonary trunk is sur-

the somatic spinal nerves of the same segments. The num-

rounded only by a thin sleeve of serous pericardium and by

ber of dermatomes involved will depend on the extent of

the fibrous pericardium. Once the sleeve of serous peri-

the dissection. If the dissection continues to spread distally,

cardium gives way, the blood enters the pericardial cavity,

the pain may be felt segmentally in the abdomen, lower

causing cardiac tamponade. Most of these injuries are fatal.

back, and legs.

An aneurysm of the ascending aorta has the highest

Penetrating Injuries of the Aorta

mortality since it may rupture into the pericardial cavity, pro-

Penetrating vascular injuries are likely to occur when the

ducing immediate cardiac tamponade; it may rupture into

entrance and exit wounds are on opposite sides of the chest,

the mediastinum or pleural cavities; it may extend into the

indicating that the bullet has crossed the midline of the

coronary arteries, causing occlusion; or it may extend to

chest. Penetrating injuries involving blood vessels and not

the aortic valve, producing acute aortic incompetence.

the heart have the highest mortality when they occur in the

Involvement of the brachiocephalic, left common carotid, or

superior mediastinum; here the aortic arch gives rise to its

left subclavian arteries at their origin from the aortic arch may

major branches, and the superior vena cava and brachio-

give rise to symptoms of cerebral ischemia or upper limb

cephalic veins are present.

ischemia.

Chapter 5

CD Figure 5-2

Aortic dissec-

tion. Type A (proximal dissec-

tion) involves the ascending

aorta or ascending and descend-

ing aorta. Type B (distal dissec-

tion) does not involve the

ascending aorta.

An aneurysm of the descending thoracic aorta can rup-

into the pericardial cavity from either of these vessels could

ture into the pleural cavity on the left side. If the dissection

result in cardiac tamponade.

progresses distally to involve the abdominal aorta, occlusion

Pulmonary Artery (Swan-Ganz)

of the mesenteric arteries could result in bowel infarction,

and occlusion of the renal arteries could result in renal

Catheterization

failure. Ischemic necrosis of the spinal cord resulting in para-

The pulmonary artery catheter is used to assess left and right

plegia could follow blockage of the posterior intercostal

ventricular function, measure pulmonary artery and right and

arteries arising from the thoracic aorta or the lumbar arteries

left atrial pressures, measure cardiac output, and take samples

arising form the abdominal aorta.

of right atrial and pulmonary arterial blood.

Rupture of the aneurysm below the diaphragm may

The catheter is introduced through the right internal

produce catastrophic retroperitoneal hemorrhage.

jugular vein, right subclavian vein, right basilic vein, or the

femoral vein. The catheter is advanced into the right atrium

The Pulmonary Trunk

through the tricuspid valve into the right ventricle (CD Fig.

5-3). The balloon is advanced into the pulmonary trunk and

Penetrating Injuries of the Pulmonary

then into the left pulmonary artery.

Trunk

Pulmonary Embolism

Any missile injury with entry or exit wounds close to the

manubrium sterni may damage the pulmonary trunk or any

In the great majority of patients, the pulmonary emboli arise

other vessel in the superior mediastinum, Remember that

from a thrombosis in the large deep veins of the lower

the pulmonary trunk and the ascending aorta together are

extremity, especially from the femoral veins, and from the

surrounded by a sheath of serous pericardium within the

internal iliac veins in the pelvis. Thromboses in the veins of

fibrous pericardium (see text Fig. 4-21), so that hemorrhage

the calf muscles following prolonged immobility, such as

The Blood Vessels of the Thorax

carotid sheath

platysma

skin

thyroid gland

sternocleido-

mastoid

muscle

investing layer of

deep fascia

common carotid

artery

catheter

sternocleidomastoid

muscle

catheter

scalenus anterior

internal

vagus nerve

subclavian

muscle

jugular

vein

arch of aorta

left pulmonary

superior

artery

vena cava

pulmonary valve

right atrium

tricuspid valve

right ventricle

catheter

CD Figure 5-3

Pulmonary artery (Swan-Ganz) catheterization. A. The catheter has been

introduced through the right internal jugular vein (posterior approach). B. Diagram show-

ing the course taken by the catheter through the right side of the heart into the pulmonary

trunk and the left pulmonary artery.

commonly occurs in long-distance plane flights, may be the

The ascending aorta below the right pulmonary

origin of pulmonary emboli.

artery and the main pulmonary trunk are derived from the

truncus arteriosus (see CD Fig. 5-4). The aorta, from the

level of the right pulmonary artery up to the level of the left

E M B R Y O L O G I C N O T E

common carotid artery, is derived from the aortic sac.

The brachiocephalic artery also is formed from

Detailed Development of the Large Arteries

the aortic sac. The remainder of the arch of the aorta is

of the Thorax and the Ductus Arteriosus

formed from the left fourth aortic arch artery and the left

The truncus arteriosus, which is the distal part of the

dorsal aorta (see CD Fig. 5-4).

bulbus cordis (CD Fig. 5-4) is continuous beyond the peri-

The fourth right aortic arch artery becomes the root

cardium with a large vessel called the aortic sac. This sac

of the right subclavian artery, which also is derived in

gives off two branches, each of which runs dorsally in the

sequence from a small part of the right dorsal aorta and

first pharyngeal arch on each side in the developing em-

the right seventh segmental artery.

bryo. The branches then pass caudally in the posterior

The third aortic arch artery on both sides becomes

wall of the embryo as the two dorsal aortae. Five addi-

the common carotid artery; this sends off a bud of

tional arteries now join the aortic sac to the dorsal aortae

mesenchyme that becomes the external carotid

(see CD Fig. 5-4). Meanwhile, the two dorsal aortae fuse

artery. The remainder of the third aortic arch artery and

throughout much of their lengths to form the descend-

part of the dorsal aorta form the internal carotid artery

ing thoracic aorta and the abdominal aorta.

on each side.

Chapter 5

CD Figure 5-4 The formation and fate of the aortic arch arteries.

The first, second, and fifth aortic arch arteries

with congenital heart disease. A persistent patent ductus

disappear completely. The right and left pulmonary

arteriosus results in high-pressure aortic blood passing

arteries are formed from the sixth aortic arch arteries.

into the pulmonary artery, which raises the pressure

The distal part of the right sixth aortic arch artery

in the pulmonary circulation. A patent ductus arteriosus

disappears, while the remainder of the left sixth aortic

is life threatening and should be ligated and divided

arch artery becomes the important ductus arteriosus,

surgically.

which after birth becomes the ligamentum arte-

Coarctation of the Aorta

riosum.

Coarctation of the aorta is a congenital narrowing of the

The descending thoracic aorta below the level of

aorta just proximal, opposite, or distal to the site of attach-

the fourth thoracic vertebra is formed from the fusion of

ment of the ligamentum arteriosum (see CD Fig. 5-1). This

the dorsal aortae (see CD Fig. 5-4).

condition is believed to result from an unusual quantity of

ductus arteriosus muscle tissue in the wall of the aorta.

Congenital Anomalies

When the ductus arteriosus contracts, the ductal muscle in

Patent Ductus Arteriosus

the aortic wall also contracts, and the aortic lumen be-

The ductus arteriosus represents the distal portion of the

comes narrowed. Later, when fibrosis takes place, the aor-

sixth left aortic arch and connects the left pulmonary

tic wall also is involved, and permanent narrowing occurs.

artery to the beginning of the descending aorta (see CD

Fig. 5-4). During fetal life, blood passes through it from

Double Aorta and Right Aortic Arch

the pulmonary artery to the aorta, thus bypassing the

Anomalies involving double parts of the arterial system

lungs. After birth, it normally constricts, later closes, and

are rare conditions that result from the persistence of

becomes the ligamentum arteriosum.

aortic arch arteries, which normally disappear. In the

Failure of the ductus arteriosus to close may occur as

case of the right aortic arch, the development of the left

an isolated congenital abnormality or may be associated

arch does not take place.

The Blood Vessels of the Thorax

E M B R Y O L O G I C N O T E

LARGE VEINS OF

Fetal Circulation and Changes in Fetal

THE THORAX

Circulation at Birth

Fetal Circulation

Penetrating Injuries

Starting at the placenta, the fetal blood may be traced in

the circulation as follows:

As has been emphasized before with arterial injuries, the

Having circulated through the capillaries of the pla-

highest mortality can occur in penetrating injuries in the re-

cental villi, the fetal blood returns through the umbilical

gion of the superior mediastinum. Behind the manubrium

vein to the fetus about 80% saturated with oxygen and

sterni lie not only the aortic arch and its large branches but

containing many important nutrients, antibodies, and

also the right and left brachiocephalic veins and the superior

hormones (CD Fig. 5-6). The oxygenated blood then

vena cava. Moreover, the thoracic cage may hide the extent

passes toward the liver. However, the greater volume of

of the bleeding, which may take place entirely within the

it bypasses the liver, since this organ is not fully func-

thoracic cavity. The cage also renders the veins relatively

tioning, and travels to the inferior vena cava by way of

inaccessible to the operating physician.

the ductus venosus. The remainder is distributed to the

liver sinusoids by offshoots of the umbilical vein, and this

Migrating Bullets

in turn passes to the inferior vena cava by the hepatic

veins. At the same time, the ductus venosus receives

Bullets entering a large artery or vein may migrate with the

poorly oxygenated blood from the gut by way of the left

blood from their site of entrance. Bullets in the aorta can

branch of the portal vein. In addition, the inferior vena

migrate to the distal branches until they become wedged,

cava already contains venous blood from the lower part

causing blockage and ischemia. In the same manner, a

of the trunk and the lower limbs of the fetus. As a conse-

bullet entering a pulmonary vein can migrate to the left

quence of this admixture of blood from these various

atrium and left ventricle and enter the systemic circulation.

sources, the inferior vena cava contains blood about 67%

A bullet entering the superior vena cava can migrate into the

saturated with oxygen.

right atrium and right ventricle and enter the pulmonary

Before considering the further passage of the fetal

circulation. Paradoxic movement of bullets through a

blood, it is necessary to examine the anatomic arrange-

patent atrial septum has been reported.

ment of the inferior vena cava and its relationship with

the right and left atria in the fetal heart (CD Fig. 5-7). In the

Superior Vena Cava or

fetus, the opening of the inferior vena cava into the right

atrium lies directly opposite the foramen ovale. Thus,

Brachiocephalic Vein

blood entering the heart through the inferior vena cava is

directed through the foramen ovale and enters the left

Thrombosis

atrium. This process is assisted by the presence of the

This condition usually results from compression of the veins

valve of the inferior vena cava.

by tumors in the superior mediastinum; enlarging lymph

The nutritious oxygenated fetal blood, on reaching

node metastases secondary to a bronchial carcinoma is a

the foramen ovale, is divided into two streams by the

common cause. Venous blockage results in engorgement of

crista dividens, which is the lower margin of the sep-

the veins of the head and neck.

tum secundum. The greater volume of blood enters the

left atrium, and the remainder, joined by venous blood

from the superior vena cava and coronary sinus, passes

Important Connections between

from the right atrium into the right ventricle.

The oxygenated blood in the left atrium is joined by

the Superior and Inferior Venae

a relatively small volume of blood from the nonaerated

fetal lungs. The left atrial blood then passes into the left

Cavae

ventricle and out into the aorta. The oxygen saturation of

In obstruction of the superior or inferior venae cavae, the

this blood is about 62%. This is distributed chiefly to the

azygos veins provide an alternative pathway for the return of

arteries of the head, neck, and upper extremities. Thus, it

venous blood to the right atrium of the heart. This is possi-

is apparent that blood that is richer in oxygen and nutri-

ble since these veins and their tributaries connect the supe-

ents is transported to the cephalic region rather than the

rior and inferior venae cavae (CD Fig. 5-5).

caudal regions of the fetus.

Chapter 5

brachiocephalic

vein

superior vena cava

subclavian vein

first rib

axillary vein

hemiazygos veins

azygos vein

internal thoracic vein

lateral thoracic vein

diaphragm

inferior vena cava

ascending lumbar

vein

lumbar veins

inferior mesenteric

inferior epigastric vein

vein ascending to

portal vein

CD Figure 5-5

The possible col-

lateral circulations of the superior

and inferior venae cavae. Note the

superficial epigastric

alternative pathways that exist for

vein

superior rectal vein

blood to return to the right atrium

internal iliac vein

of the heart if the superior vena

external iliac vein

cava becomes blocked below the

entrance of the azygos vein (upper

inguinal ligament

black bar). Similar pathways exist

if the inferior vena cava becomes

middle rectal vein

blocked below the renal veins

femoral vein

(lower black bar). Note also the

connections that exist between the

portal circulation and systemic

great saphenous

inferior rectal vein

vein

veins in the anal canal.

Changes in Fetal Circulation at Birth

Meanwhile, the right ventricular blood passes into

the pulmonary trunk. Only a small portion of this passes

Immediately after birth the umbilical cord is tied,

into the unexpanded lungs, since the vascular resistance

thus severing the placental extension of the fetal

is high. Most of the blood bypasses the lungs by being

circulation.

directed through the wide channel, the ductus arterio-

sus, into the descending thoracic aorta (see CD Fig. 5-6).

The now relatively poor oxygenated blood passes

P H Y S I O L O G I C N O T E

down the descending thoracic and abdominal aortae and

supplies the thoracic and abdominal viscera and lower

Blood Flow in the Umbilical Cord after

limbs. The fetal blood, which by this time is loaded with

Delivery

waste products of metabolism and carbon dioxide, then

returns to the placenta through the right and left umbili-

In cases in which the umbilical cord is not tied, the blood

cal arteries, where the waste products and carbon

flow may continue for several minutes after delivery,

dioxide are eliminated and oxygen is picked up. The cir-

although at a rapidly decreasing rate. A number of fac-

culatory cycle then is repeated.

tors may contribute to this diminishing flow, including (1)

The Blood Vessels of the Thorax

The diminished pulmonary vascular resistance asso-

P H Y S I O L O G I C N O T E

ciated with inflation of the lungs cause the direction of

flow (from right to left) through the ductus arteriosus

The Heart in the Newborn

to be changed to the neonatal route of left to right. The

ductus arteriosus constricts as a reaction of its muscle

The heart in the newborn is relatively large and is higher

to the raised oxygen tension. It later closes and becomes

in the thorax and in a more horizontal position than it is

the ligamentum arteriosum. One week after birth its

in later life. The pulse rate is rapid, with an average of 130

lumen is 2 mm or less in diameter, and by the end of the

beats per minute. The rate may rise considerably with

first month it usually has closed (see CD Fig. 5-8). In ad-

crying and fall to around 80 during sleep. The peripheral

dition, the wall of the ductus venosus contracts and the

circulation initially is slow in the newborn. The hands and

lumen is closed. Later the ductus becomes fibrosed to

feet may be cold and slightly cyanotic for the first few

form the ligamentum venosum.

hours after birth.

Clinical Problem Solving Questions

Read the following case histories/questions and give

were swollen 3 weeks earlier. He admitted being a heavy

the best answer for each.

smoker and had on several occasions coughed up blood-

stained sputum. On examination, his face looked puffy,

1. A 16-year-old girl, on examination in the doctor’s of-

especially around the eyes. Pitting edema was present in

fice, was found to have absent pulses in both femoral

both the upper limbs, the face, and the neck. With the

arteries. In addition, her blood pressure was higher

patient in the recumbent position, numerous dilated su-

in both upper limbs than in both lower limbs.

perficial veins were seen over the chest wall and ab-

An anteroposterior radiograph of the chest showed

domen. Later a chest radiograph revealed a large opac-

notching of the necks of the upper ribs on both sides.

ity in the upper lobe of the right lung. A diagnosis of ad-

What is your diagnosis? Why is there notching of the

vanced bronchogenic carcinoma of the right upper lobe

ribs?

was made. Can you explain the presence of edema in

2. Name the common sites on the thoracic aorta where

both the upper limbs, the face, and the neck? What is the

damage occurs in blunt trauma. Between 80% and 90%

cause of the dilated superficial veins of the chest and ab-

of such injuries result in immediate death. Explain in

dominal walls? Is there normally communication be-

anatomic terms the path commonly taken by the escap-

tween the main veins draining the upper part of the body

ing blood in cases of traumatic rupture of the thoracic

and those draining the lower half of the body?

aorta. Name the tissues that can sometimes temporarily

4. A fourth-year medical student was asked by a pediatri-

control the leak, thus permitting the patients to be taken

cian what factors are responsible for the closure of the

to the emergency department alive.

foramen ovale in the atrial septum at birth. The student

3. A 56-year-old man was seen in the emergency depart-

also was asked if oxygenated or deoxygenated blood nor-

ment complaining of swelling of both arms. On

mally passes through the foramen ovale during fetal

questioning, he said that he first noticed that his hands

life. How would you answer these questions?

Answers and Explanations

1. Coarctation of the aorta is a narrowing of the aorta just

ductus muscle in the aortic wall also contracts and the

proximal, opposite, or distal to the site of attachment of

aortic lumen becomes narrowed. Later, fibrosis occurs

the ligamentum arteriosum. It is believed to result from

and permanent narrowing takes place. The notching of

the presence of an unusual quantity of ductus arteriosus

the lower borders of the ribs is caused by the opening up

muscle tissue incorporated in the wall of the aorta.

of the collateral circulation through the subclavian, in-

When the ductus arteriosus contracts after birth, the

ternal thoracic, and posterior intercostal arteries to carry

Chapter 5

blood from above the coarctation to the distal part of

clearly indicate the presence of a superior vena caval

the aorta ; it is the dilated posterior intercostal arteries

obstruction. This obstruction was caused by the ex-

that notch the ribs.

panding metastases in the mediastinal lymph nodes

secondary to the bronchogenic carcinoma. The dilated

Blunt traumatic injury to the thoracic aorta involving

superficial veins included the lateral thoracic vein, a

horizontal deceleration occurs most commonly just dis-

tributary of the axillary vein; lumbar veins, tributaries

tal to the origin of the left subclavian artery. This site is

of the inferior vena cava; and the superficial epigastric

vulnerable since the heart and the aortic arch are mobile

vein, a tributary of the great saphenous vein of the leg

and the descending aorta is fixed. Sudden vertical de-

that drains into the femoral vein. These venous chan-

celeration, as in a fall, may result in an intimal tear at the

nels provide an alternative pathway in superior vena

root of the ascending aorta; the momentum of the heart

caval obstruction, permitting superior vena caval blood

filled with blood is sufficient to produce the tear.

to return to the heart via the inferior vena cava. The

Rupture of the ascending aorta occurs into the pericar-

superior vena cava normally communicates with the

dial cavity, producing immediate cardiac tamponade

inferior vena cava through the azygos veins. However,

and death. Rupture of the descending thoracic aorta

in this case the tumor was pressing on the superior vena

frequently occurs into the left pleural cavity. The tear

cava proximal to the entrance of the azygos vein.

initially occurs in the tunica intima; the tunica media

The foramen ovale is closed after birth by the valve-like

and adventitia and the surrounding connective tissue

flap formed by the lower part of the septum primum

and the pleura may delay the complete rupture or tem-

pressing against the septum secundum and fusing with it.

porarily control the leak. If untreated, delayed rupture

This takes place as a result of a rise in blood pressure in

and death usually occur in these cases within 2 weeks.

the left atrium, which occurs once the child takes a deep

The swelling of both upper extremities and the head

breath and the pulmonary circulation is established.

and neck, caused by edema, and the engorgement of

During fetal life, oxygenated blood passes through the

the superficial veins of the chest and abdominal walls

foramen ovale from the right atrium to the left atrium..

Chapter Outline

Large Arteries of the Head and Neck

Cavernous Sinus Thrombosis and Facial Infection

Taking the Carotid Pulse

Spread of Infection and the Emissary Veins

Carotid Sinus Sensitivity

Visibility of the External Jugular Vein

Facial Artery Pulse

The External Jugular Vein as Venous Manometer

Temporal Artery Pulse

External Jugular Vein Catheterization

Middle Meningeal Artery and

Penetrating Wounds of the Internal Jugular Vein

Extradural Hemorrhage

Internal Jugular Vein Catheterization

Atherosclerosis of the Carotid Arteries and

Subclavian Vein Thrombosis

Neurologic Injury

Subclavian Vein Catheterization

Penetrating Neck Injuries to the Carotid Arteries

Infraclavicular Approach

Anatomy of the Procedure

Aneurysms of the Carotid Arteries

Anatomy of Problems

Cerebral Circulation and the Circle of Willis

Anatomy of Complications

Compression of the Subclavian Artery and the

The Procedure in Children

Brachial Plexus at the Root of the Neck

Supraclavicular Approach

Anatomy of the Procedure

Cerebrovascular Disease

Anatomy of Complications

Cerebral Ischemia

Internal Thoracic Artery and Coronary Bypass

Clinical Problem Solving Questions

Operations

Palpation and Compression of the Subclavian Artery

Answers and Explanations

100

in Patients with Upper Limb Hemorrhage

Veins of the Head and Neck

The Sigmoid Sinus and Infection from the

Mastoid Antrum

rior border of the thyroid cartilage. This is a convenient site

LARGE ARTERIES

to take the carotid pulse.

OF THE HEAD AND_{Carotid Sinus Sensitivity}

In cases of carotid sinus hypersensitivity, pressure on one or

NECK

both carotid sinuses can cause excessive slowing of the heart

rate, a fall in blood pressure, and cerebral ischemia with

fainting.

Taking the Carotid Pulse

The bifurcation of the common carotid artery into the in-

Facial Artery Pulse

ternal and external carotid arteries (see text Figs. 6-1 and

6-3) can be easily palpated just beneath the anterior border

The facial artery (see text Fig. 6-1), as it winds around the

of the sternocleidomastoid muscle at the level of the supe-

lower margin of the mandible level with the anterior border

The Blood Vessels of the Head and Neck

of the masseter, is commonly used by the anesthetist to take

pressure on the underlying motor area in the precentral

the patient’s pulse.

gyrus. Blood may also pass outward through the fracture line

to form a soft swelling under the temporalis muscle.

To stop the hemorrhage, the torn artery or vein must be

Temporal Artery Pulse

ligated or plugged. The burr hole through the skull wall

The superficial temporal artery, as it crosses the zygomatic

should be placed about 1 to 1.5 in. (2.5 to 4 cm) above the

arch in front of the ear (see text Fig. 6-1), can also be used

midpoint of the zygomatic arch (CD Fig. 6-2).

by the anesthetist to take the patient’s pulse.

Atherosclerosis of the Carotid

Middle Meningeal Artery and

Arteries and Neurologic Injury

Extradural Hemorrhage

Approximately 70% of strokes are caused by extracranial ar-

Extradural hemorrhage results from injuries to the

teriosclerosis of the carotid and/or vertebral arteries. In the

meningeal arteries or veins. The most common artery to be

carotid arteries the atherosclerotic thromboses usually form

damaged is the anterior division of the middle meningeal

slowly in the distal part of the common carotid and the first

artery (CD Fig. 6-1). A comparatively minor blow to the side

parts of the external and internal carotid arteries. The result

of the head, resulting in fracture of the skull in the region of

is a diminished blood flow to the central nervous system. Less

the anteroinferior portion of the parietal bone, may sever the

commonly, emboli, formed of fragments of plaques or blood

artery. The arterial or venous injury is especially liable to

clots, are carried distally to lodge in the ipsilateral central

occur if the artery and vein enter a bony canal in this region.

artery of the retina or in the smaller branches of the middle

Bleeding occurs and strips up the meningeal layer of dura

cerebral artery. Such a situation could produce the classic

from the internal surface of the skull. The intracranial

syndrome of ipsilateral blindness and contralateral hemiple-

pressure rises, and the enlarging blood clot exerts local

gia, although it is unusual to have both at the same time.

central sulcus

motor area of cerebral cortex

trunk

parietal

eminence

head

pterion

anterior branch of

middle meningeal artery

nasion

baseline

external occipital

protuberance

cerebellum

mastoid

process

zygomatic

arch

CD Figure 6-1

Surface landmarks on the right side of the head. The relations of the mid-

dle meningeal artery and the brain to the surface of the skull are shown.

Chapter 6

site of

of burr hole

tragus

of ear

anterior branch of

middle meningeal

artery

blood clot

lying between

endosteal layer

and meningeal

layer of dura

CD Figure 6-2

A. Surface

landmarks for a temporal burr

hole. B. The vertical incision

zygomatic

passes through the temporalis

arch

muscle down to bone. The

middle meningeal artery lies

between the endosteal and

meningeal layers of dura and is

embedded in the endosteal

layer of dura or lies in a bony

tunnel.

likely to cause neurologic problems, provided there is ade-

Penetrating Neck Injuries to the

quate collateral circulation through the external carotid

arteries and their branches.

Carotid Arteries

Hemorrhage may be severe, with consequent hypotension

Aneurysms of the Carotid Arteries

or shock. An enlarging hematoma may press on the larynx

or trachea, compromising the airway. Injuries to the internal

Aneurysms of the carotid arteries in the neck are rare and are

carotid artery are usually associated with a central neuro-

usually caused by arteriosclerosis. They are commonly located

logic deficit. Injuries to the common carotid arteries are less

at the bifurcation of the common carotid artery. Expansion of

The Blood Vessels of the Head and Neck

the aneurysm may create pressure on the vagus nerve (causing

inserting a graft. The graft most commonly used is the great

hoarseness), glossopharyngeal nerve (causing dysphagia), or

saphenous vein of the leg. In some patients, the my-

hypoglossal nerve (causing weakness of the tongue); pressure

ocardium can be revascularized by surgically mobilizing

on the sympathetic trunk as it lies behind the carotid sheath

one of the internal thoracic arteries (see text Fig. 6-2) and

may cause Horner’s syndrome. Rupture of the aneurysm re-

joining its distal cut end to a coronary artery.

sulting in hemorrhage may exert pressure on surrounding

structures and compromise the airway (see text Fig. 6-5).

Palpation and Compression of the

Cerebral Circulation and the Circle

Subclavian Artery in Patients

of Willis

with Upper Limb Hemorrhage

The circle of Willis allows blood that enters by either internal

In severe traumatic accidents to the upper limb involving

carotid or vertebral arteries to be distributed to any part of

laceration of the brachial or axillary arteries, it is important

both cerebral hemispheres. The arterial circle permits the

to remember that the hemorrhage can be stopped by ex-

blood to flow across the midline, as shown when the internal

erting strong pressure downward and backward on the

carotid or vertebral artery on one side is blocked by disease.

third part of the subclavian artery (see text Fig. 6-2). The

use of a blunt object to exert the pressure is of great help,

and the artery is compressed against the upper surface of

Compression of the Subclavian

the first rib.

Artery and the Brachial Plexus at

the Root of the Neck

VEINS OF THE

At the root of the neck, the brachial plexus and the subcla-

vian artery enter the posterior triangle through a narrow

HEAD AND NECK

muscular-bony triangle (see text Fig. 6-2). The boundaries

of the narrow triangle are formed in front by the scalenus

The Sigmoid Sinus and Infection

anterior, behind by the scalenus medius, and below by the

first rib. In the presence of a cervical rib, the first thoracic

from the Mastoid Antrum

nerve and the subclavian artery are raised and angulated as

they pass over the rib. Partial or complete occlusion of the

Infection of the mastoid antrum of the ear may spread

artery causes ischemic muscle pain in the arm, which is

to the sigmoid venous sinus, causing thrombosis and

worsened by exercise. Rarely, pressure on the first thoracic

septicemia.

nerve causes symptoms of pain in the forearm and hand and

wasting of the small muscles of the hand.

Cavernous Sinus Thrombosis and

Cerebrovascular Disease

Facial Infection

The area of facial skin bounded by the nose, the eye,

Cerebral Ischemia

and the upper lip is a potentially dangerous zone to

Unconsciousness occurs in 5 to 10 seconds if the blood flow

have an infection. For example, a boil in this region can

to the brain is completely cut off. Irreversible brain damage

cause thrombosis of the facial vein, with spread of

with death of nervous tissue rapidly follows complete arrest

organisms through the inferior ophthalmic veins to

of cerebral blood flow. It has been estimated that neuronal

the cavernous sinus. The resulting cavernous sinus

function ceases after about 1 minute and that irreversible

thrombosis may be fatal unless adequately treated with

changes start to occur after about 4 minutes, although this

antibiotics.

time may be longer if the patient’s body has been cooled.

Spread of Scalp Infections and

Internal Thoracic Artery and

the Emissary Veins

Coronary Bypass Operations

Infections of the scalp tend to remain localized and are

In patients with occlusive coronary disease caused by ather-

usually painful because of the fibrous tissue in the subcu-

osclerosis, the diseased arterial segment can be bypassed by

taneous layer. Occasionally, an infection of the scalp

Chapter 6

spreads by the emissary veins (see text Fig. 6-8), which are

lacerated wall of the internal jugular vein. Because the wall

valveless, to the skull bones, causing osteomyelitis. Infected

of this large vein contains little smooth muscle, its injury is

blood in the diploic veins may travel by the emissary veins

not followed by contraction and retraction (as occurs with

farther into the venous sinuses and produce venous sinus

arterial injuries). Moreover, the adventitia of the vein wall is

thrombosis.

attached to the deep fascia of the carotid sheath, which hin-

ders the collapse of the vein. Blind clamping of the vein is

prohibited because the vagus and hypoglossal nerves are in

Visibility of the External

the vicinity.

Jugular Vein

Internal Jugular Vein

The external jugular vein is less obvious in children and

Catheterization

women because their subcutaneous tissue tends to be

thicker than the tissue of men. In obese individuals, the vein

The internal jugular vein is remarkably constant in position.

may be difficult to identify even when they are asked to hold

It descends through the neck from a point halfway between

their breath, which impedes the venous return to the right

the tip of the mastoid process and the angle of the jaw to the

side of the heart and distends the vein.

sternoclavicular joint. Above, it is overlapped by the anterior

The superficial veins of the neck tend to be enlarged

border of the sternocleidomastoid muscle, and below, it is

and often tortuous in professional singers because of pro-

covered laterally by this muscle. Just above the sternoclavic-

longed periods of raised intrathoracic pressure.

ular joint the vein lies beneath a skin depression between

the sternal and clavicular heads of the sternocleidomastoid

muscle. In the posterior approach, the tip of the needle and

The External Jugular Vein as a

the catheter are introduced into the vein about two finger-

Venous Manometer

breadths above the clavicle at the posterior border of the

sternocleidomastoid muscle (CD Fig. 6-4). In the anterior

The external jugular vein serves as a useful venous manome-

approach, with the patient’s head turned to the opposite

ter. Normally, when the patient is lying at a horizontal angle

side, the triangle formed by the sternal and clavicular heads

of 30°, the level of the blood in the external jugular veins

of the sternocleidomastoid muscle and the medial end of

reaches about one third of the way up the neck. As the pa-

the clavicle are identified. A shallow skin depression usually

tient sits up, the blood level falls until it is no longer visible

overlies the triangle. The needle and catheter are inserted

behind the clavicle.

into the vein at the apex of the triangle in a caudal direction

(see CD Fig. 6-4).

External Jugular Vein

Subclavian Vein Thrombosis

Catheterization

Spontaneous thrombosis of the subclavian and/or axillary

The external jugular vein can be used for catheterization,

veins occasionally occurs after excessive and unaccustomed

but the presence of valves or tortuosity may make the

use of the arm at the shoulder joint. The close relationship

passage of the catheter difficult. Because the right exter-

of these veins to the first rib and the clavicle and the possi-

nal jugular vein is in the most direct line with the supe-

bility of repeated minor trauma from these structures is

rior vena cava, it is the one most commonly used (CD

probably a factor in its development.

Fig. 6-3).

Secondary thrombosis of subclavian and/or axillary

The vein is catheterized about halfway between the

veins is a common complication of an indwelling venous

level of the cricoid cartilage and the clavicle. The passage of

catheter. Rarely, the condition may follow a radical mas-

the catheter should be performed during inspiration when

tectomy with a block dissection of the lymph nodes of the

the valves are open.

axilla. Persistent pain, heaviness, or edema of the upper

limb, especially after exercise, is a complication of this

condition.

Penetrating Wounds of the

Internal Jugular Vein

Subclavian Vein Catheterization

The hemorrhage of low-pressure venous blood into the

The subclavian vein is located in the lower anterior cor-

loose connective tissue beneath the investing layer of deep

ner of the posterior triangle of the neck (CD Fig. 6-5),

cervical fascia may present as a large, slowly expanding

where it lies immediately posterior to the medial third of

hematoma. Air embolism is a serious complication of a

the clavicle.

The Blood Vessels of the Head and Neck

angle of mandible

superior

external

vena

jugular

cava

vein

right

brachiocephalic

vein

midpoint

of clavicle

skin

external

jugular vein

platysma

right

catheter

subclavian

sternocleidomastoid

vein

muscle

external

jugular vein

investing

layer of

deep cervical

fascia

catheter

trapezius

CD Figure 6-3

Catheterization of the right external jugular vein. A.

Surface marking of

the vein. B. Site of catheterization. Note how the external jugular vein joins the subclavian

vein at a right angle. C. Cross section of the neck showing the relationships of the

external jugular vein as it crosses the posterior triangle of the neck.

Infraclavicular Approach

border of the origin of the clavicular head of the sternoclei-

domastoid muscle on the upper border of the clavicle (see

Since the subclavian vein lies close to the undersurface of

CD Fig. 6-5). The needle pierces the following structures:

the medial third of the clavicle (see CD Fig. 6-5), this is a

relatively safe site for catheterization. The vein is slightly

■ Skin

more medially placed on the left side than on the right side.

■ Superficial fascia

■ Pectoralis major muscle (clavicular head)

Anatomy of the Procedure

■ Clavipectoral fascia and subclavius muscle

■ Wall of subclavian vein

The needle should be inserted through the skin just below

the lower border of the clavicle at the junction of the medial

The needle is pointed upward and posteriorly toward

third and outer two thirds, coinciding with the posterior

the middle of the suprasternal notch.

Chapter 6

internal jugular vein

right

brachiocephalic

carotid sheath

vein

sternocleidomastoid muscle

common

skin

carotid artery

platysma

muscle

vagus

catheter

nerve

sternocleidomastoid

muscle

subclavian

deep

clavicle

vein

fascia

catheter

phrenic

scalenus

internal

nerve

jugular

muscle

vein

carotid sheath

sternal origin of

common

sternocleidomastoid muscle

carotid

sternal origin of

artery

sternocleidomastoid muscle

internal

subclavian

jugular

vagus

vein

nerve

clavicle

internal

jugular

vein

clavicular origin of

sternocleidomastoid muscle

catheter

CD Figure 6-4

Catheterization of the right internal jugular vein. A. Posterior approach.

Note the position of the catheter relative to the sternocleidomastoid muscle and the com-

mon carotid artery. B. Anterior approach. Note that the catheter is inserted into the vein

close to the apex of the triangle formed by the sternal and clavicular heads of the stern-

ocleidomastoid muscle and the clavicle.

posterior to the scalenus anterior muscle and perforated

Anatomy of Problems

the subclavian artery.

■ Hitting the clavicle: The needle may be “walked” along

the lower surface of the clavicle until its posterior edge is

Anatomy of Complications

reached.

Refer to CD Fig. 6-5.

■ Hitting the first rib: The needle may hit the first rib if it

is pointed downward and not upward.

■ Pneumothorax: The needle may pierce the cervical

■

Hitting the subclavian artery: A pulsatile resistance and

dome of the pleura, permitting air to enter the

bright red blood flow indicates that the needle has passed

pleural cavity. This complication is more common in

The Blood Vessels of the Head and Neck

CD Figure 6-5

Subclavian vein catheterization. A. Infraclavicular approach. Note the

many important anatomic structures located in this region. B. Supraclavicular approach.

The catheter enters the subclavian vein close to its junction with the internal jugular vein

to form the brachiocephalic vein.

children, in whom the pleural reflection is higher than

beneath the skin to enter the subclavian vein at the point

in adults.

where the clavicle and the first rib cross.

■ Hemothorax: The catheter may pierce the posterior wall

The more oblique approach in children minimizes the

of the subclavian vein and the pleura.

possibility of entering the subclavian artery.

■ Subclavian artery puncture: The needle pierces the wall

Supraclavicular Approach

of the artery during its insertion.

■ Internal thoracic artery injury: Hemorrhage may occur

This approach (see CD Fig. 6-5) is preferred by many for the

into the superior mediastinum.

following anatomic reasons:

■ Diaphragmatic paralysis: This occurs when the needle

■ The site of penetration of the vein wall is larger, since it

damages the phrenic nerve.

lies at the junction of the internal jugular vein and the

subclavian vein, which makes the procedure easier.

The Procedure in Children

■ The needle is pointed downward and medially toward

The needle pierces the skin in the deltopectoral groove

the mediastinum, away from the pleura, avoiding the

about 2 cm from the clavicle. The catheter is tunneled

complication of pneumothorax.

Chapter 6

■ The catheter is inserted along a more direct course into

The needle is directed downward in the direction of the

the brachiocephalic vein and superior vena cava.

opposite nipple. The needle enters the junction of the in-

ternal jugular vein and the subclavian vein. It is important

Anatomy of the Procedure

that the operator understands that the pleura is not being

penetrated and that it is possible for the needle to lie in a

With the patient in the Trendelenburg position (patient

zone between the chest wall and the cervical dome of the

supine with head tilted downward) or simple supine posi-

parietal pleura but outside the pleural space (cavity).

tion and the head turned to the opposite side, the posterior

border of the clavicular origin of the sternocleidomastoid

Anatomy of Complications

muscle is palpated (see CD Fig. 6-5). The needle is inserted

through the skin at the site where the posterior border of the

The following complications may occur as the result of dam-

clavicular origin of sternocleidomastoid is attached to the

age to neighboring anatomic structures (see CD Fig. 6-5):

upper border of the clavicle. At this point, the needle lies

■ Paralysis of the diaphragm: This is caused by injury to the

lateral to the lateral border of scalenus anterior muscle

phrenic nerve as it descends posterior to the internal jugu-

and above the first rib. The needle pierces the following

lar vein on the surface of the scalenus anterior muscle.

structures (see CD Fig. 6-5):

■ Pneumothorax or hemothorax: This is caused by

■

Skin

damage to the pleura and/or internal thoracic artery by

■

Superficial fascia and platysma

the needle passing posteriorly and downward.

■ Investing layer of deep cervical fascia

■ Brachial plexus injury: This is caused by the needle

■ Wall of the subclavian vein

passing posteriorly into the roots or trunks of the plexus.

Clinical Problem Solving Questions

Read the following case histories/questions and give

against a window. The glass was shattered and a knife-

the best answer for each.

like piece became impaled in her neck. Within seconds

the wound spurted bright red blood and she ran scream-

A 40-year-old man mentioned to his physician during a

ing to her parents. In the emergency department of the

medical checkup that on four occasions during the past

local hospital it was immediately apparent that a large

5 months he had fainted at work. On each occasion the

artery in the front of the neck had been pierced by the

fainting attack occurred while he was sitting at his desk.

glass.

He said that the attack took place when he turned his

face to the left and bent down to open a bottom drawer.

2. The examining physician made the following observa-

He also complained that he first felt dizzy before he

tions and comments, all of which were correct except

fainted. The physician noted that the patient was rather

which?

formally dressed with a stiff collar and a regimental tie.

A. The entry wound was situated along the anterior

When the physician commented on his collar, the pa-

border of the sternocleidomastoid muscle at about

tient stated that he always wore this type of collar to

the level of the upper border of the thyroid carti-

work. On careful examination of the patient no abnor-

lage.

mal physical signs were found. In fact, the man looked

B. The artery involved could be either the terminal

very fit.

part of the common carotid artery or the beginning

of the external or internal carotid arteries.

1. Using your knowledge of anatomy and physiology,

C. The arteries were situated beneath the investing

make the most likely diagnosis.

layer of deep cervical fascia within the carotid fascial

A. Atrial fibrillation

sheath.

B. Cardiac ischemia

D. The internal jugular vein, which is also located

C. Carotid sinus syndrome

within the carotid sheath, is not involved because

D. Anemia

the blood was bright red in color and spurted from

E. Petit mal (a form of epilepsy)

the wound on removing the pressure gauze pad.

Two sisters were playing in their bedroom having a pil-

E. Branches of the trigeminal nerve lie in the sheath at

low fight, when one of them tripped and fell head first

this level and are likely to have been damaged.

The Blood Vessels of the Head and Neck

A 7-year-old boy was playing in his grandparents’ garden

cut to pieces and he fell to the ground in agony and

when he suddenly disappeared from view. His grandfa-

quickly lost consciousness. When the emergency

ther rushed over to see what had happened to his grand-

personnel arrived on the scene they found the man to

son when he heard muffled crying coming from a hole

be still alive but unconscious and lying in a pool of

in the ground. On peering into the hole, the child’s

blood. They had to stop the bleeding immediately.

head was just visible about five feet from the surface.

Using your knowledge of anatomy, where would you ap-

The local rescue team determined that the child had

ply pressure at the root of the limb to stop the bleeding?

fallen down a disused well. Fortunately, the opening of

A. Just above the manubrium sterni in the midline to

the hole was large enough to allow the emergency

compress the right brachiocephalic artery

physician to be lowered to the child. Having reassured

B. Above the right sternoclavicular joint to compress

the child, it was necessary to check his vital signs. The

the right subclavian artery

only arteries that could be palpated were restricted to

C. Behind the medial part of the right clavicle, apply-

the head and neck.

ing pressure downward and backward on the right

Name sites in the head and neck where the arterial

subclavian artery as it lies on the upper surface of the

pulse can be felt.

first rib

A. On the upper surface of the head in the midline

D. High up in the right armpit to compress the axillary

B. Just in front of the auricle of the ear, the lower

artery

margin of the mandible, or the anterior border of the

E. Behind the lateral part of the right clavicle, applying

sternocleidomastoid muscle at the level of the upper

pressure backward to compress the right subclavian

margin of the thyroid cartilage

artery as it becomes the axillary artery

C. Behind the ear over the mastoid process or at the

A 45-year-old man was rushed to hospital complaining

root of the nose

of cardiac pain referred to the root of his neck. After a

D. In the midline of the front of the neck in the

thorough workup, including a coronary arteriogram,

suprasternal notch or just below the mandible

which showed extensive blockage of the coronary arter-

E. At the apex of the posterior triangle of the neck or

ies, it was decided to do an immediate triple bypass op-

halfway down the posterior border of the sternoclei-

eration. At operation, because of the poor condition of

domastoid muscle

his superficial leg veins, an artery rather than a vein was

A 53-year-old man was admitted to the emergency room

selected to perform the bypass.

unconscious. Apparently he had attempted to cross the

From the list of arteries given below, choose an artery

road on crutches when he was hit on the side of the

in the chest cavity that could be used to perform a

head by a car. On examination he was found to have a

coronary bypass.

large swelling over the left side of the head in the tem-

A. Right superior intercostal artery

poral region. The neurologic findings included a right-

B. Right and left anterior thoracic arteries

sided hemiplegia. A lateral radiograph of the skull

C. Phrenic arteries

showed a fracture line across the region of the lower

D. Musculophrenic artery

anterior end of the right parietal bone.

E. Superior epigastric artery

Name the artery that was most likely to have been

A patient with a malignant melanoma in the left tem-

damaged in the accident.

poral region was told that because of the seriousness of

A. The left middle cerebral artery

the condition and the likelihood of metastases, an ex-

B. The right posterior cerebral artery

tensive operation was required including the removal of

C. The anterior division of the left middle meningeal

the deep cervical lymph nodes in the neck.

artery

D. The posterior division of the left middle meningeal

Using your knowledge of anatomy, explain why it is

artery

necessary to remove the internal jugular vein in the

E. The left superficial temporal artery

neck as well as the deep cervical lymph nodes.

A. The deep cervical lymph nodes lie deep to the in-

A 42-year-old workman was cutting down a tree. During

ternal jugular vein, and it is necessary to remove the

the cleanup of the site, he was feeding the cut branches

vein to get at the lymph nodes.

into a large wood chipping machine and the sleeve of

B. Damage to the internal jugular vein would result in

his shirt on his right arm became caught in the ma-

serious air embolism.

chinery. Within seconds his arm was dragged into the

C. The numerous tributaries of the internal jugular

cutters. The man attempted to turn off the machine but

vein would complicate the procedure

could not reach the switch. His right upper limb was

100

Chapter 6

D. The deep cervical lymph nodes are embedded

C. The catheter tip may enter the mouth of the anterior

in the carotid sheath and the tunica adventitia of

division of the retromandibular vein.

the internal jugular vein.

D. The vein may be very small in professional singers.

E. Metastases of the melanoma commonly invade the

E. The vein is normally constricted as it passes behind

internal jugular vein.

the clavicle.

A 57-year-old woman was examined by her physician

10.

In deep penetrating injuries of the neck involving the

and found to have right-sided heart failure. As the pa-

common carotid artery, the status of the collateral cir-

tient lay propped up on pillows in bed, her physician no-

culation determines the feasibility of ligation versus a

ticed that the blood in a superficial vein on the side of

reconstructive procedure. Describe the collateral circu-

the neck (in the posterior triangle) could be easily seen.

lation of the common carotid artery. How may injury to

the artery produce loss of sight on the same side and

From the list of veins in the neck given below, select the

contralateral hemiplegia? How may a carotid artery

most likely one that the physician could see.

injury produce airway obstruction?

A. Anterior jugular vein

B. Suprascapular vein

11.

Why is air embolism a complication of a lacerated wall

C. Superficial cervical vein

of the internal jugular vein?

D. Internal jugular vein

12.

In subclavian vein catheterization using the infraclavic-

E. External jugular vein

ular approach, the following problems may occur, even

The jugular veins are commonly used to establish a

when great care is exercised: (a) The needle may hit the

central venous line. Why is it sometimes difficult to pass

clavicle; (b) the needle may hit the first rib; (c) the nee-

a catheter from the external jugular vein into the right

dle may hit the subclavian artery. How would you deal

atrium?

with these problems?

A. The catheter tip may catch in the valves.

B. The vein turns at a right angle before it drains into

the subclavian vein.

Answers and Explanations

1. C is the correct answer. The carotid sinus syndrome is

the body for taking the pulse, the following arteries are

a condition in which the carotid sinus reflex is hyper-

easily palpable: The pulsating facial artery can be felt as

sensitive. Pressure on one or both carotid sinuses can

it winds around the lower margin of the mandible in

cause excessive slowing of the heart, a fall in blood pres-

line with the anterior border of the masseter muscle

sure, and cerebral ischemia with fainting. In this

(see text Fig. 6-10). The superficial temporal artery may

patient the pressure of the stiff collar on the carotid

be palpated in front of the auricle of the ear as it ascends

sinuses, caused by bending over to gain access to the

over the zygomatic arch (see text Fig. 6-1). The classi-

bottom desk drawer, was sufficient to cause the episodes

cal site for feeling the pulse in the neck is along the an-

of fainting and loss of consciousness.

terior border of the sternocleidomastoid muscle at the

level of the upper border of the thyroid cartilage (see

2. E is the correct answer. The trigeminal nerve is not

text Fig. 6-3). Here, the common carotid artery divides

related to the carotid arteries in the neck. However, the

into the external carotid and internal carotid arteries,

hypoglossal nerve crosses the external carotid artery op-

and all three are quite superficial at this location.

posite the level of the tip of the greater cornu of the hyoid

bone.The glossopharyngeal nerve is related to the inter-

4. C is the correct answer. The anterior division of the

nal and external carotid arteries high up in the neck (see

middle meningeal artery is the most common artery to

text Fig. 6-4). The vagus nerve lies within the carotid

be damaged after a blow to the lateral side of the head.

sheath and accompanies the internal jugular vein and

The arterial or venous injury is especially liable to oc-

common and internal carotid arteries down the neck.

cur if the artery and vein enter a bony canal in the re-

The sympathetic trunk lies behind the common and

gion of the anterior inferior angle of the parietal bone

internal carotid arteries (see text Fig. 6-4).

(see CD Fig. 6-1).

3. B is the correct answer. In a difficult situation, when the

5. C is the correct answer. The arterial supply to the upper

patient’s head and neck are the only accessible parts of

limb can be cut off by applying deep pressure to the

The Blood Vessels of the Head and Neck

101

third part of the subclavian artery, as it lies on the upper

external carotid artery, however, gives off numerous im-

surface of the first rib. Here, the subclavian artery lies

portant branches in the neck that anastomose with the

behind the medial part of the clavicle and becomes

fellow branches from the opposite side.

continuous with the axillary artery (see text Fig. 6-10).

Since the internal carotid artery gives off the oph-

B is the correct answer. The anterior thoracic artery,

thalmic artery and the middle cerebral artery, severe

which is a branch of the first part of the subclavian

damage or blockage of the common carotid artery

artery, can be used in coronary bypass operations.

could cause ipsilateral blindness and contralateral

hemiplegia.

D is the correct answer. The deep cervical lymph nodes

are embedded in the carotid sheath and in the tunica

The common carotid artery is contained within the

adventitia of the internal jugular vein. The aim of the

carotid sheath beneath the investing and pretracheal

operation is to remove all the lymph nodes on the af-

layers of deep cervical fascia. Hemorrhage beneath the

fected side of the neck.

deep fascia could spread medially and compress the

larynx or the trachea, thus compromising the airway.

E is the correct answer. The external jugular vein lies

superficially beneath the platysma muscle and can be

11.

Air embolism is a serious complication of a lacerated

easily seen in a good light (in an obese patient it may

wall of the internal jugular vein. Because the wall of

be difficult to see). The vein serves as a useful venous

this large vein contains very little smooth muscle, its in-

manometer. It runs from the angle of the jaw to the

jury is not followed by contraction and retraction (as

midpoint of the clavicle (see text Fig. 6-10). The level

occurs with arterial injuries). Moreover, the outer coat

of the blood in the vein normally reaches about one

of the vein is attached to the fascia of the carotid sheath,

third of the way up the neck when the patient is lying at

which hinders the collapse of the vein.

a horizontal angle of 30°. As the patient sits up, the

12.

When performing a subclavian vein catheterization

blood level falls until the vein is no longer visible

using the infraclavicular approach, the clavicle may

behind the clavicle.

be hit by the advancing needle. The needle may then

A is the correct answer. The catheter tip may catch in

be “walked” along the lower surface of the clavicle un-

the valves. The external jugular vein has two sets of

til its posterior edge is reached and then inserted into

valves: One pair lies at its entrance into the subclavian

the subclavian vein. The needle may hit the first rib.

vein and the other pair lies abut 4 cm superior to the

This is due to the fact that the needle is pointing down-

clavicle. The valves are usually incompetent.

ward and not upward. The needle may hit the subcla-

vian artery. This is recognized by feeling the pulsatile

10.

The common carotid artery has no branches in the

resistance to the advancing needle and the presence of

neck except for its terminal branches, the internal and

bright red blood in the catheter. It indicates that the

external carotid arteries. The internal carotid artery has

needle has passed too deeply posterior to the scalenus

no branches in the neck, but at the base of the brain it

anterior muscle and perforated the wall of the subcla-

takes part in the arterial circle of Willis, where it anas-

vian artery (see CD Fig. 6-5). The needle should be

tomoses with the branches of the vertebral arteries and

partially withdrawn and the vein approached again.

the internal carotid artery of the opposite side. The

Chapter Outline

Arteries of the Upper Extremity

104

Finding the Superficial Veins of the

Upper Extremity

106

The Importance of the Collateral Circulation when

Anatomy of Basilic and Cephalic

Ligating Arteries of the Upper Extremity

104

Vein Catheterization

106

Anatomy of Arterial Injuries in the Upper Extremity 104

Thrombosis of the Superficial Veins

106

Penetrating Arterial Injuries

104

Anatomy of Arteriovenous Shunts and Fistulas

Injuries to the Axillary Artery

105

Injuries to the Brachial Artery

105

in the Upper Limb for Hemodialysis

106

Allen Test

105

External Arteriovenous Shunt

106

Injuries to the Radial Artery

105

Internal Arteriovenous Fistula

108

Injuries to the Ulnar Artery

105

Deep Veins of the Upper Extremity

108

Intraarterial Injections by Drug Users

105

Axillary-Subclavian Vein Thrombosis

108

Arterial Venous Fistulas

105

Anatomy of Subclavian Vein Catheterization

108

Anatomy of the Procedure of Arterial Puncture

105

Venous Tone and Hypovolemic Shock

108

Brachial Artery

106

Radial Artery

106

Clinical Problem Solving Questions

108

Needle Approach

106

Cutdown Approach

106

Answers and Explanations

110

Superficial Veins of the Upper Extremity

106

may be sufficient to prevent the signs of ischemia; it is rare,

ARTERIES OF THE

however, for the physician to be able to palpate the distal

pulse at the initial examination.

UPPER EXTREMITY

Anatomy of Arterial Injuries in

The Importance of the Collateral

the Upper Extremity

Circulation when Ligating

Many of the injuries are directly related to the anatomy of

the upper limb. The extreme mobility of the limb at the

Arteries of the Upper Extremity

shoulder joint permits the forearm and hand to be raised as

The arteries of the upper limb may be damaged by pene-

a shield to ward off an attack. This position of the arm com-

trating wounds or may require ligation in amputation op-

monly results in laceration of the blood vessels.

erations. Because of adequate collateral circulation around

the shoulder, elbow, and wrist joints, ligation of the main

Penetrating Arterial Injuries

arteries of the upper limb is not followed by tissue necrosis

Arterial injuries of the upper limb are common and may oc-

or gangrene, provided, of course, that the arteries forming

cur from guns, knives, automobile accidents, and iatrogenic

the collateral circulation are not diseased and that the pa-

causes. Basically, three types of arterial injury are possible,

tient’s general circulation is satisfactory. Nevertheless, it

and the structure of the artery determines the signs and

may take days or weeks for the collateral vessels to open up

symptoms as well as the type of treatment instituted.

sufficiently to provide the distal part of the limb with the

same volume of blood as previously provided by the main

1. In a completely severed artery the circular smooth-mus-

artery.

cle fibers of the tunica media contract, immediately

At the time of the injury, where there is a complete in-

slowing the bleeding. In addition, the elastic fibers and

terruption of the main arterial supply, the collateral flow

longitudinal smooth-muscle fibers of the media contract,

The Blood Vessels of the Upper Extremity

105

causing the ends of the artery to retract. The contraction

the skin of the palms is at first white, and then normally the

and retraction of the arterial ends usually slow the blood

blood quickly flows into the arches through the ulnar arter-

flow to such an extent that bleeding ceases sponta-

ies, causing the palms to promptly turn pink. This estab-

neously, and a firm blood clot plugs both ends of the sev-

lishes that the ulnar arteries are patent. The patency of the

ered artery. The loss of distal pulses is immediate.

radial arteries can be established by repeating the test, only

with the ulnar arteries compressed where they lie lateral to

2. In a partially severed artery the vessel is unable to con-

the pisiform bone

tract and retract; in fact, any retraction that does occur

causes the arterial wound to gape, resulting in serious

Injuries to the Radial Artery

bleeding. Hemorrhage into the surrounding tissues

may produce an enlarging pulsatile hematoma that

These are common and occur in the lacerations of the front of

may slowly expand along fascial planes to reach the sur-

the forearm. The close relation of the artery to the radial nerve

face and cause a severe hemorrhage. Another possibil-

and the forearm tendons means that these structures are also

ity is that the damaged arterial wall gives way, leaving

commonly damaged (see text Figs. 7-12 and 7-13). Catheter

only the tunica adventitial intact. In these circum-

injuries are also common just proximal to the wrist joint.

stances, a pseudoaneurysm is formed.

Injuries to the Ulnar Artery

Since with partial arterial injury the arterial wall is still

intact, blood flow continues into the distal end, and a

These are relatively common and occur in lacerations in the

distal pulse is usually recognizable.

front of the wrist and flexor retinaculum. Here the artery is

superficial and easily cut in glass or knife wounds (see text

3. In an artery with intimal damage only secondary to ex-

Figs. 7-12 and 7-13). The closely related ulnar nerve is fre-

ternal blunt trauma, excessive stretching, or internal

quently involved also.

damage from a catheter, there is a reduction in blood

flow and an absence of external hemorrhage. Later, as a

Intraarterial Injections by Drug Users

result of progressive thrombosis or bleeding into the

wall at the site of injury, the blood flow becomes di-

In cases of intraarterial injection by drug abusers, the patient

minished and the distal pulses disappear.

presents with a swollen and extremely painful hand. The

drug is often injected into the radial or ulnar arteries. The

Injuries to the Axillary Artery

pharmacologic agent and its diluent causes damage at

the arteriole level as the result of blockage by crystal, chem-

These are often caused by penetrating wounds in the pec-

ical necrosis of the tunica intima, or vasospasm of the

toral region, fractures of the surgical neck of the humerus,

smooth muscle in the tunica media. Extensive tissue necro-

or excessive stretching following anterior dislocations of the

sis or gangrene may occur in the area of anatomic distribu-

shoulder joint (see text Fig. 7-7). Damage to the branches of

tion of the artery injected.

the brachial plexus may be an added complication.

Arterial Venous Fistulas

Injuries to the Brachial Artery

Arteriovenous fistulas are common complications of arterial

These may follow supracondylar fractures of the lower end of

injuries in the upper limbs. This results from the close rela-

the humerus (especially in children), a site where the artery

tionship that exists between the arteries and veins in the

is close to the shaft of the humerus as it lies on the brachialis

limbs. The axillary artery has the axillary vein on its medial

muscle (see text. Fig. 7-9). Damage to the adjacent median

side; the brachial, radial, and ulnar arteries have venae

nerve may also occur. Severe dislocations of the elbow joint

comitantes running alongside.

may damage the artery in the cubital fossa. Since the brachial

Arteriovenous fistulas occur when the penetrating arte-

artery is located superficially in the upper part of the arm, it

rial injury also perforates the accompanying vein. Bleeding

is a common site for arterial catheterization. Frequently the

from the artery follows the path of least resistance, and there-

tunical intima is damaged on the wall opposite the penetra-

fore an arteriovenous communication is established with re-

tion site, and arterial thrombosis may follow.

sulting venous hypertension, varicosities, and edema distal

to the communication site.

Allen Test

This test may be used to determine the patency of the ulnar

Anatomy of the Procedure of

and radial arteries. With the patient’s hands resting in his or

her lap, the radial arteries are compressed against the ante-

Arterial Puncture

rior surface of each radius. The patient then tightly clenches

his or her fists, which closes off the superficial and deep pal-

The brachial, radial, and ulnar arteries are commonly used

mar arterial arches. When he or she opens his or her hands,

for arterial puncture.

106

Chapter 7

Brachial Artery

obese persons the veins cannot always be seen. The surface

anatomy of the superficial veins is given on text page 209.

The brachial artery is usually cannulated as it descends into

the cubital fossa on the medial border of the biceps brachii

Anatomy of Basilic and Cephalic

muscle (see text Fig. 7-11). Unfortunately, the brachial

artery has been associated with a higher incidence of post-

Vein Catheterization

catheterization thrombosis than the radial artery. This is

probably because of the motility of the brachial artery asso-

The median basilic or basilic veins are the veins of choice

ciated with movements at the elbow joint.

for central venous catheterization, because from the cubital

fossa until the basilic vein reaches the axillary vein, the

Radial Artery

basilic vein increases in diameter and is in direct line with

With the radial artery it is first essential to determine the ad-

the axillary vein (see text Fig. 7-19). The valves in the axil-

equacy of the collateral circulation of the hand by perform-

lary vein may be troublesome, but abduction of the shoulder

ing the Allen test. This precaution is necessary in case

joint may permit the catheter to move past the obstruction.

thromboid occurs during or after cannulation. The forearm

The cephalic vein does not increase in size as it ascends

is then supinated and the wrist joint is extended to an ap-

the arm, and it frequently divides into small branches as it

proximately 50° angle (CD Fig. 7-1). The radial artery can

lies within the deltopectoral triangle. One or more of these

then easily be palpated as it lies anterior to the distal end of

branches may ascend over the clavicle and join the external

the radius.

jugular vein. In its usual method of termination, the

cephalic vein joins the axillary vein at a right angle. It may

Needle Approach

be difficult to maneuver the catheter around this angle.

The needle is passed through the arterial wall at an angle of

about 25° to the anterior surface of the wrist (see CD Fig. 7-

Thrombosis of the Superficial

1). The catheter can then be advanced into the arterial lu-

men and the needle withdrawn.

Veins

Prolonged intravenous infusion and, rarely, bacterial cel-

Cutdown Approach

lulitis of the superficial fascia can produce thrombosis of the

A transverse incision is made over the radial artery just above

superficial veins. In both cases injury to the tunical intima is

the proximal transverse skin crease at the wrist. The artery is

the initiating factor.

gently mobilized on the anterior surface of the radius and

the cannula is introduced.

Anatomy of Arteriovenous

Some physicians make a vertical incision for the radial

artery cutdown to lessen the risk of cutting a nerve and also

Shunts and Fistulas in the Upper

to avoid giving the patient a horizontal cut that could po-

tentially be misinterpreted (as a suicide attempt) on the an-

Limb for Hemodialysis

terior surface of the forearm.

Vascular access for hemodialysis can be provided by the

construction of an external arteriovenous shunt or an inter-

nal arteriovenous fistula. Most methods can be performed

SUPERFICIAL

under local anesthesia.

VEINS OF THE

External Arteriovenous Shunt

This is commonly used when a short period of treatment is

UPPER EXTREMITY

required. The shunt is constructed if possible in the non-

dominant limb. The radial artery or the ulnar artery, and the

cephalic vein or the basilic vein may be used. The proce-

Finding the Superficial Veins of

dure is as follows:

■ The branches of the lateral and medial cutaneous nerves

the Upper Extremity

of the forearm are blocked with a local anesthetic.

The cephalic, basilic, median cubital, median cephalic, me-

■ A midline incision is made on the anterior surface of the

dian basilic, and median veins of the forearm can all be used

distal part of the forearm.

for venipuncture and blood transfusion. These veins are fairly

■ The cephalic vein or the basilic vein is located in the su-

large and relatively constant in position. Unfortunately, in

perficial fascia as it winds around from the dorsum of the

108

Chapter 7

hand to ascend the front of the forearm (see text Figs. 7-

from the dialyzer is inserted into the distended vein, and

18 and 7-19).

the cannula to the dialyzer is inserted into the fistula to

■

The deep fascia is incised and the artery is located. The

enter the radial artery.

radial artery can be palpated (see text Fig. 7-13) as it lies

A similar arrangement can be made using the ulnar

anterior to the distal third of the radius and between the

artery and the basilic vein.

tendons of flexor carpi radialis (medially) and the bra-

chioradialis (laterally). The ulnar artery can be felt just

lateral to the pisiform bone and can be traced proximally

into the forearm (see text Fig. 7-13).

DEEP VEINS OF

■ The appropriate artery and vein are then connected to

the dialyzer.

THE UPPER

In those patients in whom the distal vessels have been

previously used, the same vessels can be cannulated at a

EXTREMITY

more proximal site.

In children, if the distal arteries and veins are too small,

a shunt can be constructed between the brachial artery and

Axillary-Subclavian Vein

cephalic vein just proximal to the cubital fossa.

Thrombosis

Internal Arteriovenous Fistula

Spontaneous thrombosis of the axillary and or subclavian

This procedure is most often used when it is necessary to

veins occasionally occurs following excessive and

have a prolonged period of hemodialysis. The procedure is

unaccustomed use of the arm at the shoulder joint. The

as follows:

close relationship of these veins to the first rib and the

clavicle and the possibility of repeated minor trauma

■ The branches of the lateral and medial cutaneous nerves

from these structures is probably a factor in its devel-

of the forearm are blocked with a local anesthetic.

opment.

■ A midline incision is made on the anterior surface of the

Secondary thrombosis of axillary and/or subclavian

distal part of the forearm.

veins is a common complication of an indwelling venous

■ The cephalic vein is located in the superficial fascia.

catheter.

■ The deep fascia is incised and the radial artery is located

in front of the distal end of the radius, as described in the

previous section.

Anatomy of Subclavian Vein

■ A side-to-side anastomosis is performed between the

radial artery and the cephalic vein. Alternatively, an end-

Catheterization

to-end or end of vein-to-side of artery anastomosis can

be constructed. The peripheral circulation is maintained

Venous Tone and Hypovolemic Shock

by the extensive anastomoses from the ulnar artery

around the wrist and through the palmar arches.

In extreme hypovolemic shock, excessive venous tone may

■

The vein quickly becomes arterialized and distended and

inhibit venous blood flow and thus delay the introduction of

can be easily punctured with a cannula. The cannula

intravenous blood into the vascular system.

Clinical Problem Solving Questions

Read the following case histories/questions and give

from a superficial laceration in front of her left wrist.

the best answer for each.

She had sensory loss over the palmar aspect of the me-

dial one and a half fingers but normal sensation of the

A young secretary, running from her office, had a glass

back of these fingers over the middle and proximal pha-

door swing back in her face. To protect herself, she held

langes. She had difficulty in grasping a piece of paper

out her left hand, which smashed through the glass. On

between her left index and middle fingers. All her long

admission to the hospital, she was bleeding profusely

flexor tendons were intact.

The Blood Vessels of the Upper Extremity

109

The following statements concerning this patient are

the reduction of the fracture, a suitable splint was ap-

correct except which?

plied and the child was sent home. A few hours later,

A. The radial artery was cut in front of the flexor

the child complained of pain in the forearm, which

retinaculum, and this accounted for the profuse

persisted. Four hours later, the parents decided to re-

bleeding.

turn to the hospital, since the child’s left hand looked

B. The loss of skin sensation on the palmar aspect of

dusky white and the pain in the forearm was still pre-

the medial one and a half fingers was caused by the

sent. On examination, there was found to be a com-

severance of the ulnar nerve as it crossed in front of

plete loss of skin sensation of the hand. After removal

the flexor retinaculum.

of the splint, the pulse of the radial and ulnar arteries

C. The normal sensation on the back of the medial one

could not be felt. Every possible effort was made to re-

and a half fingers over the proximal phalanges was

store the circulation of the forearm, without avail.

caused by the fact that the posterior cutaneous

What has happened to this child’s circulation in the

branch of the ulnar nerve arises about 2.5 in. (6.25

forearm? What deformity would you expect this child

cm) proximal to the flexor retinaculum and was

to have 1 year later?

spared.

Why is the radial artery chosen in preference to the ul-

D. The inability to hold the piece of paper was caused

nar artery or brachial artery for direct blood pressure

by the paralysis of the second palmar interosseous

monitoring? Why are the upper limb arteries used in

muscle, which is supplied by the deep branch of the

preference to the dorsalis pedis artery of the foot? What

ulnar nerve.

are the important anatomic relations of the radial artery

E. There was no sensory loss on the palm of the hand

at the site of cannulation? Why is it necessary to extend

because the palmar cutaneous branch of the ulnar

the wrist joint when the canula is introduced?

nerve was not cut.

During an emergency procedure it is sometimes neces-

A middle-aged man with a history of chronic duodenal

sary to monitor central venous pressure via peripheral

ulcer was seen in the emergency department in a state

access. Why is the basilic vein more often used to es-

of severe shock. He was pale, restless, and sweating,

tablish a central venous pressure line than the cephalic

and his blood pressure was 80/60 mm Hg. The resi-

vein?

dent made a diagnosis of internal hemorrhage, proba-

bly due to the erosion of the gastroduodenal artery or

A 29-year-old woman was seen in the emergency de-

one of its branches, and decided to set up a blood

partment complaining of severe pain and discoloration

transfusion immediately. Based on your knowledge of

of the fourth and fifth fingers of both hands. She said

anatomy, into which superficial vein of the upper limb

that she had had similar symptoms before and that they

would you perform the transfusion: in the elbow

always occurred in very cold weather. Initially, her fin-

region or in the forearm? If the veins were too

gers turned white on exposure to cold and then became

collapsed to be identified, where, in an emergency,

deep blue in color. The color change was confined to

could you cut down on a superficial vein in the upper

the distal half of each finger and was accompanied by

limb?

an aching pain. Placing her hands in hot water was the

only treatment that relieved the pain. As the pain disap-

Palpation of the radial artery at the wrist can provide the

peared, she said, her fingers became red and swollen.

experienced medical professional with considerable in-

Using your knowledge of anatomy, make the diagnosis.

sight into the state of the patient’s circulatory system. The

A 23-year-old medical student decided to assist his fa-

degree of hardness of the arterial wall can be appreciated

ther in building a garden shed. Unfortunately, much of

by the examining finger; the pulse rate and quality of the

the wood had to be cut to length by using a hand saw.

rhythm can be determined; and the amount of pressure

He noticed on the third day that his right arm felt heavy

required to occlude the vessel can be used to assess the

and that his right hand was swollen. At the emergency

blood pressure. What are the relations of the radial artery

department, a diagnosis of right subclavian vein throm-

at this site where the pulse is taken?

bosis was made. Can you explain the possible anatomic

An 8-year-old boy fell off a swing and sustained a

reasons why thrombosis occurred in this vein in a

supracondylar fracture of his left humerus. Following

healthy individual?

110

Chapter 7

Answers and Explanations

A is the correct answer. The radial artery does not enter

transverse crease of the wrist. Here the artery lies ante-

the palm by passing in front of the flexor retinaculum;

rior to the distal third of the shaft of the radius, medial

it does so by passing forward between the two heads of

to the tendon of the brachioradialis and lateral to the

the first dorsal interosseous muscles between the first

tendon of flexor carpi radialis. It is covered anteriorly

and second metacarpal bones (see text Fig. 7-14). It was

by skin and fascia. The forearm is supinated, and the

the ulnar artery that was cut with the ulnar nerve in

wrist is extended to an approximately 50° angle (see

front of the flexor retinaculum.

CD Fig. 7-1). Extension stretches and stabilizes the

artery during the process of introducing the needle

The cephalic, basilic, and median cubital veins, and

and the catheter.

their tributaries, are located in front of the cubital fossa

and may be used for transfusion (see text Fig. 7-19). In

The basilic vein is used more often than the cephalic

the forearm, the cephalic and basilic veins can be seen

vein for the following reasons: (a) The basilic vein in-

as they wind around the lateral and medial borders of

creases progressively in diameter from the cubital fossa

the forearm, respectively. The cephalic vein lies in a

to the axillary and subclavian veins, whereas the diame-

constant position behind the styloid process of the ra-

ter of the cephalic vein increases only slightly as it as-

dius (see text Fig. 7-18), and it is here that it may be ex-

cends the upper extremity; (b) the basilic vein is in line

posed through a small skin incision.

with the axillary vein (see text Figs. 7-19, 7-22, and 7-23),

whereas the cephalic vein opens into the axillary vein at

The radial artery lies in front of the distal third of the

a right angle; and (c) the basilic vein is directly continu-

shaft of the radius; it is directly in contact with the front

ous with the end of the axillary vein, whereas the

of the bone (see text Fig. 7-11. On its lateral side lies the

cephalic vein may bifurcate into several small veins near

tendon of the brachioradialis, and on its medial side is

its termination or may join the external jugular vein.

the tendon of the flexor carpi radialis muscle. The

artery is covered anteriorly by skin and fascia.

This patient had Raynaud’s disease. The initial pallor of

At the time of sustaining the supracondylar fracture of

the fingers is due to spasm of the digital arterioles. The

the humerus or the application of the splint, the

cyanosis that follows is due to local capillary dilatation

brachial artery went into spasm in the distal third of the

caused by an accumulation of metabolites. Since there

upper arm. This effectively shut off the blood flow

is no blood flow through the capillaries, blue deoxy-

through the radial and ulnar arteries, including the col-

genated hemoglobin accumulates within them. It is

lateral circulation around the elbow joint (see text Fig.

during this period of prolonged cyanosis that the patient

7-8). During the following hours, when the child was

experiences severe aching pain. On exposing the fin-

complaining of severe pain, avascular necrosis of the tis-

gers to warmth, the vasospasm disappears, and oxy-

sues of the forearm was taking place. Later this was fol-

genated blood flows back into the very dilated capillar-

lowed by Volkmann’s contracture.

ies. Reactive hyperemia is responsible for the swelling

of the affected fingers.

The radial artery has a lower incidence of arterial

thrombosis than the brachial artery, possibly because

The subclavian vein is closely related to the upper sur-

the tunica intima of the brachial artery is more likely

face of the first rib and to the posterior surface of the

to be damaged by the point of the catheter, since the

medial third of the clavicle (see text Fig. 7-3). Repeated

brachial artery is more difficult to immobilize because

minor trauma to the vein wall by these bones during the

of the movements at the elbow joint. The dorsalis

movements of the right shoulder while sawing resulted

pedis artery can be easily cannulated. It has a higher

in damage to the tunica intima, followed by thrombo-

incidence of thrombosis, however, and sometimes the

sis. This problem is particularly likely to occur in an in-

circulation of the foot is compromised by the inade-

dividual who is not used to this type of excessive move-

quate collateral circulation. The radial artery is

ment of the shoulder. Usually there is some preexisting

usually cannulated 2 to 3 cm proximal to the distal

compression.

Chapter Outline

The Abdominal Aorta

112

The Portal Vein

115

Traumatic Injury to the Abdominal Aorta

112

Portal-Systemic Anastomoses

115

Aortic Aneurysm

112

Portal Hypertension

117

Gradual Occlusion of the Abdominal Aorta

113

Blood Flow in the Portal Vein and Malignant

Embolic Blockage of the Abdominal Aorta

113

Disease

117

Mesenteric Artery Occlusion

113

Penetrating Injuries to the Portal Vein

117

The Inferior Vena Cava

113

Clinical Problem Solving Questions

117

Caval-Caval Anastomosis

113

Compression of the Inferior Vena Cava

114

Answers and Explanations

119

Trauma to the Inferior Vena Cava

115

however, is relatively mobile and continues to move for-

ward after body impact, being finally restrained by the at-

THE ABDOMINAL

tachment of the renal artery to the aorta. Excessive stretch-

ing of the renal artery may cause intimal damage with clot

AORTA

formation. The renal vessels may be avulsed from the

hilum of the kidney, or the renal artery may be torn free

from the aorta. The hemorrhage may be contained in the

Traumatic Injury to the Abdominal

retroperitoneal space, and hypovolemic shock may not im-

mediately occur.

Aorta

Penetrating injuries to the abdominal aorta are

Because of the deep position of the aorta on the posterior

common and are usually associated with multiple intraab-

abdominal wall behind the peritoneum (see text Figs. 8-1

dominal injuries. The peritoneum has been violated, and

and 8-2), blunt injuries to the aorta are relatively rare.

hemorrhage occurs directly into the peritoneal cavity. The

In children the elasticity of the aortic wall and the usual

signs of a distended abdomen associated with those of hypo-

absence of atherosclerosis make the condition even

volemic shock make the diagnosis relatively simple. How-

more rare.

ever, when the arterial leak is small, peritoneal lavage may

In blunt trauma from an automobile accident, the ab-

be necessary to confirm the diagnosis. Penetrating injuries

dominal aorta can be injured by the crossing band of a seat

through the back or flank (especially when directed from

belt. The tunical intima is commonly damaged just distal to

the left) may cause a retroperitoneal injury to the aorta; the

the origin of the inferior mesenteric artery at the level of the

blood may be contained within the retroperitoneal space

third lumbar vertebra. The diagnosis is difficult since occlu-

and delay the onset of hypovolemic shock.

sion due to thrombosis may occur at the time of the trauma

or be delayed for several months. In the presence of com-

Aortic Aneurysms

plete occlusion, the femoral pulses are absent, and motor

and sensory deficits may be present in the lower limbs due

Localized or diffuse dilatations of the abdominal part of the

to ischemia of the peripheral nerves.

aorta (aneurysms) usually occur below the origin of the re-

Deceleration injuries to the renal vessels may occur as

nal arteries (CD Fig. 8-1). Most result from atherosclerosis,

the body stops its forward motion. The abdominal aorta,

which causes weakening of the arterial wall, and occur most

like the descending thoracic aorta, is tightly attached to the

commonly in elderly men. Large aneurysms should be sur-

vertebral column by connective tissue. The kidney,

gically excised and replaced with a prosthetic graft.

The Blood Vessels of the Abdomen, Pelvis, and Perineum

113

common

iliac

artery

CD Figure 8-1

Aneurysms of the abdominal

aorta. A. Above the origin of the renal arteries.

B. Below the level of the renal arteries. The latter

aneurysms, which are the most common, may

extend inferiorly to involve the common iliac

arteries.

clusive disease of the superior mesenteric artery is much

Gradual Occlusion of the

more common than that of the inferior mesenteric artery,

which may be explained by the angle of takeoff of the su-

Abdominal Aorta

perior artery from the aorta. In cases of embolus of the su-

perior mesenteric artery, the embolus usually lodges in the

Gradual occlusion of the aorta may occur due to athero-

region of the middle colic artery so that the jejunum may

sclerosis. Intermittent claudication in both legs may be pre-

be spared.

sent due to insufficient arterial blood reaching the muscles

of the lower limbs. If the progress of the atherosclerosis is

slow, an adequate collateral circulation may become estab-

lished (CD Fig. 8-2).

THE INFERIOR

Embolic Blockage of the Abdominal

VENA CAVA

Aorta

Caval-Caval Anastomosis

The bifurcation of the abdominal aorta where the lumen

suddenly narrows may be a lodging site for an embolus dis-

A caval-caval shunt is the opening up of an alternative ve-

charged from the heart. Severe ischemia of the lower limbs

nous pathway should the superior or inferior vena cava

results.

become blocked by disease. The anastomoses of the

vena cava are as follows (CD Fig. 8-3): The lumbar veins,

which are tributaries of the inferior vena cava, anastomose

Mesenteric Artery Occlusion

behind the diaphragm with the azygos and hemiazygos

Occlusion of the superior or inferior mesenteric arteries

veins, which are tributaries of the superior vena cava. The

with intestinal ischemia is discussed in CD Chapter 19.

lumbar veins also anastomose with the superficial veins

The occlusive process commonly occurs at the origin of

of the trunk, which eventually drain into the superior

the artery or in the proximal 1 to 2 cm of the artery and

vena cava via the lateral thoracic veins, tributaries of the

may be caused by an embolus, a thrombus, or trauma. Oc-

axillary veins.

114

Chapter 8

right subclavian artery

left subclavian artery

posterior intercostal

internal thoracic

arteries

artery

thoracic part of aorta

musculophrenic artery

diaphragm

superior epigastric

artery

phrenic artery

left renal artery

middle colic artery

superior mesenteric

artery

abdominal aorta

right colic artery

lumbar arteries

marginal artery

ileocolic artery

left colic artery

inferior epigastric artery

inferior mesenteric

artery

fourth lumbar

artery

sigmoid arteries

deep circumflex

superior rectal

iliac artery

artery

middle rectal artery

internal iliac artery

median

sacral

inferior rectal artery

artery

CD Figure 8-2

The possible collateral circulations of the abdominal aorta. Note the great

dilatation of the mesenteric arteries and their branches, which occurs if the aorta is slowly

blocked just below the level of the renal arteries (white bar).

moses of the tributaries (see CD Fig. 8-3). This alternative

Compression of the Inferior

pathway for the blood to return to the right atrium of the

heart is commonly referred to as the caval-caval shunt. The

Vena Cava

same pathway comes into effect in patients with a superior

The inferior vena cava is commonly compressed by the en-

mediastinal tumor compressing the superior vena cava.

larged uterus during the later stages of pregnancy. This produces

Clinically, the enlarged subcutaneous anastomosis between

edema of the ankles and feet and temporary varicose veins.

the lateral thoracic vein, a tributary of the axillary vein, and

Malignant retroperitoneal tumors can cause severe

the superficial epigastric vein, a tributary of the femoral

compression and eventual blockage of the inferior vena

vein, may be seen on the thoracoabdominal wall (see CD

cava. This results in the dilatation of the extensive anasto-

Fig. 8-3).

The Blood Vessels of the Abdomen, Pelvis, and Perineum

115

brachiocephalic

vein

superior vena cava

subclavian vein

first rib

axillary vein

hemiazygos veins

azygos vein

internal thoracic vein

lateral thoracic vein

diaphragm

inferior vena cava

ascending lumbar

vein

lumbar veins

inferior mesenteric

inferior epigastric vein

vein ascending to

portal vein

CD Figure 8-3

The possible collat-

eral circulations of the superior and

superficial epigastric

interior venae cavae. Note the alter-

vein

superior rectal vein

native pathways that exist for blood

internal iliac vein

to return to the right atrium of the

external iliac vein

heart if the superior vena cava be-

comes blocked below the entrance

inguinal ligament

of the azygos vein (upper black bar).

middle rectal vein

Similar pathways exist if the inferior

vena cava becomes blocked below

femoral vein

the renal veins (lower black bar).

Note also the connections that exist

between the portal circulation and

great saphenous

inferior rectal vein

vein

the systemic veins in the anal canal.

Trauma to the Inferior Vena Cava

THE PORTAL VEIN

Injuries to the inferior vena cava are commonly lethal, de-

spite the fact that the contained blood is under low pressure.

The anatomic inaccessibility of the vessel behind the liver,

Portal-Systemic Anastomoses

duodenum, and mesentery of the small intestine and the

blocking presence of the right costal margin make a surgical

Under normal conditions, the portal venous blood traverses

approach difficult. Moreover, the thin wall of the vena cava

the liver and drains into the inferior vena cava of the sys-

makes it prone to extensive tears.

temic venous circulation by way of the hepatic veins. This is

Because of the multiple anastomoses of the tributaries

the direct route (see text Fig. 8-19). However, other, smaller

of the inferior vena cava (see CD Fig. 8-3), it is possible in

communications exist between the portal and systemic sys-

an emergency to ligate the vessel. Most patients have venous

tems, and they become important when the direct route be-

congestion of the lower limbs.

comes blocked (CD Fig. 8-4).

116

Chapter 8

inferior vena cava

tributaries of

phrenic

azygos veins

veins

esophageal tributaries of

left gastric vein

liver

veins on posterior

abdominal wall

paraumbilical veins

umbilicus

colic veins

superficial veins

of anterior abdominal

wall

superior rectal vein

middle and inferior rectal

veins

CD Figure 8-4

Important portal-systemic anastomoses.

These communications are as follows:

■ At the lower third of the esophagus, the esophageal

■ The paraumbilical veins connect the left branch of the

branches of the left gastric vein (portal tributary) anasto-

portal vein with the superficial veins of the anterior

mose with the esophageal veins draining the middle third

abdominal wall (systemic tributaries). The paraumbilical

of the esophagus into the azygos veins (systemic tributary).

veins travel in the falciform ligament and accompany the

■ Halfway down the anal canal, the superior rectal veins

ligamentum teres.

(portal tributary) draining the upper half of the anal canal

■ The veins of the ascending colon, descending colon,

anastomose with the middle and inferior rectal veins (sys-

duodenum, pancreas, and liver (portal tributary) anas-

temic tributaries), which are tributaries of the internal il-

tomose with the renal, lumbar, and phrenic veins

iac and internal pudendal veins, respectively.

(systemic tributaries).

The Blood Vessels of the Abdomen, Pelvis, and Perineum

117

the liver via the hepatic artery. The wide angle of union of

Portal Hypertension

the splenic vein with the superior mesenteric vein to form

the portal vein leads to streaming of the blood flow in the

Portal hypertension is a common clinical condition; thus,

portal vein. The right lobe of the liver receives blood mainly

the list of portal-systemic anastomoses should be remem-

from the intestine, whereas the left lobe plus the quadrate

bered. Enlargement of the portal-systemic connections is

and caudate lobes receive blood from the stomach and the

frequently accompanied by congestive enlargement of the

spleen. This distribution of blood may explain the distribu-

spleen. Portacaval shunts for the treatment of portal

tion of secondary malignant deposits in the liver.

hypertension may involve the anastomosis of the portal vein,

because it lies within the lesser omentum, to the anterior

wall of the inferior vena cava behind the entrance into the

Penetrating Injuries to the

lesser sac. The splenic vein may be anastomosed to the left

renal vein after removing the spleen.

Portal Vein

Penetrating injuries to the portal vein are life threatening and

Blood Flow in the Portal Vein

are usually associated with multiple abdominal injuries. A

deep penetrating abdominal wound on the transpyloric

and Malignant Disease

plane, about two fingerbreadths to the right of the midline,

The portal vein conveys about 70% of the blood to the liver.

could easily penetrate the liver and perforate the first part

The remaining 30% is oxygenated blood, which passes to

of the duodenum, the portal vein, and the inferior vena cava.

Clinical Problem Solving Questions

Read the following case histories/questions and give

Into which hollow viscera or blood vessels may an aortic

the best answer for each.

aneurysm rarely rupture into?

A 59-year-old man was involved in a head-on automobile

Explain in anatomic terms why penetrating injuries to

accident. When seen in the emergency department, he

the inferior vena cava are commonly fatal. Explain how

was in hypovolemic shock and showed signs of extensive

it is possible to ligate the inferior vena cava below the

bruising on the lower part of the anterior abdominal wall.

level of the renal veins without adverse effects.

He was wearing a seat belt at the time of the accident. On

A 63-year-old man with a long history of a duodenal ul-

examination, his abdomen was distended and tense; he

cer was seen in the emergency department after vomit-

had hypotension and tachycardia. A diagnosis of ruptured

ing blood-stained fluid and exhibiting all the signs and

abdominal aorta was made during an emergency laparo-

symptoms of severe hypovolemic shock.

tomy. In cases of blunt traumatic injury to the abdominal

aorta, do all patients become hypotensive immediately?

The following statements concerning duodenal ulcers

Explain the possible role that the kidneys may play in

could apply to the patient’s condition except which?

causing damage to the aorta in deceleration injuries.

A. Hemorrhage from a duodenal ulcer often reveals it-

self by the passage of black stools on defecation.

A 74-year-old man was seen in the emergency depart-

B. The pyloric sphincter prevents most of the blood from

ment complaining of the sudden onset of severe lumbar

the duodenal lumen from passing up into the stomach.

back pain. Three years previously he had had a myocar-

C. The gastroduodenal artery lies behind the first part of

dial infarction. On questioning, the patient admitted

the duodenum and was probably eroded by the ulcer.

that he often experienced mild back and hip pains on

D. The gastroduodenal artery is a small branch of the

getting up in the morning, but never had he experienced

hepatic artery.

such a severe back pain. On examination, a somewhat

E. The duodenal ulcer was most likely to be situated on

tender pulsatile swelling could be felt in the abdomen at

the posterior wall of the first part of the duodenum.

the level of the umbilicus. Both femoral pulses were pre-

sent. A diagnosis of abdominal aortic aneurysm was

A 58-year-old man was in a restaurant when he suddenly

made. What is the surface marking of the abdominal

started to vomit blood. He was taken unconscious to the

aorta? Explain why the back pain had started so suddenly

emergency department of a local hospital. On examina-

and its significance. When an abdominal aneurysm rup-

tion, he had all the signs of severe hypovolemic shock.

tures, does an immediate fatal outcome always occur?

On palpation of the anterior abdominal wall, the right

118

Chapter 8

lobe of the liver was felt three fingerbreadths below the

The symptoms and signs displayed by this patient

costal margin. Several enlarged superficial veins could

can be explained by the following statements except

be seen around the umbilicus. His wife said that he had

which?

vomited blood 3 months previously and had nearly died.

A. The enlarged uterus is an abdominal organ and

She admitted that he was a chronic alcoholic. The

often compresses the inferior vena cava.

diagnosis was cirrhosis of the liver secondary to chronic

B. Venous back pressure causes the tissue fluid to ac-

alcoholism.

cumulate in the subcutaneous tissues of the feet and

ankles.

The symptoms and signs displayed by this patient can

C. Venous back pressure impairs the venous return in

be explained by the following statements except which?

the superficial veins in both the legs, leading to vari-

A. The normal flow of portal blood through the liver is

cose veins.

impaired by cirrhosis of the liver.

D. High levels of progesterone in the blood during preg-

B. The portal-systemic anastomoses become enlarged

nancy cause the smooth muscle in the wall of the

in this condition.

veins to relax, thus permitting the veins to dilate.

C. At the lower end of the esophagus, a branch from the

E. The pregnant uterus presses on the sympathetic

right gastric vein anastomoses with an esophageal

trunks, causing vasodilatation of the blood vessels of

tributary of the azygos vein.

the legs.

D. Rupture of a varicosed esophageal vein could pro-

duce a severe hemorrhage so that the patient would

After complete occlusion of the origin of the inferior

vomit up blood.

mesenteric artery with a blood clot, the blood supply of

E. With portal hypertension the paraumbilical veins

the left portion of the colon is maintained by the

linking the superficial veins of the skin (systemic

following arteries except which?

veins) to the portal vein become congested and

A. The marginal artery

visible.

B. The middle colic artery

C. The left lumbar arteries

A 56-year-old man visited his physician complaining

D. Anastomoses between the superior, middle, and

that he experiences severe pain in both legs when taking

inferior hemorrhoidal arteries

long walks. He noticed recently that the cramp-like pain

E. Sigmoid arteries

occurs after walking only a hundred yards. On ques-

tioning, he said that the pain quickly disappears on rest

In patients with an obstruction of the superior vena cava,

only to return after he walks the same distance. When

blood may return to the right atrium through the

the physician asked about his sex life the patient admit-

following anastomotic channels except which?

ted that he was experiencing difficulty with erection.

A. The lateral thoracic, lumbar, and superficial epigas-

tric veins

The symptoms and signs displayed by this patient can

B. The superior and inferior epigastric veins

be explained by the following statements except which?

C. The lateral thoracic, paraumbilical, and portal veins

A. Arteriography of the abdominal aorta revealed

D. The posterior intercostal and lumbar veins

blockage in the region of the bifurcation.

E. The lateral thoracic veins alone

B. Only the right common iliac artery was involved by

disease.

10.

If the common hepatic artery is unavoidably ligated

C. The gradual blockage of the aorta was caused by

during surgery, the arterial supply to the liver is main-

advanced arteriosclerosis.

tained by the following anastomotic connections except

D. An insufficient amount of blood was reaching both

which?

legs, causing pain (claudication) on walking.

A. The superior pancreaticoduodenal artery anasto-

E. The lack of blood entering both internal iliac

mosing with the inferior pancreaticoduodenal artery

arteries was responsible for the difficulty with

B. The right gastric artery anastomosing with the left

erection.

gastric artery

C. The gastroduodenal artery anastomosing with the

A 23-year-old woman, who was 8 months pregnant, told

splenic artery

her obstetrician that she had recently noticed that her

D. The esophageal arteries anastomosing with the infe-

feet and ankles were swollen at the end of the day. She

rior phrenic arteries

said that the swelling was worse if she had been stand-

E. The right gastroepiploic artery anastomosing with

ing for long periods. She also noticed that the veins

the left gastroepiploic artery

around her ankles were becoming prominent.

The Blood Vessels of the Abdomen, Pelvis, and Perineum

119

Answers and Explanations

Frequently, patients with blunt rupture to the abdomi-

site of the injury is inaccessible behind the liver, duo-

nal aorta may not immediately show signs of hypov-

denum, and the mesentery of the small intestine; (b)

olemic shock because the aorta is situated behind the

the presence of the right costal margin makes surgical

peritoneum in the retroperitoneal space and the blood

access difficult; (c) the thin walls of the vena cava are

may not escape immediately into the peritoneal cavity

likely to tear extensively and make repair difficult; and

(see text Fig. 5-62).

(d) the almost certain possibility that the liver is also

damaged.

On impact, the patient may be held stationary by the

seat belt, but the kidneys may continue forward until re-

The extensive anastomosis of the lumbar veins with

strained by the vascular pedicles. Avulsion of the renal

other retroperitoneal veins ensures that the blood is

artery from the side of the aorta may take place under

able to bypass the obstruction should the inferior vena

these circumstances.

cava be ligated below the level of the renal veins (see

CD Fig. 8-3).

The abdominal aorta is a midline structure that enters

the abdomen at the level of the twelfth thoracic verte-

D is the correct answer. The gastroduodenal artery is a

bra, and its entrance may be projected onto the anterior

large branch of the hepatic artery.

abdominal wall just above the transpyloric plane (see

C is the correct answer. At the lower end of the

text Fig. 8-3). The vessel extends downward to its bifur-

esophagus, a branch from the left gastric vein

cation into the common iliac arteries at the level of the

anastomoses with an esophageal tributary of the azygos

summit of the iliac crests.

vein.

The sudden onset of severe back pain can be explained

B is the correct answer. The blockage of the aorta in the

by the aneurysm suddenly expanding or rupturing and

region of the bifurcation had effectively blocked the en-

pressing on the vertebral column, which lies immedi-

trances into both common iliac arteries.

ately posterior to the aorta.

E is the correct answer. The sympathetic trunks are not

Death does not always immediately follow an abdomi-

pressed on by the pregnant uterus.

nal aneurysm rupture. This can be explained by the fact

that the hemorrhage may be initially confined to the

C is the correct answer. The left lumbar arteries do not

retroperitoneal space, and a tamponade effect may tem-

significantly contribute to the left portion of the colon.

porarily prevent further bleeding.

The middle colic artery from the superior mesenteric

artery, the sigmoid arteries, and the marginal artery, as

The abdominal aorta is crossed by the third part of the

well as the hemorrhoidal arteries, will maintain the

duodenum, and cases have been reported of an

blood supply to the left portion of the colon.

aneurysm rupturing into the duodenal lumen. The in-

ferior vena cava lies along the right side of the aorta, and

E is the correct answer. The lateral thoracic and the su-

an aneurysm has been known to rupture into it, pro-

perior epigastric veins are directly or indirectly con-

ducing a massive arteriovenous fistula.

nected with the superior vena cava only.

Penetrating injuries of the upper part of the

10.

C is the correct answer. The gastroduodenal artery does

inferior vena cava are commonly fatal because (a) the

not directly anastomose with the splenic artery.

Chapter Outline

The Arteries

122

Great Saphenous Vein Cutdown

125

Anatomy of Ankle Vein Cutdown

126

Collateral Circulation

122

Anatomy of Groin Vein Cutdown

126

Femoral Artery Catheterization

122

The Great Saphenous Vein in Coronary Bypass

Anatomy of Technique

123

Surgery

126

Anatomy of Complications

123

Intraosseous Infusion in the Infant

126

Traumatic Injury to Arteries of the Lower Limb

124

Varicose Veins

126

Anatomy of Complications of Arterial Injury

124

Varicose Leg Ulcers

126

Compartmental Syndromes

124

Traumatic Bleeding from a Varicosed Vein

127

Occlusion of the Popliteal, Anterior, and Posterior

Superficial Thrombophlebitis

127

Tibial Arteries

124

Deep Thrombophlebitis

127

Intermittent Claudication and Arterial Occlusive

Deep Vein Thrombosis and Long-Distance Air

Disease of the Lower Extremity

124

Travel

127

Femoropopliteal and Femorotibial Bypass for

Femoral Vein Catheterization

127

Lower Extremity Vascular Insufficiency

124

Anatomy of the Procedure

127

Lumbar Sympathectomy and Occlusive Arterial

Doppler Ultrasound Examination of Venous Flow

Disease

124

in the Lower Extremity

127

Aneurysms of the Lower Extremity

124

Venous Tone in Hypovolemic Shock

128

The Veins

125

Arterial Palpation

128

Great Saphenous Vein Variations and Venous

Vein Cutdown

125

Clinical Problem Solving Questions

129

Answers and Explanations

130

branches of the profunda femoris artery and the articular

THE ARTERIES

and muscular branches of the femoral and popliteal

arteries.

Collateral Circulation

Femoral Artery Catheterization

If the arterial supply to the leg is occluded, necrosis or gan-

A long, fine catheter can be inserted into the femoral

grene will follow unless an adequate bypass to the obstruc-

artery as it descends through the femoral triangle. The

tion is present—that is, a collateral circulation. Sudden

catheter is guided under fluoroscopic view along the ex-

occlusion of the femoral artery by ligature or embolism, for

ternal and common iliac arteries into the aorta. The

example, is usually followed by gangrene. However, grad-

catheter can then be passed into the inferior mesenteric,

ual occlusion such as occurs in atherosclerosis is less likely

superior mesenteric, celiac, or renal arteries. Contrast

to be followed by necrosis because the collateral blood ves-

medium can then be injected into the artery under exam-

sels have time to dilate fully. The collateral circulation for

ination and a permanent record obtained by taking a

the proximal part of the femoral artery is through the cru-

radiograph. Pressure records can also be obtained by guid-

ciate and trochanteric anastomoses; for the femoral artery

ing the catheter through the aortic valve into the left

in the adductor canal, it is through the perforating

ventricle.

The Blood Vessels of the Lower Extremity

123

Anatomy of Technique

Anatomy of Complications

The femoral artery is first located just below the inguinal lig-

The femoral vein lies immediately medial to the artery and

ament midway between the symphysis pubis and the ante-

may be entered in error. The nonpulsatile nature of the vein

rior superior iliac spine (CD Fig. 9-1). The needle or

on palpation should exclude this possibility. Since the hip

catheter is then inserted into the artery. The following struc-

joint lies posterior to the femoral artery, the erroneous pas-

tures are pierced:

sage of the needle through the posterior arterial wall may

■ Skin

cause it to pierce the psoas muscle and enter the joint cav-

■ Superficial fascia

ity. Some difficulty may be experienced in passing the

■ Deep fascia

catheter up the femoral artery if the artery is tortuous or if

■ Anterior layer of the femoral sheath

there is extensive atherosclerosis of the arterial wall.

external iliac vessels

inguinal

ligament

anterior superior

iliac spine

pubic tubercle

femoral vessels

symphysis pubis

long saphenous

vein

CD Figure 9-1

Surface markings of the major blood vessels on the anterior surface of

the left thigh.

124

Chapter 9

Traumatic Injury to Arteries of the

Intermittent Claudication and

Lower Limb

Arterial Occlusive Disease of the

Injury to the large femoral artery can cause rapid exsan-

Lower Extremity

guination of the patient. Unlike in the upper extremity,

arterial injuries of the lower limb do not have a good prog-

Atherosclerosis of the lower limb arteries is common in

nosis. The collateral circulations around the hip and knee

men. Ischemia of the muscles produces a cramp-like pain

joints, although present, are not as adequate as that around

with exercise. Intermittent claudication is a condition

the shoulder and elbow. Damage to a neighboring large

characterized by calf muscle cramping pain on exertion that

vein can further complicate the situation and causes further

is relieved by rest. Thrombosis in a diseased segment of the

impairment of the circulation to the distal part of the limb.

artery may lead to a sudden worsening of the symptoms and

even cause nocturnal ischemic pain. The common sites for

occlusion are the femoral, popliteal, and tibioperoneal ar-

Anatomy of Complications of

teries. If the obstruction occurs more proximally in the aorta

or iliac arteries, impotence is common.

Arterial Injury

A single perforating injury to an artery in the lower limb may

Femoropopliteal and Femorotibial

also perforate an accompanying vein and establish an acute

arteriovenous fistula. This complication is common in re-

Bypass for Lower Extremity

gions where large vessels run close together, such as the

femoral artery and vein in the femoral triangle and the sub-

Vascular Insufficiency

sartorial canal, and the popliteal artery and vein behind the

knee. Such a shunt produces a continuous machinery-like

Bypasses have been used with success in patients with severe

murmur over the fistula with the later development of vari-

distal extremity ischemia. In the presence of gangrene or se-

cosities and edema of the distal part of the limb.

vere rest pain, the distal limb has been successfully salvaged.

Anatomically, a true aneurysm is one whose wall con-

A reversed ipsilateral autogenous saphenous vein, a con-

tains all three layers of the arterial wall, namely, the intima,

tralateral saphenous vein, or a cephalic vein graft has been

media, and adventitia. A false aneurysm, sometimes called

used to connect the proximal femoral artery or popliteal

a pulsating hematoma, is one whose wall contains only the

artery to the distal popliteal or tibial or peroneal arteries.

tunica adventitia. An arterial perforation may lead to a false

aneurysm that becomes walled off by the adventitia and sur-

Lumbar Sympathectomy and

rounding tissues. Pressure on neighboring nerves may give

rise to neurologic symptoms.

Occlusive Arterial Disease

Lumbar sympathectomy may be advocated as a form of

Compartmental Syndromes

treatment in occlusive arterial disease of the lower extremity

Delay in the diagnosis and repair of injured arteries, espe-

to increase the blood flow through the collateral circulation.

cially when accompanied by vein damage, may lead to

Preganglionic sympathectomy is performed by removing

muscle necrosis and compartmental edema. The compart-

the upper three lumbar ganglia and the intervening parts of

ment syndromes are discussed on CD Chapter 13.

the sympathetic trunk.

Occlusions of the Popliteal, Anter-

Aneurysms of the Lower Extremity

These occur much less frequently than abdominal aortic

ior, and Posterior Tibial Arteries

aneurysms and are usually caused by atherosclerosis. Most

Popliteal artery occlusion occurs just below the beginning

patients are over 50 years of age, and the common sites are

of the artery (just below the opening in the adductor mag-

the femoral and popliteal arteries. The diagnosis is usually

nus muscle). In some cases the occlusion extends distally to

made by finding an expansile swelling along the course of

involve the origins of the anterior and posterior tibial arter-

the artery. Patients may present in the emergency depart-

ies and even the peroneal artery. Symptoms include inter-

ment with complications, which include sudden embolic

mittent claudication, night cramps, and rest pain caused by

obstruction to arteries distal to the aneurysm or sudden

ischemic neuritis. Signs include impaired or absent arterial

thrombotic occlusion of the aneurysm. Pressure on neigh-

pulses, lowered skin temperature, color changes, muscle

boring nerves may give rise to symptoms; for example, an en-

weakness, and trophic changes.

larging popliteal aneurysm may press on the tibial nerve,

The Blood Vessels of the Lower Extremity

125

causing pain in the foot. Rupture of femoral or popliteal

large one. This possibility is of great clinical importance

aneurysms is rare.

when performing a venous cutdown

Great Saphenous Vein Cutdown

THE VEINS

Exposure of the great saphenous vein through a skin inci-

sion (a “cutdown”) is usually performed at the ankle (CD

Fig. 9-2). This site has the disadvantage that phlebitis (in-

flammation of the vein wall) is a potential complication.

Great Saphenous Vein Variation

The great saphenous vein also can be entered at the groin

in the femoral triangle, where phlebitis is relatively rare;

and Venous Vein Cutdown

the larger diameter of the vein at this site permits the use

Occasionally the great saphenous vein at the medial malle-

of large-diameter catheters and the rapid infusion of large

olus is replaced by several small veins instead of a single

volumes of fluids.

saphenous nerve

great saphenous vein

medial malleolus of tibia

saphenous nerve

great saphenous vein

anterior superior

iliac spine

edge of saphenous opening

in deep fascia

femoral artery

pubic

femoral vein

great saphenous

vein

CD Figure 9-2

Great saphenous vein cutdown. A and B. At the ankle. The great saphe-

nous vein is constantly found in front of the medial malleolus of the tibia. C and D. At the

groin. The great saphenous vein drains into the femoral vein two fingerbreadths below

and lateral to the pubic tubercle.

126

Chapter 9

Anatomy of Ankle Vein Cutdown

Intraosseous Infusion in the Infant

The procedure is as follows:

This technique may be used for the infusion of fluids and

1. The sensory nerve supply to the skin immediately in

blood when it has been found impossible to obtain an intra-

front of the medial malleolus of the tibia is from

venous line. The procedure is easy and rapid to perform as

branches of the saphenous nerve, a branch of the

follows:

femoral nerve. The saphenous nerve branches are

■ With the distal leg adequately supported, the anterior

blocked with local anesthetic.

subcutaneous surface of the tibia is palpated.

2. A transverse incision is made through the skin and sub-

■ The skin is anesthetized about 1 in. (2.5 cm) distal to the

cutaneous tissue across the long axis of the vein just an-

tibial tuberosity, thus blocking the infrapatellar branch of

terior and superior to the medial malleolus (see CD

the saphenous nerve.

Fig. 9-2). Although the vein may not be visible through

■ The bone marrow needle is directed at right angles

the skin, it is constantly found at this site.

through the skin, superficial fascia, deep fascia, and tib-

ial periosteum and the cortex of the tibia. Once the

3. The vein is easily identified, and the saphenous nerve

needle tip reaches the medulla and bone marrow, the

should be recognized; the nerve usually lies just ante-

operator senses a feeling of “give.” The position of the

rior to the vein (see CD Fig. 9-2).

needle in the marrow can be confirmed by aspiration.

The needle should be directed slightly caudad to avoid

Anatomy of Groin Vein Cutdown

injury to the epiphyseal plate of the proximal end of the

tibia. The transfusion may then commence.

1. The area of thigh skin below and lateral to the scrotum

or labium majus is supplied by branches of the ilioin-

Varicose Veins

guinal nerve and the intermediate cutaneous nerve of

A varicosed vein is one that has a larger diameter than nor-

the thigh. The branches of these nerves are blocked

mal and is elongated and tortuous. Varicosity of the

with local anesthetic.

esophageal and rectal veins is described elsewhere. This

2. A transverse incision is made through the skin and sub-

condition commonly occurs in the superficial veins of the

cutaneous tissue centered on a point about 1.5 in. (4

lower limb and, although not life threatening, is responsible

cm) below and lateral to the pubic tubercle (see CD

for considerable discomfort and pain.

Fig. 9-2). If the femoral pulse can be felt (may be absent

Varicose veins have many causes, including hereditary

in patients with severe shock), the incision is carried

weakness of the vein walls and incompetent valves; elevated

medially just medial to the pulse.

intraabdominal pressure as a result of multiple pregnancies

or abdominal tumors; and thrombophlebitis of the deep

3. The great saphenous vein lies in the subcutaneous fat

veins, which results in the superficial veins becoming the

and passes posteriorly through the saphenous opening in

main venous pathway for the lower limb. It is easy to under-

the deep fascia to join the femoral vein about 1.5 in. (4

stand how this condition can be produced by incompetence

cm), or two fingerbreadths, below and lateral to the pu-

of a valve in a perforating vein. Every time the patient exer-

bic tubercle. It is important to understand that the great

cises, high-pressure venous blood escapes from the deep

saphenous vein passes through the saphenous opening

veins into the superficial veins and produces a varicosity,

to gain entrance to the femoral vein. However, the size

which might be localized to begin with but becomes more

and shape of the opening are subject to variation.

extensive later.

The successful operative treatment of varicose veins de-

The Great Saphenous Vein in

pends on the ligation and division of all the main tributaries

of the great or small saphenous veins, to prevent a collateral

Coronary Bypass Surgery

venous circulation from developing, and the ligation and di-

In patients with occlusive coronary disease caused by ather-

vision of all the perforating veins responsible for the leakage

osclerosis, the diseased arterial segment can be bypassed by

of high-pressure blood from the deep to the superficial

inserting a graft consisting of a portion of the great saphe-

veins. It is now common practice to also remove or strip the

nous vein. The venous segment is reversed so that its valves

superficial veins. Needless to say, it is imperative to ascertain

do not obstruct the arterial flow. Following removal of the

that the deep veins are patent before operative measures are

great saphenous vein at the donor site, the superficial

taken.

venous blood ascends the lower limb by passing through

Varicose Leg Ulcers

perforating veins and entering the deep veins.

The great saphenous vein can also be used to bypass

These occur in the region of the medial malleolus, are

obstructions of the brachial or femoral arteries.

caused by venous skin stasis, and may be a complication of

The Blood Vessels of the Lower Extremity

127

varicose veins; many are caused by postthrombotic incom-

petent perforating veins in the region.

Deep Vein Thrombosis and

A venous ulcer must be distinguished from an arterial

ulcer caused by atherosclerosis of the skin arteries. An arterial

Long-Distance Air Travel

ulcer tends to occur on the lateral side of the distal leg, and

Passengers who sit immobile for hours on long-distance

the leg is often pulseless and cool. A venous ulcer occurs on

flights are very prone to deep vein thrombosis in the legs.

the medial side of the distal leg because skin venous stasis

Preventative measures include stretching of the legs every

tends to be more severe on the medial side in the presence of

hour to improve the venous circulation.

varicose veins. The explanation for the laterally placed arter-

ial ulcer is that the skin over the lateral malleolus receives a

Femoral Vein Catheterization

poorer arterial supply than that over the medial malleolus.

Femoral vein catheterization is used when rapid access to a

Traumatic Bleeding from a

large vein is needed. The femoral vein has a constant rela-

Varicosed Vein

tionship to the medial side of the femoral artery just below

the inguinal ligament and is easily cannulated. However,

Profuse bleeding from a pierced varicosed vein may cause a

because of the high incidence of thrombosis with the possi-

patient to seek medical treatment. Pressure over the vein,

bility of fatal pulmonary embolism, the catheter should be

proximal to the injury, should stop the blood escaping. The

removed once the patient is stabilized.

varicosed veins have incompetent valves and venous blood

is merely draining downward by gravity from the abdominal

Anatomy of the Procedure

veins. Raising the leg to a level above the heart should also

stop the bleeding.

1. The skin of the thigh below the inguinal ligament is

supplied by the genitofemoral nerve; this nerve is

blocked with a local anesthetic.

Superficial Thrombophlebitis

2. The femoral pulse is palpated midway between the an-

Thrombosis of the superficial veins of the lower limb is often

terior superior iliac spine and the symphysis pubis, and

associated with varicose veins. The condition is painful, and

the femoral vein lies immediately medial to it.

the thrombosed vein is tender to touch; the overlying skin is

reddened and edematous. The thrombus is usually strongly

3. At a site about two fingerbreadths below the inguinal

adherent to the wall of the vein so that emboli are rarely

ligament, the needle is inserted into the femoral vein.

formed. However, should the thrombosis extend to the deep

veins through a perforating vein, embolic formation in the

Doppler Ultrasound Examination

deep vein can be a serious, although rare, complication.

of Venous Flow in the Lower

Deep Thrombophlebitis

Extremity

Thrombosis of the deep veins can occur at any time, but sig-

nificant predisposition is immobility of the lower limbs in

Posterior tibial veins: The probe is applied to the skin

bed or in a splint. The common site where the process starts

just posterior to the medial malleolus of the tibia. Here

is the veins draining the soleus muscle in the calf. It must be

the posterior tibial veins accompany the posterior tibial

assumed that the pressure of the bed on the calf veins dam-

artery between the tendon of the flexor digitorum longus

ages the tunica intima, and this together with certain predis-

and the posterior tibial nerve (CD Fig. 9-3).

posing factors, such as surgical trauma, malignant disease,

Popliteal vein: The probe is applied to the skin over the

pregnancy, or estrogen therapy, initiates thrombus forma-

popliteal space with the knee partly flexed to relax the

tion. Once formed, the thrombus may extend proximally

deep fascia. The flow signal is best heard over the vein

into the popliteal and femoral veins and even higher into the

just lateral to the popliteal artery (see CD Fig. 9-3).

iliac veins. The symptoms include discomfort and tightness

Femoral vein: The probe is placed over the vein at

in the calf, especially when the patient is using the calf mus-

midthigh as it lies in the subsartorial canal with the

cles, as in standing and walking. Tenderness of the calf mus-

femoral artery (see CD Fig. 9-3). The probe can also be

cles may be apparent, and edema of the ankles, pretibial area,

applied higher up on the skin covering the femoral trian-

or thigh may be present. The superficial veins may be dilated

gle just below the inguinal ligament. Here the femoral

and more obvious than normal. The great danger of deep

vein lies medial to the femoral artery (see CD Fig. 9-3).

vein thrombosis is the high incidence of pulmonary em-

The pulse of the femoral artery can easily be felt at the

bolism. A secondary problem is residual chronic venous in-

midpoint between the anterior superior iliac spine and

sufficiency of the lower extremities.

the symphysis pubis.

128

Chapter 9

flexor digitorum

longus tendon

popliteal

medial malleolus

tendo

vein and

of tibia

calcaneus

artery

posterior

tibial veins

and artery

tibial

posterior

nerve

tibial nerve

lateral

femur

vastus medialis

sartorius

Anterior superior

femoral artery

iliac spine

femoral vein

inguinal ligament

adductor

longus

Femoral

gracilis

midline

artery

femoral

vein

CD Figure 9-3

Doppler ultrasound of venous blood flow in the lower limb. A. Posterior

tibial veins at the ankle. B. Popliteal vein behind the knee. C. Femoral vein and the subsar-

torial (adductor) canal in the midthigh. D. Femoral vein just below the inguinal ligament.

may be called on to arrest a severe hemorrhage or palpate

Venous Tone in Hypovolemic

different parts of the arterial tree in patients with arterial

occlusion.

Shock

The femoral artery enters the thigh behind the in-

In extreme hypovolemic shock, excessive venous tone

guinal ligament at a point midway between the anterosupe-

caused by the contraction of the smooth muscle in the vein

rior iliac spine and the symphysis pubis (see text Fig. 9-2 and

walls may inhibit the venous flow and thus delay the intro-

CD Fig. 9-1). The artery is easily palpated here because it

duction of intravenous blood into the vascular system.

can be pressed backward against the pectineus and the su-

perior ramus of the pubis.

The popliteal artery can be felt by gentle palpation in

Arterial Palpation

the depths of the popliteal space provided that the deep fas-

Every health professional should know the precise position

cia is fully relaxed by passively flexing the knee joint (see text

of the main arteries within the lower limb, for he or she

Fig. 9-7).

The Blood Vessels of the Lower Extremity

129

The dorsalis pedis artery lies between the tendons of

longus. The pulsations of the artery can be felt midway be-

extensor hallucis longus and extensor digitorum longus,

tween the medial malleolus and the heel (see text Fig. 9-14).

midway between the medial and lateral malleoli on the

It should be remembered that the dorsalis pedis artery

front of the ankle (see text Fig. 9-9).

is sometimes absent and is replaced by a large perforating

The posterior tibial artery passes behind the medial

branch of the peroneal artery. In the same manner, the per-

malleolus and beneath the flexor retinaculum; it lies between

oneal artery may be larger than normal and replace the pos-

the tendons of flexor digitorum longus and flexor hallucis

terior tibial artery in the lower part of the leg.

Clinical Problem Solving Questions

Read the following case histories/questions and give

branches of the femoral artery and the muscular and

the best answer for each.

genicular branches of the popliteal artery.

E. The collateral circulation in the left leg was ade-

A 47-year-old woman complaining of a dull, aching

quate to prevent gangrene but was insufficient to

pain in the lower part of both legs visited her physician.

supply oxygen to the active leg muscles.

She stated that the pain was particularly severe at the

F. The perforating branches of the profunda femoris

end of a long day of standing at her work. On examina-

artery did not participate in the collateral circulation

tion, the patient was found to have widespread varicose

around the blocked femoral artery.

veins in both legs.

A 58-year-old businessman flew to Korea from New

The following symptoms and signs supported the diag-

York by plane. Except for infrequent visits to the toilet,

nosis except which?

he remained in his seat sleeping or reading. Toward

A. The patient stated that the skin down the medial

the end of the long flight, he experienced mild cramp-

side of the leg was irritated especially in dry weather.

like pain in his right calf. On feeling his leg, he found

B. If the patient coughed in the standing position, a

it to be tender but thought nothing more about it. On

fluid thrill was transmitted from the abdomen to the

reaching his destination, he was walking down the

hand palpating the veins.

ramp from the plane when he suddenly collapsed with

C. The skin showed marked discoloration over the me-

severe pain in his left chest and was experiencing ex-

dial malleoli and was dry and scaly.

treme respiratory distress. The airport physician made

D. The patient had a large family of six children and

the diagnosis of pulmonary embolism, secondary to

the varicose veins showed improvement during

deep vein thrombosis of the right calf.

each pregnancy.

The blood clot (embolus) reached the left lung via the

E. The great and small saphenous veins in both legs

following blood vessels except which?

were enlarged and elongated.

A. The right popliteal vein

A 65-year-old man told his physician that he could walk

B. The right common iliac vein

only about 50 yd (46 m) before a cramp-like pain in his

C. The inferior vena cava

left leg forced him to rest. After a thorough physical

D. The pulmonary trunk

examination, a diagnosis of severe intermittent claudi-

E. The left pulmonary vein

cation of the left leg was made.

A 65-year-old man was seen in the emergency depart-

The following findings in this patient supported the

ment complaining of the onset of a sudden pain in his

diagnosis except which?

right foot. He said that for the past 6 months he had

A. His femoral pulses were normal in both legs.

experienced some aching pain in the lower part of the

B. The popliteal, posterior tibial, and dorsalis pedis

right leg, but the foot pain had occurred quite sud-

pulses were present in the right leg and completely

denly and was different. On examination, a tender

absent in the left leg.

pulsatile swelling could be palpated in the right

C. Arteriography revealed a blockage of the left femoral

popliteal space. In anatomic terms explain the chronic

artery at the level of the adductor tubercle.

aching pain in the right lower leg. What is your ex-

D. The lower part of the left leg was receiving its blood

planation for the sudden onset of pain in the right

supply through the muscular and genicular

foot?

130

Chapter 9

5. Explain the significance of the valved perforating veins

7. Compare in anatomic and practical terms the advan-

of the lower limbs. What is the surface marking of the

tages and disadvantages of cutting down on the great

small saphenous vein at the ankle?

saphenous vein at the groin and ankle. What is the sur-

face marking of the great saphenous vein in the groin

6. What is the surface marking of the femoral artery? Name

and at the ankle? What is the relationship of the saphe-

the structures that are pierced by the insertion of a

nous nerve to the great saphenous vein at the ankle?

catheter into the femoral artery. What is the relationship

of the femoral artery to the femoral vein and the hip

8. What are the common complications of femoral vein

joint?

catheterization? What is the surface marking of the

femoral vein?

Answers and Explanations

D is the correct answer. During the later months of

fibula. Here the position is constant and it can be

pregnancy, the enlarged uterus presses on the inferior

readily seen.

vena cava and impedes the venous return from the

The femoral artery enters the thigh beneath the in-

lower limbs. This condition results in a worsening of

guinal ligament at a point midway between the anterior

preexisting varicosed veins.

superior iliac spine and the symphysis pubis (see CD

F is the correct answer. The profunda femoris artery

Fig. 9-1).

arises from the femoral artery about 1.5 in. (3.8 cm) be-

The following structures are pierced by a catheter en-

low the inguinal ligament. It plays a major role in the for-

tering the femoral artery in the thigh just below the in-

mation of the collateral circulation around the knee joint.

guinal ligament: (a) skin, (b) superficial fascia, (c) deep

fascia, and (d) anterior layer of femoral sheath.

E is the correct answer. The embolus does not enter the

left pulmonary vein. The embolus ascends the venous

The femoral vein lies along the medial side of the

system via the popliteal, femoral, external iliac, and

femoral artery within the femoral sheath. The cavity of

common iliac veins and inferior vena cava to reach the

the hip joint lies posterior to the femoral artery, sepa-

right atrium of the heart. It then passes into the right

rated by the psoas muscle and the fibrous joint capsule.

ventricle, pulmonary trunk, and left pulmonary artery

to finally reach the small or medium-sized branches of

The advantages of great saphenous vein cutdown at the

the left pulmonary artery, where it becomes lodged and

ankle are (a) the position of the vein in front of the me-

obstructs the circulation.

dial malleolus is constant, and (b) apart from the pres-

ence of the saphenous nerve, there are no other

The chronic aching pain in the right lower leg could be

anatomic structures to damage—the cutdown is made

explained by the pressure of the expanding popliteal

over bone. The disadvantages are (a) phlebitis is a com-

aneurysm on the tibial nerve (see text Fig. 9-7) in the

mon complication, and (b) the small diameter pre-

popliteal space. The sudden onset of severe pain in the

cludes the rapid instillation of large volumes of fluid; in

foot could be explained by the lodging of an embolus

young children the small diameter of the vein some-

in one of the arteries in the foot. The embolus could

times make it difficult to identify.

have originated as a thrombus in the wall of the

popliteal aneurysm.

The advantages of great saphenous cutdown in the

groin are (a) the larger diameter of the vein at this site

Normally, the valved perforating veins drain the super-

permits the rapid instillation of large volumes of fluid,

ficial veins through the deep fascia into the deep veins.

and (b) there is easier recognition of the vein at this site.

Incompetence of these important veins permits reflux

The disadvantages of the groin site are (a) the great

of deep venous blood into the superficial veins and

saphenous vein lies in thick subcutaneous fat about 1

commonly results in the formation of local superficial

1/2 in. below and lateral to the pubic tubercle; its iden-

varices.

tification may prove difficult in obese patients; and (b)

The small saphenous vein drains the lateral end of the

other important structures may be damaged, including

dorsal venous arch of the foot and ascends in the su-

the femoral artery and vein, if the procedure is carried

perficial fascia posterior to the lateral malleolus of the

out by an inexperienced individual.

The Blood Vessels of the Lower Extremity

131

The saphenous nerve usually lies just anterior to the

or misses the vein and traverses the psoas muscle and

great saphenous vein as it ascends anterior to the medial

the anterior part of the capsule of the hip joint; and

malleolus of the tibia (see CD Fig. 9-2).

(d) damage to the femoral nerve, which normally lies

some distance laterally to the femoral artery (midpoint

8. The common complications of femoral vein catheter-

between the anterior superior iliac spine and the pu-

ization are (a) thrombophlebitis of the femoral vein,

bic tubercle).

especially if the catheterization is prolonged (since the

catheter entering the saphenous vein at the groin also

The surface marking of the femoral vein is just medial

goes into the femoral vein, there is risk of phlebitis

to the pulsating femoral artery below the inguinal liga-

with saphenous catheterization as well); (b) hematoma

ment. If the artery is pulseless, the position of the artery

formation if the procedure is poorly carried out and

may be determined as being midway between the ante-

the vein wall is torn; (c) infection of the hip joint if an

rior superior iliac spine and the symphysis pubis; the

infected catheter pierces the femoral vein completely

vein lies just medial to it (see text Fig. 9-1).

Chapter Outline

The Lymph Vessels and Lymph Tissue

136

Examination of the Axillary Lymph Nodes

137

Edema and Lymphatic Obstruction

136

Carcinoma of the Breast and the Axillary Lymph

Nodes

138

Lymphangitis and Lymphadenitis

136

Mediastinoscopy and the Tracheobronchial

Lymph Flow in Clinical Medicine

136

Lymph Nodes

138

Lymph Vessels and the Spread of Malignant

Lymphatics of the Lower Limb

138

Disease

137

The Thymus

139

Enlargement of the Submandibular Lymph Nodes

and Swelling of the Submandibular Salivary

Allograft Rejection

139

Gland

137

Tumors of the Thymus

139

Clinical Significance of the Cervical Lymph Nodes

137

Clinical Problem Solving Questions

139

Examination of the Deep Cervical Lymph Nodes

137

Carcinoma Metastases in the Deep Cervical

Answers and Explanations

141

Lymph Nodes

137

may resemble that of an elephant, hence the name

THE LYMPH

elephantiasis.

■ Malignant metastases in lymph nodes and lymphatic

vessels: This condition may cause edema of the skin of

VESSELS AND

the breast or arm in advanced carcinoma of the breast.

LYMPH TISSUE

Lymphangitis and Lymphadenitis

Lymphangitis is an infection of the lymphatic vessels and is

Edema and Lymphatic Obstruction

a common occurrence. Red streaks along the course of the

lymphatic vessels are characteristic of the condition. For

An inability to absorb protein from the tissue fluid into the

example, a severe infection of the thumb may be followed

lymphatic capillary will result in an accumulation of protein

by the spread of the bacteria into the lymphatic vessels drain-

in the tissue fluid outside the capillary and cause edema.

ing the area. Red streaks may be seen on the anterior aspect

This occurs in several conditions:

of the forearm, following the course of the cephalic vein.

■ Congenital lymphatic obstruction (Milroy’s disease):

Once the infection reaches the lymph nodes, the nodes

In this condition the lymphatic vessels, especially those

become enlarged and tender, a condition known as

of the lower limbs, fail to develop.

lymphadenitis.

■ Surgical removal of lymph nodes and lymph vessels:

This occurs when an attempt is made to completely re-

Lymph Flow in Clinical Medicine

move cancer cells that may have spread from their pri-

mary locus. This form of edema commonly occurs in the

The factors responsible for normal lymph flow in lymphatic

upper limbs following a radical mastectomy for carci-

vessels include muscle activity, local arterial pulsation,

noma of the breast.

valves in lymphatic vessels, tissue fluid pressure, and gravity.

■ Filariasis: In this mosquito-spread disease, common in

There are clinical situations in which it is important to di-

the tropics, the worm larvae enter the lymphatic vessels

minish the speed of lymph flow. For example, a patient who

and progressively block the lymph nodes. After a number

has a severe bacterial infection of the hand may have the

of years, the lymphatic drainage of the leg may become

arm immobilized in a sling as an important part of the treat-

totally obstructed and the grossly edematous lower limb

ment. This procedure reduces the muscular activity of the

The Lymph Vessels and Lymph Tissue

137

limb and, consequently, the lymph flow, lessening the pos-

sibility of bacterial spread via the lymphatic vessels and di-

Examination of the Deep Cervical

minishing the rate of entry of toxins into the blood stream

via the lymph. In some conditions, it may be necessary to

Lymph Nodes

have the patient rest in bed to reduce lymph flow.

Lymph nodes in the neck should be examined from behind

Other clinical conditions may require an increase in

the patient. The examination is made easier by asking the

the flow of lymph in lymphatic vessels. In postural edema,

patient to flex the neck slightly to reduce the tension of the

an individual who has been standing in one position for

muscles. The groups of nodes should be examined in a

hours may experience swelling of the ankles and feet. In-

definite order to avoid omitting any.

creasing lymph flow also may be important in someone who

After the identification of enlarged lymph nodes, possi-

has had a limb immobilized for a long period in a splint.

ble sites of infection or neoplastic growth should be exam-

Muscular exercises, raising the limb to use the force of grav-

ined, including the face, scalp, tongue, mouth, tonsil, and

ity, or massage applied to the area will aid the flow of lymph

pharynx.

along the valved lymphatic vessels.

Carcinoma Metastases in the Deep

Lymph Vessels and the Spread of

Cervical Lymph Nodes

Malignant Disease

In the head and neck, all the lymph ultimately drains into

Lymphatic vessels provide a pathway for the spread of cer-

the deep cervical group of nodes. Secondary carcinoma-

tain types of malignant tumors from their site of origin.

tous deposits in these nodes are common. The primary

When the cancer cells reach a lymph node, they may be

growth may be easy to find. On the other hand, at certain

temporarily stopped by the network of reticular fibers.

anatomic sites the primary growth may be small and over-

However, the cancer cells may continue to multiply in

looked, for example, in the larynx, the pharynx, the cervical

situ, leading to the formation of a secondary growth or

part of the esophagus, and the external auditory meatus. The

metastasis.

bronchi, breast, and stomach are sometimes the site of the

primary tumor. In these cases, the secondary growth has

Enlargement of the Submandibu-

spread far beyond the local lymph nodes.

When cervical metastases occur, the surgeon usually

lar Lymph Nodes and Swelling of

decides to perform a block dissection of the cervical nodes.

This procedure involves the removal en bloc of the internal

the Submandibular Salivary Gland

jugular vein, the fascia, the lymph nodes, and the sub-

mandibular salivary gland. The aim of the operation is re-

The submandibular lymph nodes are commonly enlarged as

moval of all the lymph tissues on the affected side of the

a result of a pathologic condition of the scalp, face, maxillary

neck. The carotid arteries and the vagus nerve are carefully

sinus, or mouth cavity. One of the most common causes of

preserved. It is often necessary to sacrifice the hypoglossal

painful enlargement of these nodes is acute infection of the

and vagus nerves, which may be involved in the cancerous

teeth. Enlargement of these nodes should not be confused

deposits. In patients with bilateral spread, a bilateral block

with pathologic swelling of the submandibular salivary gland.

dissection may be necessary. An interval of 3 to 4 weeks is

necessary before removing the second internal jugular vein.

Clinical Significance of the

Examination of the Axillary

Cervical Lymph Nodes

Knowledge of the lymph drainage of an organ or region is of

Lymph Nodes

great clinical importance. Examination of a patient may re-

With the patient standing or sitting, he or she is asked to place

veal an enlarged lymph node. It is the physician’s responsi-

the hand of the side to be examined on the hip and push hard

bility to determine the cause and be knowledgeable about

medially. This action of adduction of the shoulder joint

the area of the body that drains its lymph into a particular

causes the pectoralis major muscle to contract maximally so

node. For example, an enlarged submandibular node can

that it becomes hard like a board. The examiner then pal-

be caused by a pathologic condition in the scalp, the face,

pates the axillary nodes (see text Fig. 10-3) as follows:

the maxillary sinus, or the tongue. An infected tooth of the

upper or lower jaw may be responsible. Often a physician

■ The anterior (pectoral) nodes may be palpated by press-

has to search systematically the various areas known to drain

ing forward against the posterior surface of the pectoralis

into a node to discover the cause.

major muscle on the anterior wall of the axilla.

138

Chapter 10

■ The posterior (subscapular) nodes may be palpated by

Radical mastectomy is designed to remove the pri-

pressing backward against the anterior surface of the sub-

mary tumor and the lymph vessels and nodes that drain

scapularis muscle on the posterior wall of the axilla.

the area. This means that the breast and the associated

■

The lateral nodes may be palpated against the medial

structures containing the lymph vessels and nodes must

side of the axillary vein. The examiner’s fingers are

be removed en bloc. The excised mass is therefore made

pressed laterally against the subclavian vein and the pul-

up of the following: a large area of skin overlying the tu-

sating axillary artery.

mor and including the nipple; all the breast tissue; the

■

The central nodes may be palpated in the center of the

pectoralis major and associated fascia through which the

axilla between the pectoralis major (anterior wall) and

lymph vessels pass to the internal thoracic nodes; the pec-

the subscapularis (posterior wall).

toralis minor and associated fascia related to the lymph

■

For the apical nodes, the patient is asked to relax the

vessels passing to the axilla; all the fat, fascia, and lymph

shoulder muscles and let the upper limb hang down at

nodes in the axilla; and the fascia covering the upper part

the side. The examiner then gently places the tips of the

of the rectus sheath, the serratus anterior, the subscapu-

fingers of the examining hand high up in the axilla to the

laris, and the latissimus dorsi muscles. The axillary blood

outer border of the first rib. If the nodes are enlarged they

vessels, the brachial plexus, and the nerves to the serratus

can be felt.

anterior and the latissimus dorsi are preserved. Some de-

gree of postoperative edema of the arm is likely to follow

The examination of the axillary lymph nodes always

such a radical removal of the lymph vessels draining the

forms part of the clinical examination of the breast.

upper limb.

A modified form of radical mastectomy for patients with

clinically localized cancer is also a common procedure and

Carcinoma of the Breast and the

consists of a simple mastectomy in which the pectoral mus-

cles are left intact. The axillary lymph nodes, fat, and fascia

Axillary Lymph Nodes

are removed. This procedure removes the primary tumor

The importance of knowing the lymph drainage of the

and permits pathologic examination of the lymph nodes for

breast in relation to the spread of cancer from that organ

possible metastases.

cannot be overemphasized. The lymph vessels from the me-

dial quadrants of the breast pierce the second, third, and

Mediastinoscopy and the Tracheo-

fourth intercostal spaces and enter the thorax to drain into

the lymph nodes alongside the internal thoracic artery. The

bronchial Lymph Nodes

lymph vessels from the lateral quadrants of the breast drain

into the anterior or pectoral group of axillary nodes. It fol-

Mediastinoscopy is a diagnostic procedure whereby speci-

lows, therefore, that a cancer occurring in the lateral quad-

mens of tracheobronchial lymph nodes are obtained with-

rants of the breast tends to spread to the axillary nodes.

out opening the pleural cavities. A small incision is made in

Thoracic metastases are difficult or impossible to treat, but

the midline in the neck just above the suprasternal notch,

the lymph nodes of the axilla can be removed surgically.

and the superior mediastinum is explored down to the re-

Approximately 60% of carcinomas of the breast occur in

gion of the bifurcation of the trachea. The procedure can be

the upper lateral quadrant. The lymphatic spread of cancer

used to determine the diagnosis and degree of spread of car-

to the opposite breast, to the abdominal cavity, or into

cinoma of the bronchus.

lymph nodes in the root of the neck is caused by obstruction

of the normal lymphatic pathways by malignant cells or de-

Lymphatics of the Lower Limb

struction of lymph vessels by surgery or radiotherapy. The

cancer cells are swept along the lymph vessels and follow

The superficial and deep inguinal lymph nodes not only

the lymph stream. The entrance of cancer cells into the

drain all the lymph from the lower limb, but also drain

blood vessels accounts for the metastases in distant bones.

lymph from the skin and superficial fascia of the anterior

In patients with localized cancer of the breast, most sur-

and posterior abdominal walls below the level of the um-

geons do a simple mastectomy or a lumpectomy, followed

bilicus; lymph from the external genitalia and the mucous

by radiotherapy to the axillary lymph nodes and/or hormone

membrane of the lower half of the anal canal also drains

therapy. In patients with localized cancer of the breast with

into these nodes. Remember the large distances the lymph

early metastases in the axillary lymph nodes, most authori-

has had to travel in some instances before it reaches the

ties agree that radical mastectomy offers the best chance of

inguinal nodes. For example, a patient may present with

cure. In patients in whom the disease has already spread be-

an enlarged, painful inguinal lymph node caused by lym-

yond these areas (e.g., into the thorax), simple mastectomy,

phatic spread of pathogenic organisms that entered the

followed by radiotherapy or hormone therapy, is the treat-

body through a small scratch on the undersurface of the

ment of choice.

big toe.

The Lymph Vessels and Lymph Tissue

139

the immunocompetent lymphocytes with drugs have been

THE THYMUS

moderately successful.

Tumors of the Thymus

Allograft Rejection

Thymomas are tumors of the thymus and are some of the

At about the time of birth, T lymphocytes leave the thymus

most common tumors found in the anterior mediastinum.

and populate the peripheral lymphatic tissue; it is these cells

Many of the tumors are associated with myasthenia gravis

that will bring about rejection of an allograft. Grafts between

and aplasia of blood cells. It is thought that these diseases are

identical twins or from an individual to himself or herself

autoimmune in origin and may develop as a result of the for-

will survive indefinitely, because there is no antigenic re-

mation of T lymphocytes that react to the individual’s own

sponse. Although the thymus in the adult continues to in-

tissues. Myasthenia gravis is a disease in which there is a

fluence the activities of the T lymphocytes, possibly by

possible reduction of acetylcholine receptors at the motor

means of thymosin, thymectomy has been unsuccessful in

end-plates of skeletal muscle. Thymomas may be benign or

preventing the rejection of allografts. Attempts to suppress

malignant.

Clinical Problem Solving Questions

Read the following case histories/questions and give

normal lymph flow. Describe the main factors respon-

the best answer for each.

sible for lymph flow.

Explain the mechanism of allograft rejection. What

A 23-year-old woman is treated in the emergency de-

form of immunity is lacking in a patient who has a con-

partment for an infected right index finger. Three days

genital absence of the thymus?

previously, she had got a rose thorn in her finger while

gardening. On examination, the finger is red, tender,

A 70-year-old man complaining of a small painless

and very swollen. After removing the thorn and apply-

swelling below his chin visited his physician. On ques-

ing a dressing, the physician prescribes a course of an-

tioning, he said that he had first noticed the swelling 4

tibiotics. He asks the nurse to put the patient’s right arm

months earlier and that it was gradually increasing in

in a sling, and warns the patient not to move the arm ex-

size. Because it had not caused any discomfort, he had

cessively. Explain why the patient’s arm has been

chosen to ignore it. On examination, a single, small,

placed in a sling.

hard swelling could be palpated in the submental tri-

angle. It was mobile on the deep tissues and not at-

A 54-year-old man visits his doctor complaining of a

tached to the skin.

skin infection of the auricle of the right ear. The patient

had scratched his ear 4 days previously and since then

The following statements suggest that the hard swelling

his ear has become greatly swollen, and his wife has

is a secondary malignant deposit in a lymph node ex-

noted that the right side of his neck is also swollen. The

cept which?

physician’s assistant made the diagnosis of impetigo and

A. The submental lymph nodes are located in the sub-

gave the patient an antibiotic to be taken orally. She ad-

mental triangle just below the chin.

vised the patient to place a warm compress over the ear

B. The submental lymph nodes drain the tip of the

twice daily to reduce the auricular swelling. Using your

tongue, the floor of the mouth in the region of the

knowledge of anatomy and physiology, explain the fol-

frenulum of the tongue, the gums and incisor teeth,

lowing: (a) Why is the ear swollen? (b) Why is the right

the middle third of the lower lip, and the skin over

side of the neck swollen? and (c) Why will the applica-

the chin.

tion of a warm compress to the ear reduce the swelling?

C. A small, hard-based carcinomatous ulcer was found

A 58-year-old woman following a right radical mastec-

on the right side of the tongue near the tip.

tomy (which involves the removal of the right breast

D. The deep cervical group of lymph nodes beneath

and the right axillary lymph nodes) has lymphatic

the sternocleidomastoid muscle receive lymph from

edema of the right arm because of obstruction of the

the submental lymph nodes.

140

Chapter 10

E. The submental lymph nodes lie deep to the superfi-

carcinoma of the left breast was made, with secondary

cial part of the submandibular salivary gland.

deposits in the axilla.

An 8-year-old boy was examined by a pediatrician and

The following statements concerning this patient are

found to have a painful swelling below and behind the

correct except which?

angle of the jaw on the left side. The skin over the

A. The contracting fibrous tissue of the malignant tu-

swelling was red and hot. Palpation of the neck revealed

mor had pulled on the lactiferous ducts of the nip-

a tender firm swelling beneath the anterior border of

ple, raising it above the level of the opposite nipple.

the sternocleidomastoid muscle on the left side. The

B. The dimpling of the skin was caused by the fibrous

right side of the neck was normal. Examination of the

tissue pulling on the suspensory ligaments of the

pharynx and palatine tonsils showed marked redness of

breast.

the mucous membrane and enlargement of both ton-

C. The upper lateral quadrant of the breast is drained

sils, especially the one on the left. The left tonsil also

into the pectoral or anterior axillary lymph nodes.

showed a yellow exudate draining from the tonsillar

D. The enlarged pectoral lymph nodes could be pal-

crypts.

pated against the surgical neck of the humerus.

E. The malignant tumor had spread by way of the

Using your knowledge of anatomy, name the group of

lymph vessels to the pectoral lymph nodes.

lymph nodes involved in the disease.

A 45-year-old man complaining of a lump in the groin

An 18-year-old woman complaining of severe pain and

was seen by his physician. The lump, which caused

redness around the base of the nail of the right thumb

him no pain or discomfort, was first recognized 3

visited her physician. She stated that she had trimmed

months previously. On examination, a large discrete

the cuticle (eponychium) of her nail with scissors, and

hard lump was found about 2 in. (5 cm) below and lat-

the following day the pain commenced. On examina-

eral to the pubic tubercle on the front of the right thigh.

tion, the skin folds around the root of the nail were red,

swollen, and extremely tender. The thumb was swollen,

The following signs indicated that this patient had a

and red streaks were seen coursing up the front of the

melanoma of the right big toe with secondaries in the

forearm.

inguinal lymph nodes except which?

A. Two smaller hard swellings were found immediately

The following symptoms and signs in this patient were

below the large swelling.

consistent with a diagnosis of an acute bacterial infec-

B. On flexing the right knee joint, three small hard

tion under the nail folds (paronychia) of the right

swellings could be palpated in the popliteal fossa.

thumb except which?

C. The external genitalia were found to be normal.

A. Some tender lymph nodes could be palpated in the

D. Examination of the anal canal revealed nothing ab-

infraclavicular fossa.

normal.

B. The patient’s temperature was raised.

E. A small pigmented mole was discovered beneath the

C. The infection had spread into the lymph vessels

nail of the right big toe.

draining the finger.

10.

A senior medical student taking a surgical examination

D. The red streaks on the front of the forearm were

was asked to look at a 55-year-old man. On examination

caused by the local vasodilatation of the blood ves-

of the abdomen, he found a hard, fixed mass in the mid-

sels along the course of the lymph vessels.

line, about 4 in. (10 cm) in diameter, lying on the transpy-

E. The lymph vessels from the thumb drain into the

loric plane. On questioning, the patient said that he had

supratrochlear node, which was inflamed and en-

recently lost 20 lb and had a poor appetite. The student

larged.

told the examiner that the patient was suffering from a car-

A 45-year-old woman having her yearly physical exami-

cinoma of the stomach and should have an immediate

nation was found to have a hard, painless lump in the

gastrectomy. The examiner then asked the student if he

upper lateral quadrant of the left breast. On examina-

had examined the patient’s scrotum, and the student ad-

tion with her arms at her sides, the left nipple was seen

mitted he had not. On examination, the scrotum was

to be higher than the right, and a small dimple of skin

found to contain a large, hard mass on the right side that

was noted over the lump. On examination of the left ax-

was not tethered to the skin. The inguinal lymph nodes

illa, three small, hard discrete nodules could be pal-

on the right side were normal. Explain the connection be-

pated below the lower border of the pectoralis major

tween the abdominal swelling and the scrotal swelling.

muscle. The right breast was normal. A diagnosis of

Why were the inguinal lymph nodes normal?

The Lymph Vessels and Lymph Tissue

141

Answers and Explanations

The immobilization of the patient’s arm in a sling re-

This patient had a streptococcal pharyngitis with in-

duces the muscular activity and, thus, the rate of lymph

volvement of the palatine tonsils, especially the one on

flow from the limb. This serves to limit the spread of

the left. The infection had spread on the left side to in-

toxins and bacteria from the site of infection.

volve the jugulodigastric member of the deep cervical

lymph nodes (see text Fig. 10-2). This node had en-

(a) The auricle of the ear is swollen by inflammatory

larged due to the inflammatory process and was re-

edema. Edema is an abnormal accumulation of tissue

sponsible for the tender swelling on the left side of the

fluid in the intercellular spaces. The fluid dynamics of

neck.

inflammatory edema includes the vasodilatation of the

arterioles and capillaries at the site of infection with an

E is the correct answer. The lymph vessels from the in-

outpouring of protein-rich plasma into the tissue spaces

dex finger drain into the deltopectoral nodes (see text

along with the outpouring of neutrophils. (b) The right

Fig. 10-1).

side of the neck is swollen because the bacteria have

D is the correct answer. The enlarged pectoral lymph

spread from the right auricle via the lymphatic vessels to

nodes can be palpated against the posterior surface of

the right superficial and deep cervical lymph nodes,

the contracted pectoralis major muscle (see text Fig. 10-

which are enlarged as a result of the proliferation of the

4).

contained lymphocytes. (c) In the early stages of

infection, heat causes arteriolar vasodilatation, which in

B is the correct answer. Melanomas, which are highly

turn raises blood flow through the infected skin,

malignant tumors, tend to initially spread via the lymph

hastening the arrival of neutrophils, antibodies, and an-

vessels to the local lymph nodes. These become en-

tibiotics to the site of infection. Once the infection is

larged and firm on palpation. The lymphatic drainage

controlled, the increased vascular and lymphatic flow

of the big toe is into the vertical group of superficial in-

will help reduce the local accumulation of tissue fluid

guinal lymph nodes (see text Fig. 10-7).

and cause the swelling of the ear to diminish.

10.

The student failed to examine the entire patient and

The factors responsible for lymph flow are summarized

made an erroneous diagnosis. He may have been

in the CD paragraph under Lymph Flow in Clinical

sidetracked in his thoughts by the patient stating that

Medicine.

he had a poor appetite. One thing is certain—the stu-

dent had forgotten his anatomy! (a) Malignant dis-

The mechanism of allograft rejection is summarized in

ease of the testis metastasizes to the lateral aortic

the CD paragraph under Allograft Rejection. In con-

nodes lying on the side of the body of the first lum-

genital absence of the thymus, the patient lacks T lym-

bar vertebra in the abdomen (on the transpyloric

phocytes and, therefore, cellular immunity.

plane). This is the normal lymph drainage of the

E is the correct answer. The submental lymph nodes

testis.

(b) The inguinal lymph nodes are only in-

are not covered by the superficial parts of the sub-

volved if the tumor spreads locally into the tissues of

mandibular salivary gland (see text Fig. 10-2).

the scrotum outside the testis.

Chapter Outline

Bones

147

Greater Tuberosity Fractures

152

Lesser Tuberosity Fractures

152

Bone Fractures

147

Surgical Neck Fractures

152

Rickets

147

Fractures of the Shaft of the Humerus

152

Fractures of the Distal End of the

Epiphyseal Plate Disorders

147

Humerus

152

Skull

147

Bones of the Forearm

152

Clinical Features of the Neonatal Skull

147

Fractures of the Radius and Ulna

152

Fontanelles

147

Olecranon Bursitis

154

Tympanic Membrane

147

Bones of the Hand

154

Forceps Delivery and the Facial Nerve

147

Injuries to the Bones of the Hand

154

Fractures of the Skull

147

Bones of the Lower Limb

154

Fractures of the Anterior Cranial Fossa

148

Bones of the Pelvic Girdle

154

Fractures of the Middle Cranial Fossa

148

Clinical Concept: The Pelvis is a Basin

Fractures of the Posterior Cranial Fossa

148

with Holes in its Walls

154

Bone Injuries of the Skull and Skeletal

Pelvic Measurements in Obstetrics

155

Development

148

Internal Pelvic Assessments

155

Anatomy of Common Facial Fractures

148

The Female Pelvis

155

Nasal Fractures

148

Fractures of the Pelvis

156

Maxillofacial Fractures

148

Fractures of the False Pelvis

156

Blowout Fractures of the Maxilla

148

Fractures of the True Pelvis

156

Fractures of the Zygoma or Zygomatic

Fractures of the Sacrum and Coccyx

158

Arch

149

Minor Fractures of the Pelvis

158

Mandible

149

Anatomy of Complications of Pelvic

Fractures of the Mandible

149

Fractures

158

Vertebral Column

149

Bones of the Thigh

158

Examination of the Back

149

Tenderness of the Head of the Femur and

Abnormal Curves of the Vertebral Column

150

Arthritis of the Hip Joint

158

Partial Fusion of the Sacral Vertebrae

150

Blood Supply to the Femoral Head and

Fracture of the Sacrum in Trauma of the Pelvis

150

Neck Fractures

159

Fractures of the Coccyx and Coccydynia

150

The Neck of the Femur and Coxa Valga

and Coxa Vara

159

Thoracic Bones

150

Fractures of the Femur

159

Clinical Importance of the Sternal Angle

Patellar Dislocations

161

(Angle of Louis)

150

Patellar Fractures

161

Sternum and Marrow Biopsy

150

Bones of the Leg

161

Cervical Rib

150

Fractures of the Tibia and Fibula

161

Rib Excision

151

Interosseous Infusion of the Tibia in the

Bones of the Upper Limb

151

Infant

161

Bones of the Shoulder Girdle

151

Bones of the Foot

161

Fractures of the Clavicle

151

Fractures of the Calcaneum

161

Compression of the Brachial Plexus,

Fractures of the Talus

161

Subclavian Artery, and Subclavian Vein

Fractures of the Metatarsal Bones

162

by the Clavicle

151

Fractures of the Scapula

151

Clinical Problem Solving Questions

162

Dropped Shoulder and Winged Scapula

151

Bones of the Arm

152

Answers and Explanations

165

Fractures of the Proximal End of the

Humerus

152

Humeral Head Fractures

152

Bones and Cartilage

147

Skull

BONES

Clinical Features of the Neonatal Skull

Bone

Fractures

Fontanelles

Immediately after a fracture, the patient suffers severe local

pain and is not able to use the injured part. Deformity may

Palpation of the fontanelles enables the physician to deter-

be visible if the bone fragments have been displaced relative

mine the progress of growth in the surrounding bones, the

to each other. The degree of deformity and the directions

degree of hydration of the baby (e.g., if the fontanelles are

taken by the bony fragments depend not only on the mech-

depressed below the surface, the baby is dehydrated), and

anism of injury but also on the pull of the muscles attached

the state of the intracranial pressure (a bulging fontanelle

to the fragments. Ligamentous attachments also influence

indicates raised intracranial pressure).

the deformity. In certain situations—for example, the

Samples of cerebrospinal fluid can be obtained by pass-

ileum—fractures result in no deformity because the inner

ing a long needle obliquely through the anterior fontanelle

and outer surfaces of the bone are splinted by the extensive

into the subarachnoid space or even into the lateral ventricle.

origins of muscles. In contrast, a fracture of the neck of the

Clinically, it is usually not possible to palpate the ante-

femur produces considerable displacement. The strong

rior fontanelle after 18 months, because the frontal and

muscles of the thigh pull the distal fragment upward so that

parietal bones have enlarged to close the gap.

the leg is shortened. The very strong lateral rotators rotate

Tympanic Membrane

the distal fragment laterally so that the foot points laterally.

Fracture of a bone is accompanied by a considerable

At birth, the tympanic membrane faces more downward and

hemorrhage of blood between the bone ends and into the

less laterally than in maturity; when examined with the oto-

surrounding soft tissue. The blood vessels and the fibroblasts

scope, it therefore lies more obliquely in the infant than in

and osteoblasts from the periosteum and endosteum take

the adult.

part in the repair process.

Forceps Delivery and the Facial Nerve

Rickets

In the newborn infant, the mastoid process is not developed,

and the facial nerve, as it emerges from the stylomastoid

Rickets is a defective mineralization of the cartilage matrix

foramen, is close to the surface. Thus, it can be damaged by

in growing bones. This produces a condition in which the

forceps in a difficult delivery.

cartilage cells continue to grow, resulting in excess cartilage

and a widening of the epiphyseal plates. The poorly miner-

Fractures of the Skull

alized cartilaginous matrix and the osteoid matrix are soft,

and they bend under the stress of bearing weight. The re-

Fractures of the skull are common in the adult but much

sulting deformities include enlarged costochondral junc-

less so in the young child. In the infant skull, the bones are

tions, bowing of the long bones of the lower limbs, and boss-

more resilient than in the adult skull, and they are separated

ing of the frontal bones of the skull. Deformities of the pelvis

by fibrous sutural ligaments. In the adult, the inner table of

may also occur.

the skull is particularly brittle. Moreover, the sutural liga-

ments begin to ossify during middle age.

The type of fracture that occurs in the skull depends on

Epiphyseal Plate Disorders

the age of the patient, the severity of the blow, and the area

Epiphyseal plate disorders affect only children and adoles-

of skull receiving the trauma. The adult skull may be

cents. The epiphyseal plate is the part of a growing bone

likened to an eggshell in that it possesses a certain limited re-

concerned primarily with growth in length. Trauma, infec-

silience beyond which it splinters. A severe, localized blow

tion, diet, exercise, and endocrine disorders can disturb the

produces a local indentation, often accompanied by splin-

growth of the hyaline cartilaginous plate, leading to defor-

tering of the bone. Blows to the vault often result in a series

mity and loss of function. In the femur, for example, the

of linear fractures, which radiate out through the thin areas

proximal epiphysis can slip because of mechanical stress or

of bone. The petrous parts of the temporal bones and the oc-

excessive loads. The length of the limbs can increase exces-

cipital crests strongly reinforce the base of the skull and tend

sively because of increased vascularity in the region of the

to deflect linear fractures.

epiphyseal plate secondary to infection or in the presence of

In the young child, the skull may be likened to a table-

tumors. Shortening of a limb can follow trauma to the epi-

tennis ball in that a localized blow produces a depression

physeal plate resulting from a diminished blood supply to

without splintering. This common type of circumscribed

the cartilage.

lesion is referred to as a “pond” fracture.

148

Chapter 11

skull is developed from membrane (whereas the remainder

Fractures of the Anterior Cranial Fossa

is developed from cartilage); therefore, this part of the skull

In fractures of the anterior cranial fossa, the cribriform plate

in children is relatively flexible and can absorb considerable

of the ethmoid bone may be damaged. This usually results in

force without resulting in a fracture.

tearing of the overlying meninges and underlying mucope-

Signs of fractures of the facial bones include deformity,

riosteum. The patient will have bleeding from the nose

ocular displacement, or abnormal movement accompanied

(epistaxis) and leakage of cerebrospinal fluid into the nose

by crepitation and malocclusion of the teeth. Anesthesia or

(cerebrospinal rhinorrhea). Fractures involving the orbital

paresthesia of the facial skin will follow fracture of bones

plate of the frontal bone result in hemorrhage beneath the

through which branches of the trigeminal nerve pass to

conjunctiva and into the orbital cavity, causing exophthal-

the skin.

mos. The frontal air sinus may be involved, with hemorrhage

The muscles of the face are thin and weak and cause lit-

into the nose.

tle displacement of the bone fragments. Once a fracture of

the maxilla has been reduced, for example, prolonged fixa-

Fractures of the Middle Cranial Fossa

tion is not needed. However, in the case of the mandible,

Fractures of the middle cranial fossa are common, because

the strong muscles of mastication can create considerable

this is the weakest part of the base of the skull. Anatomi-

displacement, requiring long periods of fixation.

cally, this weakness is caused by the presence of numerous

The most common facial fractures involve the nasal

foramina and canals in this region; the cavities of the mid-

bones, followed by the zygomatic bone and then the

dle ear and the sphenoidal air sinuses are particularly vul-

mandible. To fracture the maxillary bones and the supra-

nerable. The leakage of cerebrospinal fluid and blood from

orbital ridges of the frontal bones, an enormous force is

the external auditory meatus is common. The seventh and

required.

eighth cranial nerves may be involved as they pass through

Nasal Fractures

the petrous part of the temporal bone. The third, fourth,

and sixth cranial nerves may be damaged if the lateral wall

Fractures of the nasal bones, because of the prominence of

of the cavernous sinus is torn. Blood and cerebrospinal

the nose, are the most common facial fractures. Because the

fluid may leak into the sphenoidal air sinuses and then into

bones are lined with mucoperiosteum, the fracture is con-

the nose.

sidered open; the overlying skin may also be lacerated. Al-

though most are simple fractures and are reduced under

Fractures of the Posterior Cranial Fossa

local anesthesia, some are associated with severe injuries

In fractures of the posterior cranial fossa, blood may escape

to the nasal septum and require careful treatment under

into the nape of the neck deep to the postvertebral muscles.

general anesthesia.

Some days later, it tracks between the muscles and appears

Maxillofacial Fractures

in the posterior triangle, close to the mastoid process. The

mucous membrane of the roof of the nasopharynx may be

Maxillofacial fractures usually occur as the result of

torn, and blood may escape there. In fractures involving the

massive facial trauma. There is extensive facial swelling,

jugular foramen, the ninth, tenth, and eleventh cranial

midface mobility of the underlying bone on palpation,

nerves may be damaged. The strong bony walls of the hy-

malocclusion of the teeth with anterior open bite, and pos-

poglossal canal usually protect the hypoglossal nerve from

sibly leakage of cerebrospinal fluid (cerebrospinal rhinor-

injury.

rhea) secondary to fracture of the cribriform plate of the

ethmoid bone. Double vision (diplopia) may be present,

Bone Injuries of the Skull and Skeletal

owing to orbital wall damage. Involvement of the infraor-

Development

bital nerve with anesthesia or paresthesia of the skin of the

The developing bones of a child’s face are more pliable than

cheek and upper gum may occur in fractures of the body

an adult’s, and fractures may be incomplete or greenstick. In

of the maxilla. Nose bleeding may also occur in maxillary

adults, the presence of well-developed, air-filled sinuses and

fractures. Blood enters the maxillary air sinus and then

the mucoperiosteal surfaces of the alveolar parts of the up-

leaks into the nasal cavity.

per and lower jaws means that most facial fractures should

The sites of the fractures were classified by Le Fort

be considered to be open fractures, susceptible to infection

as type I, II, or III; these fractures are summarized in

and requiring antibiotic therapy.

CD Fig. 11-1.

Anatomy of Common Facial Fractures

Blowout Fractures of the Maxilla

Automobile accidents, fisticuffs, and falls are common

A severe blow to the orbit (as from a baseball) may cause the

causes of facial fractures. Fortunately, the upper part of the

contents of the orbital cavity to explode downward through

Bones and Cartilage

149

CD Figure 11-1

Le Fort classification of maxillofacial fractures. The red line denotes the

fracture line.

the floor of the orbit into the maxillary sinus. Damage to the

the ring, causing a single fracture or multiple fractures of

infraorbital nerve, resulting in altered sensation to the skin

the mandible, often far removed from the point of impact.

of the cheek, upper lip, and gum, may occur.

Fractures of the Zygoma

Vertebral Column

or Zygomatic Arch

Examination of the Back

The zygoma or zygomatic arch can be fractured by a blow

to the side of the face. Although it can occur as an isolated

It is important that the whole area of the back and legs be

fracture, as from a blow from a clenched fist, it may be asso-

examined and that the shoes be removed. Unequal length of

ciated with multiple other fractures of the face, as often seen

the legs or disease of the hip joints can lead to abnormal cur-

in automobile accidents.

vatures of the vertebral column. The patient should be

asked to walk up and down the examination room so that the

normal tilting movement of the pelvis can be observed. As

Mandible

one side of the pelvis is raised, a coronal lumbar convexity

develops on the opposite side, with a compensatory thoracic

Fractures of the Mandible

convexity on the same side. When a person assumes the

The mandible is horseshoe shaped and forms part of a

sitting position, it will be noted that the normal lumbar cur-

bony ring with the two temporomandibular joints and the

vature becomes flattened, with an increase in the interval

base of the skull. Traumatic impact is transmitted around

between the lumbar spines.

150

Chapter 11

Partial Fusion of the Sacral Vertebrae

The normal range of movement of the different parts of

the vertebral column should be tested. In the cervical re-

The first sacral vertebra can be partly or completely sepa-

gion, flexion, extension, lateral rotation, and lateral flexion

rated from the second sacral vertebra. Occasionally, on ra-

are possible. Remember that about half of the movement re-

diographs of the vertebral column, examples are seen in

ferred to as flexion is carried out at the atlantooccipital

which the fifth lumbar vertebra has fused with the first sacral

joints. In flexion, the patient should be able to touch his or

vertebra.

her chest with the chin, and in extension he or she should

be able to look directly upward. In lateral rotation the pa-

tient should be able to place the chin nearly in line with the

Fracture of the Sacrum in Trauma of

shoulder. Half of lateral rotation occurs between the atlas

the Pelvis

and the axis. In lateral flexion the head can normally be

Trauma to the true pelvis can result in fracture of the lateral

tilted 45° to each shoulder. It is important that the shoulder

mass of the sacrum.

is not raised when this movement is being tested.

In the thoracic region the movements are limited by the

Fractures of the Coccyx

presence of the ribs and sternum. When testing for rotation,

and Coccydynia

make sure that the patient does not rotate the pelvis.

In the lumbar region, flexion, extension, lateral rota-

Fractures of the coccyx are rare. However, coccydynia is

tion, and lateral flexion are possible. Flexion and extension

common and is usually caused by direct trauma to the

are fairly free. Lateral rotation, however, is limited by the

coccyx, as in falling down a flight of concrete steps. The

interlocking of the articular processes. Lateral flexion in

anterior surface of the coccyx can be palpated with a rectal

the thoracic and lumbar regions is tested by asking the pa-

examination.

tient to slide, in turn, each hand down the lateral side of

the thigh.

Thoracic Bones

Abnormal Curves of the

Clinical Importance of the Sternal

Vertebral Column

Angle (Angle of Louis)

Kyphosis is an exaggeration in the sagittal curvature present

When one is examining the chest from the front, the sternal

in the thoracic part of the vertebral column. It can be caused

angle (angle of Louis) is an important landmark. Its posi-

by muscular weakness or by structural changes in the verte-

tion can easily be felt and can often be seen by the presence

bral bodies or by intervertebral discs. In sickly adolescents,

of a transverse ridge. The finger moved to the right or to the

for example, where the muscle tone is poor, long hours of

left passes directly onto the second costal cartilage and then

study or work over a low desk can lead to a gently curved

the second rib. All other ribs can be counted from this point.

kyphosis of the upper thoracic region. The person is said to

The twelfth rib can usually be felt from behind, but in some

be “round-shouldered.” Crush fractures or tuberculous de-

obese persons this may prove difficult.

struction of the vertebral bodies leads to acute angular

kyphosis of the vertebral column. In the aged, osteoporosis

Sternum and Marrow Biopsy

(abnormal rarefaction of bone) and/or degeneration of the

intervertebral discs leads to senile kyphosis, involving the

Since the sternum possesses red hematopoietic marrow

cervical, thoracic, and lumbar regions of the column.

throughout life, it is a common site for marrow biopsy.

Lordosis is an exaggeration in the sagittal curvature pre-

Under a local anesthetic, a wide-bore needle is introduced

sent in the lumbar region. Lordosis may be caused by an

into the marrow cavity through the anterior surface of the

increase in the weight of the abdominal contents, as with

bone. The sternum may also be split at operation to allow

the gravid uterus or a large ovarian tumor, or it may be

the surgeon to gain easy access to the heart, great vessels,

caused by disease of the vertebral column such as spondy-

and thymus.

lolisthesis. The possibility that it is a postural compensation

for a kyphosis in the thoracic region or a disease of the hip

Cervical Rib

joint (congenital dislocation) must not be overlooked.

Scoliosis is a lateral deviation of the vertebral column.

A cervical rib (i.e., a rib arising from the anterior tubercle of

This is most commonly found in the thoracic region and

the transverse process of the seventh cervical vertebra) occurs

may be caused by muscular or vertebral defects. Paralysis of

in about 0.5% of humans (CD Fig. 11-2). It may have a free

muscles caused by poliomyelitis can cause severe scoliosis.

anterior end, may be connected to the first rib by a fibrous

The presence of a congenital hemivertebra can cause scol-

band, or may articulate with the first rib. The importance of

iosis. Often scoliosis is compensatory and may be caused by

a cervical rib is that it can cause pressure on the lower trunk

a short leg or hip disease.

of the brachial plexus in some patients, producing pain down

Bones and Cartilage

151

scalenus medius

brachial plexus

CD Figure 11-2

Thoracic outlet as

cervical rib

seen from above. Note the

presence of the cervical ribs (black)

on both sides. On the right side of

scalenus anterior

lower trunk of plexus

the thorax, the rib is almost

complete and articulates anteriorly

with the first rib. On the left side of

the thorax, the rib is rudimentary

but is continued forward as a

subclavian artery

fibrous band that is attached to the

first costal cartilage. Note that the

cervical rib

cervical rib may exert pressure on

fibrous band

the lower trunk of the brachial

plexus and may kink the subclavian

artery.

the medial side of the forearm and hand and wasting of the

pectoralis major. The medial end is tilted upward by the

small muscles of the hand. It can also exert pressure on the

sternocleidomastoid muscle.

overlying subclavian artery and interfere with the circulation

The close relationship of the supraclavicular nerves

of the upper limb.

to the clavicle may result in their involvement in callus for-

mation after fracture of the bone. This may be the cause of

Rib Excision

persistent pain over the side of the neck.

Rib excision is commonly performed by thoracic surgeons

Compression of the Brachial Plexus,

wishing to gain entrance to the thoracic cavity. A longitudi-

Subclavian Artery, and Subclavian Vein

nal incision is made through the periosteum on the outer

by the Clavicle

surface of the rib and a segment of the rib is removed. A sec-

ond longitudinal incision is then made through the bed of

The interval between the clavicle and the first rib in some

the rib, which is the inner covering of periosteum. After the

patients may become narrowed and thus is responsible for

operation, the rib regenerates from the osteogenetic layer of

compression of nerves and blood vessels.

the periosteum.

Fractures of the Scapula

Bones of the Upper Limb

Fractures of the scapula are usually the result of severe

trauma, such as occurs in run-over accident victims or in

Bones of the Shoulder Girdle

occupants of automobiles involved in crashes. Injuries

are usually associated with fractured ribs. Most fractures

Fractures of the Clavicle

of the scapula require little treatment because the muscles

on the anterior and posterior surfaces adequately splint the

The clavicle is a strut that holds the arm laterally so that it

fragments.

can move freely on the trunk. Unfortunately, because of its

position, it is exposed to trauma and transmits forces from

Dropped Shoulder and Winged Scapula

the upper limb to the trunk. It is the most commonly frac-

tured bone in the body. The fracture usually occurs as a re-

The position of the scapula on the posterior wall of the tho-

sult of a fall on the shoulder or outstretched hand. The force

rax is maintained by the tone and balance of the muscles at-

is transmitted along the clavicle, which breaks at its weakest

tached to it. If one of these muscles is paralyzed, the balance

point, the junction of the middle and outer thirds. After the

is upset, as in dropped shoulder, which occurs with paraly-

fracture, the lateral fragment is depressed by the weight

sis of the trapezius, or winged scapula (CD Fig. 11-3),

of the arm, and it is pulled medially and forward by the

caused by paralysis of the serratus anterior. Such imbalance

strong adductor muscles of the shoulder joint, especially the

can be detected by careful physical examination.

152

Chapter 11

Fractures of the Shaft of the Humerus

Fractures of the humeral shaft are common; displacement

of the fragments depends on the relation of the site of the

fracture to the insertion of the deltoid muscle (see CD Fig.

11-4). When the fracture line is proximal to the deltoid in-

sertion, the proximal fragment is adducted by the pectoralis

major, latissimus dorsi, and teres major muscles; the distal

fragment is pulled proximally by the deltoid, biceps, and tri-

ceps. When the fracture is distal to the deltoid insertion, the

proximal fragment is abducted by the deltoid, and the distal

fragment is pulled proximally by the biceps and triceps. The

radial nerve can be damaged where it lies in the spiral

groove on the posterior surface of the humerus under cover

of the triceps muscle.

CD Figure 11-3

Winging of the right scapula.

Fractures of the Distal End

of the Humerus

Bones of the Arm

Supracondylar fractures (see CD Fig. 11-4) are common in

children and occur when the child falls on the outstretched

Fractures of the Proximal End

hand with the elbow partially flexed. Injuries to the medial,

of the Humerus

radial, and ulnar nerves are not uncommon, although func-

tion usually quickly returns after reduction of the fracture.

Humeral Head Fractures

Damage to or pressure on the brachial artery can occur at

Fractures of the humeral head (CD Fig. 11-4) can occur

the time of the fracture or from swelling of the surrounding

during the process of anterior and posterior dislocations of

tissues; the circulation to the forearm may be interfered

the shoulder joint. The fibrocartilaginous glenoid labrum

with, leading to Volkmann’s ischemic contracture.

of the scapula produces the fracture, and the labrum can

The medial epicondyle (see CD Fig. 11-4) can be

become jammed in the defect, making reduction of the

avulsed by the medial collateral ligament of the elbow joint

shoulder joint difficult.

if the forearm is forcibly abducted. The ulnar nerve can be

injured at the time of the fracture, can become involved

Greater Tuberosity Fractures

later in the repair process of the fracture (in the callus), or

The greater tuberosity of the humerus can be fractured by di-

can undergo irritation on the irregular bony surface after the

rect trauma, displaced by the glenoid labrum during disloca-

bone fragments are reunited.

tion of the shoulder joint, or avulsed by violent contractions

of the supraspinatus muscle. The bone fragment will have the

Bones of the Forearm

attachments of the supraspinatus, teres minor, and infra-

spinatus muscles, whose tendons form part of the rotator cuff.

Fractures of the Radius and Ulna

When associated with a shoulder dislocation, severe tearing of

the cuff with the fracture can result in the greater tuberosity

Fractures of the head of the radius can occur from falls on

remaining displaced posteriorly after the shoulder joint has

the outstretched hand. As the force is transmitted along the

been reduced. In this situation, open reduction of the fracture

radius, the head of the radius is driven sharply against the ca-

is necessary to attach the rotator cuff back into place.

pitulum, splitting or splintering the head (see CD Fig. 11-4).

Fractures of the neck of the radius occur in young chil-

Lesser Tuberosity Fractures

dren from falls on the outstretched hand (see CD Fig. 11-4).

Occasionally, a lesser tuberosity fracture accompanies pos-

Fractures of the shafts of the radius and ulna may or

terior dislocation of the shoulder joint. The bone fragment

may not occur together (see CD Fig. 11-4). Displacement of

receives the insertion of the subscapularis tendon (see CD

the fragments is usually considerable and depends on the

Fig. 11-4), a part of the rotator cuff.

pull of the attached muscles. The proximal fragment of the

radius is supinated by the supinator and the biceps brachii

Surgical Neck Fractures

muscles (see CD Fig. 11-4). The distal fragment of the

The surgical neck of the humerus (see CD Fig. 11-4),

radius is pronated and pulled medially by the pronator

which lies immediately distal to the lesser tuberosity, can be

quadratus muscle. The strength of the brachioradialis and

fractured by a direct blow on the lateral aspect of the shoulder

extensor carpi radialis longus and brevis shortens and angu-

or in an indirect manner by falling on the outstretched hand.

lates the forearm. In fractures of the ulna, the ulna angulates

Bones and Cartilage

153

anatomical neck

head

greater tuberosity

SUB

surgical neck

deltoid tuberosity

shaft of humerus

olecranon process

trochlear notch

head

coronoid process

coronoid

radial fossa

fossa

bicipital tuberosity

lateral epicondyle

medial

epicondyle

capitulum

trochlea

shaft of ulna

shaft

of radius

CD Figure 11-4

A. Common

fractures of the humerus.

B. Common fractures of the

radius and ulna. The

displacement of the bony

fragments on the site of the

head

fracture line and the pull of the

muscles. CF pull of common

flexure muscles, D deltoid,

styloid process

PM pectoralis major,

S supraspinatus, SUB

subscapularis, and TR triceps.

posteriorly. To restore the normal movements of pronation

and an anterior dislocation of the radial head with rupture

and supination, the normal anatomic relationship of the ra-

of the anular ligament. In Galeazzi’s fracture, the proximal

dius, ulna, and interosseous membrane must be regained.

third of the radius is fractured and the distal end of the ulna

A fracture of one forearm bone may be associated with

is dislocated at the distal radioulnar joint.

a dislocation of the other bone. In Monteggia’s fracture, for

Fractures of the olecranon process can result from a

example, the shaft of the ulna is fractured by a force applied

fall on the flexed elbow or from a direct blow. Depending on

from behind. There is a bowing forward of the ulnar shaft

the location of the fracture line, the bony fragment may be

154

Chapter 11

displaced by the pull of the triceps muscle, which is inserted

The blood vessels to the scaphoid enter its proximal and

on the olecranon process (see CD Fig. 11-4). Avulsion frac-

distal ends, although the blood supply is occasionally con-

tures of part of the olecranon process can be produced by

fined to its distal end. If the latter occurs, a fracture de-

the pull of the triceps muscle. Good functional return after

prives the proximal fragment of its arterial supply, and this

any of these fractures depends on the accurate anatomic re-

fragment undergoes avascular necrosis. Deep tenderness

duction of the fragment.

in the anatomic snuffbox after a fall on the outstretched

Colles’ fracture is a fracture of the distal end of the

hand in a young adult makes one suspicious of a fractured

radius resulting from a fall on the outstretched hand. It com-

scaphoid.

monly occurs in patients older than 50 years. The force dri-

Dislocation of the lunate bone occasionally occurs in

ves the distal fragment posteriorly and superiorly, and the

young adults who fall on the outstretched hand in a way that

distal articular surface is inclined posteriorly (CD Fig. 11-5).

causes hyperextension of the wrist joint. Involvement of the

This posterior displacement produces a posterior bump,

median nerve is common.

sometimes referred to as the “dinner-fork deformity” be-

Fractures of the metacarpal bones can occur as a re-

cause the forearm and wrist resemble the shape of that eat-

sult of direct violence, such as the clenched fist striking a

ing utensil. Failure to restore the distal articular surface to its

hard object. The fracture always angulates dorsally. The

normal position will severely limit the range of flexion of the

“boxer’s fracture” commonly produces an oblique fracture

wrist joint.

of the neck of the fifth and sometimes the fourth metacarpal

Smith’s fracture is a fracture of the distal end of the

bones. The distal fragment is commonly displaced proxi-

radius and occurs from a fall on the back of the hand. It is

mally, thus shortening the finger posteriorly.

a reversed Colles’ fracture because the distal fragment is

Bennett’s fracture is a fracture of the base of the

displaced anteriorly (see CD Fig. 11-5).

metacarpal of the thumb caused when violence is applied

along the long axis of the thumb or the thumb is forcefully

Olecranon Bursitis

abducted. The fracture is oblique and enters the car-

pometacarpal joint of the thumb, causing joint instability.

A small subcutaneous bursa is present over the olecranon

Fractures of the phalanges are common and usually

process of the ulna, and repeated trauma often produces

follow direct injury.

chronic bursitis.

Bones of the Hand

Bones of the Lower Limb

Injuries to the Bones of the Hand

Bones of the Pelvic Girdle

Fracture of the scaphoid bone is common in young adults;

Clinical Concept: The Pelvis Is a

unless treated effectively, the fragments will not unite, and

Basin with Holes in Its Walls

permanent weakness and pain of the wrist will result, with

the subsequent development of osteoarthritis. The fracture

The walls of the pelvis are formed by bones and ligaments;

line usually goes through the narrowest part of the bone,

these are partly lined with muscles (obturator internus and

which because of its location is bathed in synovial fluid.

piriformis) covered with fascia and parietal peritoneum. On

CD Figure 11-5

Fractures of the distal end of the radius.

A. Colles’ fracture. B. Smith’s fracture.

Bones and Cartilage

155

the outside of the pelvis are the attachments of the gluteal

the baby’s head as it descends through the pelvis during

muscles and the obturator externus muscle. The greater part

childbirth (CD Figs. 11-6 and 11-7A).

of the bony pelvis is thus sandwiched between inner and

outer muscles.

Internal Pelvic Assessments

The basin has anterior, posterior, and lateral walls and

Internal pelvic assessments are made by vaginal examination

an inferior wall or floor formed by the important levator ani

during the later weeks of pregnancy, when the pelvic tis-

and coccygeus muscles and their covering fascia.

sues are softer and more yielding than in the newly pregnant

The basin has many holes: The posterior wall has holes

condition.

on the anterior surface of the sacrum, the anterior sacral

■ Pubic arch: Spread the fingers under the pubic arch and

foramina, for the passage of the anterior rami of the sacral

examine its shape. Is it broad or angular? The examiner’s

spinal nerves. The sacrotuberous and sacrospinous liga-

four fingers should be able to rest comfortably in the

ments convert the greater and lesser sciatic notches into the

angle below the symphysis.

greater and lesser sciatic foramina. The greater sciatic fora-

■ Lateral walls: Palpate the lateral walls and determine

men provides an exit from the true pelvis into the gluteal re-

whether they are concave, straight, or converging. The

gion for the sciatic nerve, the pudendal nerve, and the gluteal

prominence of the ischial spines and the position of the

nerves and vessels; the lesser sciatic foramen provides an en-

sacrospinous ligaments are noted.

trance into the perineum from the gluteal region for the pu-

■ Posterior wall: The sacrum is palpated to determine

dendal nerve and the internal pudendal vessels. (One can

whether it is straight or well curved. Finally, if the patient

make a further analogy here: For the wires to gain entrance

has relaxed the perineum sufficiently, an attempt is made

to the apartment below, without going through the floor,

to palpate the promontory of the sacrum. The second

they have to pierce the wall [greater sciatic foramen] to get

finger of the examining hand is placed on the promon-

outside the building and then return through a second hole

tory, and the index finger of the free hand, outside the

[lesser sciatic foramen]. In the case of the human body, the

vagina, is placed at the point on the examining hand

pudendal nerve and internal pudendal vessels are the wires

where it makes contact with the lower border of the sym-

and the levator ani and the coccygeus muscles are the floor.)

physis. The fingers are then withdrawn and the distance

The lateral pelvic wall has a large hole, the obturator

measured (CD Fig. 11-7B), providing the measurement

foramen, which is closed by the obturator membrane, ex-

of the diagonal conjugate, which is normally about 5 in.

cept for a small opening that permits the obturator nerve to

(13 cm). The anteroposterior diameter from the sacro-

leave the pelvis and enter the thigh.

coccygeal joint to the lower border of the symphysis is

then estimated.

Pelvic Measurements in Obstetrics

■ Ischial tuberosities: The distance between the ischial

The capacity and shape of the female pelvis are of funda-

tuberosities may be estimated by using the closed fist

mental importance in obstetrics. The female pelvis is well

(CD Fig. 11-7D). It measures about 4 in. (10 cm), but it

adapted for the process of childbirth. The pelvis is shallower

is difficult to measure exactly.

and the bones are smoother than in the male. The size of the

Needless to say, considerable clinical experience is re-

pelvic inlet is similar in the two sexes, but in the female, the

quired to be able to assess the shape and size of the pelvis by

cavity is larger and cylindrical and the pelvic outlet is wider

vaginal examination.

in both the anteroposterior and the transverse diameters.

Four terms relating to areas of the pelvis are commonly

used in clinical practice:

The Female Pelvis

■ The pelvic inlet or brim of the true pelvis (CD Fig. 11-

Deformities of the pelvis may be responsible for dystocia

6) is bounded anteriorly by the symphysis pubis, laterally

(difficult labor). A contracted pelvis may obstruct the nor-

by the iliopectineal lines, and posteriorly by the sacral

mal passage of the fetus. It may be indirectly responsible for

promontory.

dystocia by causing conditions such as malpresentation or

■ The pelvic outlet of the true pelvis (see CD Fig. 11-6) is

malposition of the fetus, premature rupture of the fetal

bounded in front by the pubic arch, laterally by the is-

membranes, and uterine inertia.

chial tuberosities, and posteriorly by the coccyx. The

The cause of pelvic deformities may be congenital

sacrotuberous ligaments also form part of the margin of

(rare) or acquired from disease, poor posture, or fractures

the outlet.

caused by injury. Pelvic deformities are more common in

■ The pelvic cavity is the space between the inlet and the

women who have grown up in a poor environment and are

outlet (see CD Fig. 11-6).

undernourished. It is probable that these women suffered in

■ The axis of the pelvis is an imaginary line joining

their youth from minor degrees of rickets.

the central points of the anteroposterior diameters from

In 1933, Caldwell and Moloy classified pelves into four

the inlet to the outlet and is the curved course taken by

groups: gynecoid, android, anthropoid, and platypelloid

156

Chapter 11

promontory

pelvic inlet

pelvic outlet

diagonal conjugate

axis of pelvis

Female

Male

pelvic inlet

pelvic outlet

pelvic cavity

CD Figure 11-6

Pelvic inlet, pelvic outlet, diagonal

conjugate, and axis of the pelvis. Some of the main

pubic arch

differences between the female and the male pelvis are

also shown.

(CD. Fig. 11-7C).The gynecoid type, present in about 41%

Fractures of the Pelvis

of women, is the typical female pelvis, which was previously

described.

Fractures of the False Pelvis

The android type, present in about 33% of white fe-

Fractures of the false pelvis caused by direct trauma occa-

males and 16% of black females, is the male or funnel-

sionally occur. The upper part of the ilium is seldom dis-

shaped pelvis with a contracted outlet.

placed because of the attachment of the iliacus muscle on

The anthropoid type, present in about 24% of white fe-

the inside and the gluteal muscles on the outside.

males and 41% of black females, is long, narrow, and oval

shaped.

Fractures of the True Pelvis

The platypelloid type, present in only about 2% of

The mechanism of fractures of the true pelvis can be better

women, is a wide pelvis flattened at the brim, with the

understood if the pelvis is regarded not only as a basin but

promontory of the sacrum pushed forward.

also as a rigid ring (see CD Fig. 11-8). The ring is made up

158

Chapter 11

anterior superior

iliac spine

CD Figure 11-8

A-C. Different types of

fractures of the pelvic basin. D. Avulsion

fractures of the pelvis. The sartorius

muscle is responsible for the avulsion of

anterior inferior

the anterior superior iliac spine; the

iliac spine

straight head of the rectus femoris muscle,

for the avulsion of the anterior inferior iliac

spine; and the hamstring muscles, for the

ischial tuberosity

avulsion of the ischial tuberosity.

of bone on either side of the joint is more common than dis-

fascial beneath the parietal peritoneum can be the source of

ruption of the joint.

a massive hemorrhage, which may be life threatening.

The forces responsible for the disruption of the bony

The male urethra is often damaged, especially in vertical

ring may be anteroposterior compression, lateral compres-

shear fractures that may disrupt the urogenital diaphragm.

sion, or shearing.

The bladder, which lies immediately behind the pubis in

A heavy fall on the greater trochanter of the femur

both sexes, is occasionally damaged by spicules of bone; a full

may drive the head of the femur through the floor of the

bladder is more likely to be injured than is an empty bladder.

acetabulum into the pelvic cavity.

The rectum lies within the concavity of the sacrum and

is protected and rarely damaged. Fractures of the sacrum or

Fractures of the Sacrum and Coccyx

ischial spine may be thrust into the pelvic cavity, tearing the

Fractures of the lateral mass of the sacrum may occur as part

rectum.

of a pelvic fracture. Fractures of the coccyx are rare.

Nerve injuries can follow sacral fractures; the laying

down of fibrous tissue around the anterior or posterior nerve

Minor Fractures of the Pelvis

roots or the branches of the sacral spinal nerves can result in

The anterior superior iliac spine may be pulled off by the

persistent pain.

forcible contraction of the sartorius muscle in athletes (see

Damage to the sciatic nerve may occur in fractures

CD Fig. 11-8). In a similar manner the anterior inferior il-

involving the boundaries of the greater sciatic notch. The

iac spine may be avulsed by the contraction of the rectus

peroneal part of the sciatic nerve is most often involved, re-

femoris muscle (origin of the straight head). The ischial

sulting in the inability of a conscious patient to dorsiflex the

tuberosity can be avulsed by the contraction of the ham-

ankle joint or failure of an unconscious patient to reflexly

string muscles. Healing may occur by fibrous union, possi-

plantar-flex (ankle jerk) the foot.

bly resulting in elongation of the muscle unit and some

reduction in muscular efficiency.

Bones of the Thigh

Anatomy of Complications of Pelvic Fractures

Tenderness of the Head of the Femur

Fractures of the true pelvis are commonly associated with

and Arthritis of the Hip Joint

injuries to the soft pelvic tissues.

If damaged, the thin pelvic veins—namely, the internal

The head of the femur—that is, that part that is not intraac-

iliac veins and their tributaries—that lie in the parietal pelvic

etabular—can be palpated on the anterior aspect of the thigh

Bones and Cartilage

159

just inferior to the inguinal ligament and just lateral to the

the leg is shortened (as measured from the anterior superior

pulsating femoral artery. Tenderness over the head of the fe-

iliac spine to the adductor tubercle or medial malleolus).

mur usually indicates the presence of arthritis of the hip joint.

The gluteus maximus, the piriformis, the obturator inter-

nus, the gemelli, and the quadratus femoris rotate the distal

Blood Supply to the Femoral Head

fragment laterally, as seen by the toes pointing laterally.

and Neck Fractures

Trochanteric fractures commonly occur in the young

and middle-aged as a result of direct trauma. The fracture

Anatomic knowledge of the blood supply to the femoral

head explains why avascular necrosis of the head can occur

after fractures of the neck of the femur. In the young, the

epiphysis of the head is supplied by a small branch of the ob-

turator artery, which passes to the head along the ligament

of the femoral head. The upper part of the neck of the femur

receives a profuse blood supply from the medial femoral cir-

cumflex artery (see text Fig. 12-25). These branches pierce

the capsule and ascend the neck deep to the synovial mem-

brane. As long as the epiphyseal cartilage remains, no

communication occurs between the two sources of blood.

type 1

type 2

In the adult, after the epiphyseal cartilage disappears, an

anastomosis between the two sources of blood supply is es-

tablished. Fractures of the femoral neck interfere with or

completely interrupt the blood supply from the root of the

femoral neck to the femoral head. The scant blood flow

along the small artery that accompanies the round ligament

may be insufficient to sustain the viability of the femoral

head, and ischemic necrosis gradually takes place.

type 3

type 4

The Neck of the Femur and Coxa Valga

and Coxa Vara

The neck of the femur is inclined at an angle with the shaft;

the angle is about 160° in the young child and about 125°

in the adult. An increase in this angle is referred to as coxa

valga, and it occurs, for example, in cases of congenital dis-

location of the hip. In this condition, adduction of the hip

joint is limited. A decrease in this angle is referred to as coxa

vara, and it occurs in fractures of the neck of the femur

and in slipping of the femoral epiphysis. In this condition,

abduction of the hip joint is limited. Shenton’s line is a use-

ful means of assessing the angle of the femoral neck on a

radiograph of the hip region (see text Fig. 11-66).

Fractures of the Femur

Fractures of the neck of the femur are common and are of

two types, subcapital and trochanteric. The subcapital frac-

ture occurs in the elderly and is usually produced by a mi-

nor trip or stumble. Subcapital femoral neck fractures are

particularly common in women after menopause. This gen-

der predisposition is because of a thinning of the cortical

CD Figure 11-9

A. Fractures of the neck of the femur.

and trabecular bone caused by estrogen deficiency. Avascu-

B. Displacement of the lower bone fragment caused by the

lar necrosis of the head is a common complication. If the

pull of the powerful muscles. Note in particular the outward

rotation of the leg so that the foot characteristically points

fragments are not impacted, considerable displacement oc-

laterally. GM gluteus maximus, AM adductor muscles,

curs. The strong muscles of the thigh (CD Fig. 11-9), in-

GE gemelli, HS hamstring muscles, OI obturator

cluding the rectus femoris, the adductor muscles, and the

internus, PI piriformis, QF quadratus femoris,

hamstring muscles, pull the distal fragment upward, so that

RF rectus femoris.

160

Chapter 11

line is extracapsular, and both fragments have a profuse

quadriceps, and laterally rotated by the adductors and the

blood supply. If the bone fragments are not impacted, the

weight of the foot (see CD Fig. 11-10).

pull of the strong muscles will produce shortening and

In fractures of the middle third of the shaft of the fe-

lateral rotation of the leg, as previously explained.

mur, the distal fragment is pulled upward by the hamstrings

Fractures of the shaft of the femur usually occur in

and the quadriceps (see CD Fig. 11-10), resulting in con-

young and healthy persons. In fractures of the upper third

siderable shortening. The distal fragment is also rotated

of the shaft of the femur, the proximal fragment is flexed by

backward by the pull of the two heads of the gastrocnemius

the iliopsoas; abducted by the gluteus medius and minimus;

(see CD Fig. 11-10).

and laterally rotated by the gluteus maximus, the piriformis,

In fractures of the distal third of the shaft of the femur,

the obturator internus, the gemelli, and the quadratus

the same displacement of the distal fragment occurs as seen

femoris (CD Fig. 11-10). The lower fragment is adducted by

in fractures of the middle third of the shaft. However, the

the adductor muscles, pulled upward by the hamstrings and

distal fragment is smaller and is rotated backward by the

GME

GMI

GAST

QDF

HAM

QDF

CD Figure 11-10

Fractures of the shaft

of the femur. A. Upper third of the

femoral shaft. Note the displacement

caused by the pull of the powerful

muscles. B. Middle third of the femoral

shaft. Note the posterior displacement of

the lower fragment caused by the

gastrocnemius muscle. C. Lower third of

the femoral shaft. Note the excessive

displacement of the lower fragment

popliteal

caused by the pull of the gastrocnemius

artery

muscle, threatening the integrity of the

popliteal artery. AM adductor muscles,

GAST gastrocnemius, GE gemelli,

GM gluteus maximus, GME gluteus

medius, GMI gluteus minimus,

HAM hamstrings, IP iliopsoas,

OI obturator internus, PI piriformis,

GAST

QDF quadriceps femoris,

QF quadratus femoris.

Bones and Cartilage

161

gastrocnemius muscle (see CD Fig. 11-10) to a greater

aged and elderly; they usually result from direct violence to

degree and may exert pressure on the popliteal artery and

the lateral side of the knee joint, as when a person is hit by

interfere with the blood flow through the leg and foot.

the bumper of an automobile. The tibial condyle may

From these accounts it is clear that knowledge of the

show a split fracture or be broken up, or the fracture line

different actions of the muscles of the leg is necessary to un-

may pass between both condyles in the region of the inter-

derstand the displacement of the fragments of a fractured

condylar eminence. As a result of forced abduction of the

femur. Considerable traction on the distal fragment is usu-

knee joint, the medial collateral ligament can also be torn

ally required to overcome the powerful muscles and restore

or ruptured.

the limb to its correct length before manipulation and oper-

Fractures of the distal end of the tibia are considered

ative therapy to bring the proximal and distal fragments into

with the ankle joint.

correct alignment.

Intraosseous Infusion of the Tibia

Patellar Dislocations

in the Infant

The patella is a sesamoid bone lying within the quadriceps

The technique may be used for the infusion of fluids and

tendon. The importance of the lower horizontal fibers of the

blood when it has been found impossible to obtain an intra-

vastus medialis and the large size of the lateral condyle of

venous line. The procedure is easy and rapid to perform, as

the femur in preventing lateral displacement of the patella

follows:

have been emphasized. Congenital recurrent dislocations

1. With the distal leg adequately supported, the anterior

of the patella are caused by underdevelopment of the lateral

subcutaneous surface of the tibia is palpated.

femoral condyle. Traumatic dislocation of the patella results

from direct trauma to the quadriceps attachments of

2. The skin is anesthetized about 1 in. (2.5 cm) distal to

the patella (especially the vastus medialis), with or without

the tibial tuberosity, thus blocking the infrapatellar

fracture of the patella.

branch of the saphenous nerve.

3. The bone marrow needle is directed at right angles

Patellar Fractures

through the skin, superficial fascia, deep fascia, and tib-

A patella fractured as a result of direct violence, as in an au-

ial periosteum and the cortex of the tibia. Once the nee-

tomobile accident, is broken into several small fragments.

dle tip reaches the medulla and bone marrow, the

Because the bone lies within the quadriceps femoris tendon,

operator senses a feeling of “give.” The position of the

little separation of the fragments takes place. The close rela-

needle in the marrow can be confirmed by aspiration.

tionship of the patella to the overlying skin may result in the

The needle should be directed slightly caudad to avoid

fracture being open. Fracture of the patella as a result of in-

injury to the epiphyseal plate of the proximal end of the

direct violence is caused by the sudden contraction of the

tibia. The transfusion may then commence.

quadriceps snapping the patella across the front of the

femoral condyles. The knee is in the semiflexed position, and

Bones of the Foot

the fracture line is transverse. Separation of the fragments

usually occurs.

Fractures of the Calcaneum

Compression fractures of the calcaneum result from falls

Bones of the Leg

from a height. The weight of the body drives the talus down-

ward into the calcaneum, crushing it in such a way that it

Fractures of the Tibia and Fibula

loses vertical height and becomes wider laterally. The pos-

Fractures of the tibia and fibula are common. If only one

terior portion of the calcaneum above the insertion of the

bone is fractured, the other acts as a splint and displacement

tendo calcaneus can be fractured by posterior displacement

is minimal. Fractures of the shaft of the tibia are often open

of the talus. The sustentaculum tali can be fractured by

because the entire length of the medial surface is covered

forced inversion of the foot.

only by skin and superficial fascia. Fractures of the distal

third of the shaft of the tibia are prone to delayed union or

Fractures of the Talus

nonunion. This can be because the nutrient artery is torn at

the fracture line, with a consequent reduction in blood flow

Fractures occur at the neck or body of the talus. Neck frac-

to the distal fragment; it is also possible that the splint-like

tures occur during violent dorsiflexion of the ankle joint

action of the intact fibula prevents the proximal and distal

when the neck is driven against the anterior edge of the dis-

fragments from coming into apposition.

tal end of the tibia. The body of the talus can be fractured by

Fractures of the proximal end of the tibia, at the tib-

jumping from a height, although the two malleoli prevent

ial condyles (tibial plateau), are common in the middle-

displacement of the fragments.

162

Chapter 11

Fractures of the Metatarsal Bones

Stress fracture of a metatarsal bone is common in jog-

gers and in soldiers after long marches; it can also occur in

The base of the fifth metatarsal can be fractured during

nurses and hikers. It occurs most frequently in the distal

forced inversion of the foot, at which time the tendon of in-

third of the second, third, or fourth metatarsal bone. Mini-

sertion of the peroneus brevis muscle pulls off the base of

mal displacement occurs because of the attachment of the

the metatarsal.

interosseous muscles.

Clinical Problem Solving Questions

Read the following case histories/questions and give

had received a blow on the head with an empty bottle.

the best answer for each.

On examination, the patient was conscious and had a

large dough-like swelling over the back of the head

A 19-year-old boy was suspected of having leukemia. It

that was restricted to the area over the occipital bone.

was decided to confirm the diagnosis by performing a

The skin was intact, and the swelling fluctuated on

bone marrow biopsy.

palpation.

The following statements concerning this procedure

The following statements concerning this patient are

are correct except which?

correct except which?

A. The biopsy was taken from the lower end of the

A. The hematoma, although large, did not extend for-

tibia.

ward to the orbital margins and did not extend later-

B. Red bone marrow specimens can be obtained from

ally as far as the temporal lines.

the sternum or the iliac crests.

B. The hematoma was located just beneath the scalp

C. At birth, the marrow of all bones of the body is red

and was superficial to the periosteum of the occipi-

and hematopoietic.

tal bone.

D. The blood-forming activity of bone marrow in many

C. The swelling did not occupy the subcutaneous tis-

long bones gradually lessens with age, and the red

sue of the scalp.

marrow is gradually replaced by yellow marrow.

D. The hematoma was restricted to one skull bone and

was situated beneath the periosteum.

A 45-year-old man with extensive maxillofacial injuries

after an automobile accident was brought to the emer-

A 45-year-old woman visited her physician because of a

gency department. Evaluation of the airway revealed

low back pain of 3 months’ duration. She was otherwise

partial obstruction. Despite an obvious fractured

very fit. On examination of her back, nothing abnormal

mandible, an attempt was made to move the tongue for-

was discovered. The physician then listened to her

ward from the posterior pharyngeal wall by pushing the

chest, examined her thyroid gland, and finally exam-

angles of the mandible forward. This maneuver failed to

ined both breasts. A large, hard mass was found in the

move the tongue, and it became necessary to hold the

left breast.

tongue forward directly to pull it away from the posterior

pharyngeal wall.

The following facts supported the diagnosis of carci-

noma of the left breast with secondaries in the vertebral

The most likely reason the physician was unable to pull

column except which?

the tongue forward in this patient is which?

A. The lump in the breast was painless and the pa-

A. The hypoglossal nerves were damaged on both sides

tient had noticed it while showering 6 months

of the neck.

previously.

B. Spasm of the styloglossus muscles

B. Several large, hard, pectoral lymph nodes were

C. The mandibular origin of the genioglossus muscles

found in the left axilla.

was floating because of bilateral fractures of the body

C. A lateral radiograph of the lumbar vertebral column

of the mandible.

showed extensive metastases in the bodies of the

D. The presence of a blood clot in the mouth

second and third lumbar vertebrae.

E. The resistance of the patient

D. The lump was situated in the upper outer quadrant

A 46-year-old man was seen in the emergency depart-

of the left breast and was fixed to surrounding

ment after being knocked down in a street brawl. He

tissues.

Bones and Cartilage

163

E. Although the cancer had spread by the lymph ves-

The following statements concerning this case are

sels, no evidence of spread via the bloodstream was

correct except which?

present.

A. The clavicle is one of the most common bones in

the body to be fractured.

A 65-year-old man and a 10-year-old boy were involved

B. Anatomically, the weakest part of the clavicle is the

in a severe automobile accident. In both patients the

junction of the medial and middle thirds, and this is

thorax had been badly crushed. Radiographic examina-

where the fracture commonly occurs.

tion revealed that the man had five fractured ribs but

C. The lateral bony fragment is depressed downward by

the boy had no fractures.

the weight of the arm.

What is the most likely explanation for this difference

D. The lateral fragment is pulled forward and medially

in medical findings?

by the pectoral muscles.

A. The patients were in different seats in the vehicle.

E. The medial fragment is elevated by the sternoclei-

B. The boy was wearing his seat belt and the man was

domastoid muscle.

not.

F. The supraclavicular nerves or a communicating

C. The chest wall of a child is very elastic, and fractures

vein between the cephalic and internal jugular vein

of ribs in children are rare.

may be damaged by the bone fragments.

D. The man anticipated the impact and tensed his

A 22-year-old medical student fell off her bicycle onto

muscles, including those of the shoulder girdle and

her outstretched hand. She thought she had sprained

abdomen.

her right wrist joint and treated herself by binding her

An 18-year-old woman was thrown from a horse while

wrist with an elastic bandage. Three weeks later, how-

attempting to jump a fence. She landed heavily on

ever, she was still experiencing pain on moving her

the ground, striking the lower part of her chest on

wrist and so decided to visit the emergency department.

the left side. On examination in the emergency de-

On examination of the dorsal surfaces of both hands,

partment she was conscious but breathless. The lower

with the fingers and thumbs fully extended, a localized

left side of her chest was badly bruised, and the ninth

tenderness could be felt in the anatomic snuffbox of her

and tenth ribs were extremely tender to touch. She

right hand. A diagnosis of fracture of the right scaphoid

had severe tachycardia, and her systolic blood pressure

bone was made.

was low.

The following statements concerning this patient are

correct except which?

The following statements are possibly correct except

A. The fracture line on the scaphoid bone may deprive

which?

the proximal fragment of its arterial supply.

A. There was evidence of tenderness and muscle spasm

B. A bony fragment deprived of its blood supply may

in the left upper quadrant of the anterior abdominal

undergo ischemic necrosis.

wall.

C. Because the scaphoid bone articulates with other

B. A posteroanterior radiograph of the chest revealed

bones, the fracture line may enter a joint cavity and

fractures of the left ninth and tenth ribs near their

become bathed in synovial fluid, which would in-

angles.

hibit repair.

C. The blunt trauma to the ribs could not result in

D. The scaphoid bone is an easy bone to immobilize

injury to the underlying spleen.

because of its small size.

D. The presence of blood in the peritoneal cavity had

E. Fractures of the scaphoid bone have a high incidence

irritated the parietal peritoneum, producing reflex

of nonunion.

spasm of the upper abdominal muscles.

E. The muscles of the anterior abdominal wall are

A heavily built, middle-aged man running down a flight

supplied by thoracic spinal nerves.

of stone steps misjudged the position of one of the steps

and fell suddenly onto his buttocks. Following the fall,

A 15-year-old girl, while demonstrating to her friends

he complained of severe bruising of the area of the cleft

her proficiency at standing on her hands, suddenly

between the buttocks and persistent pain in this area.

went off balance and put all her body weight on her left

outstretched hand. A distinctive cracking noise was

The following statements concerning this patient are

heard, and she felt a sudden pain in her left shoulder re-

correct except which?

gion. On examination in the emergency department,

A. The lower end of the vertebral column was trauma-

the smooth contour of her left shoulder was absent. The

tized by the stone step.

clavicle was obviously fractured, and the edges of the

B. The coccyx can be palpated beneath the skin in the

bony fragments could be palpated.

natal cleft.

164

Chapter 11

C. The anterior surface of the coccyx cannot be felt

13.

Fracture of the neck of the femur in the adult com-

clinically.

monly results in avascular necrosis of part of the

D. The coccyx is usually severely bruised or fractured.

femoral head. Can you explain this on anatomic

E. The pain is felt in the distribution of dermatomes S4

grounds? Trochanteric fractures are never accompa-

and S5.

nied by avascular necrosis. Why?

An elderly woman was run over by an automobile as she

A 37-year-old woman was involved in a light plane

was crossing the road. Radiographic examination of the

accident. She and her husband were flying home from

pelvis in the emergency department of the local hospi-

a business trip when they had to make a forced land-

tal revealed a fracture of the ilium and iliac crest on the

ing in a field due to fog. On landing, the plane hit

left side.

a tree and came to rest on its nose. Her husband

was killed on impact and she was thrown from the

10.

The following statements about fractures of the pelvis

cockpit. She was evaluated in the emergency depart-

are correct except which?

ment with multiple injuries. Radiographic examina-

A. Fractures of the ilium have little displacement.

tion of her pelvis showed a fracture of her left ilium

B. Displacement is prevented by the presence of the il-

and iliac crest.

iacus and the gluteal muscles on the inner and outer

surfaces of this bone, respectively.

14.

From your knowledge of anatomy, would you expect

C. If two fractures occur in the ring forming the true

much displacement of the bony fragments?

pelvis, the fracture will be unstable and displace-

A 25-year-old man was running across a field when

ment will occur.

he caught his right foot in a rabbit hole. As he fell,

D. Fractures of the true pelvis do not cause injury to the

the right foot was violently rotated laterally and

pelvic viscera.

overeverted. On attempting to stand, he could place

E. The postvertebral and abdominal muscles are re-

no weight on his right foot. On examination by a

sponsible for elevating the lateral part of the pelvis

physician, the right ankle was considerably swollen,

should two fractures occur.

especially on the lateral side. After further exami-

F. A heavy fall on the greater trochanter of the femur

nation, including a radiograph of the ankle, a diag-

may drive the head of the femur through the floor of

nosis of severe fracture dislocation of the ankle joint

the acetabulum and into the pelvic cavity.

was made.

A pregnant woman visited an antenatal clinic. A vaginal

examination revealed that the sacral promontory could

15.

The following statements concerning this patient are

be easily palpated and that the diagonal conjugate

correct except which?

measured less than 4 in. (10 cm).

A. This type of fracture dislocation is caused by forced

external rotation and overeversion of the foot.

11.

The following statements concerning this examination

B. The talus is externally rotated against the lateral

are correct except which?

malleolus of the fibula, causing it to fracture.

A. Normally it is difficult or impossible to feel the

C. The torsion effect on the lateral malleolus produces

sacral promontory by means of a vaginal examina-

a spiral fracture.

tion.

D. The medial ligament of the ankle joint is strong and

B. The normal diagonal conjugate measures about 10

never ruptures.

in. (25 cm).

E. If the talus is forced to move farther laterally and

C. This patient’s pelvis was flattened anteroposteriorly,

continues to rotate, the posterior inferior margin of

and the sacral promontory projected too far forward.

the tibia will be sheared off.

D. It is likely that this patient would have an obstructed

labor.

16.

A 32-year-old woman was rock climbing when she de-

E. This patient was advised to have a cesarean section.

cided to jump from a ledge down to a flat rock some five

feet below. On landing she maintained her balance but

On a routine anteroposterior radiographic examination

experienced a severe pain in her right foot in the region

of a patient’s right hip joint, the long axis of the neck of

of the heel. On examination later in the emergency de-

the femur was found to be at an angle of 160° with the

partment of the local hospital, the physician’s assistant

long axis of the femoral shaft.

noted the extreme tenderness felt over the sides and in-

12.

Is this angle normal in a 5-year-old child? In a 35-year-

ferior surface of the right calcaneum. She also noted

old man? What is the clinical condition called in which

that the right calcaneum appeared wider than the one

the angle is smaller than normal? Which movement of

on the left. Using your knowledge of anatomy, make the

the hip joint is limited by this condition?

diagnosis.

Bones and Cartilage

165

Answers and Explanations

A is the correct answer. In a 19-year-old boy, the bone

12.

This angle is within normal limits in a 5-year-old child.

marrow at the lower end of the tibia is yellow.

It is too great in a 35-year-old man; the condition is

called coxa valga, in which adduction of the hip joint is

C is the correct answer. The genioglossus muscle arises

limited. When the angle of the femoral neck is smaller

from the superior mental spines behind the symphysis

than normal (coxa vara), abduction of the hip joint is

menti of the mandible (see text Fig. 11-10).

limited.

B is the correct answer. The hematoma was located

13.

Fractures of the neck of the femur in the adult com-

deep to the periosteum of the occipital bone.

monly result in avascular necrosis of part of the femoral

E is the correct answer. The carcinoma of the left breast

head. The femoral head receives its blood supply from

was in an advanced stage and had spread by way of the

two sources—a small artery, a branch of the obturator

lymph vessels to the axillary lymph nodes and by the

artery, that runs with the round ligament of the femoral

bloodstream to the bodies of the second and third lum-

head and a profuse blood supply from the medial

bar vertebrae. Carcinoma of the thyroid, bronchus,

femoral circumflex femoral artery, branches that as-

breast, kidney, and prostate tend to metastasize via the

cend the femoral neck beneath the synovial membrane.

bloodstream to bones.

Fracture of the femoral neck may deprive the femoral

head of part or all of the blood from the medial femoral

C is the correct answer. The chest wall of a child is very

circumflex femoral artery, and avascular necrosis will

elastic, and fractures of ribs in children are rare.

occur. In trochanteric fractures, both fragments have a

C is the correct answer. Trauma to the lower part of the

profuse blood supply.

woman’s left chest could easily severely damage the

14.

Most fractures of the upper part of the ilium have little

spleen in the abdomen, resulting in hemorrhage into

displacement of the bone fragments. This is because

the peritoneal cavity.

the iliacus muscle is attached to the inner surface and

B is the correct answer. Anatomically, the weakest part of

the gluteal muscles are attached to the outer surface

the clavicle is the junction of the middle and lateral thirds,

(see text Fig. 11-54). Splinting the bones is unnecessary

and that is where the fracture occurred in this patient.

because of the attachment of these muscles.

D is the correct answer. The scaphoid bone is a difficult

15.

D is the correct answer. Although the medial ligament

bone to immobilize because of its position and small

of the ankle joint is strong, extreme force can result in

size.

rupture of the ligament, or the ligament can be torn

from the medial malleolus, or the pull on the ligament

C is the correct answer. The anterior surface of the coc-

can fracture the medial malleolus.

cyx can be palpated with a gloved finger placed in the

anal canal.

16.

This woman had suffered a compression fracture

of the right calcaneum as a result of the fall from a

10.

D is the correct answer. Fractures of the true pelvis are

height. The weight of the body drives the talus down-

commonly associated with injuries to the soft pelvic vis-

ward into the calcaneum, crushing it in such a way that

cera, especially the bladder and the urethra.

it loses vertical height and becomes wider laterally. The

11.

B is the correct answer. The normal diagonal conjugate

diagnosis was confirmed on an anteroposterior and a

measures about 5 in. (11.5 cm) (see CD Fig. 11-6).

lateral radiograph of the right ankle.

Chapter Outline

General Clinical Features Concerning

Radioulnar Joint

174

Radioulnar Joint Disease

174

Joints

169

Wrist Joint

174

Examination of Joints

169

Wrist Joint Injuries

174

Dislocation of Joints

169

Falls on the Outstretched Hand

174

Presence of Cartilaginous Discs within Joints

169

Joints of the Pelvis

174

Loss of Joint Innervation

169

Changes in the Pelvic Joints with Pregnancy

174

Value of Joint Classification

169

Changes in the Pelvic Joints with Age

174

Joint Pain and Joint Innervation

169

Sacroiliac Joint Disease

175

Temporomandibular Joint

169

Joints of the Lower Limb

175

Clinical Significance of the Temporomandibular

Hip Joint

175

Joint

169

Referred Pain from the Hip Joint

175

Dislocation of the Temporomandibular Joint

169

Congenital Dislocation of the Hip

175

Traumatic Dislocation of the Hip

175

Joints of the Vertebral Column

170

Hip Joint Stability and Trendelenburg’s Sign

175

Abnormal Curves of the Vertebral Column

170

Arthritis of the Hip Joint

175

Dislocations of the Vertebral Column

170

Knee Joint

175

Fractures of the Vertebral Column

170

Strength of the Knee Joint

175

Fractures of the Spinous Processes,

Knee Injury and the Synovial Membrane

176

Transverse Processes, or Laminae

170

Ligamentous Injury of the Knee Joint

176

Anterior and Lateral Compression Fractures

170

Medial Collateral Ligament

176

Fracture Dislocations

170

Lateral Collateral Ligament

176

Vertical Compression Fractures

170

Cruciate Ligaments

176

Fractures of the Odontoid Process of the Axis

172

Meniscal Injury of the Knee Joint

178

Fractures of the Pedicles of the Axis

Pneumoarthrography of the Knee Joint

178

(Hangman’s Fracture)

172

Arthroscopy of the Knee Joint

179

Spondylolisthesis

172

Ankle Joint

179

Ankle Joint Stability

179

Joints of the Upper Limb

172

Acute Sprains of the “Lateral Ankle”

179

Sternoclavicular Joint

172

Acute Sprains of the “Medial Ankle”

179

Sternoclavicular Joint Injuries

172

Fracture Dislocations of the Ankle Joint

179

Acromioclavicular Joint

172

Joints of the Foot

179

Acromioclavicular Joint Injuries

172

Metatarsophalangeal Joint of the Big Toe

179

Acromioclavicular Joint Dislocation

172

Clinical Examination of the Arches of the Foot

179

Shoulder Joint

173

The “Stone Bridge” Mechanisms for Arch

Stability of the Shoulder Joint

173

Support

179

Dislocations of the Shoulder Joint

173

Maintenance of the Medial Longitudinal Arch

181

Anterior-Inferior Dislocations

173

Maintenance of the Lateral Longitudinal Arch

181

Posterior Dislocations

173

Maintenance of the Transverse Arch

181

Shoulder Pain

173

Physiologic Note: Muscle Tone and the

Elbow Joint

173

Arches of the Foot

181

Stability of the Elbow Joint

173

Clinical Problems Associated with the Arches

Dislocations of the Elbow Joint

173

of the Foot

181

Arthrocentesis of the Elbow Joint

173

Damage to the Ulnar Nerve with Elbow Joint

Clinical Problem Solving Questions

182

Injuries

173

Radiology of the Elbow Region after Injury

174

Answers and Explanations

185

Joints

169

such as the ankle, elbow, or wrist, whereas tuberculous

GENERAL CLINICAL

arthritis also affects synovial joints and may start in the syn-

ovial membrane or in the bone.

FEATURES

Joint Pain and Joint Innervation

CONCERNING

Remember that more than one joint may receive the same

nerve supply. For example, the hip and knee joints are

JOINTS

both supplied by the obturator nerve. Thus, a patient with

disease limited to one of these joints may experience pain

in both.

Examination of Joints

When examining a patient, the clinician should assess the

normal range of movement of all joints. When the bones

of a joint are no longer in their normal anatomic relation-

TEMPOROMANDIB-

ship with one another, then the joint is said to be

dislocated.

ULAR JOINT

Dislocation of Joints

Clinical Significance of the

Some joints are particularly susceptible to dislocation be-

cause of lack of support by ligaments, the poor shape of the

Temporomandibular Joint

articular surfaces, or the absence of adequate muscular sup-

port. The shoulder joint, temporomandibular joint, and

The temporomandibular joint lies immediately in front of

acromioclavicular joints are good examples. Dislocation of

the external auditory meatus. The great strength of the lat-

the hip is usually congenital, being caused by inadequate

eral temporomandibular ligament prevents the head of the

development of the socket that normally holds the head of

mandible from passing backward and fracturing the tym-

the femur firmly in position.

panic plate when a severe blow falls on the chin.

The articular disc of the temporomandibular joint may

become partially detached from the capsule, and this results

Presence of Cartilaginous Discs

in its movement becoming noisy and producing an audible

click during movements at the joint.

within Joints

The presence of cartilaginous discs within joints, especially

weightbearing joints, as in the case of the knee, makes

Dislocation of the

them particularly susceptible to injury in sports. During a

rapid movement the disc loses its normal relationship to

Temporomandibular Joint

the bones and becomes crushed between the weightbear-

Dislocation sometimes occurs when the mandible is de-

ing surfaces.

pressed. In this movement, the head of the mandible and

the articular disc both move forward until they reach the

summit of the articular tubercle. In this position, the

Loss of Joint Innervation

joint is unstable, and a minor blow on the chin or a sud-

In certain diseases of the nervous system (e.g., syringomyelia),

den contraction of the lateral pterygoid muscles, as in

the sensation of pain in a joint is lost. This means that the warn-

yawning, may be sufficient to pull the disc forward be-

ing sensations of pain felt when a joint moves beyond the nor-

yond the summit. In bilateral cases the mouth is fixed in

mal range of movement are not experienced. This phenome-

an open position, and both heads of the mandible lie in

non results in the destruction of the joint.

front of the articular tubercles. Reduction of the disloca-

tion is easily achieved by pressing the gloved thumbs

downward on the lower molar teeth and pushing the jaw

Value of Joint Classification

backward. The downward pressure overcomes the tension

Knowledge of the classification of joints is of great value be-

of the temporalis and masseter muscles, and the back-

cause, for example, certain diseases affect only certain types

ward pressure overcomes the spasm of the lateral ptery-

of joints. Gonococcal arthritis affects large synovial joints

goid muscles.

170

Chapter 12

greatest. In unilateral dislocations the inferior articular process

JOINTS OF THE

of one vertebra is forced forward over the anterior margin of

the superior articular process of the vertebra below. Because

the articular processes normally overlap, they become locked

VERTEBRAL

in the dislocated position. The spinal nerve on the same side

is usually nipped in the intervertebral foramen, producing se-

COLUMN

vere pain. Fortunately, the large size of the vertebral canal al-

lows the spinal cord to escape damage in most cases.

Bilateral cervical dislocations are almost always associ-

Abnormal Curves of the Vertebral

ated with severe injury to the spinal cord. Death occurs im-

mediately if the upper cervical vertebrae are involved be-

Column

cause the respiratory muscles, including the diaphragm

(phrenic nerves C3 to C5), are paralyzed.

Kyphosis is an exaggeration in the sagittal curvature pre-

sent in the thoracic part of the vertebral column. It can be

caused by muscular weakness, by structural changes in the

Fractures of the Vertebral Column

vertebral bodies, or by intervertebral discs. In sickly adoles-

cents, for example, where the muscle tone is poor, long

Fractures of the Spinous Processes,

hours of study or work over a low desk can lead to a gently

Transverse Processes, or Laminae

curved kyphosis of the upper thoracic region. The person

Fractures of the spinous processes, transverse processes, or

is said to be “round-shouldered.” Crush fractures or tuber-

laminae are caused by direct injury or, in rare cases, by se-

culous destruction of the vertebral bodies leads to acute an-

vere muscular activity.

gular kyphosis of the vertebral column. In the aged, osteo-

porosis (abnormal rarefaction of bone) and/or degenera-

Anterior and Lateral Compression

tion of the intervertebral discs leads to senile kyphosis,

Fractures

involving the cervical, thoracic, and lumbar regions of the

column.

Anterior compression fractures of the vertebral bodies are

Lordosis is an exaggeration in the sagittal curvature pre-

usually caused by an excessive flexion compression type of

sent in the lumbar region. Lordosis may be caused by an in-

injury and take place at the sites of maximum mobility or at

crease in the weight of the abdominal contents, as with the

the junction of the mobile and fixed regions of the column.

gravid uterus or a large ovarian tumor, or it may be caused

It is interesting to note that the body of a vertebra in such a

by disease of the vertebral column such as spondylolisthesis.

fracture is crushed, whereas the strong posterior longitudi-

The possibility that it is a postural compensation for a kypho-

nal ligament remains intact. The vertebral arches remain

sis in the thoracic region or a disease of the hip joint (con-

unbroken and the intervertebral ligaments remain intact so

genital dislocation) must not be overlooked.

that vertebral displacement and spinal cord injury do not

Scoliosis is a lateral deviation of the vertebral column.

occur. When injury causes excessive lateral flexion in ad-

This is most commonly found in the thoracic region and

dition to excessive flexion, the lateral part of the body is also

may be caused by muscular or vertebral defects. Paralysis of

crushed.

muscles caused by poliomyelitis can cause severe scoliosis.

The presence of a congenital hemivertebra can cause scol-

Fracture Dislocations

iosis. Often scoliosis is compensatory and may be caused by

a short leg or hip disease.

Fracture dislocations are usually caused by a combination of

a flexion and rotation type of injury; the upper vertebra is ex-

cessively flexed and twisted on the lower vertebra. Here

Dislocations of the Vertebral

again, the site is usually where maximum mobility occurs,

as in the lumbar region, or at the junction of the mobile and

Column

fixed region of the column, as in the lower lumbar verte-

brae. Because the articular processes are fractured and the

Dislocations without fracture occur only in the cervical re-

ligaments are torn, the vertebrae involved are unstable, and

gion because the inclination of the articular processes of the

the spinal cord is usually severely damaged or severed, with

cervical vertebrae permits dislocation to take place without

accompanying paraplegia.

fracture of the processes. In the thoracic and lumbar re-

gions, dislocations can occur only if the vertically placed ar-

Vertical Compression Fractures

ticular processes are fractured.

Dislocations commonly occur between the fourth and

Vertical compression fractures occur in the cervical and

fifth or fifth and sixth cervical vertebrae, where mobility is

lumbar regions, where it is possible to fully straighten the

172

Chapter 12

vertebral column (CD Fig. 12-1). In the cervical region,

with the neck straight, an excessive vertical force applied

JOINTS OF THE

from above will cause the ring of the atlas to be disrupted

and the lateral masses to be displaced laterally (Jefferson’s

UPPER LIMB

fracture). If the neck is slightly flexed, the lower cervical ver-

tebrae remain in a straight line and the compression load is

transmitted to the lower vertebrae, causing disruption of the

Sternoclavicular Joint

intervertebral disc and breakup of the vertebral body. Pieces

Sternoclavicular Joint Injuries

of the vertebral body are commonly forced back into the

spinal cord.

The strong costoclavicular ligament firmly holds the medial

It is possible for nontraumatic compression fractures to

end of the clavicle to the first costal cartilage. Violent forces

occur in severe cases of osteoporosis and for pathologic frac-

directed along the long axis of the clavicle usually result in

tures to take place.

fracture of that bone, but dislocation of the sternoclavicular

In the straightened lumbar region, an excessive force

joint takes place occasionally.

from below can cause the vertebral body to break up, with

Anterior dislocation results in the medial end of

protrusion of fragments posteriorly into the spinal canal.

the clavicle projecting forward beneath the skin; it

Fractures of the Odontoid Process of

may also be pulled upward by the sternocleidomastoid

muscle.

the Axis

Posterior dislocation usually follows direct trauma ap-

Fractures of the odontoid process are relatively common

plied to the front of the joint that drives the clavicle back-

and result from falls or blows on the head (see CD Fig. 12-

ward. This type is the more serious because the displaced

1). Excessive mobility of the odontoid fragment or rupture

clavicle may press on the trachea, esophagus, and major

of the transverse ligament can result in compression injury

blood vessels in the root of the neck.

to the spinal cord.

If the costoclavicular ligament ruptures completely, it is

difficult to maintain the normal position of the clavicle once

Fracture of the Pedicles of the Axis

reduction has been accomplished.

(Hangman’s Fracture)

Severe extension injury of the neck, such as might occur in

Acromioclavicular Joint

an automobile accident or a fall, is the usual cause of hang-

man’s fracture. Sudden overextension of the neck, as pro-

Acromioclavicular Joint Injuries

duced by the knot of a hangman’s rope beneath the chin, is

the reason for the common name. Because the vertebral

The plane of the articular surfaces of the acromioclavicular

canal is enlarged by the forward displacement of the verte-

joint passes downward and medially so that there is a ten-

bral body of the axis, the spinal cord is rarely compressed (see

dency for the lateral end of the clavicle to ride up over the

CD Fig. 12-1).

upper surface of the acromion. The strength of the joint de-

pends on the strong coracoclavicular ligament, which binds

the coracoid process to the undersurface of the lateral part

Spondylolisthesis

of the clavicle. The greater part of the weight of the upper

In spondylolisthesis, the body of a lower lumbar vertebra,

limb is transmitted to the clavicle through this ligament,

usually the fifth, moves forward on the body of the vertebra

and rotary movements of the scapula occur at this important

below and carries with it the whole of the upper portion of

ligament.

the vertebral column. The essential defect is in the pedicles

of the migrating vertebra. It is now generally believed that, in

Acromioclavicular Joint Dislocation

this condition, the pedicles are abnormally formed and

accessory centers of ossification are present and fail to unite.

A severe blow on the point of the shoulder, as is incurred

The spine, laminae, and inferior articular processes remain

during blocking or tackling in football or any severe fall,

in position, whereas the remainder of the vertebra, having

can result in the acromion being thrust beneath the lateral

lost the restraining influence of the inferior articular

end of the clavicle, tearing the coracoclavicular ligament.

processes, slips forward. Because the laminae are left behind,

This condition is known as shoulder separation. The dis-

the vertebral canal is not narrowed, but the nerve roots may

placed outer end of the clavicle is easily palpable. As in the

be pressed on, causing low backache and sciatica. In severe

case of the sternoclavicular joint, the dislocation is easily

cases the trunk becomes shortened, and the lower ribs con-

reduced, but withdrawal of support results in immediate re-

tact the iliac crest.

dislocation.

Joints

173

Injury to the shoulder joint is followed by pain, limita-

Shoulder Joint

tion of movement, and muscle atrophy owing to disuse. It is

important to appreciate that pain in the shoulder region can

Stability of the Shoulder Joint

be caused by disease elsewhere and that the shoulder joint

The shallowness of the glenoid fossa of the scapula and the

may be normal; for example, diseases of the spinal cord and

lack of support provided by weak ligaments make this joint

vertebral column and the pressure of a cervical rib can cause

an unstable structure. Its strength almost entirely depends

shoulder pain. Irritation of the diaphragmatic pleura or peri-

on the tone of the short muscles that bind the upper end of

toneum can produce referred pain via the phrenic and

the humerus to the scapula—namely, the subscapularis in

supraclavicular nerves.

front, the supraspinatus above, and the infraspinatus and

teres minor behind. The tendons of these muscles are fused

Elbow Joint

to the underlying capsule of the shoulder joint. Together,

these tendons form the rotator cuff.

Stability of the Elbow Joint

The least supported part of the joint lies in the inferior

The elbow joint is stable because of the wrench-shaped ar-

location, where it is unprotected by muscles.

ticular surface of the olecranon and the pulley-shaped

trochlea of the humerus; it also has strong medial and lateral

Dislocations of the Shoulder Joint

ligaments. When examining the elbow joint, the physician

The shoulder joint is the most commonly dislocated large

must remember the normal relations of the bony points. In

joint.

extension, the medial and lateral epicondyles and the top of

the olecranon process are in a straight line; in flexion, the

Anterior-Inferior Dislocations

bony points form the boundaries of an equilateral triangle.

Sudden violence applied to the humerus with the joint fully

Dislocations of the Elbow Joint

abducted tilts the humeral head downward onto the inferior

weak part of the capsule, which tears, and the humeral head

Elbow dislocations are common, and most are posterior. Pos-

comes to lie inferior to the glenoid fossa. During this move-

terior dislocation usually follows falling on the outstretched

ment, the acromion has acted as a fulcrum. The strong flex-

hand. Posterior dislocations of the joint are common in chil-

ors and adductors of the shoulder joint now usually pull the

dren because the parts of the bones that stabilize the joint are

humeral head forward and upward into the subcoracoid po-

incompletely developed. Avulsion of the epiphysis of the me-

sition.

dial epicondyle is also common in childhood because then

the medial ligament is much stronger than the bond of union

Posterior Dislocations

between the epiphysis and the diaphysis.

Posterior dislocations are rare and are usually caused by

Arthrocentesis of the Elbow Joint

direct violence to the front of the joint.

On inspection of the patient with shoulder disloca-

The anterior and posterior walls of the capsule are weak, and

tion, the rounded appearance of the shoulder is seen to be

when the joint is distended with fluid, the posterior aspect of

lost because the greater tuberosity of the humerus is no

the joint becomes swollen. Aspiration of joint fluid can eas-

longer bulging laterally beneath the deltoid muscle. A sub-

ily be performed through the back of the joint on either side

glenoid displacement of the head of the humerus into the

of the olecranon process.

quadrangular space can cause damage to the axillary

Damage to the Ulnar Nerve with

nerve, as indicated by paralysis of the deltoid muscle and

loss of skin sensation over the lower half of the deltoid.

Elbow Joint Injuries

Downward displacement of the humerus can also stretch

The close relationship of the ulnar nerve to the medial side

and damage the radial nerve.

of the joint often results in its becoming damaged in dislo-

cations of the joint or in fracture dislocations in this re-

Shoulder Pain

gion. The nerve lesion can occur at the time of injury or

The synovial membrane, capsule, and ligaments of the

weeks, months, or years later. The nerve can be involved in

shoulder joint are innervated by the axillary nerve and the

scar tissue formation or can become stretched owing to lat-

suprascapular nerve. The joint is sensitive to pain, pressure,

eral deviation of the forearm in a badly reduced supra-

excessive traction, and distension. The muscles surrounding

condylar fracture of the humerus. During movements of

the joint undergo reflex spasm in response to pain originat-

the elbow joint, the continued friction between the medial

ing in the joint, which in turn serves to immobilize the joint

epicondyle and the stretched ulnar nerve eventually results

and thus reduce the pain.

in ulnar palsy.

174

Chapter 12

Radiology of the Elbow Region after

Injury

In examining lateral radiographs of the elbow region, it is

important to remember that the lower end of the humerus

is normally angulated forward 45° on the shaft; when exam-

ining a patient, the physician should see that the medial epi-

condyle, in the anatomic position, is directed medially and

posteriorly and faces in the same direction as the head of the

humerus.

Radioulnar Joint

Radioulnar Joint Disease

The proximal radioulnar joint communicates with the el-

bow joint, whereas the distal radioulnar joint does not com-

CD Figure 12-2

Fractures of the distal end of the radius.

A. Colles’ fracture. B. Smith’s fracture.

municate with the wrist joint. In practical terms, this means

that infection of the elbow joint invariably involves the prox-

imal radioulnar joint. The strength of the proximal radioul-

nar joint depends on the integrity of the strong anular liga-

the clavicle, and finally, to the sternum. If the forces are ex-

ment. Rupture of this ligament occurs in cases of anterior

cessive, different parts of the upper limb give way under

dislocation of the head of the radius on the capitulum of the

the strain. The area affected seems to be related to age. In

humerus. In young children, in whom the head of the ra-

a young child, for example, there may be a posterior dis-

dius is still small and undeveloped, a sudden jerk on the arm

placement of the distal radial epiphysis; in the teenager the

can pull the radial head down through the anular ligament.

clavicle might fracture; in the young adult the scaphoid is

commonly fractured; and in the elderly the distal end of

the radius is fractured about 1 in. (2.5 cm) proximal to the

Wrist Joint

wrist joint (Colles’ fracture) (CD Fig. 12-2).

Wrist Joint Injuries

The wrist joint is essentially a synovial joint between the dis-

tal end of the radius and the proximal row of carpal bones.

JOINTS OF THE

The head of the ulna is separated from the carpal bones by

the strong triangular fibrocartilaginous ligament, which sep-

PELVIS

arates the wrist joint from the distal radioulnar joint. The

joint is stabilized by the strong medial and lateral ligaments.

Changes in the Pelvic Joints with

Because the styloid process of the radius is longer than

that of the ulna, abduction of the wrist joint is less extensive

Pregnancy

than adduction. In flexion-extension movements, the hand

can be flexed about 80° but extended to only about 45°. The

During pregnancy, the symphysis pubis and the ligaments

range of flexion is increased by movement at the midcarpal

of the sacroiliac and sacrococcygeal joints undergo soften-

joint.

ing in response to hormones, thus increasing the mobility

A fall on the outstretched hand can strain the anterior lig-

and increasing the potential size of the pelvis during child-

ament of the wrist joint, producing synovial effusion, joint

birth. The hormones responsible are estrogen and proges-

pain, and limitation of movement. These symptoms and signs

terone produced by the ovary and the placenta. An addi-

must not be confused with those produced by a fractured

tional hormone, called relaxin, produced by these organs

scaphoid or dislocation of the lunate bone, which are similar.

can also have a relaxing effect on the pelvic ligaments.

Falls on the Outstretched Hand

Changes in the Pelvic Joints with

In falls on the outstretched hand, forces are transmitted

from the scaphoid to the distal end of the radius, from the

Age

radius across the interosseous membrane to the ulna, and

from the ulna to the humerus; thence, through the glenoid

Obliteration of the cavity in the sacroiliac joint occurs in

fossa of the scapula to the coracoclavicular ligament and

both sexes after middle age.

Joints

175

Hip Joint Stability and Trendelen-

Sacroiliac Joint Disease

burg’s Sign

The sacroiliac joint is innervated by the lower lumbar and

The stability of the hip joint when a person stands on one leg

sacral nerves so that disease in the joint can produce low back

with the foot of the opposite leg raised above the ground de-

pain and pain referred along the sciatic nerve (sciatica).

pends on three factors:

The sacroiliac joint is inaccessible to clinical examina-

tion. However, a small area located just medial to and below

■ The gluteus medius and minimus must be functioning

the posterior superior iliac spine is where the joint comes

normally.

closest to the surface. In disease of the lumbosacral region,

■ The head of the femur must be located normally within

movements of the vertebral column in any direction cause

the acetabulum.

pain in the lumbosacral part of the column. In sacroiliac

■ The neck of the femur must be intact and must have a

disease, pain is extreme on rotation of the vertebral column

normal angle with the shaft of the femur.

and is worst at the end of forward flexion. The latter move-

If any one of these factors is defective, then the pelvis

ment causes pain because the hamstring muscles hold the

will sink downward on the opposite, unsupported side. The

hip bones in position while the sacrum is rotating forward as

patient is then said to exhibit a positive Trendelenburg’s

the vertebral column is flexed.

sign (CD Fig. 12-3).

Normally, when walking, a person alternately contracts

the gluteus medius and minimus, first on one side and then

JOINTS OF THE

on the other. By this means he or she is able to raise the

pelvis first on one side and then on the other, allowing the

leg to be flexed at the hip joint and moved forward—that is,

LOWER LIMB

the leg is raised clear of the ground before it is thrust forward

in taking the forward step. A patient with a right-sided con-

genital dislocation of the hip, when asked to stand on the

Hip Joint

right leg and raise the opposite leg clear of the ground, will

Referred Pain from the Hip Joint

exhibit a positive Trendelenburg’s sign, and the unsup-

ported side of the pelvis will sink below the horizontal. If the

The femoral nerve not only supplies the hip joint but, via

patient is asked to walk, he or she will show the characteris-

the intermediate and medial cutaneous nerves of the thigh,

tic “dipping” gait. In patients with bilateral congenital dislo-

also supplies the skin of the front and medial side of the

cation of the hip, the gait is typically “waddling” in nature.

thigh. It is not surprising, therefore, for pain originating in

the hip joint to be referred to the front and medial side of the

Arthritis of the Hip Joint

thigh. The posterior division of the obturator nerve supplies

both the hip and knee joints. This would explain why hip

A patient with an inflamed hip joint will place the femur in

joint disease sometimes gives rise to pain in the knee joint.

the position that gives minimum discomfort—that is, the po-

sition in which the joint cavity has the greatest capacity to

Congenital Dislocation of the Hip

contain the increased amount of synovial fluid secreted. The

hip joint is partially flexed, abducted, and externally rotated.

The stability of the hip joint depends on the ball-and-socket

Osteoarthritis, the most common disease of the hip

arrangement of the articular surfaces and the strong liga-

joint in the adult, causes pain, stiffness, and deformity. The

ments. In congenital dislocation of the hip, the upper lip of

pain may be in the hip joint itself or referred to the knee (the

the acetabulum fails to develop adequately, and the head of

obturator nerve supplies both joints). The stiffness is caused

the femur, having no stable platform under which it can

by the pain and reflex spasm of the surrounding muscles.

lodge, rides up out of the acetabulum onto the gluteal sur-

The deformity is flexion, adduction, and external rotation

face of the ilium.

and is produced initially by muscle spasm and later by mus-

Traumatic Dislocation of the Hip

cle contracture.

Traumatic dislocation of the hip is rare because of its

strength; it is usually caused by motor vehicle accidents.

Knee Joint

However, should it occur, it usually does so when the joint

Strength of the Knee Joint

is flexed and adducted. The head of the femur is displaced

posteriorly out of the acetabulum, and it comes to rest on the

The strength of the knee joint depends on the strength of the

gluteal surface of the ilium (posterior dislocation). The

ligaments that bind the femur to the tibia and on the tone of

close relation of the sciatic nerve to the posterior surface of

the muscles acting on the joint. The most important muscle

the joint makes it prone to injury in posterior dislocations.

group is the quadriceps femoris; provided that this is well

176

Chapter 12

normal

positive Trendelenburg's sign

CD Figure 12-3

Trendelenburg’s test.

developed, it is capable of stabilizing the knee in the pres-

occur at its femoral or tibial attachments. It is useful to re-

ence of torn ligaments.

member that tears of the menisci result in localized tender-

ness on the joint line, whereas sprains of the medial collat-

Knee Injury and the Synovial

eral ligament result in tenderness over the femoral or tibial

attachments of the ligament.

Membrane

Lateral Collateral Ligament

The synovial membrane of the knee joint is extensive, and if

the articular surfaces, menisci, or ligaments of the joint are

Forced adduction of the tibia on the femur can result in in-

damaged, the large synovial cavity becomes distended with

jury to the lateral collateral ligament (less common than

fluid. The wide communication between the suprapatellar

medial ligament injury).

bursa and the joint cavity results in this structure becoming

distended also. The swelling of the knee extends three or

Cruciate Ligaments

four fingerbreadths above the patella and laterally and me-

dially beneath the aponeuroses of insertion of the vastus lat-

Injury to the cruciate ligaments can occur when excessive

eralis and medialis, respectively.

force is applied to the knee joint. Tears of the anterior cru-

ciate ligament are common; tears of the posterior cruciate

Ligamentous Injury of the Knee Joint

ligament are rare. The injury is always accompanied by

damage to other knee structures; the collateral ligaments

Four ligaments—the medial collateral ligament, the lateral

are commonly torn or the capsule may be damaged. The

collateral ligament, the anterior cruciate ligament, and the

joint cavity quickly fills with blood (hemarthrosis) so that

posterior cruciate ligament—are commonly injured in the

the joint is swollen. Examination of patients with a rup-

knee. Sprains or tears occur depending on the degree of

tured anterior cruciate ligament shows that the tibia can be

force applied.

pulled excessively forward on the femur; with rupture of

the posterior cruciate ligament, the tibia can be made to

Medial Collateral Ligament

move excessively backward on the femur (CD Fig. 12-4).

Forced abduction of the tibia on the femur can result in par-

Because the stability of the knee joint depends largely on

tial tearing of the medial collateral ligament, which can

the tone of the quadriceps femoris muscle and the integrity

178

Chapter 12

of the collateral ligaments, operative repair of isolated torn

being subjected to a severe grinding force, and it splits

cruciate ligaments is not always attempted. The knee is im-

along its length (CD Fig. 12-5). When the torn part of the

mobilized in slight flexion in a cast, and active physiother-

meniscus becomes wedged between the articular surfaces,

apy on the quadriceps femoris muscle is begun at once.

further movement is impossible, and the joint is said to

Should, however, the capsule of the joint and the collat-

“lock.”

eral ligaments be torn in addition, early operative repair is

Injury to the lateral meniscus is less common, proba-

essential.

bly because it is not attached to the lateral collateral liga-

ment of the knee joint and is consequently more mobile.

Meniscal Injury of the Knee Joint

The popliteus muscle sends a few of its fibers into the lat-

eral meniscus, and these can pull the meniscus into a

Injuries of the menisci are common. The medial meniscus

more favorable position during sudden movements of the

is damaged much more frequently than the lateral, and

knee joint.

this is probably because of its strong attachment to the me-

dial collateral ligament of the knee joint, which restricts its

Pneumoarthrography of the Knee

mobility. The injury occurs when the femur is rotated on

Joint

the tibia, or the tibia is rotated on the femur, with the knee

joint partially flexed and taking the weight of the body.

Air can be injected into the synovial cavity of the knee joint

The tibia is usually abducted on the femur, and the medial

so that soft tissues can be studied. This technique is based on

meniscus is pulled into an abnormal position between the

the fact that air is less radiopaque than structures such as the

femoral and tibial condyles (CD Fig. 12-4A). A sudden

medial and lateral menisci, so their outline can be visual-

movement between the condyles results in the meniscus

ized on a radiograph (see text Fig. 12-43).

medial meniscus

CD Figure 12-5

Tears of the medial meniscus of the knee joint. A. Complete bucket han-

dle tear. B. The meniscus is torn from its peripheral attachment. C. Tear of the posterior

portion of the meniscus. D. Tear of the anterior portion of the meniscus.

Joints

179

Arthroscopy of the Knee Joint

Joints of the Foot

Arthroscopy involves the introduction of a lighted instru-

ment into the synovial cavity of the knee joint through a

Metatarsophalangeal Joint of the Big

small incision. This technique permits the direct visualiza-

Toe

tion of structures, such as the cruciate ligaments and the

Hallux valgus, which is a lateral deviation of the great toe at

menisci, for diagnostic purposes.

the metatarsophalangeal joint, is a common condition. Its

incidence is greater in women than in men and is associated

Ankle Joint

with badly fitting shoes. It is often accompanied by the pres-

ence of a short first metatarsal bone. Once the deformity is

Ankle Joint Stability

established, it is progressively worsened by the pull of the

flexor hallucis longus and extensor hallucis longus muscles.

The ankle joint is a hinge joint possessing great stability.

Later, osteoarthritic changes occur in the metatarsopha-

The deep mortise formed by the lower end of the tibia and

langeal joint, which then becomes stiff and painful; the con-

the medial and lateral malleoli securely holds the talus in

dition is then known as hallux rigidus.

position.

Clinical Examination of the Arches of

Acute Sprains of the “Lateral Ankle”

the Foot

Acute sprains of the lateral ankle are usually caused by ex-

On examination of the imprint of a wet foot on the floor

cessive inversion of the foot with plantar flexion of the ankle.

made with the person in the standing position, one can see

The anterior talofibular ligament and the calcaneofibular

that the heel, the lateral margin of the foot, the pad under

ligament are partially torn, giving rise to great pain and local

the metatarsal heads, and the pads of the distal phalanges are

swelling.

in contact with the ground (see text Figs. 12-41 and 12-42).

The medial margin of the foot, from the heel to the first

Acute Sprains of the “Medial Ankle”

metatarsal head, is arched above the ground because of the

important medial longitudinal arch. The pressure exerted

Acute sprains of the medial ankle are similar to but less

on the ground by the lateral margin of the foot is greatest at

common than those of the lateral ankle. They may occur

the heel and the fifth metatarsal head and least between

to the medial or deltoid ligament as a result of excessive

these areas because of the presence of the low-lying lateral

eversion. The great strength of the medial ligament usually

longitudinal arch. The transverse arch involves the bases of

results in the ligament pulling off the tip of the medial

the five metatarsals and the cuboid and cuneiform bones.

malleolus.

This is, in fact, only half an arch, with its base on the lateral

border of the foot and its summit on the foot’s medial bor-

Fracture Dislocations of the Ankle

der. The foot has been likened to a half-dome, so that when

Joint

the medial borders of the two feet are placed together, a

complete dome is formed.

Fracture dislocations of the ankle are common and are

From this description, it can be understood that the

caused by forced external rotation and overeversion of the

body weight on standing is distributed through a foot via the

foot. The talus is externally rotated forcibly against the lat-

heel behind and six points of contact with the ground in

eral malleolus of the fibula. The torsion effect on the

front, namely, the two sesamoid bones under the head of the

lateral malleolus causes it to fracture spirally. If the force

first metatarsal and the heads of the remaining four

continues, the talus moves laterally, and the medial

metatarsals.

ligament of the ankle joint becomes taut and pulls off the

tip of the medial malleolus. If the talus is forced to move

The “Stone Bridge” Mechanisms for

still farther, its rotary movement results in its violent con-

tact with the posterior inferior margin of the tibia, which

Arch Support

shears off.

Examination of the design of any stone bridge reveals the

Other less common types of fracture dislocation are

following engineering methods used for its support (CD

caused by forced overeversion (without rotation), in which

Fig. 12-6).

the talus presses the lateral malleolus laterally and causes it

to fracture transversely. Overinversion (without rotation), in

■ The shape of the stones: The most effective way of sup-

which the talus presses against the medial malleolus, pro-

porting the arch is to make the stones wedge shaped,

duces a vertical fracture through the base of the medial

with the thin edge of the wedge lying inferiorly. This

malleolus.

applies particularly to the important stone that occupies

180

Chapter 12

"keystone"

keystone

shape of stones

shape of bones

short plantar

ligament

long plantar

ligament

calcaneonavicular

ligament

staples

strong plantar ligaments

tendon of flexor

hallucis longus

tie beam

peroneus longus

suspension bridge

CD Figure 12-6

Different methods by which the arches of the foot may be supported.

the center of the arch and is referred to as the “key-

beam connecting the ends effectively prevents separation

stone.”

of the pillars and consequent sagging of the arch.

■ The inferior edges of the stones are tied together: This is

■ A suspension bridge: Here, the maintenance of the arch

accomplished by interlocking the stones or binding their

depends on multiple supports suspending the arch from

lower edges together with metal staples. This method ef-

a cable above the level of the bridge.

fectively counteracts the tendency of the lower edges of the

stones to separate when the arch is weightbearing.

Using the bridge analogy, one can now examine the

■ The use of the tie beams: When the span of the bridge is

methods used to support the arches of the feet (see CD Fig.

large and the foundations at either end are insecure, a tie

12-6).

Joints

181

Maintenance of the Medial Longitudi-

■ Suspending the arch from above are the peroneus

longus tendon and the peroneus brevis.

nal Arch

■ Shape of the bones: The sustentaculum tali hold up

the talus; the concave proximal surface of the navicular

bone receives the rounded head of the talus; the slight

P H Y S I O L O G I C N O T E

concavity of the proximal surface of the medial

cuneiform bone receives the navicular. The rounded

Muscle Tone and the Arches of the Foot

head of the talus is the keystone in the center of the

The arches of the feet are maintained by the shape of the

arch (see CD Fig. 12-6).

bones, strong ligaments, and muscle tone. Which of

■ The inferior edges of the bones are tied together by

these factors is the most important? Basmajian and

the plantar ligaments, which are larger and stronger

Stecko demonstrated electromyographically that the tib-

than the dorsal ligaments. The most important ligament

ialis anterior, the peroneus longus, and the small mus-

is the plantar calcaneonavicular ligament (see CD Fig.

cles of the foot play no important role in the normal static

12-6). The tendinous extensions of the insertion of the

support of the arches. They are commonly totally inac-

tibialis posterior muscle play an important role in this

tive. However, during walking and running, all these

respect.

muscles become active. Standing immobile for long pe-

■ Tying the ends of the arch together are the plantar

riods, especially if the person is overweight, places

aponeurosis, the medial part of the flexor digitorum bre-

excessive strain on the bones and ligaments of the feet

vis, the abductor hallucis, the flexor hallucis longus, the

and results in fallen arches or flat feet. Athletes, route-

medial part of the flexor digitorum longus, and the flexor

marching soldiers, and nurses are able to sustain their

hallucis brevis (see CD Fig. 12-6).

arches provided that they receive adequate training to

■ Suspending the arch from above are the tibialis ante-

develop their muscle tone.

rior and posterior and the medial ligament of the ankle

joint.

Clinical Problems Associated with the

Arches of the Foot

Maintenance of the Lateral Longitudi-

nal Arch

Of the three arches, the medial longitudinal is the largest

and clinically the most important. The shape of the

■ Shape of the bones: Minimal shaping of the distal end of

bones, the strong ligaments, especially those on the plan-

the calcaneum and the proximal end of the cuboid. The

tar surface of the foot, and the tone of muscles all play an

cuboid is the keystone.

important role in supporting the arches. It has been

■ The inferior edges of the bones are tied together by the

shown that in the active foot the tone of muscles is an im-

long and short plantar ligaments and the origins of the

portant factor in arch support. When the muscles are fa-

short muscles from the forepart of the foot (see CD Fig.

tigued by excessive exercise (a long-route march by an

12-6).

army recruit), by standing for long periods (waitress or

■ Tying the ends of the arch together are the plantar

nurse), by being overweight, or by illness, the muscular

aponeurosis, the abductor digiti minimi, and the lateral

support gives way, the ligaments are stretched, and pain is

part of the flexor digitorum longus and brevis.

produced.

■ Suspending the arch from above are the peroneus

Pes planus (flat foot) is a condition in which the medial

longus and the brevis (see CD Fig. 12-6).

longitudinal arch is depressed or collapsed. As a result, the

forefoot is displaced laterally and everted. The head of the

Maintenance of the Transverse Arch

talus is no longer supported, and the body weight forces it

■ Shape of the bones: The marked wedge shaping of the

downward and medially between the calcaneum and the

cuneiform bones and the bases of the metatarsal bones

navicular bone. When the deformity has existed for some

(see text Fig. 12-42)

time, the plantar, calcaneonavicular, and medial ligaments

■ The inferior edges of the bones are tied together by the

of the ankle joint become permanently stretched, and the

deep transverse ligaments, the strong plantar ligaments,

bones change shape. The muscles and tendons are also per-

and the origins of the plantar muscles from the forepart

manently stretched. The causes of flat foot are both congen-

of the foot; the dorsal interossei and the transverse head

ital and acquired.

of the adductor hallucis are particularly important in this

Pes cavus (clawfoot) is a condition in which the medial

respect.

longitudinal arch is unduly high. Most cases are caused by

■ Tying the ends of the arch together is the peroneus

muscle imbalance, in many instances resulting from po-

longus tendon.

liomyelitis.

182

Chapter 12

Clinical Problem Solving Questions

Read the following case histories/questions and give

particularly daring dive, he surfaced quickly and climbed

the best answer for each.

out of the pool, holding his head between his hands. He

said that he had hit the bottom of the pool with his head

and now had severe pain in the root of the neck, which

General Joint Questions

was made worse when he tried to move his neck. A lateral

A 31-year-old woman has a history of poliomyelitis af-

radiograph revealed that the right inferior articular

fecting the anterior horn cells of the lower thoracic and

process of the fifth cervical vertebra was forced over the

lumbar segments of the spinal cord on the left side. On

anterior margin of the right superior articular process of

examination, she has severe right lateral flexion defor-

the sixth cervical vertebra, producing a unilateral disloca-

mity of the vertebral column.

tion with nipping of the right sixth cervical nerve.

The following statements are true about this case ex-

The following symptoms and signs confirmed the diag-

cept which?

nosis except which?

A. The virus of poliomyelitis attacks and destroys the

A. The head was rotated to the right.

motor anterior horn cells of the spinal cord.

B. There was spasm of the deep neck muscles on the

B. The disease resulted in the paralysis of the muscles

right side of the neck, which were tender to touch.

that normally laterally flex the vertebral column on

C. The patient complained of severe pain in the region

the left side.

of the back of the neck and right shoulder.

C. The muscles on the right side of the vertebral col-

D. The slightest movement produced severe pain in the

umn are unapposed.

right sixth cervical dermatome.

D. The right lateral flexion deformity is caused by the

E. The large size of the vertebral canal in the cervical

slow degeneration of the sensory nerve fibers origi-

region permitted the spinal cord to escape injury.

nating from the vertebral muscles on the right side.

A 50-year-old coal miner was crouching at the mine

A 20-year-old woman severely sprains her left ankle

face when a large rock suddenly became dislodged

while playing tennis. When she tries to move the foot so

from the roof of the mine shaft and struck him on the

that the sole faces medially, she experiences severe pain.

upper part of his back. The emergency department

physician suspected a displacement of the upper tho-

What is the correct anatomic term for the movement of

racic spines on the sixth thoracic spine.

the foot that produces the pain?

A. Pronation

The following physical signs confirmed a diagnosis of

B. Inversion

fracture dislocation between the fifth and sixth thoracic

C. Supination

vertebrae except which?

D. Eversion

A. A lateral radiograph revealed fractures involving the

superior articular processes of the sixth thoracic ver-

Joints of the Skull

tebra and the inferior articular processes of the fifth

3. An exhausted medical student decided to brush up on

thoracic vertebra.

gross anatomy by attending a lecture given by an old and

B. Considerable forward displacement of the body of

revered visiting professor. After 45 minutes the lecture be-

the fifth thoracic vertebra on the sixth thoracic ver-

gan to bore him, and his mind began to wander. He could

tebra occurred.

not forget the attractive brunette nurse in the surgical

C. The patient had signs and symptoms of spinal shock.

clinic whom he had dated the previous evening. After 5

D. The large size of the vertebral canal in the thoracic

more minutes he found he just could not keep his eyes

region leaves plenty of space around the spinal cord

open. When would this lecture end? Just then, he invol-

for bony displacement.

untarily opened his mouth wide and yawned. To his great

E. The patient later showed signs and symptoms of

consternation he could not close his mouth. His jaw was

paraplegia.

stuck in the open position. What is your diagnosis?

A 66-year-old woman was seen in the emergency de-

partment complaining of a burning pain over the upper

Joints of the Vertebral Column

part of her right arm. The pain had started 2 days previ-

An 11-year-old boy was showing off in front of friends by

ously and had progressively worsened. Physical exami-

diving into the shallow end of a swimming pool. After one

nation revealed weakness and wasting of the right

Joints

183

deltoid and biceps brachii muscles. The patient also

A 22-year-old student was driving home from a party

had hyperesthesia in the skin over the lower part of the

and crashed his car head on into a brick wall. On

right deltoid and down the lateral side of the arm. Ra-

examination in the emergency department, he was

diologic examination showed extensive spur formation

found to have a fracture dislocation of the seventh tho-

on the bodies of the fourth, fifth, and sixth cervical ver-

racic vertebra, with signs and symptoms of severe dam-

tebrae. These signs and symptoms suggested severe os-

age to the spinal cord.

teoarthritis of the cervical vertebral column.

8. On recovery from spinal shock, he was found to have

This disease produced the following changes in the ver-

the following signs and symptoms except which?

tebrae and related structures except which?

A. Fracture dislocation of the seventh thoracic verte-

A. Repeated trauma and aging had resulted in degen-

bra, which would result in severe damage to the sev-

erative changes at the articulating surfaces of the

enth thoracic segment of the spinal cord

fourth, fifth, and sixth cervical vertebrae.

B. A band of cutaneous hyperesthesia extending around

B. Extensive spur formation resulted in narrowing of

the abdominal wall on the left side at the level of the

the intervertebral foramina with pressure on the

umbilicus that was caused by the irritation of the cord

nerve roots.

immediately above the site of the lesion

C. The burning pain and hyperesthesia were caused by

C. On the right side, total analgesia, thermoanesthesia,

pressure on the third and fourth cervical posterior

and partial loss of tactile sense of the skin of the ab-

roots.

dominal wall below the level of the umbilicus in-

D. The weakness and wasting of the deltoid and biceps

volving the whole of the right leg

brachii muscles were caused by pressure on the fifth

D. Upper motor neuron paralysis of his left leg

and sixth cervical anterior roots.

E. Unequal sensory and motor losses on the two sides,

E. Movements of the neck intensified the symptoms by

which indicate a left hemisection of the spinal cord

exerting further pressure on the nerve roots.

F. Coughing or sneezing raised the pressure within the

Joints of the Ribs

vertebral canal and resulted in further pressure on

9. A 36-year-old woman went sailing with her husband

the roots.

and they were caught in a severe gale. While the hus-

A medical student offered to move a grand piano for his

band at the helm desperately managed to keep the boat

landlady. He had just finished his final examinations in

under control, the wife tried to get the sails down. Even-

anatomy and was in poor physical shape. He struggled

tually the squall died down and they were able to return

with the antique monstrosity and suddenly experienced

safely to port. The next morning, the woman woke up

an acute pain in the back, which extended down the

with severe pain over the left side of her chest. On be-

back and outer side of his left leg. On examination in

ing examined in the emergency department of the local

the emergency department, he was found to have a

hospital for a suspected myocardial infarction, the

slight scoliosis with the convexity on the right side. The

physician found that the patient was acutely tender over

deep muscles of the back in the left lumbar region felt

her left costal margin, which was made worse on taking

firmer than normal. No evidence of muscle weakness

a deep breath. What is the possible diagnosis?

was present, but the left ankle jerk was diminished.

Joints of the Upper Extremity

The symptoms and signs of this patient strongly suggest a

diagnosis of prolapsed intervertebral disc except which?

10. Separation of the acromioclavicular joint is common in

A. The pain was the worst over the left lumbar region

football and soccer players. Explain why such separa-

opposite the fifth lumbar spine.

tions are unstable after reduction.

B. The pain was accentuated by coughing.

A father, seeing his 3-year-old son playing in the garden,

C. With the patient supine, flexing the left hip joint

ran up and picked him up by both hands and swung

with the knee extended caused a marked increase in

him around in a circle. The child’s enjoyment sud-

the pain.

denly turned to tears, and he said his left elbow hurt.

D. A lateral radiograph of the lumbar vertebral column

On examination, the child held his left elbow joint

revealed nothing abnormal.

semiflexed and his forearm pronated.

E. A magnetic resonance imaging study revealed the

presence of small fragments of the nucleus pulposus

11. The following statements concerning this case are con-

that had herniated outside the anulus in the disc be-

sistent with the diagnosis of dislocation of the superior

tween the fifth lumbar vertebra and the sacrum.

radioulnar joint except which?

F. The pain occurred in the dermatomes of the third

A. The head of the radius was pulled out of the anular

and fourth lumbar segments on the left side.

ligament.

184

Chapter 12

B. At age 3 years, the child’s anular ligament has a large

E. On reduction of the fracture the distal end of the ra-

diameter and the head of the radius can easily be

dius should lie at an angle of 15° anteriorly.

pulled out of the ligament by traction.

F. The hand should always be splinted in the position

C. The incidence of this condition is equal in both sexes.

of function.

D. The pain from the joint caused reflex contraction of

A 22-year-old medical student fell off her bicycle onto

the surrounding muscles to protect the joint from

her outstretched hand. She thought she had sprained her

further movement.

right wrist joint and treated herself by binding her wrist

E. The subluxation of the joint can be treated by

with an elastic bandage. Three weeks later, however, she

pulling downward on the forearm and at the same

was still experiencing pain on moving her wrist and so de-

time performing the movement of pronation and

cided to visit the emergency department. On examina-

supination. Finally, the elbow joint is flexed and

tion of the dorsal surfaces of both hands, with the fingers

held in that position.

and thumbs fully extended, a localized tenderness could

A 60-year-old woman fell down the stairs and was admit-

be felt in the anatomic snuffbox of her right hand. A di-

ted to the emergency department with severe right shoul-

agnosis of fracture of the right scaphoid bone was made.

der pain. On examination, the patient was sitting up with

14.

The following statements concerning this patient are

her right arm by her side and her right elbow joint sup-

correct except which?

ported by the left hand. Inspection of the right shoulder

A. The scaphoid bone is an easy bone to immobilize

showed loss of the normal rounded curvature and evi-

because of its small size.

dence of a slight swelling below the right clavicle. Any at-

B. A bony fragment deprived of its blood supply may

tempt at active or passive movement of the shoulder joint

undergo ischemic necrosis.

was stopped by severe pain in the shoulder. A diagnosis

C. Because the scaphoid bone articulates with other

of dislocation of the right shoulder joint was made.

bones, the fracture line may enter a joint cavity and

become bathed in synovial fluid, which would in-

12.

The following statements concerning this patient are

hibit repair.

consistent with the diagnosis except which?

D. The fracture line on the scaphoid bone may deprive

A. This patient had a subcoracoid dislocation of the

the proximal fragment of its arterial supply.

right shoulder joint.

E. Fractures of the scaphoid bone have a high inci-

B. The head of the humerus was dislocated downward

dence of nonunion.

through the weakest part of the capsule of the joint.

C. The pull of the pectoralis major and subscapularis

15.

A 46-year-old woman slipped on a shiny floor and sus-

muscles had displaced the upper end of the

tained a fracture of the fifth metacarpal bone on her left

humerus medially.

hand. What type of angulation of the fragments is com-

D. The greater tuberosity of the humerus no longer dis-

monly found in fractures at this site? When a splint is

placed the deltoid muscle laterally, and the curve of

applied with the little finger flexed, in which direction

the shoulder was lost.

should the little finger be pointing?

E. The integrity of the axillary nerve should always be

tested by touching the skin over the upper half of the

Joints of the Lower Extremity

deltoid muscle.

A medical student, while playing football, collided with

A 63-year-old man fell down a flight of stairs and sus-

another player and fell to the ground. As he fell, the

tained a fracture of the lower end of the left radius. On

right knee, which was taking the weight of his body, was

examination the distal end of the radius was displaced

partially flexed; the femur was rotated medially; and the

posteriorly. This patient had sustained a Colles’ fracture.

leg was abducted on the thigh. A sudden pain was felt

in the right knee joint, and he was unable to extend it.

13.

The following statements concerning this case are cor-

The student was diagnosed as having a torn medial

rect except which?

meniscus of the knee joint.

A. Occasionally the styloid process of the ulna is also

fractured.

16. The following statements concerning this case con-

B. The median nerve may be injured at the time of the

firmed the diagnosis except which?

fall.

A. The right knee joint quickly became swollen.

C. When the fracture is reduced, the styloid process of

B. Severe local tenderness was felt along the medial

the radius should come to lie about 0.75 in. (1.9 cm)

side of the joint line.

proximal to that of the ulna.

C. The medial meniscus split along part of its length,

D. The fracture produces posterior angulation of the

and the detached portion became jammed between

distal fragment of the radius.

the articular surfaces, limiting further extension.

Joints

185

D. The trauma stimulated the production of synovial

E. Because the cruciate ligaments are located outside

fluid, which filled the joint cavity.

the synovial membrane, bleeding from a torn liga-

E. The distension of the suprapatellar bursa was re-

ment does not enter the joint cavity.

sponsible for the large amount of swelling above the

A 25-year-old man was running across a field when he

injured knee.

caught his right foot in a rabbit hole. As he fell, the right

F. The pain sensation from the injured knee was con-

foot was violently rotated laterally and overeverted. On

fined to the femoral nerve as it ascended to the cen-

attempting to stand, he could place no weight on his

tral nervous system.

right foot. On examination by a physician, the right an-

A 27-year-old woman was found to have an unstable

kle was considerably swollen, especially on the lateral

right knee joint following a severe automobile accident.

side. After further examination, including a radiograph

On examination it was possible to pull the tibia exces-

of the ankle, a diagnosis of severe fracture dislocation of

sively forward on the femur. A diagnosis of ruptured an-

the ankle joint was made.

terior cruciate ligament was made.

18.

The following statements concerning this patient are

17.

The following statements concerning this patient are

correct except which?

A. This type of fracture dislocation is caused by forced

A. The anterior cruciate ligament is attached to

external rotation and overeversion of the foot.

the tibia in the anterior part of the intercondylar

B. The talus is externally rotated against the lateral

area.

malleolus of the fibula, causing it to fracture.

B. The anterior cruciate ligament passes upward, back-

C. The medial ligament of the ankle joint is strong and

ward, and laterally from its tibial attachment.

never ruptures.

C. The anterior cruciate ligament is attached above to

D. The torsion effect on the lateral malleolus produces

the posterior part of the medial surface of the lateral

a spiral fracture.

femoral condyle.

E. If the talus is forced to move farther laterally and

D. The anterior cruciate ligament is more commonly

continues to rotate, the posterior inferior margin of

torn than is the posterior cruciate ligament.

the tibia will be sheared off.

Answers and Explanations

1. D is the correct answer. The right lateral flexion defor-

4. A is the correct answer. The right inferior articular

mity is not caused by the slow degeneration of the sen-

process of the fifth cervical vertebra was forced over the

sory nerve fibers originating from the vertebral muscle

anterior margin of the right superior articular process of

on the right side. It is the motor nerves supplying the

the sixth cervical vertebra, causing the head of the pa-

vertebral muscles on the left side that are affected in

tient to be rotated to the left.

this patient.

5. D is the correct answer. The vertebral canal in the tho-

2. B is the correct answer. Moving the foot at the subtalar

racic region is small and round and little space is

and midtarsal joints so that the sole faces medially is

around the spinal cord for bony displacement to occur

called inversion.

without causing severe damage to the cord.

3. The student had dislocated his temporomandibular

6. C is the correct answer. The burning pain and hyperes-

joints on both sides. When he yawned, his lateral

thesia were caused by pressure on the fifth and sixth cer-

pterygoid muscles reflexly contracted forcibly and

vical posterior roots.

pulled the head of the mandible and the articular disc

7. F is the correct answer. The pain occurred in the der-

forward over the summit of the articular tubercle in

matomes of the fifth lumbar and first sacral segments on

each joint. Reduction is easily performed by pressing

the left side.

gloved thumbs downward and backward on the last

molar teeth. The lateral pterygoid, the temporalis, and

8. A is the correct answer. Fracture dislocation of the

the masseter muscle tension is overcome and the head

seventh thoracic vertebra would result in severe

of the mandible snaps back over the articular tubercle

damage to the tenth thoracic segment of the spinal

to assume its normal anatomical position.

cord.

186

Chapter 12

The localized tenderness over the left costal margin is

of the deltoid muscle. The skin of the curve of the

strongly suggestive of subluxation of one of the inter-

shoulder, including the skin covering the upper half of

chondral joints on the costal margin. Subluxation of a

the deltoid muscle, is supplied by the supraclavicular

joint implies that the ligaments and capsule are

nerves.

stretched or torn but the damage is not so severe that the

13.

C is the correct answer. The normal position of the tip

articulating surfaces lose contact with one another.

of the styloid process of the radius is about 0.75 in. (1.9

This condition can be extremely painful and in this pa-

cm) distal to that of the ulna.

tient was secondary to trauma caused by excessive

pulling of the muscles connecting the thoracic cage to

14.

A is the correct answer. The scaphoid bone is a difficult

the upper limb. The sixth, seventh, eighth, ninth, and

bone to immobilize because of its position and small

tenth costal cartilages articulate with each other along

size.

their borders by small synovial joints.

15.

Fractured metacarpal bones show dorsal angulation

10.

In subluxation of the acromioclavicular joint, the lat-

caused by the forward pull of the long flexor tendons

eral end of the clavicle elevates and becomes more

and the lumbricals and interossei on the distal frag-

prominent than normal; there is a definite step down

ment. When flexed individually, all fingers (excluding

onto the acromion. A dislocation occurs when the dam-

the thumb) point toward the tubercle of the scaphoid.

age to the restraining structures is more severe and the

When a finger is unstable following a fracture, it

articulating surfaces lose contact with one another. In

should be aligned so that its tip points to the scaphoid

the case of the acromioclavicular joint, the clavicle rises

tubercle; failure to achieve this will result in malfunc-

above the acromion and the joint is very unstable.

tion.

The main strength of the acromioclavicular joint de-

16.

F is the correct answer. The sensation of pain from the

pends on the integrity of the strong coracoclavicular lig-

knee joint ascends to the central nervous system via the

ament (see text Fig. 12-14). Should this ligament be dis-

femoral, obturator, common peroneal, and tibial nerves.

rupted, the acromioclavicular joint dislocates; the lat-

17.

E is the correct answer. The synovial membrane cover-

eral end of the clavicle rides over the acromion and the

ing the cruciate ligaments (see text Fig. 12-31) is torn

upper limb is depressed.

along with the ligaments, and the joint cavity quickly

11.

B is the correct answer. Under age 6 years, the child’s

fills with blood.

head of the radius is of a relatively small size and may

18.

C is the correct answer. Although the medial ligament

easily be pulled out of the anular ligament by traction

of the ankle joint is strong, extreme force can result in

on the forearm.

rupture of the ligament, the ligament can be torn from

12.

E is the correct answer. The integrity of the axillary

the medial malleolus, or the pull on the ligament can

nerve is tested by touching the skin over the lower half

fracture the medial malleolus.

Chapter Outline

General Clinical Features Concerning

Rupture of the Supraspinatus Tendon

195

Muscles

189

Axillary Nerve and the Quadrangular Space

196

Muscle Tone

189

Carpal Tunnel Syndrome

196

Muscle Attachments

189

Tenosynovitis of the Synovial Sheaths of the

Muscle Shape and Form

189

Flexor Tendons

196

Segmental Innervation of Muscle

189

Trigger Finger

198

Mallet Finger

198

Muscles of the Head

189

Boutonniere Deformity

198

Lacerations of the Scalp

189

Dupuytren’s Contracture

198

Facial Muscle Paralysis

189

Muscles of the Lower Limb

199

Muscles of the Neck

191

Gluteus Maximus and Intramuscular Injections

199

Sternocleidomastoid Muscle and Protection

from Trauma

191

Gluteus Maximus and Bursitis

199

Congenital Torticollis

191

Gluteus Medius and Minimus and Poliomyelitis

199

Spasmodic Torticollis

191

Quadriceps Femoris as a Knee-Joint Stabilizer

200

Clinical Significance of the Deep Fascia of the

Rupture of the Rectus Femoris

200

Neck

191

Rupture of the Ligamentum Patellae

200

Fascial Spaces

191

Femoral Sheath and Femoral Hernia

200

Acute Infections of the Fascial Spaces

of the Neck

191

Adductor Muscles and Cerebral Palsy

201

Chronic Infection of the Fascial Spaces

The Adductor Magnus and Popliteal Aneurysms

202

of the Neck

191

Semimembranosus Bursa Swelling

202

Clinical Significance of the Triangles of the Neck

191

Anterior Compartment of the Leg Syndrome

202

Muscles of the Abdominal Wall

192

Tenosynovitis and Dislocation of the Peroneus

Hematoma of the Rectus Sheath

192

Longus and Brevis Tendons

202

Abdominal Muscles, Abdominothoracic Rhythm,

Gastrocnemius and Soleus Muscle Tears

202

and Visceroptosis

192

Ruptured Tendo Calcaneus

202

Muscle Rigidity and Referred Pain

193

Rupture of the Plantaris Tendon

202

Surgery and the Tendinous Intersections of the

Plantaris Tendon and Autografts

202

Rectus Abdominis Muscle

193

Plantar Fasciitis

202

Psoas Abscess

193

Clinical Problems Associated with the Arches

Muscles of the Pelvis

193

of the Foot

203

Pelvic Floor

193

Bursae and Bursitis in the Lower Limb

203

Functional Significance of the Pelvic Floor

in the Female

193

Clinical Problem Solving Questions

203

Injury to the Pelvic Floor

194

Muscles of the Upper Limb

194

Answers and Explanations

206

Rotator Cuff Tendinitis

194

Skeletal Muscles

189

tal innervation of the following muscles should be known

GENERAL CLINICAL

because they can be tested by eliciting simple muscle re-

flexes in the patient (CD Fig. 13-1).

FEATURES

■ Biceps brachii tendon reflex: C5 and 6 (flexion of the el-

bow joint by tapping the biceps tendon)

■ Triceps tendon reflex: C6, 7, and 8 (extension of the el-

CONCERNING

bow joint by tapping the triceps tendon)

■ Brachioradialis tendon reflex: C5, 6, and 7 (supination

MUSCLES

of the radioulnar joints by tapping the insertion of the

brachioradialis tendon)

■ Abdominal superficial reflexes (contraction of underly-

Muscle Tone

ing abdominal muscles by stroking the skin): Upper ab-

dominal skin T6-7, middle abdominal skin T8-9, and

Determination of the tone of a muscle is an important clin-

lower abdominal skin T10-12

ical examination. If a muscle is flaccid, then either the af-

■ Patellar tendon reflex (knee jerk): L2, 3, and 4 (exten-

ferent, the efferent, or both neurons involved in the reflex

sion of the knee joint on tapping the patellar tendon)

arc necessary for the production of muscle tone have been

■ Achilles tendon reflex (ankle jerk): S1 and S2 (plantar

interrupted. For example, if the nerve trunk to a muscle is

flexion of the ankle joint on tapping the Achilles tendon)

severed, both neurons will have been interrupted. If po-

liomyelitis has involved the motor anterior horn cells at a

level in the spinal cord that innervates the muscle, the ef-

MUSCLES OF THE

ferent motor neurons will not function. If, conversely, the

muscle is found to be hypertonic, the possibility exists of a

lesion involving higher motor neurons in the spinal cord or

HEAD

brain.

Lacerations of the Scalp

Muscle Attachments

The tension of the epicranial aponeurosis (see text Fig. 13-

The importance of knowing the main attachments of all the

6), produced by the tone of the occipitofrontalis muscles, is

major muscles of the body need not be emphasized. Only

important in all deep wounds of the scalp. If the aponeuro-

with such knowledge is it possible to understand the normal

sis has been divided, the wound will gape open. For

and abnormal actions of individual muscles or muscle

satisfactory healing to take place, the opening in the

groups. How can one even attempt to analyze, for example,

aponeurosis must be closed with sutures.

the abnormal gait of a patient without this information?

Often a wound caused by a blunt object such as a

baseball bat closely resembles an incised wound. This is

Muscle Shape and Form

because the scalp is split against the unyielding skull, and

the pull of the occipitofrontalis muscles causes a gaping

The general shape and form of muscles should also be

wound. This anatomic fact may be of considerable foren-

noted, since a paralyzed muscle or one that is not used (such

sic importance.

as occurs when a limb is immobilized in a cast) quickly at-

rophies and changes shape. In the case of the limbs, it is al-

ways worth remembering that a muscle on the opposite side

Facial Muscle Paralysis

of the body can be used for comparison.

The facial muscles are innervated by the facial nerve. Dam-

age to the facial nerve in the internal acoustic meatus (by a

tumor), in the middle ear (by infection or operation), in the

Segmental Innervation of Muscle

facial nerve canal (perineuritis, Bell’s palsy), or in the

Skeletal muscle receives a segmental innervation. Most of

parotid gland (by a tumor) or caused by lacerations of the

these muscles are innervated by two, three, or four spinal

face will cause distortion of the face, with drooping of

nerves and therefore by the same number of segments of the

the lower eyelid, and the angle of the mouth will sag on the

spinal cord. To paralyze a muscle completely, it is thus nec-

affected side. This is essentially a lower motor neuron le-

essary to section several spinal nerves or to destroy several

sion. An upper motor neuron lesion (involvement of the

segments of the spinal cord.

pyramidal tracts) will leave the upper part of the face normal

Learning the segmental innervation of all the muscles

because the neurons supplying this part of the face receive

of the body is an impossible task. Nevertheless, the segmen-

corticobulbar fibers from both cerebral cortices.

Skeletal Muscles

191

layers (see text Fig. 13-11). These fascial layers are easily rec-

MUSCLES OF THE

ognizable to the surgeon at operation.

NECK

Fascial Spaces

Between the more dense layers of deep fascia in the neck is

Sternocleidomastoid Muscle and

loose connective tissue that forms potential spaces that are

clinically important. Among the more important spaces are

Protection from Trauma

the visceral, retropharyngeal, submandibular, and mastica-

tory spaces (CD Fig. 13-2).

The sternocleidomastoid, a strong, thick muscle crossing

The deep fascia and the fascial spaces are important

the side of the neck (see text Fig. 13-9), protects the

because organisms originating in the mouth, teeth, phar-

underlying soft structures from blunt trauma. Suicide

ynx, and esophagus can spread among the fascial planes

attempts by cutting one’s throat often fail because the

and spaces, and the tough fascia can determine the direc-

individual first extends the neck before making several

tion of spread of infection and the path taken by pus. It is

horizontal cuts with a knife. Extension of the cervical part

possible for blood, pus, or air in the retropharyngeal space

of the vertebral column and extension of the head at the

to spread downward into the superior mediastinum of the

atlantooccipital joint cause the carotid sheath with its

thorax.

contained large blood vessels to slide posteriorly beneath

the sternocleidomastoid muscle. To achieve the desired

Acute Infections of the Fascial Spaces of

result with the head and neck fully extended, some indi-

viduals have to make several attempts and only succeed

the Neck

when the larynx and the greater part of the sternocleido-

Dental infections most commonly involve the lower

mastoid muscles have been severed. The common sites for

molar teeth. The infection spreads medially from

the wounds are immediately above and below the hyoid

the mandible into the submandibular and masticatory

bone.

spaces and pushes the tongue forward and upward.

Further spread downward may involve the visceral space

and lead to edema of the vocal cords and airway ob-

Congenital Torticollis

struction.

Most cases of congenital torticollis are a result of excessive

Ludwig’s angina is an acute infection of the sub-

stretching of the sternocleidomastoid muscle during a diffi-

mandibular fascial space and is commonly secondary to

cult labor. Hemorrhage occurs into the muscle and may be

dental infection.

detected as a small, rounded “tumor” during the early weeks

after birth. Later, this becomes invaded by fibrous tissue,

Chronic Infection of the Fascial Spaces of

which contracts and shortens the muscle. The mastoid

the Neck

process is thus pulled down toward the sternoclavicular joint

of the same side, the cervical spine is flexed, and the face

Tuberculous infection of the deep cervical lymph

looks upward to the opposite side. If left untreated, asym-

nodes can result in liquefaction and destruction of one or

metrical growth changes occur in the face, and the cervical

more of the nodes. The pus is at first limited by the in-

vertebrae may become wedge shaped.

vesting layer of the deep fascia. Later, this becomes

eroded at one point, and the pus passes into the less re-

stricted superficial fascia. A dumbbell-shaped abscess is

Spasmodic Torticollis

now present. The clinician is aware of the superficial ab-

Spasmodic torticollis, which results from repeated chronic

scess but must not forget the existence of the deeply

contractions of the sternocleidomastoid and trapezius mus-

placed abscess.

cles, is usually psychogenic in origin. Section of the spinal

part of the accessory nerve may be necessary in severe

Clinical Significance of the

cases.

Triangles of the Neck

Clinical Significance of the Deep

The triangles of the neck (see text Fig. 13-12) assist

the medical examiner in accurately localizing a wound,

Fascia of the Neck

tumor, or swelling. Commit to memory the boundaries

The deep fascia in certain areas of the neck forms distinct

and make a list of the important contents of each

sheets called the investing, pretracheal, and prevertebral

triangle.

192

Chapter 13

esophagus

trachea

carotid sheath

thyroid gland

sternocleidomastoid

muscle

sternothyroid

superior belly of

visceral space

sternohyoid muscle

omohyoid muscle

pretracheal

layer of deep

cervical fascia

temporalis

retropharyngeal

space

zygomatic

arch

medial pterygoid

muscle

mylohyoid muscle

masseter

submandibular

muscle

masticatory

space

mandible

investing

pretracheal layer

layer of deep

prevertebral

of deep cervical fascia

cervical fascia

layer of deep

cervical fascia

CD Figure 13-2

A. Cross section of the neck showing the visceral space. B. Sagittal

section of the neck showing the positions of the retropharyngeal and submandibular

spaces. C. Vertical section of the body of the mandible close to the angle showing the

masticatory space.

vessels may be stretched during a severe bout of coughing or

in the later months of pregnancy, which may predispose to

MUSCLES OF THE

the condition. The cause is usually blunt trauma to the ab-

dominal wall, such as a fall or a kick. The symptoms that fol-

ABDOMINAL WALL

low the trauma include midline abdominal pain. An acutely

tender mass confined to one rectus sheath is diagnostic.

Hematoma of the Rectus Sheath

Abdominal Muscles, Abdominotho-

Hematoma of the rectus sheath is uncommon but impor-

racic Rhythm, and Visceroptosis

tant, since it is often overlooked. It occurs most often on the

right side below the level of the umbilicus. The source of

The abdominal muscles contract and relax with respiration,

the bleeding is the inferior epigastric vein or, more rarely,

and the abdominal wall conforms to the volume of the ab-

the inferior epigastric artery (see text Fig. 19-7). These

dominal viscera. There is an abdominothoracic rhythm.

Skeletal Muscles

193

Normally, during inspiration, when the sternum moves for-

culous abscess. Tuberculous disease of the thoracolumbar

ward and the chest expands, the anterior abdominal wall

region of the vertebral column results in the destruction of

also moves forward. If, when the chest expands the anterior

the vertebral bodies, with possible extension of pus laterally

abdominal wall remains stationary or contracts inward, it is

under the psoas fascia (CD Fig. 13-3). From there, the pus

highly probable that the parietal peritoneum is inflamed

tracks downward, following the course of the psoas muscle,

and has caused a reflex contraction of the abdominal

and appears as a swelling in the upper part of the thigh be-

muscles.

low the inguinal ligament. It may be mistaken for a

The shape of the anterior abdominal wall depends on

femoral hernia.

the tone of its muscles. A middle-aged woman with poor ab-

dominal muscles who has had multiple pregnancies is often

incapable of supporting her abdominal viscera. The lower

MUSCLES OF THE

part of the anterior abdominal wall protrudes forward, a con-

dition known as visceroptosis. This should not be confused

with an abdominal tumor such as an ovarian cyst or with the

PELVIS

excessive accumulation of fat in the fatty layer of the super-

ficial fascia.

Pelvic Floor

Muscle Rigidity and Referred Pain

The pelvic diaphragm is a gutter-shaped sheet of muscle

Sometimes it is difficult for a physician to decide whether

formed by the levatores ani and coccygeus muscles and their

the muscles of the anterior abdominal wall of a patient are

covering fasciae (see text Figs. 13-19 and 13-20). From their

rigid because of underlying inflammation of the parietal

origin, the muscle fibers on the two sides slope downward and

peritoneum or whether the patient is voluntarily contracting

backward to the midline, producing a gutter that slopes

the muscles because he or she resents being examined or be-

downward and forward.

cause the physician’s hand is cold. This problem is usually

A rise in the intraabdominal pressure, caused by the

easily solved by asking the patient, who is lying supine on

contraction of the diaphragm and the muscles of the ante-

the examination table, to rest the arms by the sides and draw

rior and lateral abdominal walls, is counteracted by the

up the knees to flex the hip joints. It is practically impossible

contraction of the muscles forming the pelvic floor. By this

for a patient to keep the abdominal musculature tensed

means, the pelvic viscera are supported and do not “drop

when the thighs are flexed. Needless to say, the examiner’s

out” through the pelvic outlet. Contraction of the puborec-

hand should be warm.

talis fibers greatly assists the anal sphincters in maintaining

A pleurisy involving the lower costal parietal pleura

continence under these conditions by pulling the anorectal

causes pain in the overlying skin that may radiate down into

junction upward and forward. During the act of defecation,

the abdomen. Although it is unlikely to cause rigidity of the

however, the levator ani continues to support the pelvic

abdominal muscles, it may cause confusion in making a di-

viscera but the puborectalis fibers relax with the anal

agnosis unless these anatomic facts are remembered:

sphincters.

■ The xiphoid process-T7

Functional Significance of the Pelvic

■ The umbilicus-T10

Floor in the Female

■ The pubis-L1

The female pelvic floor serves an important function dur-

ing the second stage of labor (CD Fig. 13-4). At the pelvic

Surgery and the Tendinous

inlet, the widest diameter is transverse so that the longest

axis of the baby’s head (anteroposterior) takes up the trans-

Intersections of the Rectus

verse position. When the head reaches the pelvic floor, the

gutter shape of the floor tends to cause the baby’s head to

Abdominis Muscle

rotate so that its long axis comes to lie in the anteroposte-

Note that the anterior wall of the rectus sheath is firmly at-

rior position. The occipital part of the head now moves

tached to the tendinous intersections of the rectus abdo-

downward and forward along the gutter until it lies under

minis muscle. The posterior wall of the sheath, however, has

the pubic arch. As the baby’s head passes through the

no attachment to the muscle.

lower part of the birth canal, the small gap that exists in the

anterior part of the pelvic diaphragm becomes enormously

enlarged so that the head may slip through into the per-

Psoas Abscess

ineum. Once the baby has passed through the perineum,

The psoas fascia covers the anterior surface of the psoas

the levatores ani muscles recoil and take up their previous

muscle and can influence the direction taken by a tuber-

position.

Skeletal Muscles

195

CD Figure 13-4

Stages in rotation

of the baby’s head during the second

stage of labor. The shape of the

pelvic floor plays an important part in

this process.

which are fused to the underlying capsule of the shoulder

joint, plays an important role in stabilizing the shoulder

joint. Lesions of the cuff are a common cause of pain in the

shoulder region. Excessive overhead activity of the upper

limb may be the cause of tendinitis, although many cases

appear spontaneously. During abduction of the shoulder

joint, the supraspinatus tendon is exposed to friction against

130˚

the acromion (CD Fig. 13-5). Under normal conditions, the

amount of friction is reduced to a minimum by the large

subacromial bursa, which extends laterally beneath the del-

toid. Degenerative changes in the bursa are followed by de-

generative changes in the underlying supraspinatus tendon,

and these may extend into the other tendons of the rotator

cuff. Clinically, the condition is known as subacromial bur-

50˚

sitis, supraspinatus tendinitis, or pericapsulitis. It is char-

acterized by the presence of a spasm of pain in the middle

range of abduction (CD Fig. 13-5), when the diseased area

impinges on the acromion.

Rupture of the Supraspinatus

Tendon

CD Figure 13-5

Subacromial bursitis, supraspinatus ten-

In advanced cases of rotator cuff tendinitis, the necrotic

dinitis, or pericapsulitis showing the painful arc in the mid-

supraspinatus tendon can become calcified or rupture. Rup-

dle range of abduction, when the diseased area impinges

ture of the tendon seriously interferes with the normal

on the lateral edge of the acromion.

196

Chapter 13

abduction movement of the shoulder joint. It will be re-

(CD Fig. 13-6). Clinically, the syndrome consists of a burn-

membered that the main function of the supraspinatus mus-

ing pain or “pins and needles” along the distribution of the

cle is to hold the head of the humerus in the glenoid fossa at

median nerve to the lateral three and a half fingers and weak-

the commencement of abduction. The patient with a rup-

ness of the thenar muscles. It is produced by compression of

tured supraspinatus tendon is unable to initiate abduction of

the median nerve within the tunnel. The exact cause of the

the arm. However, if the arm is passively assisted for the first

compression is difficult to determine, but thickening of the

15° of abduction, the deltoid can then take over and com-

synovial sheaths of the flexor tendons or arthritic changes in

plete the movement to a right angle.

the carpal bones are thought to be responsible in many cases.

As you would expect, no paresthesia occurs over the thenar

eminence because this area of skin is supplied by the palmar

Axillary Nerve and the

cutaneous branch of the median nerve, which passes super-

ficially to the flexor retinaculum. The condition is dramati-

Quadrangular Space

cally relieved by decompressing the tunnel by making a

A subglenoid dislocation of the head of the humerus into

longitudinal incision through the flexor retinaculum.

the quadrangular space (see text Fig. 13-24) can cause dam-

age to the axillary nerve, as indicated by paralysis of the del-

Tenosynovitis of the Synovial

toid muscle and loss of skin sensation over the lower half of

the deltoid muscle.

Sheaths of the Flexor Tendons

Tenosynovitis is an infection of a synovial sheath. It most

Carpal Tunnel Syndrome

commonly results from the introduction of bacteria into a

The carpal tunnel, formed by the concave anterior surface of

sheath through a small penetrating wound, such as

the carpal bones and closed by the flexor retinaculum, is

that made by the point of a needle or thorn. Rarely, the

tightly packed with the long flexor tendons of the fingers,

sheath may become infected by extension of a pulp-space

their surrounding synovial sheaths, and the median nerve

infection.

palmaris longus

flexor retinaculum

median nerve

palmar cutaneous branch

palmar cutaneous branch of median nerve

of ulnar nerve

muscles of

muscles of thenar eminence

hypothenar eminence

flexor carpi radialis

ulnar artery

ulnar nerve

ridge of trapezium

flexor digitorum

superficialis

flexor pollicis longus

flexor digitorum

profundus

abductor pollicis longus

hamate

trap

hook of hamate

extensor pollicis brevis

trape-

capitate

zoid

superficial branch

flexor synovial sheath

of radial nerve

extensor carpi ulnaris

radial artery

posterior cutaneous branch of

ulnar nerve

cephalic vein

basilic vein

extensor carpi radialis

extensor digiti minimi

longus and brevis

extensor digitorum

extensor pollicis longus

extensor indicis extensor retinaculum

CD Figure 13-6

Cross section of the hand showing the relation of the tendons, nerves,

and arteries to the flexor and extensor retinacula.

Skeletal Muscles

197

extensor digitorum

axis of

interossei and lumbrical

rotation

muscles

dorsal

extensor

vincula

expansion

flexor digitorum

brevia

profundus

vincula

longa

lumbrical

extensor

interosseous

digitorum

3rd metacarpal

flexor digitorum

superficialis

extensor digitorum

3rd metacarpal

interosseous

lumbrical

flexor digitorum

profundus

superficialis

CD Figure 13-7

Insertions of long flexor and extensor tendons in the fingers. Insertions

of the lumbrical and interossei muscles are also shown. The uppermost figure illustrates

the action of the lumbrical and interossei muscles in flexing the metacarpophalangeal

joints and extending the interphalangeal joints.

Infection of a digital sheath results in distension of the

and may compress the blood supply to the tendons that travel

sheath with pus; the finger is held semiflexed and is swollen.

in the vincula longa and brevia (CD Fig. 13-7). Rupture or

Any attempt to extend the finger is accompanied by extreme

later severe scarring of the tendons may follow.

pain because the distended sheath is stretched. As the inflam-

A further increase in pressure can cause the sheath to

matory process continues, the pressure within the sheath rises

rupture at its proximal end. Anatomically, the digital sheath

198

Chapter 13

of the index finger is related to the thenar space, whereas

that of the ring finger is related to the midpalmar space. The

sheath for the middle finger is related to both the thenar and

midpalmar spaces. These relationships explain how infec-

tion can extend from the digital synovial sheaths and involve

the palmar fascial spaces.

In the case of infection of the digital sheaths of the little

finger and thumb, the ulnar and radial bursae are quickly in-

volved. Should such an infection be neglected, pus may

burst through the proximal ends of these bursae and enter

the fascial space of the forearm between the flexor digitorum

profundus anteriorly and the pronator quadratus and the in-

terosseous membrane posteriorly. This fascial space in the

extensor expansion

forearm is commonly referred to clinically as the space of

Parona.

Trigger Finger

lumbrical

In trigger finger, there is a palpable and even audible snapping

when a patient is asked to flex and extend the fingers. It is

interosseous

caused by the presence of a localized swelling of one of the

extensor digitorum

long flexor tendons that catches on a narrowing of the fibrous

flexor sheath anterior to the metacarpophalangeal joint. It may

take place either in flexion or in extension. A similar condition

occurring in the thumb is called trigger thumb. The situation

can be relieved surgically by incising the fibrous flexor sheath.

Mallet Finger

Avulsion of the insertion of one of the extensor tendons into

the distal phalanges can occur if the distal phalanx is

forcibly flexed when the extensor tendon is taut. The last 20°

of active extension is lost, resulting in a condition known as

mallet finger (CD Fig. 13-8).

Boutonnière Deformity

Avulsion of the central slip of the extensor tendon proximal

to its insertion into the base of the middle phalanx results in

a characteristic deformity (CD Fig. 13-8C). The deformity

results from flexing of the proximal interphalangeal joint

and hyperextension of the distal interphalangeal joint. This

injury can result from direct end-on trauma to the finger, di-

rect trauma over the back of the proximal interphalangeal

CD Figure 13-8

A. Posterior view of normal dorsal exten-

joint, or laceration of the dorsum of the finger.

sor expansion. The extensor expansion near the proximal

interphalangeal joint splits into three parts: a central part,

which is inserted into the base of the middle phalanx, and

Dupuytren’s Contracture

two lateral parts, which converge to be inserted into the

base of the distal phalanx. B. Mallet or baseball finger. The

Dupuytren’s contracture is a localized thickening and con-

insertion of the extensor expansion into the base of the dis-

tracture of the palmar aponeurosis (CD Fig.13-9). It com-

tal phalanx ruptured; sometimes a flake of bone on the

monly starts near the root of the ring finger and draws that

base of the phalanx is pulled off. C. Boutonnière deformity.

finger into the palm, flexing it at the metacarpophalangeal

The insertion of the extensor expansion into the base of the

middle phalanx is ruptured. The arrows indicate the direc-

joint. Later, the condition involves the little finger in the

tion of the pull of the muscles and the deformity.

same manner. In long-standing cases, the pull on the fibrous

sheaths of these fingers results in flexion of the proximal

Skeletal Muscles

199

palmar digital artery

palmar digital nerve

fibrous flexor sheath

deep transverse

1st dorsal interosseous

palmar ligament

adductor pollicis

palmar aponeurosis

abductor digiti minimi

flexor digiti minimi

abductor pollicis brevis

flexor pollicis brevis

deep branch of ulnar

nerve and artery

flexor retinaculum

palmaris brevis

ridge of trapezium

extensor pollicis brevis

hook of hamate

abductor pollicis longus

pisiform

palmar cutaneous branch

tubercle of scaphoid

of ulnar nerve

radial artery

flexor carpi ulnaris

ulnar nerve

flexor carpi radialis

ulnar artery

palmar cutaneous branch

CD Figure 13-9

Anterior view

flexor digitorum superficialis

of median nerve

of the palm of the hand. The

median nerve

palmar aponeurosis has been

palmaris longus

left in position.

interphalangeal joints. The distal interphalangeal joints are

lar injections. To avoid injury to the underlying sciatic

not involved and are actually extended by the pressure of the

nerve, the injection should be given well forward on the

fingers against the palm.

upper outer quadrant of the buttock.

Bursitis, or inflammation of a bursa, can be caused by

acute or chronic trauma.

MUSCLES OF THE

Gluteus Maximus and Bursitis

LOWER LIMB

An inflamed bursa becomes distended with excessive

amounts of fluid and can be extremely painful. The bursae as-

sociated with the gluteus maximus are prone to inflammation.

Gluteus Maximus and

Gluteus Medius and Minimus and

Intramuscular Injections

Poliomyelitis

The gluteus maximus is a large, thick muscle with coarse

fasciculi that can be easily separated without damage. The

The gluteus medius and minimus muscles may be para-

great thickness of this muscle makes it ideal for intramuscu-

lyzed when poliomyelitis involves the lower lumbar and

200

Chapter 13

sacral segments of the spinal cord. They are supplied by the

The femoral canal, the compartment for the lymphatic

superior gluteal nerve (L4 and 5 and S1). Paralysis of these

vessels, occupies the medial part of the sheath. It is about 0.5

muscles seriously interferes with the ability of the patient to

in. (1.3 cm) long, and its upper opening is referred to as the

tilt the pelvis when walking.

femoral ring. The femoral septum, which is a condensa-

tion of extraperitoneal tissue, plugs the opening of the

femoral ring.

Quadriceps Femoris as a

A femoral hernia is more common in women than in

men (possibly because of their wider pelvis and femoral

Knee-Joint Stabilizer

canal). The hernial sac passes down the femoral canal,

The quadriceps femoris is an important extensor muscle for

pushing the femoral septum before it. On escaping through

the knee joint. Its tone greatly strengthens the joint; there-

the lower end of the femoral canal, it expands to form a

fore, this muscle mass must be carefully examined when

swelling in the upper part of the thigh deep to the deep fas-

disease of the knee joint is suspected. Both thighs should be

cia. With further expansion, the hernial sac may turn up-

examined, and the size, consistency, and strength of the

ward to cross the anterior surface of the inguinal ligament.

quadriceps muscles should be tested. Reduction in size

The neck of the sac always lies below and lateral to the

caused by muscle atrophy can be tested by measuring the

pubic tubercle. This serves to distinguish it from an in-

circumference of each thigh a fixed distance above the su-

guinal hernia, which lies above and medial to the pubic tu-

perior border of the patella.

bercle. The neck of the sac is narrow and lies at the femoral

The vastus medialis muscle extends farther distally than

ring. The ring is related anteriorly to the inguinal ligament,

the vastus lateralis. Remember that the vastus medialis is the

posteriorly to the pectineal ligament and the superior ramus

first part of the quadriceps muscle to atrophy in knee-joint

of the pubis, medially to the sharp free edge of the lacunar

disease and the last to recover.

ligament, and laterally to the femoral vein. Because of these

anatomic structures, the neck of the sac is unable to expand.

Once an abdominal viscus has passed through the neck into

Rupture of the Rectus Femoris

the body of the sac, it may be difficult to push it up and

The rectus femoris muscle can rupture in sudden violent ex-

return it to the abdominal cavity (irreducible hernia).

tension movements of the knee joint. The muscle belly re-

Furthermore, after the patient strains or coughs, a piece of

tracts proximally, leaving a gap that may be palpable on the

bowel may be forced through the neck, and its blood vessels

anterior surface of the thigh. In complete rupture of the

may be compressed by the femoral ring, seriously impairing

muscle, surgical repair is indicated.

its blood supply (strangulated hernia). A femoral hernia

is a dangerous condition and should always be treated

surgically.

Rupture of the Ligamentum

When considering the differential diagnosis of a

femoral hernia, it is important to consider diseases that may

Patellae

involve other anatomic structures close to the inguinal liga-

This can occur when a sudden flexing force is applied to the

ment. For example:

knee joint when the quadriceps femoris muscle is actively

contracting.

■ Inguinal canal: The swelling of an inguinal hernia lies

above the medial end of the inguinal ligament. Should

the hernial sac emerge through the superficial inguinal

Femoral Sheath and Femoral

ring to start its descent into the scrotum, the swelling will

lie above and medial to the pubic tubercle. The sac of a

Hernia

femoral hernia lies below and lateral to the pubic

The hernial sac descends through the femoral canal within

tubercle.

the femoral sheath.

■ Superficial inguinal lymph nodes: Usually, more than

The femoral sheath is a prolongation downward into the

one lymph node is enlarged. In patients with inflam-

thigh of the fascial lining of the abdomen. It surrounds the

mation of the nodes (lymphadenitis), carefully examine

femoral vessels and lymphatic vessels for about 1 in. (2.5 cm)

the entire area of the body that drains its lymph into

below the inguinal ligament (CD Fig. 13-10). The femoral

these nodes. A small, unnoticed skin abrasion may be

artery, as it enters the thigh below the inguinal ligament, oc-

found. Never forget the mucous membrane of the lower

cupies the lateral compartment of the sheath. The femoral

half of the anal canal—it may have an undiscovered

vein, which lies on its medial side and is separated from it by

carcinoma.

a fibrous septum, occupies the intermediate compartment.

■ Great saphenous vein: A localized dilatation of the ter-

The lymphatics, which are separated from the vein by a

minal part of the great saphenous vein, a saphenous

fibrous septum, occupy the most medial compartment.

varix, can cause confusion, especially because a hernia

Skeletal Muscles

201

inguinal ligament

femoral vein

femoral sheath

femoral canal

femoral artery

pubic tubercle

lymphatic vessel

pectineus

femoral nerve

iliopsoas

fascia transversalis

transversus

extraperitoneal fat

external iliac artery and vein

peritoneum

internal oblique

external oblique

femoral sheath

femoral ring

femoral canal

inguinal ligament

membranous layer

femoral artery

fatty layer

fascia

superficial fascia

iliaca

pubis

femoral canal

lymphatic vessel

deep fascia

lymph node

CD Figure 13-10

Right femoral sheath and its contents.

and a varix increase in size when the patient is asked to

■ Femoral artery: An expansile swelling lying along the

cough. (Elevated intraabdominal pressure drives the

course of the femoral artery that fluctuates in time with

blood downward.) The presence of varicose veins else-

the pulse rate should make the diagnosis of aneurysm of

where in the leg should help in the diagnosis.

the femoral artery certain.

■ Psoas sheath: Tuberculous infection of a lumbar verte-

bra can result in the extravasation of pus down the psoas

Adductor Muscles and

sheath into the thigh (CD Fig. 13-3). The presence of a

swelling above and below the inguinal ligament,

Cerebral Palsy

together with clinical signs and symptoms referred

to the vertebral column, should make the diagnosis

In patients with cerebral palsy who have marked spasticity of

obvious.

the adductor group of muscles, it is common practice to

202

Chapter 13

perform a tenotomy of the adductor longus tendon and to

Tenosynovitis and Dislocation of

divide the anterior division of the obturator nerve. In addi-

tion, in some severe cases the posterior division of the obtu-

the Peroneus Longus and Brevis

rator nerve is crushed. This operation overcomes the spasm

of the adductor group of muscles and permits slow recovery

Tendons

of the muscles supplied by the posterior division of the ob-

turator nerve.

Tenosynovitis (inflammation of the synovial sheaths) can af-

fect the tendon sheaths of the peroneus longus and brevis

muscles as they pass posterior to the lateral malleolus. Treat-

The Adductor Magnus and

ment consists of immobilization, heat, and physiotherapy.

Tendon dislocation can occur when the tendons of per-

Popliteal Aneurysms

oneus longus and brevis dislocate forward from behind the

The pulsations of the wall of the femoral artery against the

lateral malleolus. For this condition to occur, the superior

tendon of adductor magnus at the opening of the adductor

peroneal retinaculum must be torn. It usually occurs in

magnus is thought to contribute to the cause of popliteal

older children and is caused by trauma.

aneurysms.

Gastrocnemius and Soleus

Semimembranosus Bursa Swelling

Muscle Tears

Semimembranosus bursa swelling is the most common

swelling found in the popliteal space. It is made tense by

Tearing of the gastrocnemius or soleus muscles will pro-

extending the knee joint and becomes flaccid when the

duce severe localized pain over the damaged muscle.

joint is flexed. It should be distinguished from a Baker’s

Swelling may be present.

cyst, which is centrally located and arises as a pathologic

(osteoarthritis) diverticulum of the synovial membrane

Ruptured Tendo Calcaneus

through a hole in the back of the capsule of the knee

joint.

Rupture of the tendo calcaneus is common in middle-aged

men and frequently occurs in tennis players. The rupture oc-

curs at its narrowest part, about 2 in. (5 cm) above its inser-

Anterior Compartment of the

tion. A sudden, sharp pain is felt, with immediate disability.

The gastrocnemius and soleus muscles retract proximally,

Leg Syndrome

leaving a palpable gap in the tendon. It is impossible for the

patient to actively plantar flex the foot. The tendon should be

The anterior compartment syndrome is produced by an in-

sutured as soon as possible and the leg immobilized with the

crease in the intracompartmental pressure that results from

ankle joint plantar flexed and the knee joint flexed.

an increased production of tissue fluid. Soft tissue injury

associated with bone fractures is a common cause, and

early diagnosis is critical. The deep, aching pain in the an-

Rupture of the Plantaris Tendon

terior compartment of the leg that is characteristic of this

Rupture of the plantaris tendon is rare, although tearing of

syndrome can become severe. Dorsiflexion of the foot at

the fibers of the soleus or partial tearing of the tendo calca-

the ankle joint increases the severity of the pain. Stretching

neus is frequently diagnosed as such a rupture.

of the muscles that pass through the compartment by pas-

sive plantar flexion of the ankle also increases the pain. As

the pressure rises, the venous return is diminished, thus

Plantaris Tendon and Autografts

producing a further rise in pressure. In severe cases, the ar-

terial supply is eventually cut off by compression, and the

The plantaris muscle, which is often missing, can be used

dorsalis pedis arterial pulse disappears. The tibialis ante-

for tendon autografts in repairing severed flexor tendons to

rior, the extensor digitorum longus, and the extensor hal-

the fingers; the tendon of the palmaris longus muscle can

lucis longus muscles are paralyzed. Loss of sensation is

also be used for this purpose.

limited to the area supplied by the deep peroneal nerve—

that is, the skin cleft between the first and second toes. The

Plantar Fasciitis

surgeon can open the anterior compartment of the leg by

making a longitudinal incision through the deep fascia and

Plantar fasciitis, which occurs in individuals who do a great

thus decompress the area and prevent anoxic necrosis of

deal of standing or walking, causes pain and tenderness of

the muscles.

the sole of the foot. It is believed to be caused by repeated

Skeletal Muscles

203

minor trauma. Repeated attacks of this condition induce os-

inflammation: the bursa over the ischial tuberosity; the

sification in the posterior attachment of the aponeurosis,

greater trochanter bursa; the prepatellar and superficial in-

forming a calcaneal spur.

frapatellar bursae; the bursa between the tendons of inser-

tion of the sartorius, gracilis, and semitendinosus muscles

on the medial proximal aspect of the tibia; and the bursa be-

Clinical Problems Associated with

tween the tendo calcaneus and the upper part of the calca-

neum (long-distance runner’s ankle).

the Arches of the Foot

Two important bursae communicate with the knee

See CD Chapter 12.

joint, and they can become distended if excessive amounts

of synovial fluid accumulate within the joint. The supra-

patellar bursa extends proximally about three fingerbreadths

Bursae and Bursitis in the

above the patella beneath the quadriceps femoris muscle.

The bursa, which is associated with the insertion of the

Lower Limb

semimembranosus muscle, may enlarge in patients with os-

A variety of bursae are found in the lower limb where skin,

teoarthritis of the knee joint.

tendons, ligaments, or muscles repeatedly rub against bony

The anatomic bursae described should not be confused

points or ridges.

with adventitious bursae, which develop in response to ab-

Bursitis, or inflammation of a bursa, can be caused by

normal and excessive friction. For example, a subcutaneous

acute or chronic trauma, crystal disease, infection, or dis-

bursa sometimes develops over the tendo calcaneus in re-

ease of a neighboring joint that communicates with

sponse to badly fitting shoes. A bunion is an adventitial

the bursa. An inflamed bursa becomes distended with ex-

bursa located over the medial side of the head of the first

cessive amounts of fluid. The following bursae are prone to

metatarsal bone.

Clinical Problem Solving Questions

Read the following case histories/questions and give

E. The loss of muscle tone is caused by interruption of

the best answer for each.

a nervous reflex arc.

A woman recently took up employment in a factory.

She is a machinist, and for 6 hours a day she has to

General Muscle Information

move a lever repeatedly, which requires that she extend

In a 63-year-old man, a magnetic resonance imaging

and flex her right wrist joint. At the end of the second

scan of the lower thoracic region of the vertebral

week of her employment, she began to experience pain

column reveals the presence of a tumor pressing on the

over the posterior surface of her wrist and noticed a

lumbar segments of the spinal cord. He has a loss of sen-

swelling in the area.

sation in the skin over the anterior surface of the left

2. The following statements concerning this patient are

thigh and is unable to extend his left knee joint. Exam-

correct except which?

ination reveals that the muscles of the front of the left

A. Extension of the wrist joint is brought about by sev-

thigh have atrophied and have no tone and that the left

eral muscles that include the extensor digitorum

knee jerk is absent.

muscle.

1. The following statements concerning this patient are

B. The wrist joint is diseased.

correct except which?

C. Repeated unaccustomed movements of tendons

A. The tumor is interrupting the normal function of

through their synovial sheaths can produce trau-

the efferent motor fibers of the spinal cord on the left

matic inflammation of the sheaths.

side.

D. The diagnosis is traumatic tenosynovitis of the long

B. The quadriceps femoris muscles on the front of the

tendons of the extensor digitorum muscle.

left thigh are atrophied.

C. The loss of skin sensation is confined to the

Head and Neck Muscles

dermatomes L1, 2, 3, and 4.

D. The absence of the left knee jerk is because of

A 43-year-old woman was seen in the emergency de-

involvement of the first lumbar spinal segment.

partment with a large abscess in the middle of the right

204

Chapter 13

posterior triangle of the neck. The abscess was red, hot,

and fell to the floor, catching her right lumbar region

and fluctuant. The abscess showed evidence that it was

on the edge of the chair.

pointing and about to rupture. The physician decided

5. The following statements about this patient are correct

to incise the abscess and insert a drain. The patient

except which?

returned to the department for the dressings to be

A. A lumbar puncture (spinal tap) should always be

changed 5 days later. She stated that she felt much bet-

performed in back injuries to exclude damage to the

ter and that her neck was no longer painful. However,

spinal cord.

there was one thing that she could not understand. She

B. Anteroposterior and lateral radiographs exclude the

could no longer raise her right hand above her head to

presence of a fracture, especially of a transverse

brush her hair.

process.

The following statements explain the signs and symp-

C. A 24-hour specimen of urine should be examined for

toms in this case, suggesting that the spinal part of the

blood to exclude or confirm injury to the right kidney.

accessory nerve had been incised, except which?

D. Careful examination of the erector spinae muscles

A. To raise the hand above the head, it is necessary for

or quadratus lumborum muscle may reveal extreme

the trapezius muscle, assisted by the serratus ante-

tenderness and therefore injury to these muscles.

rior, to contract and rotate the scapula so that the

E. Examination of the back revealed a large bruised

glenoid cavity faces upward.

area in the right lumbar region, which was ex-

B. The trapezius muscle is innervated by the spinal

tremely tender to touch.

part of the accessory nerve.

C. As the spinal part of the accessory nerve crosses the

Muscles of the Thoracic Wall

posterior triangle of the neck, it is deeply placed, be-

ing covered by the skin, the superficial fascia, the in-

A resident obtained a sample of pleural fluid from a pa-

vesting layer of deep cervical fascia, and the levator

tient’s right pleural cavity. He inserted the needle close

scapulae muscle.

to the upper border of the sixth rib in the anterior axil-

D. The surface marking of the spinal part of the acces-

lary line.

sory nerve is as follows: Bisect at right angles a line

6. Name the muscles that the needle pierced in order to

joining the angle of the jaw to the tip of the mastoid

enter the pleural cavity.

process. Continue the second line downward and

A. Trapezius and latissimus dorsi

backward across the posterior triangle.

B. Trapezius and serratus anterior

E. The knife opening the abscess had cut the accessory

C. Serratus anterior, external intercostal, internal inter-

nerve.

costal, and innermost intercostal

A 46-year-old man was seen in the emergency depart-

D. External intercostal and internal intercostal

ment after being knocked down in a street brawl. He

E. Latissimus dorsi, serratus anterior, and external in-

had received a blow on the head with an empty bottle.

tercostal

On examination, the patient was conscious and had a

large gaping wound on the top of the head.

Abdominal Muscles

Why did the wound in this patient gape wide open

A 75-year-old man with chronic bronchitis noticed that

when he was hit with a blunt object and not a knife?

a bulge was developing in his left groin. On examina-

A. The skin on the top of the head was excessively tight.

tion, an elongated swelling was seen above the medial

B. The blow of the bottle had split the epicranial

end of the left inguinal ligament. When the patient

aponeurosis against the underlying skull and the

coughed, the swelling enlarged but did not descend

tone of the occipitofrontalis muscle had pulled the

into the scrotum. The patient had weak abdominal

skin wound open.

muscles.

C. The subcutaneous tissue of the scalp contains

smooth muscle, which pulled the wound open.

7. The symptoms and signs displayed by this patient can

D. A hematoma was formed beneath the scalp and

be explained by the following statements except which?

forced the wound open.

A. The inguinal swelling was a direct inguinal hernia.

E. The underlying parietal bone of the skull was frac-

B. The cause of the hernia was weak abdominal

tured and forced the wound open.

muscles.

C. The hernial sac was wide and in direct communica-

tion with the peritoneal cavity.

Muscles of the Back

D. A rise in intraabdominal pressure on coughing

A 75-year-old woman was dusting the top of a high

caused the hernial swelling to expand.

closet while balanced on a chair. She lost her balance

E. The swelling did not involve the conjoint tendon.

Skeletal Muscles

205

A 40-year-old woman noticed a painful swelling in her

eminence appeared to be functioning normally, al-

right groin after helping her husband move some heavy

though there was some loss of power compared with the

furniture. On examination, a small tender swelling was

activity of the muscles of the left thenar eminence.

noted in the right groin.

12.

The following statements concerning this patient are

The symptoms and signs displayed by this patient can

correct except which?

be explained by the following statements except which?

A. Altered skin sensation was felt in the skin areas sup-

A. The neck of a femoral hernial sac is situated below

plied by the digital branches of the median nerve.

and medial to the pubic tubercle.

B. The muscles of the thenar eminence showed some

B. A hernial sac formed of parietal peritoneum was

evidence of wasting as seen by flattening of the

forced downward.

thenar eminence.

C. The peritoneum was forced through the right

C. The muscles of the thenar eminence are supplied by

femoral canal.

the recurrent muscular branch of the median nerve.

D. The patient had a right-sided femoral hernia.

D. The median nerve enters the palm through the

E. The excessive exertion caused a rise in intraabdom-

carpal tunnel.

inal pressure.

E. The median nerve occupies a large space between

the tendons behind the flexor retinaculum.

Following a sudden severe blow on the anterior ab-

F. This patient has carpal tunnel syndrome.

dominal wall from the hind leg of a horse, a patient

complained of pain and swelling below the umbilicus.

13.

Following a radical mastectomy operation a woman no-

On examination, extensive bruising of the skin was ob-

ticed that her right shoulder blade projected backwards.

served over the lower part of the right rectus muscle. On

Can you explain this deformity?

gentle palpation, a deep swelling confined to the right

14.

A 40-year-old man visited his physician complaining of

rectus sheath was felt. Given that the deep swelling was

pain of 3 weeks’ duration in his right shoulder. On ex-

due to a collection of blood (hematoma), which blood

amination, the patient could actively abduct his right

vessels were likely to have been ruptured?

shoulder to 50°; thereafter, he experienced severe pain

10.

In a patient with a history of tuberculosis, an angular

that prevented further movement. If the arm was then

kyphosis of the lumbar vertebral column suddenly de-

passively raised above a right angle, it could be held ac-

veloped. On examination, a swelling was found in the

tively without pain in that position. If the patient at-

groin, just below the right inguinal ligament. On deep

tempted to lower the arm, he again experienced severe

palpation of the anterior abdominal wall above the right

pain in the middle range of abduction. What is your di-

inguinal ligament, a further swelling could be felt. Dig-

agnosis?

ital pressure on the first swelling caused expansion of

A 64-year-old man consulted his physician because he

the second swelling and vice versa. What is the diagno-

had noticed during the past 6 months a thickening of

sis? Explain the swelling in anatomical terms.

the skin at the base of his left ring finger. As he de-

scribed it: “There appears to be a band of tissue that is

Pelvic Muscles

pulling my ring finger into the palm.” On examination

of the palms of both hands, a localized thickening of

11. A multiparous 57-year-old woman visited her gynecolo-

subcutaneous tissue could be felt at the base of the left

gist complaining of a “bearing-down” feeling in the

ring and little fingers. The metacarpophalangeal joint

pelvis and of low backache, both of which were worse

of the ring finger could not be fully extended, either ac-

when she was tired. On vaginal examination, the exter-

tively or passively.

nal os of the cervix was found to be located just within

the vaginal orifice. A diagnosis of uterine prolapse was

15.

The following statements concerning this patient are

made. What are the main supports of the uterus?

correct except which?

A. The deep fascia beneath the skin of the palm is

thickened to form the palmar aponeurosis.

Muscles of the Upper Limb

B. The distal end of the aponeurosis gives rise to five

A 50-year-old woman complaining of severe “pins and

slips to the five fingers.

needles” in her right hand and lateral fingers visited her

C. Each slip is attached to the base of the proximal

physician. She said that she had experienced difficulty

phalanx and to the fibrous flexor sheath of each

in buttoning up her clothes when dressing. On physical

finger.

examination the patient pointed to her thumb and in-

D. Fibrous contraction of the slip to the ring finger re-

dex, middle, and ring fingers as the areas where she felt

sulted in permanent flexion of the metacarpopha-

discomfort. No objective impairment of sensation was

langeal joint.

found in these areas. The muscles of the thenar

E. The patient had Dupuytren’s contracture.

206

Chapter 13

Muscles of the Lower Limb

C. A large amount of force would be necessary to re-

store the leg to its original length.

D. The hamstrings and quadriceps femoris muscles

A 54-year-old man was told by his physician to reduce

were responsible for the leg shortening.

his weight. He was prescribed a diet and was advised to

E. The right leg was 2 in. (5 cm) shorter than the left

exercise more. One morning while jogging, he heard a

leg.

sharp snap and felt a sudden pain in his right lower calf.

On examination in the emergency department, the

18.

A 42-year-old woman was seen in the emergency de-

physician noted that the upper part of the right calf was

partment after slipping on some ice on the way to work.

swollen and a gap was apparent between the swelling

She complained of pain on movement of her right an-

and the heel. A diagnosis of rupture of the right Achilles

kle joint. The physician asked the patient to evert her

tendon was made.

right foot. Which of the following muscles everts

the foot?

16.

The following statements concerning this patient are

A. The tibialis anterior muscle

correct except which?

B. The flexor hallucis longus muscle

A. With the patient supine, gentle squeezing of the up-

C. The peroneus longus muscle

per part of the right calf did not produce plantar flex-

D. The tibialis anterior muscle

ion of the ankle joint.

E. The flexor digitorum longus muscle

B. The Achilles tendon is the tendon of insertion of the

gastrocnemius and soleus muscles.

19.

A 61-year-old woman was being examined for os-

C. The Achilles tendon is inserted into the posterior

teoarthritis of the left hip joint by an orthopedic sur-

surface of the talus.

geon. He flexed the left hip joint with the knee flexed.

D. Rupture of the Achilles tendon results in the bellies

What structure normally limits the flexion of this joint

of the gastrocnemius and soleus muscles retracting

with the knee flexed?

upward, leaving a gap between the divided ends of

A. The hamstring muscles

the tendon.

B. The iliofemoral ligament

E. Normally, the gastrocnemius and soleus muscles are

C. The adductor magnus muscle

the main muscles responsible for plantar flexion of

D. The anterior abdominal wall

the ankle joint.

E. The ischiofemoral ligament

A 25-year-old man was admitted to the emergency de-

20.

A physician’s assistant asked a patient to walk up and

partment after an automobile accident. Apart from

down the examining room so that she might study his

other superficial injuries, he was found to have a frac-

gait. Which of the following muscles plays an impor-

ture of the middle third of the right femur.

tant role in lifting the left foot off the ground while

walking?

17.

The following statements concerning this patient are

A. The left gluteus medius muscle

possible except which?

B. The left gluteus maximus muscle

A. The soleus muscle was responsible for the backward

C. The right adductor longus muscle

rotation of the distal fragment.

D. The right gluteus medius muscle

B. A lateral radiograph showed overlap of the frag-

E. None of the above

ments, with the distal fragment rotated backward.

Answers and Explanations

1. D is the correct answer. The patellar tendon reflex

scapulae muscle as it crosses the posterior triangle of the

(knee jerk) involves L2, 3, and 4 segments of the spinal

neck (see text Fig. 13-9).

cord.

4. B is the correct answer. A blunt object forcibly striking

2. B is the correct answer. The wrist joint is not diseased.

the head often splits the epicranial aponeurosis against

This patient has traumatic tenosynovitis of the long ten-

the underlying skull, causing the skin wound to gape

dons of the extensor digitorum muscle.

open as if incised by a knife.

3. C is the correct answer. The spinal part of the accessory

5. A is the correct answer. A lumbar puncture (spinal

nerve, which supplies the sternocleidomastoid and

tap) is not required in cases of simple trauma to the

the trapezius muscles, lies superficial to the levator

back.

Skeletal Muscles

207

C is the correct answer. On the anterior axillary line (a

12.

E is the correct answer. The median nerve occupies a

line extending vertically downward from the lower bor-

small restricted space in the carpal (see CD Fig. 13-6).

der of the pectoralis major muscle) at the level of the

13.

This patient has a winged scapula caused by the paraly-

upper border of the sixth rib, the needle would pierce

sis of the serratus anterior muscle. The nerve supply to

the skin, fascia, the serratus anterior muscle, the exter-

the serratus anterior muscle is the thoracodorsal nerve,

nal intercostal muscle, the internal intercostal muscle,

a branch of the posterior cord of the brachial plexus.

the innermost intercostal muscle, and the parietal

Sometimes during a radical mastectomy operation,

pleura (see text Fig. 3-4).

which involves the clearing out of the lymph nodes and

E is the correct answer. The conjoint tendon, formed

fat in the axilla, the nerve is sacrificed since it may be

by the fusion of the tendons of the internal oblique and

involved in malignant disease (see text Fig. 13-23).

transversus abdominis muscles, greatly strengthens the

14.

This patient had supraspinatus tendinitis. During

posterior wall of the inguinal canal. A weakness of the

the middle range of abduction, the tendon of the

conjoint tendon and the lower abdominal musculature

supraspinatus impinges against the outer border of the

was responsible for the bulge, which constitutes a direct

acromion. Normally, the larger subacromial bursa in-

inguinal hernia.

tervenes and ensures that the movement is relatively

A is the correct answer. The neck of the femoral hernial

free of friction and is painless. In this condition, the

sac is situated below and lateral to the pubic tubercle

bursa has degenerated and the supraspinatus tendon ex-

(see CD Fig. 13-10).

hibits a localized area of collagen degeneration (see

CD Fig. 13-5).

A sudden unexpected blow on the anterior abdominal

wall causes excessive stretching of this structure. In this

15.

B is the correct answer. The distal end of the palmar

case the right inferior epigastric artery, which lies

aponeurosis gives rise to four slips, which pass to the

within the rectus sheath, was ruptured and the bleeding

four medial fingers (see CD Fig. 13-9).

occurred into the sheath. If a person is expecting a

16.

C is the correct answer. The Achilles tendon is inserted

blow, he or she automatically contracts his abdominal

into the posterior surface of the calcaneum (see text

muscles and protects the underlying structures.

Fig. 13-55).

10.

The patient had a tuberculous infection of the lumbar

vertebral column with destruction of the bodies of the

17.

A is the correct answer. The gastrocnemius muscle is

vertebrae, hence the kyphosis. The tuberculous pus ex-

responsible for the backward rotation of the distal frag-

tended laterally and to the right and entered the right

ment of the fractured femur.

psoas fascial sheath. From there, it extended downward

18.

C is the correct answer. The peroneus longus everts the

into the thigh, producing a swelling above and below

foot.

the inguinal ligament. Since the pus in each swelling

was continuous, pressure could be transmitted from

19.

D is the correct answer. Flexion of the hip joint (with

one swelling to the other (see CD Fig. 13-3).

the knee flexed) is limited by the thigh coming in con-

tact with the anterior abdominal wall.

11.

The uterus is mainly supported by the tone of the leva-

tores ani muscles. In addition, the ligaments of the

20.

D is the correct answer. The right gluteus medius and

visceral layer of pelvic fascia, namely, the transverse cer-

the right gluteus minimus tilt the pelvis so that the left

vical, sacrocervical, and pubocervical ligaments, play

lower limb is raised, thus permitting the left foot to be

an important role.

advanced forward clear of the ground.

Chapter Outline

The Skull

213

Cerebral Artery Occlusion

219

Anterior Cerebral Artery Occlusion

219

The Thinnest Part of the Lateral Wall of the Skull

213

Middle Cerebral Artery Occlusion

221

Fractures of the Skull

213

Internal Carotid Artery Occlusion

221

Fractures of the Facial Bones

213

Vertebral Artery Occlusion

221

Rises in Supratentorial Pressure

213

Basilar Artery Occlusion

222

Rises in Subtentorial Pressure

213

Central Branch Artery Occlusion

222

Movements of the Brain Relative to the Skull and

Transient Ischemic Attacks

222

Meninges in Head Injuries

214

Hydrocephalus

222

Intracranial Hemorrhage

215

Hydrocephalus Resulting from Excessive Formation

Computed Tomography Scans of Extradural

of Cerebrospinal Fluid

222

Hydrocephalus Resulting from Blockage of

and Subdural Hematomas

215

Cerebrospinal Fluid Circulation

222

Cerebral Arteriography

216

Hydrocephalus Resulting from Diminished

Congenital Aneurysms

217

Absorption of Cerebrospinal Fluid

222

Subarachnoid Hemorrhage

217

Clinical Problem Solving Questions

222

Cerebral Hemorrhage

217

Answers and Explanations

223

Cerebral Ischemia

219

Rises in Supratentorial Pressure

THE SKULL

The common causes of a rise in supratentorial pressure are

intracerebral hemorrhage, subarachnoid hemorrhage, sub-

The Thinnest Part of the Lateral

dural hemorrhage, epidural hemorrhage, and cerebral

edema. Two forms of caudal herniation of the brain through

Wall of the Skull

the tentorial notch of the tentorium cerebelli can occur as a

result of the raised supratentorial pressure:

The thinnest part of the lateral wall of the skull is where

the anteroinferior corner of the parietal bone articulates

■ Central herniation syndrome: In this syndrome the

with the greater wing of the sphenoid; this point is known

thalamus and midbrain are pushed caudally through the

as the pterion. This is a very important area since it over-

tentorial notch.

lies the anterior division of the middle meningeal artery

■ Uncal herniation syndrome: In this syndrome the uncus

and vein.

of the temporal lobe is displaced medially and pushes the

midbrain against the opposite sharp edge of the tentorial

notch. At the same time, the displaced uncus presses on

Fractures of the Skull

the ipsilateral oculomotor nerve at the notch, resulting in

a sluggishly reactive and dilated pupil (CD Fig. 14-1).

See Chapter 11 of the CD-ROM.

Rises in Subtentorial Pressure

Fractures of the Facial Bones

Posterior cranial fossa lesions such as those in cerebellar

See Chapter 11 of the CD-ROM.

hemorrhage cause a rise in pressure that can directly com-

The Skull, the Brain, the Meninges, and the Blood Supply of the Brain

213

left oculomotor nerve

herniated uncus of

falx cerebri

left cerebral hemisphere

superior

sagittal sinus

left cerebral

hemisphere

straight

sinus

midbrain (cut)

tentorium cerebelli

edge of tentorial

right trochlear nerve

notch on right side

temporal lobe

uncus

CD Figure 14-1

A. Lateral view of the interior of the skull showing the falx cerebri, ten-

torium cerebelli, and brainstem. As the result of abnormal supratentorial pressure, the un-

cus of the left cerebral hemisphere has herniated down through the tentorial notch of the

tentorium cerebelli and is pressing on the left oculomotor nerve. B. The position of the

uncus on the temporal lobe of the left cerebral hemisphere in a normal brain.

press the brainstem or its blood supply. Indirect compres-

sion can follow upward herniation of the cerebellum

Movements of the Brain Relative

through the tentorial notch or downward herniation of the

cerebellar tonsils through the foramen magnum. In the

to the Skull and Meninges in

latter instance the medulla will also be displaced and

pressed upon. The problem can be compounded by pres-

Head Injuries

sure on the cerebral aqueduct in the midbrain or the roof

of the fourth ventricle, producing an acute obstructive

Brain injuries are produced by displacement and distortion of

hydrocephalus.

the neuronal tissues at the moment of impact (CD Fig. 14-2).

214

Chapter 14

trauma due to negative pressure

direct cerebral trauma

trauma due to

negative pressure

distortion of brainstem

direct cerebellar trauma

subdural hemorrhage

epidural hemorrhage

intracerebral hemorrhage

direct cerebral

trauma

secondary trauma due to cerebral

C ^momentum

CD Figure 14-2

A. Mechanisms of acute cerebral injury when a blow is applied to the

lateral side of the head. B. Varieties of intracranial hemorrhage. C. Mechanism of cerebral

trauma following a blow on the chin. The movement of the brain within the skull can also

tear the cerebral veins.

The brain, which is incompressible, may be likened to a log

edge of the falx cerebri; the superior surface of the cerebellum

soaked with water floating in water. The brain is floating in

presses against the inferior surface of the tentorium cerebelli.

the cerebrospinal fluid in the subarachnoid space and is ca-

It follows from these anatomic facts that blows on the

pable of a certain amount of anteroposterior and lateral glid-

front or back of the head lead to displacement of the brain,

ing movement. The anteroposterior movement is limited by

which may produce severe cerebral damage, stretching and

the attachment of the superior cerebral veins to the superior

distortion of the brainstem, and stretching and even tearing

sagittal sinus. In lateral movements, the lateral surface of one

of the commissures of the brain. Blows to the side of the

hemisphere hits the side of the skull, and the medial surface

head produce less cerebral displacement, and the injuries to

of the opposite hemisphere hits the side of the falx cerebri (see

the brain consequently tend to be less severe. The falx cere-

CD Fig. 14-2). In superior movements, the superior surfaces

bri, however, is a tough structure and may cause consider-

of the cerebral hemispheres hit the vault of the skull, and the

able damage to the softer brain tissue in cases where there

superior surface of the corpus callosum may hit the sharp free

has been a severe blow to the side of the head (see CD Fig.

The Skull, the Brain, the Meninges, and the Blood Supply of the Brain

215

14-2). Furthermore, glancing blows to the head may result

Subdural hemorrhage results from tearing of the supe-

in considerable rotation of the brain, causing shearing

rior cerebral veins at their point of entrance into the supe-

strains and distortion, particularly in areas where further ro-

rior sagittal sinus. The cause is usually a blow on the front or

tation is prevented by bony prominences in the anterior and

the back of the head, causing excessive anteroposterior dis-

middle cranial fossae. Brain lacerations are likely to occur

placement of the brain within the skull.

when the brain is forcibly thrown against the sharp edges of

This condition, which is much more common than

bone within the skull—the lesser wing of the sphenoid, for

middle meningeal hemorrhage, can be produced by a sud-

example.

den minor blow. Once the vein is torn, blood under low

When the brain is suddenly given momentum within

pressure begins to accumulate in the potential space be-

the skull, the part of the brain that moves away from the

tween the dura and the arachnoid. In about half the cases

skull wall is subjected to diminished pressure, because

the condition is bilateral.

the cerebrospinal fluid has not had time to accommodate

Acute and chronic forms of the clinical condition oc-

the brain movement (see CD Fig. 14-2). This results in a

cur, depending on the speed of accumulation of fluid in the

suction effect on the brain surface, with rupture of surface

subdural space. For example, if the patient starts to vomit,

blood vessels.

the venous pressure will rise as a result of a rise in the in-

A sudden severe blow to the head, as in an automobile

trathoracic pressure. Under these circumstances, the sub-

accident, may result in damage to the brain at the following

dural blood clot will increase rapidly in size and produce

two sites: (1) at the point of impact and (2) at the pole of the

acute symptoms. In the chronic form, over a course of sev-

brain opposite the point of impact, where the brain is

eral months the small blood clot will attract fluid by osmo-

thrown against the skull wall. This is referred to as contre-

sis so that a hemorrhagic cyst is formed, which gradually

coup injury.

expands and produces pressure symptoms. In both forms the

Movements of the brain relative to the skull and dural

blood clot must be removed through burr holes in the skull.

septa may seriously injure the cranial nerves that are teth-

ered as they pass through the various foramina. This partic-

ularly applies to the long, slender nerves, such as the

COMPUTED

trochlear, abducent, and occulomotor nerves. Furthermore,

the fragile cortical veins that tether the brain and drain into

TOMOGRAPHY

the dural sinuses may be torn, resulting in severe subdural

or subarachnoid hemorrhage. The large arteries found at

the base of the brain are tortuous, and this, coupled with

SCANS OF

their strong walls, explains why they are seldom damaged.

EXTRADURAL AND

Intracranial Hemorrhage

SUBDURAL

Intracranial hemorrhage may result from trauma or cerebral

vascular lesions. Four varieties are considered here: ex-

tradural, subdural, subarachnoid, and cerebral.

HEMATOMAS

Extradural hemorrhage results from injuries to the

meningeal arteries or veins. The most common artery to be

The different appearances of blood clots in these two condi-

damaged is the anterior division of the middle meningeal

tions as seen on computed tomography (CT) scans is related

artery. A comparatively minor blow to the side of the head,

to the anatomy of the area (CD Fig. 14-3). In an extradural

resulting in fracture of the skull in the region of the an-

hemorrhage the blood strips the meningeal layer of the dura

teroinferior portion of the parietal bone, may sever the

from the endosteal layer of dura (periosteum of the skull),

artery. The arterial or venous injury is especially liable to oc-

producing a lens-shaped hyperdense collection of blood that

cur if the artery and vein enter a bony canal in this region.

compresses the brain and displaces the midline structures to

Bleeding occurs and strips the meningeal layer of dura from

the opposite side. The shape of the blood clot is determined

the internal surface of the skull. The intracranial pressure

by the adherence of the meningeal layer of dura to the

rises, and the enlarging blood clot exerts local pressure on

periosteal layer of dura.

the underlying motor area in the precentral gyrus. Blood

In patients with subdural hematoma the blood accu-

may also pass outward through the fracture line to form a

mulates in the extensive potential space between the

soft swelling under the temporalis muscle.

meningeal layer of dura and the arachnoid, producing a

To stop the hemorrhage, the torn artery or vein must be

long, crescent-shaped, hyperdense rim of blood that extends

ligated or plugged. The burr hole through the skull wall

from anterior to posterior along the inner surface of the skull.

should be placed about 1 to 1.5 in. (2.5 to 4 cm) above the

With a large hematoma, the brain sulci are obliterated, and

midpoint of the zygomatic arch.

the midline structures are displaced to the opposite side.

216

Chapter 14

periosteum

periosteal

skull bone

(endosteal)

layer of dura

periosteal

layer of

epidural

blood clot

dura

meningeal

layer of

dura

meningeal

arachnoid

layer of

dura

periosteum

distorted

skull bone

arachnoid

right

ventricle

subdural

blood clot

periosteal

deflected

layer of

falx cerebri

dura

meningeal

distorted

layer of

lateral

dura

ventricles

arachnoid

CD Figure 14-3

Diagrammatic representation of an extradural hemorrhage and a

subdural hemorrhage. A. Extradural hemorrhage from the middle meningeal artery or

vein on the left side. The hematoma is lens-shaped and occupies the space between the

endosteal layer of dura (periosteum of the skull) and the meningeal layer of dura (true

dura, hence the name extradural). B. Subdural hemorrhage from the cerebral veins at the

site of entrance into the venous sinus on the right side. The hematoma is crescent-shaped

and occupies the space between the meningeal layer of dura and the arachnoid, (i.e.,

beneath the dura).

With the patient under general anesthesia and in the supine

CEREBRAL

position, the head is centered on a radiographic apparatus

that will take repeated radiographs at 2-second intervals.

Both anteroposterior and lateral projections are obtained. A

ARTERIOGRAPHY

radiopaque medium is rapidly injected into the lumen of

the common carotid or vertebral arteries. As the radiopaque

The technique of cerebral arteriography is used to detect ab-

material is introduced, a series of films are exposed. By this

normalities of the cerebral arteries and localization of space-

means the cerebral arteries can be demonstrated and their

occupying lesions such as tumors, blood clots, or abscesses.

position and patency determined (CD Figs. 14-4 to 14-7).

The Skull, the Brain, the Meninges, and the Blood Supply of the Brain

217

CD Figure 14-4

Lateral internal carotid arteriogram.

This technique is not without risk because the insertion of a

needle through the wall of an artery or the manipulation of

Subarachnoid Hemorrhage

a catheter within its lumen may dislodge an atheromatous

Subarachnoid hemorrhage results from leakage or rupture

plaque, leading to cerebral embolism.

of a congenital aneurysm on the circle of Willis or, less com-

monly, from an angioma. The symptoms, which are sudden

Congenital Aneurysms

in onset, include severe headache, stiffness of the neck, and

loss of consciousness. The diagnosis is established by with-

Congenital aneurysms occur most commonly at the site

drawing heavily blood-stained cerebrospinal fluid through a

where two arteries join in the formation of the circle of Willis

lumbar puncture (spinal tap).

(CD Fig. 14-8). At this point, there is a deficiency in the tu-

nica media that so weakens the arterial wall that an aneurysm

develops. The enlarging aneurysm may press on neighboring

Cerebral Hemorrhage

structures, such as the optic, oculomotor, trochlear, and ab-

ducent nerves, and produce signs and symptoms or may sud-

Cerebral hemorrhage is generally caused by rupture of the

denly rupture into the subarachnoid space.

thin-walled lenticulostriate artery, a branch of the middle

The Skull, the Brain, the Meninges, and the Blood Supply of the Brain

219

CD Figure 14-6

Anteroposterior internal carotid arteriogram.

cerebral artery. The hemorrhage involves the vital cortico-

lowing blockage of one of the intracranial vessels will depend

bulbar and corticospinal fibers in the internal capsule and

on the location of the blockage and the status of the collat-

produces hemiplegia on the opposite side of the body. The

eral circulation. The blood supply to the functional areas of

patient immediately loses consciousness, and the paralysis is

the cerebral cortex is shown in text Fig. 14-17.

evident when consciousness is regained.

Cerebral Artery Occlusion

Cerebral Ischemia

Anterior Cerebral Artery Occlusion

It has been pointed out that there are two distinct yet inter-

connected vascular systems supplying the brain. The carotid

If the occlusion of the artery is proximal to the anterior com-

arteries are the major suppliers of the cerebral hemispheres,

municating artery, the collateral circulation is usually ade-

and the basilar and vertebral arteries are the major suppliers

quate to preserve the circulation. Occlusion distal to the

of the brainstem and cerebellum. The neurologic deficit fol-

communicating artery may produce the following signs and

The Skull, the Brain, the Meninges, and the Blood Supply of the Brain

221

anterior communicating artery

anterior cerebral artery

internal carotid artery

middle cerebral artery

posterior communicating artery

posterior cerebral artery

basilar artery

vertebral artery

CD Figure 14-8

A. The formation of the circle of Willis from the two internal carotid and

two vertebral arteries. B. The distribution of blood from the four main arteries.

symptoms:

tion, the following may be seen:

■ Contralateral hemiparesis and hemisensory loss involv-

■ Loss of vision on the same side as the internal carotid

ing mainly the leg and foot

artery occlusion due to blockage of the ophthalmic artery

■ Inability to identify objects correctly, apathy, and person-

■ Decreased level of consciousnes

ality changes

Vertebral Artery Occlusion

Middle Cerebral Artery Occlusion

This produces a variable clinical picture and may include

Occlusion of the artery may produce the following signs and

the following signs and symptoms:

symptoms.

■ Ipsilateral pain and temperature sensory loss of the face and

■ Contralateral hemiparesis and hemisensory loss

contralateral pain and temperature sensory loss of the body

■ Aphasia if the left hemisphere is affected (rarely if the

■ Ipsilateral loss of the gag reflex, dysphagia, and hoarse-

right hemisphere is affected)

ness as the result of lesions of the nuclei of the glos-

■ Homonymous hemianopia

sopharyngeal and vagus nerves

■ Anosognosia if the right hemisphere is affected (rarely if

■ Vertigo, nystagmus, nausea, and vomiting

the left hemisphere is affected)

■ Ipsilateral Horner’s syndrome

■ Ipsilateral ataxia

Internal Carotid Artery Occlusion

If the lesion is more extensive, the corticospinal tracts

This may produce all the symptoms and signs of anterior

may be involved, producing contralateral hemiparesis of the

and middle cerebral artery occlusion, depending on the de-

body. Contralateral loss of position and vibration sense may

gree of collateral circulation at the circle of Willis; in addi-

also be lost due to damage to the medial lemniscus.

222

Chapter 14

the subarachnoid space and cannot be absorbed by the

Basilar Artery Occlusion

arachnoid villi, the hydrocephalus is the communicating

type (i.e., the cerebrospinal fluid inside the brain commu-

Since this artery gives off numerous branches to the pons,

nicates with that on the outside).

cerebellar peduncles, and cerebellum, total blockage of this

artery can produce lesions of the trigeminal, abducent, and

Hydrocephalus Resulting from

facial nerve nuclei, quadriplegia, and coma (reticular for-

Excessive Formation of

mation). If occlusion is restricted to branches of the basilar

Cerebrospinal Fluid

artery, there may be contralateral hemiparesis, contralateral

sensory loss, or evidence of cerebellar dysfunction.

This condition is rare and may occur when there is a tumor

of the choroid plexuses.

Central Branch Artery Occlusion

Hydrocephalus Resulting from Block-

Small artery occlusion will cause discrete areas of brain

age of Cerebrospinal Fluid Circulation

necrosis. The signs and symptoms produced will obviously

depend on the area involved. For example, a lesion of the in-

An obstruction of the interventricular foramen by a tumor

ternal capsule may result in contralateral hemiplegia.

will block the drainage of the lateral ventricle on that side.

The continued production of cerebrospinal fluid by the

choroid plexus of that ventricle will cause distention of that

Transient Ischemic Attacks

ventricle and atrophy of the surrounding neural tissue.

These are brief, self-limited focal neurologic deficits caused

An obstruction in the cerebral aqueduct in the mid-

by embolic or thrombotic occlusion of arteries supplying the

brain may be congenital or result from inflammation or

brain. The signs and symptoms will depend on the area of

pressure from a tumor. This causes a symmetrical disten-

brain involved.

sion of both lateral ventricles and distension of the third

For further information on the clinical neuroanatomy

ventricle.

of this area, please consult Clinical Neuroanatomy, 6th ed.,

Obstruction of the foramina in the roof of the fourth

by R.S. Snell, Lippincott Williams & Wilkins.

ventricle by inflammatory exudate, or by tumor growth, will

produce symmetrical dilatation of both lateral ventricles

and the third and fourth ventricle.

Hydrocephalus

Sometimes inflammatory exudate secondary to menin-

Hydrocephalus is an abnormal increase in the volume of the

gitis will block the subarachnoid space and obstruct the flow

cerebrospinal fluid within the skull. If hydrocephalus is ac-

of cerebrospinal fluid over the outer surface of the cerebral

companied by raised cerebrospinal fluid pressure, it is

hemispheres. Here, again, the entire ventricular system of

caused by either (1) an abnormal increase in fluid formation,

the brain will become distended.

(2) blockage of the fluid circulation, or (3) diminished ab-

sorption of the fluid. Rarely, hydrocephalus occurs with nor-

Hydrocephalus Resulting from

mal cerebrospinal fluid pressure, and in these patients com-

Diminished Absorption of

pensatory hypoplasia or atrophy of the brain substance exists.

Cerebrospinal Fluid

When the block of the movement of cerebrospinal fluid

lies within the brain, the hydrocephalus is the noncommu-

Interference with the absorption of cerebrospinal fluid at the

nicating type (i.e., the cerebrospinal fluid inside the brain

arachnoid granulations can be caused by inflammatory exu-

does not communicate with that on the outside). If the fluid

date, venous thrombosis or pressure on the venous sinuses,

is able to pass through the roof of the fourth ventricle into

or obstruction of the internal jugular vein.

Clinical Problem Solving Questions

Read the following case histories/questions and give

tion, he was found to have a dough-like swelling over the

the best answer for each.

right temporalis muscle. He also had the signs of right-

sided hemiplegia. Later, a right-sided, fixed, dilated pupil

1. A 36-year-old man was admitted to the emergency de-

developed. A lateral radiograph of the skull showed a lin-

partment unconscious. He had been hit on the side of

ear fracture running downward and forward across the

the head by a taxi while crossing the road. On examina-

right pterion. His coma deepened, and he died 6 hours

The Skull, the Brain, the Meninges, and the Blood Supply of the Brain

223

after the accident. Using your knowledge of anatomy,

as a third-floor window, and yet it is known that if an

make the diagnosis. Explain the clinical findings. How

adult falls from a similar height, it would be fatal. Can

would you explain the homolateral hemiplegia?

you give an anatomic explanation, based on age, for this

difference in survival?

Severe injury to the soft structures within the skull may

follow head trauma. What structures exist within the

Using your knowledge of the anatomic pathways along

skull to limit damage to the cerebral hemispheres and

which the cerebrospinal fluid flows, name the sites at

other parts of the brain? Which blood vessels are dam-

which pathologic blockage may occur.

aged more commonly, the cerebral arteries or the

cerebral veins? Which cranial nerves are likely to be

There are no anastomoses of clinical importance be-

damaged in head injuries? What is the reason for their

tween the terminal end arteries within the brain sub-

susceptibility?

stance, but there are many important anastomoses be-

tween the large arteries, both within and outside the

A 51-year-old woman was examined in the emergency

skull, and these may play a major role in determining

department complaining of a severe headache. She said

the extent of brain damage in cerebral vascular disease.

that the headache had started about 1 hour after she

Name the sites at which important arterial anastomoses

had hit her head on the mantle piece of a fireplace af-

take place.

ter bending down to poke the fire. Four hours later it

was noticed that she was becoming mentally confused

A 35-year-old man was seen in the emergency depart-

and was developing a left-sided hemiplegia on the side

ment with a history of sudden excruciating, generalized

opposite the head injury. Her deep reflexes were exag-

headache while gardening. Ten minutes later the pa-

gerated, and she had a positive Babinski response on the

tient collapsed to the ground in a state of unconscious-

left side. A CT scan demonstrated a right subdural

ness. After being carried indoors and placed on a settee,

hematoma. Explain in anatomic terms the develop-

he regained consciousness but appeared confused. He

ment of a subdural hematoma.

complained of a severe headache and a stiff neck. Phys-

ical examination revealed some rigidity of the neck but

Which part of the base of the skull is most prone to frac-

nothing further. A careful neurologic examination 4

ture? Can you give an anatomic reason for this answer?

days later revealed some loss of tone of the muscles of

It is not uncommon to read in newspapers of the sur-

the left leg. Using your knowledge of anatomy, make a

vival of a baby that has fallen from a great height, such

diagnosis. What caused the neck rigidity?

Answers and Explanations

1. The initial loss of consciousness was due to cerebral

2. The meninges and the cerebrospinal fluid afford a re-

trauma. The swelling over the right temporalis muscle

markable degree of protection to the brain tissue. The

and the radiographic finding of a linear fracture over

dural partitions limit the extent of side-to-side, forward

the anterior inferior angle of the right parietal bone

and backward, and rotation movements of the brain

(pterion) would suggest that the right middle

within the skull.

meningeal artery had been damaged and an extradural

The thin-walled cerebral veins are liable to be damaged

hemorrhage had occurred. Blood had extravasated

during excessive movements of the brain relative to the

through the fracture line into the overlying temporalis

skull, especially at the point where the veins join the

muscle and soft tissue. The right homolateral hemi-

dural venous sinuses. The thick-walled cerebral arteries

plegia was due to the compression of the left cerebral

are rarely damaged.

peduncle against the edge of the tentorial notch of the

tentorium cerebelli. This is unusual. A left hemiplegia

The small-diameter cranial nerves of long length are

due to pressure on the right precentral gyrus is more

particularly prone to damage during head injuries. The

common.

trochlear, abducent, and oculomotor nerves are com-

monly injured.

The right-sided, fixed, dilated pupil was due to the

pressure on the right oculomotor nerve by the hip-

3. A subdural hematoma is an accumulation of blood clot

pocampal gyrus, which had herniated through the ten-

in the interval between the meningeal layer of dura and

torial notch.

the arachnoid mater. It results from tearing of the supe-

224

Chapter 14

rior cerebral veins at their point of entrance into the su-

Once the terminal branches of the cerebral arteries

perior sagittal sinus. The cause is usually a blow to the

enter the brain substance, no further anastomoses oc-

front or the back of the head (which may be minor), re-

cur. Blockage of such end arteries by disease is quickly

sulting in excessive anteroposterior displacement of the

followed by neuronal death and necrosis. The follow-

brain within the skull.

ing important anastomoses exist between the cerebral

arteries: (1) the circle of Willis, (2) anastomoses be-

The middle cranial fossa is the part of the skull most

tween the branches of the cerebral arteries on the sur-

prone to fracture, since it possesses numerous foramina

face of the cerebral hemispheres and the cerebellar

and canals and has air spaces, namely, the sphenoid air

hemispheres, and

(3) anastomoses between the

sinus and the tympanic cavity. The foramen magnum

branches of the internal and external carotid arteries at

in the posterior cranial fossa is very large but its bound-

their origin at the common carotid artery, at the anas-

aries are extremely thick.

tomosis between the branches of the ophthalmic

In infants the skull bones are more resilient than in

artery within the orbit and the facial and maxillary ar-

adults, and they are separated by fibrous sutural liga-

teries, and between the meningeal branches of the in-

ments. In adults the inner table of the skull is particu-

ternal carotid artery and the middle meningeal artery.

larly brittle and the sutural ligaments begin to ossify

This patient had a congenital aneurysm of the anterior

during middle age.

communicating artery. The sudden onset of a severe

The common sites for blockage of the flow of cere-

headache, which is often so dramatic that the patient

brospinal fluid are where the passages are narrowest,

feels as though he has been hit on the head, is char-

namely, the interventricular foramina (between the lat-

acteristic of rupture of a congenital aneurysm into the

eral and third ventricles), the cerebral aqueduct of the

subarachnoid space. The stiff or rigid neck is due to

midbrain, the median aperture, and the lateral aper-

meningeal irritation caused by the presence of blood

tures in the roof of the fourth ventricle. It is possible for

in the subarachnoid space. This patient had no

inflammatory exudate secondary to meningitis or a

evidence of previous pressure on the optic nerve lead-

cerebral tumor to narrow down or even obliterate the

ing to unilateral visual defect, which sometimes oc-

opening in the tentorial notch so that the passage of the

curs when the aneurysm is situated on the anterior

cerebrospinal fluid to the outer surface of the cerebral

part of the circle of Willis. The loss of tone in the left

hemisphere is impeded or stopped. Inflammatory exu-

leg muscles is difficult to explain, although it may be

date may also block the drainage of the fluid into the su-

due to penetration of the hemorrhage into the right

perior sagittal sinus at the arachnoid villi.

cerebral hemisphere.

Chapter Outline

Clinical Testing of the Cranial Nerves

227

Infraorbital Nerve Block

232

Area of Anesthesia

232

Testing the Integrity of the Olfactory Nerve

227

Indications

232

Testing the Integrity of the Optic Nerve

227

Procedure

233

Testing the Integrity of the Oculomotor,

Intraoral Method

233

Extraoral Method

233

Trochlear, and Abducent Nerves

227

Pterygopalatine Ganglion Block

233

Testing the Integrity of the Trigeminal Nerve

227

Area of Anesthesia

233

Testing the Integrity of the Facial Nerve

228

Indications

233

Procedure

234

Testing the Integrity of the Vestibulocochlear

Mandibular Nerve Block

234

Nerve

229

Auriculotemporal Nerve Block

234

Testing the Integrity of the Glossopharyngeal

Area of Anesthesia

234

Nerve

229

Indications

234

Procedure

234

Testing the Integrity of the Vagus Nerve

229

Anatomy of Complications

235

Testing the Integrity of the Accessory Nerve

229

Lingual Nerve and Inferior Alveolar Nerve

Testing the Integrity of the Hypoglossal Nerve

229

Blocks

235

Area of Anesthesia

235

Clinical Anatomy of Trigeminal Nerve

Indications

235

Blocks

229

Procedure

235

Ophthalmic Nerve Block

229

Mental Nerve Block

236

Supraorbital Nerve Block

230

Area of Anesthesia

236

Area of Anesthesia

230

Indications

236

Indications

230

Procedure

236

Procedure

230

Intraoral Method

236

Supratrochlear Nerve Block

231

Extraoral Method

237

Area of Anesthesia

231

Special Areas for Nerve Blocks

237

Indications

231

Tooth Nerve Blocks

237

Procedure

231

Supraperiosteal Infiltration

237

Infratrochlear Nerve Block

232

Dental Nerve Blocks

238

Area of Anesthesia

232

Anesthesia of the Nose

238

Indications

232

Nasal Interior

238

Procedure

232

Nasal Exterior

238

External Nasal Nerve Block

232

Anesthesia of the Ear

240

Area of Anesthesia

232

Anesthesia of the Scalp

240

Indications

232

Procedure

232

Clinical Problem Solving Questions

240

Maxillary Nerve Block

232

Answers and Explanations

242

The Cranial Nerves and Trigeminal Nerve Blocks

227

object. It is important not to miss loss or impairment of

vision in the central area of the field (central scotoma).

CLINICAL TESTING

Blindness in one half of each visual field is called hemi-

anopia. Lesions of the optic tract and optic radiation

OF THE CRANIAL

produce the same hemianopia for both eyes, that is,

homonymous hemianopia. Bitemporal hemianopia is a loss

NERVES

of the lateral halves of the fields of vision of both eyes (i.e.,

loss of function of the medial half of both retinas). This con-

Systematic examination of the 12 cranial nerves is an im-

dition is most commonly produced by a tumor of the pitu-

portant part of the examination of every neurologic patient.

itary gland exerting pressure on the optic chiasma.

It may reveal a lesion of a cranial nerve nucleus or its cen-

tral connections, or it may show an interruption of the lower

Testing the Integrity of the

motor neurons.

The letter symbols commonly used to indicate the

Oculomotor, Trochlear, and

functional components of each cranial nerve are shown in

text Table 15-1. The different components of the cranial

Abducent Nerves

nerves, their functions, and the openings in the skull

through which the nerves leave the cranial cavity are sum-

The oculomotor, trochlear, and abducent nerves innervate

marized in text Table 15-2.

the muscles that move the eyeball. The oculomotor nerve

supplies all the orbital muscles except the superior oblique

and the lateral rectus. It also supplies the levator palpebrae

Testing the Integrity of the

superioris and the smooth muscles concerned with accom-

modation—namely, the sphincter pupillae and the ciliary

Olfactory Nerve

muscle. The trochlear nerve supplies the superior oblique

The olfactory nerve can be tested by applying substances

muscle, and the abducent nerve supplies the lateral rectus.

with different odors to each nostril in turn. It should be re-

To examine the ocular muscles, the patient’s head is

membered that food flavors depend on the sense of smell

fixed and he or she is asked to move the eyes in turn to the

and not on the sense of taste. Fractures of the anterior cra-

left, to the right, upward, and downward, as far as possible in

nial fossa or cerebral tumors of the frontal lobes may pro-

each direction.

duce lesions of the olfactory nerves, with consequent loss of

In complete third-nerve paralysis the eye cannot be

the sense of smell (anosmia).

moved upward, downward, or inward. At rest the eye looks

laterally (external strabismus) because of the activity of the

lateral rectus and downward because of the activity of the su-

Testing the Integrity of the

perior oblique. The patient sees double (diplopia). Droop-

ing of the upper eyelid (ptosis) occurs because of paralysis of

Optic Nerve

the levator palpebrae superioris. The pupil is widely dilated

The optic nerve is evaluated by first asking the patient

and nonreactive to light because of the paralysis of the

whether any changes in eyesight have been noted. The acu-

sphincter pupillae and the unopposed action of the dilator

ity of vision is then tested by using charts with lines of print

pupillae (supplied by the sympathetic). Accommodation of

of varying size. The retinas and optic discs should then be

the eye is paralyzed.

examined with an ophthalmoscope. When examining the

In fourth-nerve paralysis the patient complains of dou-

optic disc, it should be remembered that the intracranial

ble vision on looking straight downward. This is because the

subarachnoid space extends forward around the optic nerve

superior oblique is paralyzed and the eye turns medially as

to the back of the eyeball. The retinal artery and vein run in

the inferior rectus pulls the eye downward.

the optic nerve and cross the subarachnoid space of the

In sixth-nerve paralysis the patient cannot turn the eye-

nerve sheath a short distance behind the eyeball. A rise in

ball laterally. When looking straight ahead, the lateral rectus

cerebrospinal fluid pressure in the subarachnoid space will

is paralyzed, and the unopposed medial rectus pulls the

compress the thin walls of the retinal vein as it crosses the

eyeball medially, causing internal strabismus.

space, resulting in congestion of the retinal veins, edema of

the retina, and bulging of the optic disc (papilledema).

Testing the Integrity of the

The visual fields should then be tested. The patient is

asked to gaze straight ahead at a fixed object with the eye be-

Trigeminal Nerve

ing tested, with the opposite eye covered. A small object is

then moved in an arc around the periphery of the field of vi-

The trigeminal nerve has sensory and motor roots. The sen-

sion, and the patient is asked whether he or she can see the

sory root passes to the trigeminal ganglion, from which

228

Chapter 15

emerge the ophthalmic (V1), maxillary (V2), and mandibu-

The anatomic relationship of this nerve to other struc-

lar (V3) divisions. The motor root joins the mandibular

tures enables a physician to localize lesions of the nerve ac-

division.

curately. If the sixth and seventh nerves are not functioning,

The sensory function can be tested by using a cotton

this would suggest a lesion within the pons of the brain. If

wisp over each area of the face supplied by the divisions of

the eighth and seventh nerves are not functioning, this

the trigeminal nerve (CD Fig. 15-1).

would suggest a lesion in the internal acoustic meatus. If the

The motor function can be tested by asking the patient

patient is excessively sensitive to sound in one ear, the lesion

to clench the teeth. The masseter and the temporalis mus-

probably involves the nerve to the stapedius. Loss of taste

cles, which are innervated by the mandibular division of the

over the anterior two thirds of the tongue implies that the

trigeminal nerve, can be palpated and felt to harden as they

seventh nerve is damaged proximal to the point where it

contract.

gives off the chorda tympani.

To test the facial nerve, the patient is asked to show the

teeth by separating the lips with the teeth clenched, and

Testing the Integrity of the

then to close the eyes. Taste on each half of the anterior two

thirds of the tongue can be tested with sugar, salt, vinegar,

Facial Nerve

and quinine for the sweet, salty, sour, and bitter sensations,

The facial nerve supplies the muscles of facial expression;

respectively.

supplies the anterior two thirds of the tongue with taste

It should be remembered that the part of the facial

fibers; and is secretomotor to the lacrimal, submandibular,

nerve nucleus that controls the muscles of the upper part of

and sublingual glands.

the face receives corticobulbar fibers from both cerebral

V1 (ophthalmic

division)

greater

occipital

nerve (C2)

V2 (maxillary

division)

great auricular

nerve (C2 and C3)

V3 (mandibular

C2 and C3

division)

posterior

primary

rami

anterior primary

rami

CD Figure 15-1

The facial cutaneous distribution of the ophthalmic (V1), maxillary (V2),

and mandibular (V3) divisions of the trigeminal nerve. Note that the skin over the angle of

the jaw is supplied by the great auricular nerve (C2 and C3 segments of the spinal cord).

The Cranial Nerves and Trigeminal Nerve Blocks

229

cortices. Therefore, in patients with an upper motor neuron

muscle, which is supplied by the external laryngeal branch

lesion, only the muscles of the lower part of the face will be

of the superior laryngeal branch of the vagus. Hoarseness or

paralyzed. However, in patients with a lower motor neuron

absence of the voice may occur. Laryngoscopic examination

lesion, all the muscles on the affected side of the face will be

may reveal abductor paralysis.

paralyzed. The lower eyelid will droop, and the angle of the

mouth will sag. Tears will flow over the lower eyelid, and

Testing the Integrity of the

saliva will dribble from the corner of the mouth. The patient

will be unable to close the eye and cannot expose the teeth

Accessory Nerve

fully on the affected side.

The accessory nerve supplies the sternocleidomastoid and

the trapezius muscles by means of its spinal part. The pa-

Testing the Integrity of the

tient should be asked to rotate the head to one side against

resistance, causing the sternocleidomastoid of the opposite

Vestibulocochlear Nerve

side to come into action. Then the patient should be asked

The vestibulocochlear nerve innervates the utricle and sac-

to shrug the shoulders, causing the trapezius muscles to

cule, which are sensitive to static changes in equilibrium;

come into action.

the semicircular canals, which are sensitive to changes in

dynamic equilibrium; and the cochlea, which is sensitive to

Testing the Integrity of the

sound.

Disturbances of vestibular function include dizzi-

Hypoglossal Nerve

ness (vertigo) and nystagmus. The latter is an uncontrol-

lable pendular movement of the eyes. Disturbances of

The hypoglossal nerve supplies the muscles of the tongue.

cochlear function reveal themselves as deafness and ringing

The patient is asked to put out the tongue, and if a lesion

in the ears (tinnitus). The patient’s ability to hear a voice or

of the nerve is present, it will be noted that the tongue

a tuning fork should be tested, with each ear tested

deviates toward the paralyzed side (CD Fig. 15-2). This

separately.

can be explained as follows. One of the genioglossus mus-

cles, which pull the tongue forward, is paralyzed on the af-

fected side. The other, normal genioglossus muscle

Testing the Integrity of the

pulls the unaffected side of the tongue forward, leaving the

paralyzed side of the tongue stationary. The result is the

Glossopharyngeal Nerve

tip of the tongue’s deviation toward the paralyzed side.

The glossopharyngeal nerve supplies the stylopharyngeus

In patients with long-standing paralysis, the muscles on the

muscle and sends secretomotor fibers to the parotid gland.

affected side are wasted, and the tongue is wrinkled on

Sensory fibers innervate the posterior one third of the

that side.

tongue.

The integrity of this nerve may be evaluated by testing

the patient’s general sensation and that of taste on the poste-

CLINICAL

rior third of the tongue.

ANATOMY OF

Testing the Integrity of the

Vagus Nerve

TRIGEMINAL

The vagus nerve innervates many important organs, but the

NERVE BLOCKS

examination of this nerve depends on testing the function of

the branches to the pharynx, soft palate, and larynx. The

pharyngeal reflex may be tested by touching the lateral wall

of the pharynx with a spatula. This should immediately

Ophthalmic Nerve Block

cause the patient to gag—that is, the pharyngeal muscles

will contract.

The terminal branches of the ophthalmic division of the

The innervation of the soft palate can be tested by ask-

trigeminal nerve that emerge onto the face and nose include

ing the patient to say “ah.” Normally, the soft palate rises

the supraorbital, supratrochlear, infratrochlear, external

and the uvula moves backward in the midline.

nasal, and lacrimal nerves (CD Fig. 15-3). The latter nerve

All the muscles of the larynx are supplied by the recur-

gives off only a few branches to the skin and is seldom

rent laryngeal branch of the vagus, except the cricothyroid

blocked.

230

Chapter 15

right

hypoglossal nerve

cut right hypoglossal

intact hypoglossal

nerve

CD Figure 15-2

Diagrammatic rep-

right half

resentation of the action of the right

of tongue

and left genioglossus muscles of the

atrophied

tongue. A. The right and left muscles

contract equally together and as a re-

sult (B) the tip of the tongue is pro-

truded in the midline. C. The right

hypoglossal nerve (which innervates

the genioglossus muscle and the in-

trinsic tongue muscles on the same

side) is cut and as a result the right

side of the tongue is atrophied and

wrinkled. D. When the patient is

asked to protrude the tongue, the tip

genioglossus

points to the side of the nerve lesion.

E. The origin and insertion and direc-

muscle

tion of pull of the genioglossus mus-

cle.

Supraorbital Nerve Block

This involves the following:

Area of Anesthesia

supraorbital nerve

Skin of the upper eyelid, the forehead, and the scalp as far

supratrochlear nerve

back as the vertex (CD Fig. 15-4)

lacrimal nerve

infratrochlear nerve

Indications

Repair of lacerations of the upper eyelid, forehead, and scalp

external nasal nerve

Procedure

The supraorbital nerve emerges from the orbital cavity in the

same vertical plane as the pupil when the patient is looking

CD Figure 15-3

Anterior view of the skull showing the

straight ahead (see CD Fig. 15-4). If the nerve passes through

branches of the ophthalmic (V1) division of the trigeminal

nerve emerging onto the face.

the supraorbital notch, this can easily be palpated on the

The Cranial Nerves and Trigeminal Nerve Blocks

231

supratrochlear nerve

supraorbital nerve

infratrochlear nerve

external nasal nerve

supratrochlear area

supraorbital

area

site for injection of

supraorbital nerve

site for injection of

infratrochlear

supratrochlear nerv

area

external nasal

site for injection of

area

infratrochlear nerve

site for injection of

external nasal nerve

CD Figure 15-4

Supraorbital, supratrochlear, infratrochlear, and external nasal nerve

blocks. A. The positions of the nerves on the face; the supraorbital nerve emerging from

the orbital cavity in the same vertical plane as the pupil. B. The areas of skin anesthetized

by blocking these nerves. C. Sites where the nerves may be blocked. The supraorbital and

supratrochlear nerves may be blocked by raising a horizontal wheal of anesthetic solution

above the orbital margin.

supraorbital margin, which is the site for injection. If the

Indications

notch is a foramen, however, it is small and difficult to feel,

Repair of lacerations of the medial end of the eyelid and the

and the needle is inserted into the skin over the supraorbital

forehead close to the midline

margin in line with the pupil.

Supratrochlear Nerve Block

Procedure

This involves the following:

The supratrochlear nerve winds around the supraorbital

margin about a fingerbreadth medial to the supraorbital

Area of Anesthesia

nerve. The needle is inserted at the point where the

Skin of the upper eyelid and the lower forehead close to the

bridge of the nose meets the supraorbital margin (see CD

midline (see CD Fig. 15-4)

Fig. 15 -4).

232

Chapter 15

Infratrochlear Nerve Block

Procedure

This involves the following:

The external nasal nerve is blocked at the point where it

emerges between the nasal bone and the upper lateral nasal

Area of Anesthesia

cartilage (see CD Fig. 15-4).

Skin of the medial ends of the eyelids and the side of the root

of the nose (see CD Fig. 15-4)

Maxillary Nerve Block

This block is not used in emergency medicine. The infraor-

Indications

bital nerve, which is a continuation of the maxillary nerve

Repair of lacerations of the medial eyelids and the root of

onto the face, is commonly blocked. Occasionally, the

the nose

pterygopalatine ganglion is blocked.

Procedure

Infraorbital Nerve Block

The infratrochlear nerve emerges from the orbital cavity at

This involves the following:

the junction of the superior and medial walls, which is the

site for injection (see CD Fig. 15-4).

Area of Anesthesia

External Nasal Nerve Block

Skin of the lower eyelid, the lateral nose, the cheek, and

This involves the following:

the skin and mucous membrane of the upper lip and the

upper gingiva. Since the anesthetic agent also blocks the an-

Area of Anesthesia

terior and middle superior alveolar nerves, the upper

Skin of the side of the nose down as far as the tip (see CD

incisor, canine, and premolar teeth are also affected (CD

Fig. 15-4)

Fig. 15-5).

Indications

Repair of lacerations of the skin of the nose

Lacerations of the cheek, side of the nose, and the upper lip

trigeminal nerve

foramen rotundum

maxillary nerve (V2) in

zygomatic arch

pterygopalatine fossa

(partially removed

for clarity)

lateral

pterygoid

infraorbital nerve

plate

anterior superior alveolar nerve

middle superior alveolar nerve

pterygopalatine ganglion

in pterygopalatine fossa

posterior superior

alveolar nerve

mandibular notch

CD Figure 15-5

Lateral view of the skull showing the maxillary (V2) division of the

trigeminal nerve leaving the trigeminal ganglion and passing forward to become the infra-

orbital nerve, which emerges on the face. Note the location of the pterygopalatine gan-

glion (parasympathetic) in the pterygopalatine fossa. Note also the sensory innervation of

the teeth of the upper jaw.

The Cranial Nerves and Trigeminal Nerve Blocks

233

Procedure

and is directed upward and outward toward the foramen

(see CD Fig. 15-6).

The infraorbital nerve emerges from the infraorbital

foramen as a direct continuation of the maxillary nerve

Pterygopalatine Ganglion Block

(CD Fig. 15-6). The opening of the foramen is situated about

1 cm below the midpoint of the lower border of the orbit and

The pterygopalatine ganglion is a small parasympathetic

faces downward and medially.

ganglion and is suspended from the lower border of the max-

illary nerve in the pterygopalatine fossa (CD Fig. 15-7). Pass-

Intraoral Method

ing through the ganglion without interruption are the sen-

With the index finger of the left hand palpating the infraor-

sory fibers from the orbit, the nose, the hard and soft palate,

bital foramen through the skin of the cheek and serving as a

the gums, and the tonsillar region of the pharynx.

guide, the needle is inserted into the reflection of the mu-

cous membrane from the upper lip onto the gingiva (see

Area of Anesthesia

CD Fig. 15-6). The site for the needle insertion is just pos-

The lower nasal cavity, hard and soft palates, the upper gum,

terior to the canine tooth and is directed upward to the

the teeth of the upper jaw, and the tonsillar region of the

infraorbital foramen.

pharynx

Extraoral Method

Indications

The infraorbital foramen is palpated below the lower mar-

gin of the orbit, and the needle is inserted through the skin

Repair of lacerations involving the palate

infraorbital nerve

CD Figure 15-6

Infraorbital nerve block. A.

Extraoral method shows the infraorbital nerve

emerging from the infraorbital foramen. The

infraorbital foramen lies on the same vertical

line that passes through the supraorbital

notch, the mental foramen, and the first pre-

molar tooth. The blocking needle is inserted in

the direction of the infraorbital foramen just

below the lower margin of the orbit. B. The

area of skin anesthetized by blocking the infra-

infraorbital

orbital nerve. C. Intraoral method. The needle

nerve area

is inserted into the reflection of the mucous

membrane from the upper lip onto the gingiva

just posterior to the canine tooth and is di-

rected toward the infraorbital foramen.

234

Chapter 15

maxillary nerve

nasal nerves

trigeminal ganglion

pterygopalatine

ganglion in

pterygopalatine

nasopalatine

fossa

nerve

greater palatine

nerve emerging

from greater

pharyngeal nerve

palatine foramen

lesser palatine nerve

nasopalatine

nerves

CD Figure

15-7

Blocking the ptery-

gopalatine ganglion. A. Lateral view of the

greater palatine nerve

skull showing the insertion of the needle

into the greater palatine foramen in order

upper 3rd

to block the ganglion. B. The undersurface

molar tooth

of the palate showing the position of the

lesser palatine nerve

greater

greater palatine foramen in relation to the

palatine

upper third molar tooth and the soft

foramen

palate. Note the distribution of the

soft palate

branches of the maxillary nerve through

uvula

the ganglion to the walls of the nose and

the palate.

Procedure

Auriculotemporal Nerve Block

The ganglion and, therefore, the sensory fibers may be

This involves the following:

blocked by inserting a long-angled needle into the

greater palatine foramen with the mouth wide open (see CD

Area of Anesthesia

Fig. 15-7). The foramen is located at the posterior portion of

The external auditory meatus, the tympanic membrane, the

the hard palate just medial to the gumline of the third molar

upper part of the auricle, and the scalp in the temporal re-

tooth. The greater palatine foramen leads superiorly into the

gion (CD Fig. 15-8)

pterygopalatine fossa. Injection of the anesthetic blocks the

greater and lesser palatine nerves, the orbital nerves, the nasal

Indications

nerves, and the pharyngeal nerves.

Repair of lacerations of the auricle and scalp

Mandibular Nerve Block

Procedure

This block is rarely used. However, the auriculotemporal

nerve, the lingual nerve, and the inferior alveolar nerve,

The auriculotemporal nerve is easily blocked as it ascends in

which are branches of the mandibular nerve, are commonly

front of the auricle over the posterior root of the zygoma, be-

blocked.

hind the superficial temporal artery (see CD Fig. 15-8).

The Cranial Nerves and Trigeminal Nerve Blocks

235

auriculotemporal

nerve area

superficial

temporal

auriculotemporal

artery

nerve

tragus

head of

mandible

superficial

temporal

auriculotemporal

artery

nerve

zygomatic

arch

CD Figure 15-8

Blocking the au-

riculotemporal nerve. A. The rela-

tionship of the auriculotemporal

nerve to the superficial temporal

head of

site for injection

artery and the tragus of the ear.

mandible

Note the area of skin supplied by

this sensory nerve. The needle is in-

serted just behind the pulsating su-

perficial temporal artery and in

front of the tragus; the needle is di-

rected horizontally medially. B. The

surface marking of the auriculotem-

poral nerve and its relationship to

the superficial temporal artery and

the temporomandibular joint. X

marks the site for injection.

Anatomy of Complications

and the lower gums. The inferior alveolar nerve supplies the

The superficial temporal artery may be pierced if the needle

lower teeth and gums and the skin of the lower lip and chin.

is inserted too far anteriorly.

Indications

Lingual Nerve and Inferior Alveolar

Repair of lacerations of the tongue, floor of the mouth, and

Nerve Blocks

lower lip and chin

These involve the following:

Procedure

Area of Anesthesia

Both the lingual and inferior alveolar nerves may be blocked

The lingual nerve supplies the mucous membrane of the an-

as they pass downward and forward in the infratemporal

terior two thirds of the tongue and the floor of the mouth (taste

fossa on the lateral surface of the medial pterygoid muscle

is supplied by the chorda tympani branch of the facial nerve),

and on the medial surface of the ramus of the mandible

236

Chapter 15

(CD Fig. 15-9). With the patient’s mouth wide open, the an-

Indications

terior border of the ramus of the mandible is palpated just

Repair of lacerations of the lower lip

above the third molar tooth. The blocking needle is inserted

above the palpating finger and between the mucosa and the

Procedure

inner surface of the ramus of the mandible, and the barrel

of the syringe lies in line with the interval between the

The mental nerve may be blocked as it emerges from the

bicuspids on the opposite side of the mandible (see CD Fig.

mental foramen on the body of the mandible (CD Fig. 15-

15-9). The needle is advanced posteriorly and slightly supe-

10). The foramen lies on the same vertical line that passes

riorly until the tip lies in close proximity to the mandibular

through the supraorbital notch, the infraorbital foramen,

foramen. The anesthetic solution will infiltrate around the

and the first premolar tooth.

nerves.

Intraoral Method

Mental Nerve Block

The left index finger palpates the position of the mental

foramen. The needle is inserted through the reflexion of the

This involves the following:

mucous membrane from the lower lip onto the gum

between the apices of the premolar teeth (see CD Fig. 15-

Area of Anesthesia

10). The point of the needle is directed toward the mental

The lower lip and gums

foramen.

mandibular foramen

buccal nerve

lingual nerve

inferior alveolar

nerve

mandibular nerve

(V3)

nerve to the mylohyoid

and the anterior belly

of the digastric

inferior

alveolar

mental nerve

nerve

emerging from

the mental foramen

CD Figure 15-9

Lingual and inferior alveolar

nerve blocks. A. The location of the buccal, lin-

gual, and inferior alveolar nerves in relation to

the mandible. B. The needle is inserted just

above the lower third molar tooth and directed

between the mucosa and the inner surface of

the ramus of the mandible; the barrel of the sy-

ringe lies in line with the interval between the

bicuspids on the opposite side of the

mandible. The needle is advanced posteriorly

and slightly superiorly until the tip lies in close

proximity to the mandibular foramen.

The Cranial Nerves and Trigeminal Nerve Blocks

237

supraorbital notch for

supraorbital nerve

infraorbital foramen

for infraorbital nerve

mental foramen

for mental nerve

CD Figure 15-10

Mental nerve and

tooth nerve blocks. A. Extraoral mental

nerve block. The surface marking of the

mental nerve as it emerges from the

mental foramen. The mental foramen

lies on the same vertical plane as the

supraorbital notch, the pupil (when the

mental nerve

patient is looking straight ahead), the in-

area

fraorbital foramen, and the first premo-

lar tooth. The mental foramen is pal-

pated, and the needle is inserted through

alveolar bone

the skin and is directed toward the fora-

alveolar nerve

periosteum

men. B. Area of skin anesthesia pro-

apical foramen

duced by blocking the mental nerve. C.

Intraoral mental nerve block. The needle

mucous membrane

pupal sensory

is inserted through the reflection of the

nerve

mucous membrane between the apices

of the premolar teeth and is directed to-

ward the mental foramen. D. Suprape-

riosteal infiltration. Needle is inserted

through the mucous membrane with the

bevel against the periosteum and is ad-

vanced until it reaches the level of the

apex of the tooth.

Extraoral Method

anesthetic diffuses through the periosteum and the alveo-

The mental foramen is palpated, and the needle is inserted

lar bone to reach the dental nerve fibers entering the

through the skin. When the mandible is contacted with the

apices of the dental roots; it also reaches the nerves sup-

needle, the point is directed toward the mental foramen (see

plying the mucoperiosteum of the gums and the periodon-

CD Fig. 15-10).

tal membrane.

The labiogingival or buccogingival folds, where the

mucous membrane lining the lips or cheek are reflected

Special Areas for Nerve Blocks

onto the gums, are identified. This may be accomplished in

the maxilla by pulling the upper lip downward, and in the

Tooth Nerve Blocks

case of the mandible by pulling the lower lip upward. At the

point where the mucous membrane becomes fused with the

Two techniques are commonly used—supraperiosteal

periosteum to form the mucoperiosteum of the gum, the

infiltration and dental nerve blocks.

needle is inserted with the bevel against the periosteum (see

CD Fig. 15-10). The needle is advanced until it reaches the

Supraperiosteal Infiltration

level of the apex of the root of the tooth, and the anesthetic

This technique is commonly used in an emergency for the

solution is injected. If anesthesia is not produced, it may be

relief of toothache. The anesthetic solution is applied di-

necessary to repeat the injection on the palatal surface of the

rectly to the outer surface of the periosteum opposite the

gums. Failure to produce an adequate nerve block may be

apices of the roots of the teeth (see CD Fig. 15-10). The

due to the needle tip being inserted too far away from the

238

Chapter 15

apex of the tooth—that is, too far away from the periosteum

Anesthesia of the Nose

or too far above or below the tooth apex. The technique is

This involves the following:

less successful for mandibular teeth because of the density

of the bone structure of the mandible.

Nasal Interior

The upper teeth are innervated by the anterior, middle,

and superior alveolar branches of the maxillary division of

The lateral wall of the nose is innervated by the anterior eth-

the trigeminal nerve. The buccal nerve, a branch of the

moidal branch of the nasociliary branch of the ophthalmic

mandibular division of the trigeminal nerve, supplies the

division of the trigeminal nerve, from branches of the max-

lateral surface of the gum and the greater palatine and the

illary division of the trigeminal nerve, and from the olfac-

nasopalatine nerves, from the maxillary nerve, supply the

tory nerve. The nasal septum is innervated by branches of

medial surface of the gum.

the anterior ethmoidal nerve, by branches of the maxillary

The lower teeth are innervated by the inferior alveolar

nerve, and from the olfactory nerve.

nerve, a branch of the mandibular division of the trigeminal

Analgesia of the mucous membrane can easily be ob-

nerve. The buccal nerve supplies the lateral surface of the

tained by placing pledgets soaked in local anesthetic in the

gums, and the lingual nerve, a branch of the mandibular

nose between the conchae and the septum for 5 to 10 minutes.

nerve, supplies the medial surface.

Nasal Exterior

Dental Nerve Blocks

The skin of the nose is innervated by the supratrochlear and

For the maxillary teeth, the anterior and middle superior

infratrochlear branches of the ophthalmic division of the

alveolar nerves are blocked along with the infraorbital

trigeminal nerve and the infraorbital nerve, a continuation

nerve as described on page 232 of the CD. For the

of the maxillary division of the trigeminal nerve (CD Fig.

mandibular teeth, the inferior alveolar nerve is blocked as

15-11). Skin analgesia is obtained by infiltrating first the

described on page 235 of the CD.

base of the nose and then the nasofacial groove, thus

supratrochlear

nerve (V1)

infratrochlear

nerve (V1)

infraorbital

nerve (V2)

external nasal

nerve (V1)

CD Figure 15-11

Anesthesia of the external nose. A. The sensory nerves that supply the skin

of the nose emerging from the skull. B. The extent of the skin supplied by these nerves. C. The

sites (X) where the needle is introduced to produce anesthesia over the area shown in B.

240

Chapter 15

blocking the terminal branches of the ophthalmic and max-

Anesthesia of the Scalp

illary nerves (see CD Fig. 15-11).

The anterior part of the scalp extending back as far as the

vertex is innervated by the supraorbital and supratrochlear

Anesthesia of the Ear

branches of the ophthalmic division of the trigeminal nerve

The auricle is innervated by the greater auricular nerve (C2

(CD Fig. 15-13). The posterior part of the scalp is inner-

and C3), a branch of the cervical plexus (CD Fig. 15-12).

vated by the greater occipital nerve (C2) and the lesser oc-

This nerve mainly supplies the skin on the medial and lateral

cipital nerve (C2). The lateral part of the scalp is supplied by

surfaces of the inferior part of the auricle. The

the auriculotemporal branch of the mandibular division of

auriculotemporal branch of the mandibular division of the

the trigeminal nerve. A small area over the temple is sup-

trigeminal nerve supplies the lateral and upper part of the au-

plied by the zygomaticotemporal nerve from the maxillary

ricle. The lesser occipital nerve (C2) may also supply a small

division of the trigeminal nerve.

area on the medial surface. The external auditory meatus is

A subcutaneous infiltration with anesthetic solution is

also innervated by the auricular branch of the vagus nerve.

made around the circumference of the head from just

Anesthesia of the skin is obtained by multiple subcuta-

above the nose and eyebrows to the ear and back to the ex-

neous injections along a line that is continued circumferen-

ternal occipital protuberance (see CD Fig. 15-13). A large

tially around the auricle (see CD Fig. 15-12). The external

volume of anesthetic is required to completely anesthetize

auditory meatus may be anesthetized by using a four-quad-

the scalp.

rant block of the canal; in addition, several drops of anes-

thetic solution may be instilled into the canal to anesthetize

the tympanic membrane.

Clinical Problem Solving Questions

Read the following case histories/questions and give

ing the physical examination the patient was asked to pro-

the best answer for each.

trude his tongue, which deviated to the left.

2. The following statements would explain the physical

A 73-year-old woman visited her physician because she had

signs in this patient except which?

noticed that the right side of her face was sagging downward.

A. The genioglossus muscles are responsible for pro-

She first noticed the condition on waking up two mornings

truding the tongue.

ago. Otherwise she felt very well. On examination the pa-

B. The genioglossus muscle is supplied by the glos-

tient had a complete right-sided facial paralysis, the right

sopharyngeal nerve.

lower eyelid was drooping, and the right angle of the mouth

C. Paralysis of the left genioglossus muscle permitted

was sagging. A diagnosis of Bell’s palsy was made.

the right genioglossus to pull the tongue forward and

1. Further examination of this patient demonstrated the

turned the tip to the left side.

following signs and symptoms except which?

D. The hypoglossal nerve descends in the neck be-

A. Tears tended to flow easily over the right lower eyelid.

tween the internal carotid artery and the internal

B. Saliva dribbled from the right corner of her mouth.

jugular vein.

C. The patient was unable to close her right eye com-

E. At about the level of the tip of the greater cornu of

pletely.

the hyoid bone the hypoglossal nerve turns forward

D. The patient was unable to expose the teeth fully on

and crosses the internal and external carotid arteries

the right side of her mouth.

and the lingual artery to enter the tongue.

E. The muscles on the right side of her forehead

F. The point of the knife blade severed the left hy-

worked perfectly normally when she was asked to

poglossal nerve.

raise her right eyebrow.

A 43-year-old woman was seen in the emergency depart-

A 17-year-old boy was seen in the emergency department af-

ment with a large abscess in the middle of the right posterior

ter receiving a stab wound at the front of the neck. The knife

triangle of the neck. The abscess was red, hot, and fluctuant.

entrance wound was located on the left side of the neck just

The abscess showed evidence that it was pointing and about

lateral to the tip of the greater cornu of the hyoid bone. Dur-

to rupture. The physician decided to incise the abscess and

The Cranial Nerves and Trigeminal Nerve Blocks

241

insert a drain. The patient returned to the department for

experienced, the patient mapped out the skin area over the

the dressings to be changed 5 days later. She stated that she

right side of the lower jaw extending backward and upward

felt much better and that her neck was no longer painful.

over the side of the head to the vertex.

However, there was one thing that she could not under-

5. The following signs and symptoms in this patient

stand. She could no longer raise her right hand above her

strongly suggest a diagnosis of trigeminal neuralgia

head to brush her hair.

except which?

3. The following statements explain the signs and symp-

A. The skin area where the patient experienced the

toms in this case, suggesting that the spinal part of the

pain was innervated by the mandibular division of

accessory nerve had been incised, except which?

the trigeminal nerve.

A. To raise the hand above the head, it is necessary for

B. The stabbing nature of the pain is characteristic of

the trapezius muscle, assisted by the serratus ante-

the disease.

rior, to contract and rotate the scapula so that the

C. The trigger mechanism, stimulation of an area

glenoid cavity faces upward.

that received its sensory innervation from the

B. The trapezius muscle is innervated by the spinal

trigeminal nerve, is characteristic of trigeminal

part of the accessory nerve.

neuralgia.

C. As the spinal part of the accessory nerve crosses the

D. Examination of the actions of the masseter and the

posterior triangle of the neck, it is deeply placed, be-

temporalis muscles showed evidence of weakness on

ing covered by the skin, the superficial fascia, the in-

the right side.

vesting layer of deep cervical fascia, and the levator

E. The patient experienced hyperesthesia in the distri-

scapulae muscle.

bution of the right auriculotemporal nerve.

D. The surface marking of the spinal part of the acces-

A 10-year-old boy was playing darts with his friends. He bent

sory nerve is as follows: Bisect at right angles a line

down to pick up a fallen dart when another dart fell from the

joining the angle of the jaw to the tip of the mastoid

dart board and hit him on the side of his face. On examina-

process. Continue the second line downward and

tion in the emergency department a small skin wound was

backward across the posterior triangle.

found over the right parotid salivary gland. Then, 6 months

E. The knife opening the abscess had cut the accessory

later, the boy’s mother noticed that before mealtimes the

nerve.

boy began to sweat profusely on the facial skin close to the

A 35-year-old woman had a partial thyroidectomy for the

healed dart wound.

treatment of thyrotoxicosis. During the operation a ligature

6. The following statements can explain this phenome-

slipped off the right superior thyroid artery. To stop the he-

non except which?

morrhage, the surgeon blindly grabbed for the artery with

A. The point of the dart had entered the parotid salivary

artery forceps. The operation was completed without further

gland and damaged the parasympathetic secretomo-

incident. The following morning the patient spoke with a

tor fibers to the gland.

husky voice.

B. The secretomotor fibers to the parotid gland arise in

4. The following statements about this patient would ex-

the otic ganglion.

plain the husky voice except which?

C. The preganglionic parasympathetic fibers originate

A. Laryngoscopic examination revealed that the right

in the superior salivatory nucleus of the facial nerve.

vocal cord was slack, causing the huskiness of the

D. The skin over the parotid salivary gland is innervated

voice.

by the great auricular nerve, which was also dam-

B. The vocal cord is tensed by the contraction of the

aged by the dart.

cricothyroid muscle.

E. On regeneration of the damaged nerves some of the

C. The cricothyroid muscle tilts back the cricoid carti-

parasympathetic nerves to the parotid salivary gland

lage and pulls forward the thyroid cartilage.

had crossed over and joined the sympathetic secre-

D. The cricothyroid muscle is innervated by the recur-

tomotor nerves to the sweat glands in the distal end

rent laryngeal nerve.

of the great auricular nerve.

E. The superior thyroid artery is closely related to the

F. The patient has Frey’s syndrome.

external laryngeal nerve.

A 31-year-old woman fell off her bicycle and lacerated

A 43-year-old woman visited her physician complaining of

the skin of her forehead just above the left eyebrow.

severe intermittent pain on the right side of her face. The

7. What is the sensory innervation of the skin of the fore-

pain was precipitated by exposing the right side of her face

head? Where may these nerves be blocked?

to a draft of cold air. The pain was stabbing in nature and

lasted about 12 hours before finally disappearing. When

A 27-year-old man was involved in a motorcycle acci-

asked to point out on her face the area where the pain was

dent and was seen in the emergency department with

242

Chapter 15

extensive lacerations of the right ear. It was decided to

10. On examination, a patient is found to have a bitempo-

suture the skin lesions under local anesthesia.

ral hemianopia. An enlargement of which anatomic

structure is likely to cause this condition?

8. How would you anesthetize the ear?

11. A patient is suspected of having a lesion of the glos-

A 63-year-old woman visited her physician with a

sopharyngeal nerve. How would you test the integrity of

swelling over the parotid gland on the right side. She

this cranial nerve?

stated that she had first noticed the swelling

months previously, and since that time it had rapidly

12. A 47-year-old woman is seen by a neurologist because of

increased in size. Recently, she had noticed that the

trouble reading the newspaper. She said that the print

right side of her face “felt weak” and she could no

starts to tilt and she begins to see double. She also stated

longer whistle for her dog. On examination, a hard

that she has difficulty walking down steps because she

swelling deeply attached to the parotid gland was

cannot easily look downward with her right eye. On

found. On testing the facial muscles, it was found

physical examination, the patient was found to have

that the muscles on the right side were weaker than

weakness of the movement of the right eye, both down-

those on the left side.

ward and laterally. Using your knowledge of anatomy,

explain the signs and symptoms.

9. What is the connection between the parotid swelling

and the right-sided facial weakness?

Answers and Explanations

E is the correct answer. In this patient all the facial mus-

The skin of the forehead is innervated by the supraor-

cles on the right side were paralyzed. When making the

bital and supratrochlear branches of the frontal nerve, a

diagnosis of Bell’s palsy, it is imperative that one makes

branch of the ophthalmic division of the trigeminal

the distinction between an upper motor neuron palsy

nerve. The nerves may be blocked as they emerge onto

and a lower motor neuron palsy. The part of the facial

the forehead around the superior margin of the orbital

nucleus of the facial nerve that controls the muscles of

cavity.

the upper part of the face receives corticonuclear fibers

The auricle receives its sensory innervation from the

from both cerebral hemispheres. Therefore, it follows

greater auricular nerve (C2 and C3), the auriculotem-

that with a lesion involving the upper motor neurons,

poral nerve (mandibular division of the trigeminal

only the muscles of the lower part of the face will be

nerve), and the auricular branch of the vagus nerve.

paralyzed. In this patient all the facial muscles on the

Analgesia of the skin can be obtained by multiple sub-

affected side were paralyzed, indicating that the lesion

cutaneous injections that are continued circumferen-

was confined to the facial nerve.

tially around the auricle.

B is the correct answer. The genioglossus muscle is sup-

The facial nerve, the retromandibular vein, and the ex-

plied by the hypoglossal nerve.

ternal carotid artery lie within the parotid salivary

C is the correct answer. The spinal part of the accessory

gland. This patient had a highly invasive carcinoma of

nerve lies superficial to the levator scapulae muscle in

the right parotid gland, which quickly involved the

the posterior triangle of the neck.

right facial nerve, with consequent weakness of the

right facial muscles. The method used clinically to test

D is the correct answer. The cricothyroid muscle is in-

the integrity of the facial nerve is fully described on CD

nervated by the external laryngeal nerve, which was

p. 228. A benign tumor of the parotid gland tends not to

damaged in this patient.

damage the facial nerve.

D is the correct answer. The motor portion of the

10.

Bitemporal hemianopia is a loss of both temporal fields

trigeminal nerve is unaffected in patients with trigemi-

of vision and is due to the interruption of the optic

nal neuralgia.

nerve fibers derived from the medial halves of both

C is the correct answer. The secretomotor fibers to the

retinae. Pressure on the optic chiasma by a tumor of

parotid salivary gland originate in the inferior salivatory

the pituitary gland is the most common cause of the

nucleus of the glossopharyngeal nerve.

condition.

Chapter Outline

Vertebral Column

246

Subarachnoid Space

250

Examination of the Back

246

Spinal Tap (Lumbar Puncture)

250

Anatomy of “Not Getting In”

253

Abnormal Curves of the Vertebral Column

246

Anatomy of Complications of Lumbar Puncture

253

Dislocations of the Vertebral Column

246

Block of the Subarachnoid Space

253

Fractures of the Vertebral Column

246

Caudal Anesthesia

253

Spinal Nerve Root Pain

246

Herniated Intervertebral Discs

247

Congenital Anomalies

255

Disease and the Intervertebral Foramina

247

Scoliosis

255

Narrowing of the Spinal Canal

249

Spina Bifida

255

Sacroiliac Joint Disease

249

Relationship of the Vertebral Body to the

Spinal Cord

250

Spinal Nerve

255

Spinal Cord Ischemia

250

Clinical Problem Solving Questions

257

Spinal Cord Injuries

250

Relationship of Spinal Cord Segments to Vertebral

Answers and Explanations

259

Numbers

250

Fractures of the Vertebral Column

VERTEBRAL

See Chapter 12, CD-ROM.

COLUMN

Spinal Nerve Root Pain

Spinal nerve roots exit from the vertebral canal through the

Examination of the Back

intervertebral foramina. Each foramen is bounded superi-

See Chapter 11, CD-ROM.

orly and inferiorly by the pedicles, anteriorly by the inter-

vertebral disc and the vertebral body, and posteriorly by the

articular processes and joints (see text Fig. 16-3). In the lum-

Abnormal Curves of the

bar region, the largest foramen is between the first and sec-

ond lumbar vertebrae and the smallest is between the fifth

Vertebral Column

lumbar and first sacral vertebra.

One of the complications of osteoarthritis of the verte-

See Chapter 11, CD-ROM.

bral column is the growth of osteophytes, which com-

monly encroach on the intervertebral foramina, causing

pain along the distribution of the segmental nerve. The

Dislocations of the

fifth lumbar spinal nerve is the largest of the lumbar spinal

nerves, and it exits from the vertebral column through the

Vertebral Column

smallest intervertebral foramen. For this reason, it is the

See Chapter 12, CD-ROM.

most vulnerable.

The Verterbral Column, the Spinal Cord, and the Meninges

247

Osteoarthritis as a cause of root pain is suggested by the

A lateral herniation may press on one or two roots and often

patient’s age, its insidious onset, and a history of back pain

involves the nerve root going to the intervertebral foramen

of long duration; this diagnosis is made only when all other

just below. However, because C8 nerve roots exist and an

causes have been excluded. For example, a prolapsed disc

eighth cervical vertebral body does not, the thoracic and

usually occurs in a younger age group and often has an

lumbar roots exit below the vertebra of the corresponding

acute onset.

number. Thus, the L5 nerve root exits between the fifth lum-

bar and first sacral vertebrae. Moreover, because the nerve

roots move laterally as they pass toward their exit, the root cor-

Herniated Intervertebral Discs

responding to that disc space (L4 in the case of the L4-5 disc)

The structure and function of the intervertebral disc is

is already too lateral to be pressed on by the herniated disc.

described on text page 581. The resistance of these discs to

Herniation of the L4-5 disc usually gives rise to symptoms

compression forces is substantial, as seen, for example,

referable to the L5 nerve roots, even though the L5 root exits

in circus acrobats who can support four or more of their

between L5 and S1 vertebrae. The nucleus pulposus occa-

colleagues on their shoulders. Nevertheless, the discs are

sionally herniates directly backward, and if it is a large her-

vulnerable to sudden shocks, particularly if the vertebral

niation, the whole cauda equina may be compressed, pro-

column is flexed and the disc is undergoing degene-

ducing paraplegia.

rative changes, that result in herniation of the nucleus

An initial period of back pain is usually caused by the

pulposus.

injury to the disc. The back muscles show spasm, especially

The discs most commonly affected are those in areas

on the side of the herniation, because of pressure on the

where a mobile part of the column joins a relatively immo-

spinal nerve root. As a consequence, the vertebral column

bile part—that is, the cervicothoracic junction and the

shows a scoliosis, with its concavity on the side of the lesion.

lumbosacral junction. In these areas, the posterior part of

Pain is referred down the leg and foot in the distribution of

the anulus fibrosus ruptures, and the nucleus pulposus is

the affected nerve. Since the sensory posterior roots most

forced posteriorly like toothpaste out of a tube. This is

commonly pressed on are the fifth lumbar and the first

referred to as a herniation of the nucleus pulposus. This

sacral, pain is usually felt down the back and lateral side of

herniation can result either in a central protrusion in the

the leg, radiating to the sole of the foot. This condition is

midline under the posterior longitudinal ligament of the

often called sciatica. In severe cases paresthesia or actual

vertebrae or in a lateral protrusion at the side of the posterior

sensory loss may be present.

ligament close to the intervertebral foramen (CD Fig. 16-1).

Pressure on the anterior motor roots causes muscle

The escape of the nucleus pulposus will produce narrowing

weakness. Involvement of the fifth lumbar motor root pro-

of the space between the vertebral bodies, which may be vi-

duces weakness of dorsiflexion of the ankle, whereas pres-

sible on radiographs. Slackening of the anterior and poste-

sure on the first sacral motor root causes weakness of plantar

rior longitudinal ligaments results in abnormal mobility of

flexion, and the ankle jerk may be diminished or absent (see

the vertebral bodies, producing local pain and subsequent

CD Fig. 16-1).

development of osteoarthritis.

A large, centrally placed protrusion may give rise to

Cervical disc herniations are less common than herni-

bilateral pain and muscle weakness in both legs. Acute

ations in the lumbar region (see text Fig. 16-21). The discs

retention of urine may also occur.

most susceptible to this condition are those between the

A correlation between the disc lesion, the nerve

fifth and sixth or sixth and seventh vertebrae. Lateral protru-

roots involved, the pain dermatome, the muscle weakness,

sions cause pressure on a spinal nerve or its roots. Each

and the missing or diminished reflex is shown in CD

spinal nerve emerges above the corresponding vertebra;

Table 16-1.

thus, protrusion of the disc between the fifth and sixth cer-

vical vertebrae can cause compression of the C6 spinal

Disease and the Intervertebral

nerve or its roots (see CD Fig. 16-1). Pain is felt near the

lower part of the back of the neck and shoulder and along

Foramina

the area in the distribution of the spinal nerve involved.

Central protrusions may press on the spinal cord and the an-

The intervertebral foramina (see text Fig. 16-3) transmit

terior spinal artery and involve the various nerve tracts of the

the spinal nerves and the small segmental arteries and

spinal cord.

veins, all of which are embedded in areolar tissue. Each

Lumbar disc herniations are more common than cer-

foramen is bounded above and below by the pedicles of ad-

vical disc herniations (see CD Fig. 16-1). The discs usually

jacent vertebrae, in front by the lower part of the vertebral

affected are those between the fourth and fifth lumbar verte-

body and by the intervertebral disc, and behind by the ar-

brae and between the fifth lumbar vertebra and the sacrum.

ticular processes and the joint between them. In this situa-

In the lumbar region the roots of the cauda equina run pos-

tion, the spinal nerve is vulnerable and may be pressed on

teriorly over several intervertebral discs (see CD Fig. 16-1B).

or irritated by disease of the surrounding structures. Her-

248

Chapter 16

foramen

magnum

occipital bone

atlas

L5—S1

disc

nucleus

pulposus

anulus fibrous

CD Figure 16-1

A and B. Posterior views of vertebral bodies in the cervical and lumbar

regions showing the relationship that might exist between the herniated nucleus pulposus

and the spinal nerve roots. Note that there are eight cervical spinal nerves but only seven

cervical vertebrae. In the lumbar region, for example, the emerging L4 nerve roots pass out

laterally close to the pedicle of the fourth lumbar vertebra and are not related to the inter-

vertebral disc between the fourth and fifth lumbar vertebrae. C. Posterolateral herniation of

the nucleus pulposus of the intervertebral disc between the fifth lumbar vertebra and the

first sacral vertebra showing pressure on the S1 nerve root. D. An intervertebral disc that

has herniated its nucleus pulposus posteriorly. E. Pressure on the L5 motor nerve root pro-

duces weakness of dorsiflexion of the ankle; pressure on the S1 motor nerve root produces

weakness of plantar flexion of the ankle joint.

The Verterbral Column, the Spinal Cord, and the Meninges

249

Summary of Important Features Found in Cervical and Lumbosacral

CD Table 16-1

Root Syndromes

Root Injury

Dermatome Pain

Muscle Supplied

Movement Weakness

Reflex Involved

Lower lateral aspect

Deltoid and biceps

Shoulder abduction,

Biceps

of upper arm

elbow flexion

Lateral aspect of

Extensor carpi radialis

Wrist extensors

Brachioradialis

forearm

longus and brevis

Middle finger

Triceps and flexor carpi

Extension of elbow

Triceps

radialis

and flexion of wrist

Medial aspect of

Flexor digitorum

Finger flexion

None

forearm

superficialis and

profundus

Groin

Iliopsoas

Hip flexion

Cremaster

Anterior aspect of

Iliopsoas, sartorius, hip

Hip flexion, hip

Cremaster

thigh

adductors

adduction

Medial aspect of

Iliopsoas, sartorius,

Hip flexion, knee

Patellar

knee

quadriceps, hip

extension, hip

adductors

adduction

Medial aspect of

Tibialis anterior,

Foot inversion, knee

Patellar

calf

quadriceps

extension

Lateral part of lower

Extensor hallucis

Toe extension, ankle

None

leg and dorsum

longus, extensor

dorsiflexion

of foot

digitorum longus

Lateral edge of

Gastrocnemius, soleus

Ankle plantar flexion

Ankle jerk

foot

Posterior part of

Flexor digitorum longus,

Ankle plantar flexion,

None

thigh

flexor hallucis longus

toe flexion

niation of the intervertebral disc, fractures of the vertebral

stenosis in the cauda equina area can lead to neurologic

bodies, and osteoarthritis involving the joints of the articu-

compression. Symptoms vary from mild discomfort in the

lar processes or the joints between the vertebral bodies

lower back to severe pain radiating down the leg with the

can all result in pressure, stretching, or edema of the

inability to walk.

emerging spinal nerve. Such pressure would give rise to

dermatomal pain, muscle weakness, and diminished or ab-

sent reflexes.

Sacroiliac Joint Disease

The clinical aspects of this joint are referred to again

because disease of this joint can cause low back pain and

Narrowing of the Spinal Canal

may be confused with disease of the lumbosacral joints.

After about the fourth decade of life the spinal canal be-

Essentially, the sacroiliac joint is a synovial joint that has

comes narrowed by aging. Osteoarthritic changes in the

irregular elevations on one articular surface that fit into

joints of the articular processes with the formation of os-

corresponding depressions on the other articular surface.

teophytes, together with degenerative changes in the inter-

It is a strong joint and is responsible for the transfer of

vertebral discs and the formation of large osteophytes be-

weight from the vertebral column to the hip bones. The

tween the vertebral bodies, can lead to narrowing of the

joint is innervated by the lower lumbar and sacral nerves so

spinal canal and intervertebral foramina. In persons in

that disease in the joint may produce low back pain and

whom the spinal canal was originally small, significant

sciatica.

250

Chapter 16

The sacroiliac joint is inaccessible to clinical exami-

below the level of the lesion. The symptoms and signs of

nation. However, a small area located just medial to and

spinal shock and paraplegia in flexion and extension are be-

below the posterosuperior iliac spine is where the joint

yond the scope of this book. For further information, a text-

comes closest to the surface. In disease of the lumbosacral

book of neurology should be consulted.

region, movements of the vertebral column in any

direction cause pain in the lumbosacral part of the

Relationships of Spinal Cord

column. In sacroiliac disease, pain is extreme on rotation

of the vertebral column and is worst at the end of forward

Segments to Vertebral Numbers

flexion. The latter movement causes pain because the

hamstring muscles hold the hip bones in position while

Because the spinal cord is shorter than the vertebral co-

the sacrum is rotating forward as the vertebral column is

lumn, the spinal cord segments do not correspond numeri-

flexed.

cally with the vertebrae that lie at the same level (CD Fig.

16-2). The following list helps determine which spinal seg-

ment is contiguous with a given vertebral body:

SPINAL CORD

Vertebrae

Spinal Segment

Cervical

Add 1

Upper thoracic

Add 2

Spinal Cord Ischemia

Lower thoracic (T7-9)

Add 3

Tenth thoracic

L1 and 2 cord segments

The blood supply to the spinal cord is surprisingly meager,

Eleventh thoracic

L3 and 4 cord segments

considering the importance of this nervous tissue. The

Twelfth thoracic

L5 cord segment

longitudinally running anterior and posterior spinal arteries

First lumbar

Sacral and coccygeal cord

are of small and variable diameter, and the reinforcing seg-

segments

mental arteries vary in number and in size. Ischemia of the

spinal cord can easily follow minor damage to the arterial

supply as a result of regional anesthesia, pain block proce-

dures, or aortic surgery.

SUBARACHNOID

Spinal Cord Injuries

SPACE

The degree of spinal cord injury at different vertebral le-

vels is largely governed by anatomic factors. In the cervical

Spinal Tap (Lumbar Puncture)

region, dislocation or fracture dislocation is common, but

the large size of the vertebral canal often results in the

Lumbar puncture may be performed to withdraw a sample

spinal cord escaping severe injury. However, when consi-

of cerebrospinal fluid for examination. Fortunately, the

derable displacement occurs, the cord is sectioned and

spinal cord terminates below at the level of the lower bor-

death occurs immediately. Respiration ceases if the lesion

der of the first lumbar vertebra in the adult. (In the infant,

occurs above the segmental origin of the phrenic nerves

it may reach as low as the third lumbar vertebra.) The sub-

(C3, 4, and 5).

arachnoid space extends down as far as the lower border of

In fracture dislocations of the thoracic region, dis-

the second sacral vertebra. The lower lumbar part of the

placement is often considerable, and the small size

vertebral canal is thus occupied by the subarachnoid

of the vertebral canal results in severe injury to the spinal

space, which contains the cauda equina—that is, the lum-

cord.

bar and sacral nerve roots and the filum terminale. A nee-

In fracture dislocations of the lumbar region, two

dle introduced into the subarachnoid space in this region

anatomic facts aid the patient. First, the spinal cord in the

usually pushes the nerve roots to one side without causing

adult extends only down as far as the level of the lower bor-

damage.

der of the first lumbar vertebra. Second, the large size of the

With the patient lying on the side with the vertebral col-

vertebral foramen in this region gives the roots of the cauda

umn well flexed, the space between adjoining laminae in

equina ample room. Nerve injury may therefore be mini-

the lumbar region is opened to a maximum (CD Fig. 16-3).

mal in this region.

An imaginary line joining the highest points on the iliac

Injury to the spinal cord can produce partial or complete

crests passes over the fourth lumbar spine (see text Fig. 16-

loss of function at the level of the lesion and partial or com-

22). With a careful aseptic technique and under local anes-

plete loss of function of afferent and efferent nerve tracts

thesia, the lumbar puncture needle, fitted with a stylet, is

The Verterbral Column, the Spinal Cord, and the Meninges

253

passed into the vertebral canal above or below the fourth

caudal displacement of the uncus through the tentorial

lumbar spine (see CD Fig. 16-3). The needle will pass

notch or a dangerous displacement of the medulla

through the following anatomic structures before it enters

through the foramen magnum, when the lumbar cere-

the subarachnoid space: skin, superficial fascia, supra-

brospinal fluid pressure is reduced.

spinous ligament, interspinous ligament, ligamentum

flavum, areolar tissue (containing the internal vertebral ve-

Block of the Subarachnoid Space

nous plexus in the epidural space), dura mater, and arach-

A block of the subarachnoid space in the vertebral canal,

noid mater. The depth to which the needle will have to pass

which may be caused by a tumor of the spinal cord or the

varies from 1 in. (2.5 cm) or less in a child to as much as 4

meninges, can be detected by compressing the internal

in. (10 cm) in obese adults.

jugular veins in the neck. This raises the cerebral venous

As the stylet is withdrawn, a few drops of blood com-

pressure and inhibits the absorption of cerebrospinal fluid

monly escape. This usually indicates that the point of the

in the arachnoid granulations, thus producing a rise in the

needle is situated in one of the veins of the internal vertebral

manometric reading of the cerebrospinal fluid pressure. If

plexus and has not yet reached the subarachnoid space. If

this rise fails to occur, the subarachnoid space is blocked

the entering needle should stimulate one of the nerve roots

and the patient is said to exhibit a positive Queckenstedt’s

of the cauda equina, the patient will experience a fleeting

sign.

discomfort in one of the dermatomes, or a muscle will

twitch, depending on whether a sensory or a motor root was

impaled. If the needle is pushed too far anteriorly, it may hit

CAUDAL

the body of the third or fourth lumbar vertebra (see CD Fig.

16-3).

The cerebrospinal fluid pressure can be measured by

ANESTHESIA

attaching a manometer to the needle. In the recumbent

position, the normal pressure is about 60-150 mm H₂O. It

Solutions of anesthetics may be injected into the sacral

is interesting to note that the cerebrospinal fluid pressure

canal through the sacral hiatus. The solutions pass upward

normally fluctuates slightly with the heart beat and with

in the loose connective tissue and bathe the spinal nerves

each phase of respiration.

as they emerge from the dural sheath. Caudal anesthesia

is used in operations in the sacral region, including

Anatomy of “Not Getting In”

anorectal surgery and culdoscopy. Obstetricians use this

method of nerve block to relieve the pains during the first

If bone is encountered, the needle should be withdrawn as

and second stages of labor. Its advantage is that, adminis-

far as the subcutaneous tissue, and the angle of insertion

tered by this method, the anesthetic does not affect

should be changed. The most common bone encountered

the infant.

is the spinous process of the vertebra above or below the

The sacral hiatus is palpated as a distinct depression in

path of insertion. If the needle is directed laterally rather

the midline about 1.6 in. (4 cm) above the tip of the coccyx

than in the midline, it may hit the lamina or an articular

in the upper part of the cleft between the buttocks. The hia-

process.

tus is triangular or U shaped and is bounded laterally by the

sacral cornua (CD Fig. 16-4).

Anatomy of Complications of

The size and shape of the hiatus depend on the num-

Lumbar Puncture

ber of laminae that fail to fuse in the midline posteriorly.

■ Postlumbar puncture headache: This headache starts af-

The common arrangement is for the hiatus to be formed

ter the procedure and lasts 24 to 48 hours. The cause is a

by the nonfusion of the fifth and sometimes the fourth

leak of cerebrospinal fluid through the dural puncture,

sacral vertebrae.

and it usually follows the use of a wide-bore needle. The

With a careful aseptic technique and under local anes-

leak reduces the volume of cerebrospinal fluid, which, in

thesia, the needle, fitted with a stylet, is passed into the ver-

turn, causes a downward displacement of the brain and

tebral (sacral) canal through the sacral hiatus.

stretches the nerve-sensitive meninges—a headache fol-

The needle pierces the skin and fascia and the sacro-

lows. The headache is relieved by assuming the recum-

coccygeal membrane that fills in the sacral hiatus (see CD

bent position. Using small-gauge styletted needles and

Fig.

16-4). The membrane is formed of dense fibrous

avoiding multiple dural holes reduce the incidence of

tissue and represents the fused supraspinous and inter-

headache.

spinous ligaments as well as the ligamentum flavum. A

■ Brain herniation: Lumbar puncture is contraindicated in

distinct feeling of

“give” is felt when the ligament is

cases in which intracranial pressure is significantly

penetrated.

raised. A large tumor, for example, above the tentorium

Note that the sacral canal is curved and follows the gen-

cerebelli with a high intracranial pressure may result in a

eral curve of the sacrum (see CD Fig. 16-4). The anterior

The Verterbral Column, the Spinal Cord, and the Meninges

255

wall, formed by the fusion of the bodies of the sacral verte-

brae, is rough and ridged. The posterior wall, formed by the

fusion of the laminae, is smooth. The average distance be-

tween the sacral hiatus and the lower end of the subarach-

noid space at the second sacral vertebra is about 2 in. (5 cm)

in adults.

Note also that the sacral canal contains the dural sac

(containing the cauda equina), which is tethered to the coc-

cyx by the filum terminale; the sacral and coccygeal nerves

as they emerge from the dural sac surrounded by their dural

sheath; and the thin-walled veins of the internal vertebral

venous plexus.

CONGENITAL

CD Figure 16-5

Posterior view of a woman with scoliosis

ANOMALIES

resulting from a congenital hemivertebra in the lower

thoracic region.

Scoliosis

Scoliosis results from a congenital hemivertebra. A hemiver-

tebra is caused by a failure in development of one of the two

ossification centers that appear in the centrum of the body

RELATIONSHIP OF

of each vertebra (CD Fig. 16-5).

THE VERTEBRAL

Spina Bifida

BODY TO THE

In spina bifida, the spines and arches of one or more adja-

cent vertebrae fail to develop. The condition occurs most

frequently in the lower thoracic, lumbar, and sacral regions.

SPINAL NERVE

Beneath this defect, the meninges and spinal cord may or

may not be involved in varying degrees. This condition is a

Since the fully developed vertebral body is intersegmental in

result of failure of the mesenchyme, which grows in be-

position, each spinal nerve leaves the vertebral canal through

tween the neural tube and the surface ectoderm, to form the

the intervertebral foramen and is closely related to the inter-

vertebral arches in the affected region. The types of spina

vertebral disc. This fact is of great clinical significance in cases

bifida are shown in CD Figs. 16-6 and 16-7.

with prolapse of an intervertebral disc (see CD Fig. 16-1).

The Verterbral Column, the Spinal Cord, and the Meninges

257

CD Figure 16-7

A. Meningocele in the lumbosacral region. (Courtesy of L. Thompson.)

B. Meningomyelocele in the upper thoracic region. (Courtesy of G. Avery.)

Clinical Problem Solving Questions

Read the following case histories/questions and give

physician suspected a displacement of the upper

the best answer for each.

thoracic spines on the sixth thoracic spine.

An 11-year-old boy was showing off in front of friends by div-

2. The following physical signs confirmed a diagnosis of

ing into the shallow end of a swimming pool. After one par-

fracture dislocation between the fifth and sixth thoracic

ticularly daring dive, he surfaced quickly and climbed out of

vertebrae except which?

the pool, holding his head between his hands. He said that

A. A lateral radiograph revealed fractures involving the

he had hit the bottom of the pool with his head and now had

superior articular processes of the sixth thoracic ver-

severe pain in the root of the neck, which was made worse

tebra and the inferior articular processes of the fifth

when he tried to move his neck. A lateral radiograph re-

thoracic vertebra.

vealed that the right inferior articular process of the fifth cer-

B. Considerable forward displacement of the body of

vical vertebra was forced over the anterior margin of the

the fifth thoracic vertebra on the sixth thoracic ver-

right superior articular process of the sixth cervical vertebra,

tebra occurred.

producing a unilateral dislocation with nipping of the right

C. The patient had signs and symptoms of spinal shock.

sixth cervical nerve.

D. The large size of the vertebral canal in the thoracic

1. The following symptoms and signs confirmed the diag-

region leaves plenty of space around the spinal cord

nosis except which?

for bony displacement.

A. The head was rotated to the right.

E. The patient later showed signs and symptoms of

B. There was spasm of the deep neck muscles on the

paraplegia.

right side of the neck, which were tender to touch.

A 66-year-old woman was seen in the emergency depart-

C. The patient complained of severe pain in the region

ment complaining of a burning pain over the upper part of

of the back of the neck and right shoulder.

her right arm. The pain had started 2 days previously and

D. The slightest movement produced severe pain in

had progressively worsened. Physical examination revealed

the right sixth cervical dermatome.

weakness and wasting of the right deltoid and biceps brachii

E. The large size of the vertebral canal in the cervical

muscles. The patient also had hyperesthesia in the skin over

region permitted the spinal cord to escape injury.

the lower part of the right deltoid and down the lateral side

A 50-year-old coal miner was crouching at the mine

of the arm. Radiologic examination showed extensive spur

face when a large rock suddenly became dislodged

formation on the bodies of the fourth, fifth, and sixth cervi-

from the roof of the mine shaft and struck him on the

cal vertebrae. These signs and symptoms suggested severe

upper part of his back. The emergency department

osteoarthritis of the cervical vertebral column.

258

Chapter 16

3. This disease produced the following changes in the ver-

B. An imaginary line joining the anterior superior iliac

tebrae and related structures except which?

spines passes over the fourth lumbar spine.

A. Repeated trauma and aging had resulted in degen-

C. The needle should be inserted above or below the

erative changes at the articulating surfaces of the

fourth lumbar spine.

fourth, fifth, and sixth cervical vertebrae.

D. To enter the subarachnoid space, the needle will pass

B. Extensive spur formation resulted in narrowing of

through the skin, superficial fascia, supraspinous lig-

the intervertebral foramina with pressure on the

ament, interspinous ligament, ligamentum flavum,

nerve roots.

areolar tissue (containing the internal vertebral ve-

C. The burning pain and hyperesthesia were caused by

nous plexus), dura mater, and arachnoid mater.

pressure on the third and fourth cervical posterior

E. The spinal cord ends below in the adult at the level

roots.

of the lower border of the first lumbar vertebra.

D. The weakness and wasting of the deltoid and biceps

F. With the patient in the lateral prone position, the

brachii muscles were caused by pressure on the fifth

normal cerebrospinal fluid pressure is about 60-150

and sixth cervical anterior roots.

mm H₂O.

E. Movements of the neck intensified the symptoms by

A 22-year-old student was driving home from a party and

exerting further pressure on the nerve roots.

crashed his car head on into a brick wall. On examination

F. Coughing or sneezing raised the pressure within the

in the emergency department, he was found to have a frac-

vertebral canal and resulted in further pressure on

ture dislocation of the seventh thoracic vertebra, with signs

the roots.

and symptoms of severe damage to the spinal cord.

A medical student offered to move a grand piano for his

6. On recovery from spinal shock he was found to have the

landlady. He had just finished his final examinations in

following signs and symptoms except which?

anatomy and was in poor physical shape. He struggled with

A. Upper motor neuron paralysis of his left leg

the antique monstrosity and suddenly experienced an acute

B. A band of cutaneous hyperesthesia extending

pain in the back, which extended down the back and outer

around the abdominal wall on the left side at the

side of his left leg. On examination in the emergency de-

level of the umbilicus, which was caused by the irri-

partment, he was found to have a slight scoliosis with the

tation of the cord immediately above the site of the

convexity on the right side. The deep muscles of the back in

lesion

the left lumbar region felt firmer than normal. No evidence

C. On the right side, total analgesia, thermoanesthesia,

of muscle weakness was present, but the left ankle jerk was

and partial loss of tactile sense of the skin of the ab-

diminished.

dominal wall below the level of the umbilicus in-

volving the whole of the right leg

4. The symptoms and signs of this patient strongly suggest

D. Fracture dislocation of the seventh thoracic verte-

a diagnosis of prolapsed intervertebral disc except

bra, which would result in severe damage to the sev-

which?

enth thoracic segment of the spinal cord

A. The pain was the worst over the left lumbar region

E. Unequal sensory and motor losses on the two sides,

opposite the fifth lumbar spine.

which indicate a left hemisection of the spinal cord

B. The pain was accentuated by coughing.

C. With the patient supine, flexing the left hip joint

A 45-year-old woman visited her physician because of a low

with the knee extended caused a marked increase in

back pain of 3 months’ duration. She was otherwise very fit.

the pain.

On examination of her back, nothing abnormal was discov-

D. A lateral radiograph of the lumbar vertebral column

ered. The physician then listened to her chest, examined

revealed nothing abnormal.

her thyroid gland, and finally examined both breasts. A

E. A magnetic resonance imaging study revealed the

large, hard mass was found in the left breast.

presence of small fragments of the nucleus pulposus

7. The following facts support the diagnosis of carcinoma

that had herniated outside the anulus in the disc be-

of the left breast with secondaries in the vertebral col-

tween the fifth lumbar vertebra and the sacrum.

umn except which?

F. The pain occurred in the dermatomes of the third

A. The lump in the breast was painless and the patient

and fourth lumbar segments on the left side.

had noticed it while showering 6 months previously.

5. When performing a lumbar puncture (spinal tap) on an

B. Several large, hard, pectoral lymph nodes were

adult, the following anatomic facts have to be taken into

found in the left axilla.

consideration except which?

C. A lateral radiograph of the lumbar vertebral column

A. With the patient in the lateral prone or upright sit-

showed extensive metastases in the bodies of the sec-

ting position, the vertebral column should be well

ond and third lumbar vertebrae.

flexed to separate the spines and laminae of adjacent

D. The lump was situated in the upper outer quadrant

vertebrae.

of the left breast and was fixed to surrounding tissues.

The Verterbral Column, the Spinal Cord, and the Meninges

259

E. Although the cancer had spread by the lymph ves-

B. Anteroposterior and lateral radiographs exclude the

sels, no evidence of spread via the bloodstream was

presence of a fracture, especially of a transverse

present.

process.

A 75-year-old woman was dusting the top of a high closet

C. A 24-hour specimen of urine should be examined

while balanced on a chair. She lost her balance and fell to

for blood to exclude or confirm injury to the right

the floor, catching her right lumbar region on the edge of

kidney.

the chair.

D. Careful examination of the erector spinae muscles

or quadratus lumborum muscle may reveal extreme

8. The following statements about this patient are correct

tenderness and therefore injury to these muscles.

except which?

E. A lumbar puncture (spinal tap) should always be

A. Examination of the back revealed a large bruised

performed in back injuries to exclude damage to the

area in the right lumbar region, which was extremely

spinal cord.

tender to touch.

Answers and Explanations

1. A is the correct answer. The right inferior articular

5. B is the correct answer. An imaginary line joining the

process of the fifth cervical vertebra was forced over the

highest points of the iliac crests passes over the fourth

anterior margin of the right superior articular process of

lumbar spine.

the sixth cervical vertebra, causing the head of the pa-

6. D is the correct answer. Fracture dislocation of the sev-

tient to be rotated to the left.

enth thoracic vertebra would result in severe damage to

2. D is the correct answer. The vertebral canal in the tho-

the tenth thoracic segment of the spinal cord.

racic region is small and round and little space is

7. E is the correct answer. The carcinoma of the left breast

around the spinal cord for bony displacement to occur

was in an advanced stage and had spread by way of the

without causing severe damage to the cord.

lymph vessels to the axillary lymph nodes and by the

3. C is the correct answer. The burning pain and hyperes-

bloodstream to the bodies of the second and third lum-

thesia were caused by pressure on the fifth and sixth cer-

bar vertebrae. Carcinoma of the thyroid, bronchus,

vical posterior roots.

breast, kidney, and prostate tend to metastasize via the

bloodstream to bones.

4. F is the correct answer. The pain occurred in the der-

matomes of the fifth lumbar and first sacral segments on

8. E is the correct answer. A lumbar puncture (spinal tap)

the left side.

is not required in cases of simple trauma to the back.

Chapter Outline

Cervical Plexus

263

Arterial Innervation and Raynaud’s Disease

271

Lesions of the Phrenic Nerve and Paralysis of the

Intercostal Nerves

272

Diaphragm

263

Skin Innervation of the Chest Wall and

Brachial Plexus

263

Referred Pain

272

Herpes Zoster

272

Clinical Notes on the Nerves of the Upper

Limb

263

Lumbar Plexus

272

Dermatomes and Cutaneous Nerves

Clinical Notes on the Nerves of the Lower

of the Upper Limb

263

Limb

272

Tendon Reflexes and the Segmental Innervation of

Tendon Reflexes of the Lower Limb

272

Muscles of the Upper Limb

263

Femoral Nerve Injury

272

Brachial Plexus Injuries

263

Sciatic Nerve Injury

272

Upper Lesions of the Brachial Plexus (Erb-Duchenne

Trauma to the Sciatic Nerve

273

Palsy)

264

Sciatica

273

Lower Lesions of the Brachial Plexus (Klumpke

Palsy)

265

Common Peroneal Nerve Injury

273

Compression of the Brachial Plexus, Subclavian Artery,

Tibial Nerve Injury

273

and Subclavian Vein by the Clavicle

265

Obturator Nerve Injury

274

Long Thoracic Nerve Injuries

266

Referred Pain from the Hip Joint

274

Axillary Nerve Injuries

266

Sacral Plexus

274

Radial Nerve Injuries

266

Pressure from the Fetal Head on the Sacral Plexus

274

Injuries to the Radial Nerve in the Axilla

268

Invasion of the Sacral Plexus by Malignant Tumors

274

Motor

268

Sensory

268

Referred Pain from the Obturator Nerve

274

Trophic Changes

268

Clinical Anatomy of Spinal Nerve Blocks

274

Injuries to the Radial Nerve in the Spiral Groove of

the Humerus

268

Brachial Plexus Block

274

Injuries to the Deep Branch of the Radial Nerve

268

Interscalene Block

274

Injuries to the Superficial Radial Nerve

268

Supraclavicular Block

276

Infraclavicular Block

276

Musculocutaneous Nerve Injuries

269

Axillary Block

276

Median Nerve Injuries

269

Musculocutaneous Nerve Block

276

Injuries to the Median Nerve at the Elbow

269

Motor

269

Median Nerve Block

276

Sensory

269

Ulnar Nerve Block

277

Vasomotor Changes

269

Radial Nerve Block

278

Trophic Changes

269

Injuries to the Median Nerve at the Wrist

270

Digital Nerve Blocks

278

Carpal Tunnel Syndrome

270

Thoracic Spinal Nerve Blocks

280

Ulnar Nerve Injuries

270

Intercostal Nerve Block

280

Injuries to the Ulnar Nerve at the Elbow

270

Motor

270

Anterior Abdominal Nerve Blocks

282

Sensory

271

Lumbar Spinal Nerve Blocks

283

Vasomotor Changes

271

Ilioinguinal and Iliohypogastric Nerve Blocks

283

Injuries to the Ulnar Nerve at the Wrist

271

Genitofemoral Nerve Block

283

The Spinal Nerves and Spinal Nerve Blocks

263

Femoral Nerve Block

283

Superficial Peroneal Nerve Block

287

Saphenous Nerve Block

284

Deep Peroneal Nerve Block

288

Lateral Cutaneous Nerve of the Thigh Block

284

Toe Nerve Blocks

289

Sacral Spinal Nerve Blocks

285

Pudendal Nerve Blocks

290

Tibial Nerve Block

285

Clinical Problem Solving Questions

290

Sural Nerve Block

286

Common Peroneal Nerve Block

287

Answers and Explanations

293

they exit from the cord in a spinal nerve of the same seg-

ment, pass to the skin in two or more different cutaneous

CERVICAL PLEXUS

nerves.

The skin over the point of the shoulder and halfway

down the lateral surface of the deltoid muscle is supplied by

Lesions of the Phrenic Nerve and

the supraclavicular nerves (C3 and 4). Pain may be referred

to this region as a result of inflammatory lesions involving

Paralysis of the Diaphragm

the diaphragmatic pleura or peritoneum. The afferent stim-

The diaphragm may be paralyzed because of pressure from

uli reach the spinal cord via the phrenic nerves (C3, 4, and

malignant tumors in the mediastinum on the phrenic nerve.

5). Pleurisy, peritonitis, subphrenic abscess, or gallbladder

Surgical crushing or sectioning of the phrenic nerve in the

disease may therefore be responsible for shoulder pain.

neck, producing paralysis of the diaphragm on one side, was

once used as part of the treatment of lung tuberculosis,

Tendon Reflexes and the Segmental

especially of the lower lobes. The immobile dome of the

diaphragm rests the lung.

Innervation of Muscles of the

Upper Limb

BRACHIAL PLEXUS

The skeletal muscle receives a segmental innervation. Most

muscles are innervated by several spinal nerves and there-

fore by several segments of the spinal cord. A physician

should know the segmental innervation of the following

CLINICAL NOTES

muscles because it is possible to test them by eliciting

simple muscle reflexes in the patient:

ON THE NERVES OF

■ Biceps brachii tendon reflex: C5 and 6 (flexion of the

elbow joint by tapping the biceps tendon)

THE UPPER LIMB

■ Triceps tendon reflex: C6, 7, and 8 (extension of the

elbow joint by tapping the triceps tendon)

■ Brachioradialis tendon reflex: C5, 6, and 7 (supination

Dermatomes and Cutaneous

of the radioulnar joints by tapping the insertion of the

brachioradialis tendon)

Nerves of the Upper Limb

It may be necessary for a physician to test the integrity of the

Brachial Plexus Injuries

spinal cord segments of C3 through T1. The diagrams in

CD Figs. 17-1 and 17-2 show the arrangement of the der-

The roots, trunks, and divisions of the brachial plexus reside

matomes of the upper limb. It is seen that the dermatomes

in the lower part of the posterior triangle of the neck,

for the upper cervical segments C3 to 6 are located along the

whereas the cords and most of the branches of the plexus lie

lateral margin of the upper limb; the C7 dermatome is situ-

in the axilla. Complete lesions involving all the roots of the

ated on the middle finger; and the dermatomes for C8, T1,

plexus are rare. Incomplete injuries are common and are

and T2 are along the medial margin of the limb. The nerve

usually caused by traction or pressure; individual nerves can

fibers from a particular segment of the spinal cord, although

be divided by stab wounds.

264

Chapter 17

transverse cutaneous nerve of neck

supraclavicular nerves

anterior cutaneous branch of second

intercostal nerve

upper lateral cutaneous nerve of arm

medial cutaneous nerve of arm

lower lateral cutaneous nerve of arm

medial cutaneous nerve of forearm

lateral cutaneous nerve of forearm

lateral cutaneous branch of

T10

subcostal nerve

T11

T12

femoral branch of genitofemoral

nerve

median nerve

ulnar nerve

ilioinguinal nerve

lateral cutaneous nerve of thigh

obturator nerve

medial cutaneous nerve of thigh

intermediate cutaneous nerve of thigh

infrapatellar branch of saphenous nerve

lateral sural cutaneous nerve

saphenous nerve

superficial peroneal nerve

deep peroneal nerve

Figure

17-1

Dermatomes

and

distribution of cutaneous nerves on the

anterior aspect of the body.

and infraspinatus (lateral rotator of the shoulder); the sub-

Upper Lesions of the Brachial Plexus

clavius (depresses the clavicle); the biceps brachii (supina-

(Erb-Duchenne Palsy)

tor of the forearm, flexor of the elbow, weak flexor of the

Upper lesions of the brachial plexus are injuries resulting

shoulder), and the greater part of the brachialis (flexor of

from excessive displacement of the head to the opposite

the elbow), and the coracobrachialis (flexor of the shoul-

side and depression of the shoulder on the same side. This

der); and the deltoid (abductor of the shoulder) and the

causes excessive traction or even tearing of C5 and 6 roots

teres minor (lateral rotator of the shoulder). Thus, the limb

of the plexus. It occurs in infants during a difficult delivery

will hang limply by the side, medially rotated by the un-

or in adults after a blow to or fall on the shoulder. The

opposed sternocostal part of the pectoralis major; the fore-

suprascapular nerve, the nerve to the subclavius, and the

arm will be pronated because of loss of the action of the bi-

musculocutaneous and axillary nerves all possess nerve

ceps. The position of the upper limb in this condition has

fibers derived from C5 and 6 roots and will therefore be

been likened to that of a porter or waiter hinting for a tip

functionless. The following muscles will consequently be

(CD Fig.17-3). In addition, there will be a loss of sensation

paralyzed: the supraspinatus (abductor of the shoulder)

down the lateral side of the arm.

The Spinal Nerves and Spinal Nerve Blocks

265

greater occipital nerve

third cervical nerve

great auricular nerve

fourth cervical nerve

lesser occipital nerve

supraclavicular nerve

first thoracic nerve

posterior cutaneous nerve of arm

medial cutaneous nerve of arm

posterior cutaneous nerve of forearm

medial cutaneous nerve of forearm

lateral cutaneous nerve of forearm

T10

T11

lateral cutaneous branch of T12

T12

posterior cutaneous branches of

L1, 2, and 3

radial nerve

ulnar nerve

posterior cutaneous branches of

S1, 2, and 3

branches of posterior cutaneous

nerve of thigh

posterior cutaneous nerve of thigh

obturator nerve

lateral cutaneous nerve

of calf

sural nerve

saphenous nerve

lateral plantar nerve

CD Figure 17-2

Dermatomes and distribu-

medial plantar nerve

tion of cutaneous nerves on the posterior

aspect of the body.

Lower Lesions of the Brachial Plexus

of the arm. If the eighth cervical nerve is also damaged, the

extent of anesthesia will be greater and will involve the medial

(Klumpke Palsy)

side of the forearm, hand, and medial two fingers.

Lower lesions of the brachial plexus are usually traction in-

Lower lesions of the brachial plexus can also be

juries caused by excessive abduction of the arm, as occurs in

produced by the presence of a cervical rib or malignant

the case of a person falling from a height clutching at an ob-

metastases from the lungs in the lower deep cervical lymph

ject to save himself or herself. The first thoracic nerve is usu-

nodes.

ally torn. The nerve fibers from this segment run in the ulnar

and median nerves to supply all the small muscles of the

Compression of the Brachial

hand. The hand has a clawed appearance caused by hyper-

extension of the metacarpophalangeal joints and flexion of

Plexus, Subclavian Artery, and

the interphalangeal joints. The extensor digitorum is unop-

posed by the lumbricals and interossei and extends the

Subclavian Vein by the Clavicle

metacarpophalangeal joints; the flexor digitorum superficialis

and profundus are unopposed by the lumbricals and interos-

The interval between the clavicle and the first rib in some

sei and flex the middle and terminal phalanges, respectively.

patients may become narrowed and thus is responsible for

In addition, loss of sensation will occur along the medial side

compression of nerves and blood vessels.

266

Chapter 17

CD Figure 17-4

Winging of the right scapula.

and the underlying greater tuberosity can be readily pal-

pated. Because the supraspinatus is the only other abductor

of the shoulder, this movement is much impaired. Paralysis

of the teres minor is not recognizable clinically.

CD Figure 17-3

Erb-Duchenne palsy (waiter’s tip).

Radial Nerve Injuries

The radial nerve (see text Fig. 17-21), which arises from the

posterior cord of the brachial plexus, characteristically gives

Long Thoracic Nerve Injuries

off its branches some distance proximal to the part to be

innervated.

The long thoracic nerve, which arises from C5, 6, and 7 and

supplies the serratus anterior muscle, can be injured by

■ In the axilla it gives off three branches: the posterior cu-

blows to or pressure on the posterior triangle of the neck or

taneous nerve of the arm, which supplies the skin on the

during the surgical procedure of radical mastectomy. Paral-

back of the arm down to the elbow; the nerve to the long

ysis of the serratus anterior results in the inability to rotate the

head of the triceps; and the nerve to the medial head of

scapula during the movement of abduction of the arm above

the triceps.

a right angle. The patient therefore experiences difficulty in

■ In the spiral groove of the humerus it gives off four

raising the arm above the head. The vertebral border and

branches: the lower lateral cutaneous nerve of the arm,

inferior angle of the scapula will no longer be kept closely

which supplies the lateral surface of the arm down to the

applied to the chest wall and will protrude posteriorly, a con-

elbow; the posterior cutaneous nerve of the forearm,

dition known as “winged scapula” (CD Fig.17-4).

which supplies the skin down the middle of the back of

the forearm as far as the wrist; the nerve to the lateral

head of the triceps; and the nerve to the medial head of

Axillary Nerve Injuries

the triceps and the anconeus.

The axillary nerve (see text Fig. 17-20B), which arises from

■ In the anterior compartment of the arm above the lat-

the posterior cord of the brachial plexus (C5 and 6), can be

eral epicondyle it gives off three branches: the nerve to a

injured by the pressure of a badly adjusted crutch pressing

small part of the brachialis, the nerve to the brachioradi-

upward into the armpit. The passage of the axillary nerve

alis, and the nerve to the extensor carpi radialis longus.

backward from the axilla through the quadrangular space

■ In the cubital fossa it gives off the deep branch of the

makes it particularly vulnerable here to downward displace-

radial nerve and continues as the superficial radial nerve.

ment of the humeral head in shoulder dislocations or frac-

The deep branch supplies the extensor carpi radialis

tures of the surgical neck of the humerus. Paralysis of the

brevis and the supinator in the cubital fossa and all the

deltoid and teres minor muscles results. The cutaneous

extensor muscles in the posterior compartment of the

branches of the axillary nerve, including the upper lateral

forearm. The superficial radial nerve is sensory and sup-

cutaneous nerve of the arm, are functionless, and conse-

plies the skin over the lateral part of the dorsum of

quently there is a loss of skin sensation over the lower half

the hand and the dorsal surface of the lateral three and a

of the deltoid muscle. The paralyzed deltoid wastes rapidly,

half fingers proximal to the nail beds (CD Fig. 17-5).

268

Chapter 17

Sensory

(The ulnar nerve supplies the medial part of the dorsum

of the hand and the dorsal surface of the medial one

A small loss of skin sensation occurs down the posterior sur-

and a half fingers; the exact cutaneous areas innervated

face of the lower part of the arm and down a narrow strip on

by the radial and ulnar nerves on the hand are subject to

the back of the forearm. A variable area of sensory loss is pre-

variation.)

sent on the lateral part of the dorsum of the hand and on the

The radial nerve is commonly damaged in the axilla

dorsal surface of the roots of the lateral three and a half fin-

and in the spiral groove.

gers. The area of total anesthesia is relatively small because

of the overlap of sensory innervation by adjacent nerves.

Injuries to the Radial Nerve

in the Axilla

Trophic Changes

In the axilla the nerve can be injured by the pressure of the

Trophic changes are slight.

upper end of a badly fitting crutch pressing up into

the armpit or by a drunkard falling asleep with one arm over

Injuries to the Radial Nerve in the

the back of a chair. It can also be badly damaged in the axilla

Spiral Groove of the Humerus

by fractures and dislocations of the proximal end of the

humerus. When the humerus is displaced downward in dis-

In the spiral groove of the humerus, the radial nerve can be

locations of the shoulder, the radial nerve, which is wrapped

injured at the time of fracture of the shaft of the humerus or

around the back of the shaft of the bone, is pulled down-

subsequently involved during the formation of the callus.

ward, stretching the nerve in the axilla excessively.

The pressure of the back of the arm on the edge of the op-

The clinical findings in injury to the radial nerve in the

erating table in an unconscious patient has also been known

axilla are as follows.

to injure the nerve at this site. The prolonged application of

a tourniquet to the arm in a person with a slender triceps

Motor

muscle is often followed by temporary radial palsy.

The clinical findings in injury to the radial nerve in the

The triceps, the anconeus, and the long extensors of the

spiral groove are as follows:

wrist are paralyzed. The patient is unable to extend the el-

The injury to the radial nerve occurs most commonly

bow joint, the wrist joint, and the fingers. Wristdrop, or flex-

in the distal part of the groove, beyond the origin of the

ion of the wrist (CD Fig. 17-6), occurs as a result of the

nerves to the triceps and the anconeus and beyond the ori-

action of the unopposed flexor muscles of the wrist. Wrist-

gin of the cutaneous nerves.

drop is very disabling because one is unable to flex the fin-

gers strongly for the purpose of firmly gripping an object

■ Motor: The patient is unable to extend the wrist and the

with the wrist fully flexed. (Try it on yourself.) If the wrist

fingers, and wristdrop occurs.

and proximal phalanges are passively extended by holding

■ Sensory: A variable small area of anesthesia is present

them in position with the opposite hand, the middle and

over the dorsal surface of the hand and the dorsal surface

distal phalanges of the fingers can be extended by the action

of the roots of the lateral three and a half fingers.

of the lumbricals and interossei, which are inserted into the

■ Trophic changes: These are very slight or absent.

extensor expansions.

The brachioradialis and supinator muscles are also par-

Injuries to the Deep Branch of the

alyzed, but supination is still performed well by the biceps

Radial Nerve

brachii.

The deep branch of the radial nerve is a motor nerve to the

extensor muscles in the posterior compartment of the fore-

arm. It can be damaged in fractures of the proximal end of the

radius or during dislocation of the radial head. The nerve sup-

ply to the supinator and the extensor carpi radialis longus will

be undamaged, and because the latter muscle is powerful, it

will keep the wrist joint extended, and wristdrop will not oc-

cur. No sensory loss occurs because this is a motor nerve.

Injuries to the Superficial Radial Nerve

Division of the superficial radial nerve, which is sensory, as

in a stab wound, results in a variable small area of anesthe-

sia over the dorsum of the hand and the dorsal surface of the

CD Figure 17-6

Wristdrop.

roots of the lateral three and a half fingers.

The Spinal Nerves and Spinal Nerve Blocks

269

Musculocutaneous Nerve Injuries

The musculocutaneous nerve (see text Fig. 17-9) is rarely in-

jured because of its protected position beneath the biceps

brachii muscle. If it is injured high up in the arm, the biceps

and coracobrachialis are paralyzed and the brachialis mus-

cle is weakened (the latter muscle is also supplied by the ra-

dial nerve). Flexion of the forearm at the elbow joint is then

produced by the remainder of the brachialis muscle and the

flexors of the forearm. When the forearm is in the prone po-

sition, the extensor carpi radialis longus and the brachiora-

dialis muscles assist in flexion of the forearm. There is also

sensory loss along the lateral side of the forearm. Wounds or

cuts of the forearm can sever the lateral cutaneous nerve of

the forearm, a continuation of the musculocutaneous nerve

beyond the cubital fossa, resulting in sensory loss along the

CD Figure 17-7

Median nerve palsy.

lateral side of the forearm.

Median Nerve Injuries

accompanied by adduction. The latter deviation is caused by

The median nerve (see text Fig. 17-9), which arises from the

the paralysis of the flexor carpi radialis and the strength of the

medial and lateral cords of the brachial plexus, gives off no cu-

flexor carpi ulnaris and the medial half of the flexor digito-

taneous or motor branches in the axilla or in the arm. In the

rum profundus. No flexion is possible at the interphalangeal

proximal third of the front of the forearm, by unnamed

joints of the index and middle fingers, although weak flexion

branches or by its anterior interosseous branch, it supplies all

of the metacarpophalangeal joints of these fingers is at-

the muscles of the front of the forearm except the flexor carpi

tempted by the interossei. When the patient tries to make a

ulnaris and the medial half of the flexor digitorum profundus,

fist, the index and to a lesser extent the middle fingers tend

which are supplied by the ulnar nerve. In the distal third of

to remain straight, whereas the ring and little fingers flex (CD

the forearm, it gives rise to a palmar cutaneous branch, which

Fig. 17-7). The latter two fingers are, however, weakened by

crosses in front of the flexor retinaculum and supplies the skin

the loss of the flexor digitorum superficialis.

on the lateral half of the palm (see CD Fig. 17-5). In the palm

Flexion of the terminal phalanx of the thumb is lost be-

the median nerve supplies the muscles of the thenar emi-

cause of paralysis of the flexor pollicis longus. The muscles

nence and the first two lumbricals and gives sensory innerva-

of the thenar eminence are paralyzed and wasted so that the

tion to the skin of the palmar aspect of the lateral three and a

eminence is flattened. The thumb is laterally rotated and

half fingers, including the nail beds on the dorsum.

adducted. The hand looks flattened and “ape-like.”

From a clinical standpoint, the median nerve is injured

occasionally in the elbow region in supracondylar fractures

Sensory

of the humerus. It is most commonly injured by stab

Skin sensation is lost on the lateral half or less of the palm of

wounds or broken glass just proximal to the flexor retinacu-

the hand and the palmar aspect of the lateral three and a half

lum; here it lies in the interval between the tendons of the

fingers. Sensory loss also occurs on the skin of the distal part

flexor carpi radialis and flexor digitorum superficialis, over-

of the dorsal surfaces of the lateral three and a half fingers.

lapped by the palmaris longus.

The area of total anesthesia is considerably less because of

The clinical findings in injury to the median nerve are

the overlap of adjacent nerves.

as follows.

Vasomotor Changes

Injuries to the Median Nerve

at the Elbow

The skin areas involved in sensory loss are warmer and drier

than normal because of the arteriolar dilatation and absence

Motor

of sweating resulting from loss of sympathetic control.

The pronator muscles of the forearm and the long flexor

Trophic Changes

muscles of the wrist and fingers, with the exception of the

flexor carpi ulnaris and the medial half of the flexor digito-

In long-standing cases, changes are found in the hand and

rum profundus, will be paralyzed. As a result, the forearm is

fingers. The skin is dry and scaly, the nails crack easily, and

kept in the supine position; wrist flexion is weak and is

atrophy of the pulp of the fingers is present.

270

Chapter 17

Injuries to the Median Nerve

Having entered the palm by passing in front of the

flexor retinaculum, the superficial branch of the ulnar

at the Wrist

nerve supplies the skin of the palmar surface of the medial

■ Motor: The muscles of the thenar eminence are paralyzed

one and a half fingers (see CD Fig. 17-5), including their

and wasted so that the eminence becomes flattened. The

nail beds; it also supplies the palmaris brevis muscle. The

thumb is laterally rotated and adducted. The hand looks

deep branch supplies all the small muscles of the hand ex-

flattened and “ape-like.” Opposition movement of the

cept the muscles of the thenar eminence and the first two

thumb is impossible. The first two lumbricals are para-

lumbricals, which are supplied by the median nerve.

lyzed, which can be recognized clinically when the

The ulnar nerve is most commonly injured at the

patient is asked to make a fist slowly, and the index and

elbow, where it lies behind the medial epicondyle, and at

middle fingers tend to lag behind the ring and little fingers.

the wrist, where it lies with the ulnar artery in front of the

■ Sensory, vasomotor, and trophic changes: These

flexor retinaculum. The injuries at the elbow are usually

changes are identical to those found in the elbow lesions.

associated with fractures of the medial epicondyle. The su-

perficial position of the nerve at the wrist makes it vulnera-

Perhaps the most serious disability of all in median nerve

ble to damage from cuts and stab wounds.

injuries is the loss of ability to oppose the thumb to the other

The clinical findings in injury to the ulnar nerve are as

fingers and the loss of sensation over the lateral fingers. The

follows.

delicate pincer-like action of the hand is no longer possible.

Carpal Tunnel Syndrome

Injuries to the Ulnar Nerve

at the Elbow

The carpal tunnel, formed by the concave anterior surface

of the carpal bones and closed by the flexor retinaculum, is

Motor

tightly packed with the long flexor tendons of the fingers,

their surrounding synovial sheaths, and the median nerve.

The flexor carpi ulnaris and the medial half of the flexor dig-

Clinically, the syndrome consists of a burning pain or “pins

itorum profundus muscles are paralyzed. The paralysis of

and needles” along the distribution of the median nerve to

the flexor carpi ulnaris can be observed by asking the patient

the lateral three and a half fingers and weakness of the

to make a tightly clenched fist. Normally, the synergistic ac-

thenar muscles. It is produced by compression of the me-

tion of the flexor carpi ulnaris tendon can be observed as it

dian nerve within the tunnel. The exact cause of the com-

passes to the pisiform bone; the tightening of the tendon will

pression is difficult to determine, but thickening of the

be absent if the muscle is paralyzed. The profundus tendons

synovial sheaths of the flexor tendons or arthritic changes in

to the ring and little fingers will be functionless, and the ter-

the carpal bones are thought to be responsible in many

minal phalanges of these fingers are therefore not capable of

cases. As would be expected, no paresthesia occurs over the

being markedly flexed. Flexion of the wrist joint will result

thenar eminence because this area of skin is supplied by the

in abduction, owing to paralysis of the flexor carpi ulnaris.

palmar cutaneous branch of the median nerve, which passes

The medial border of the front of the forearm will show flat-

superficially to the flexor retinaculum. The condition is dra-

tening, owing to the wasting of the underlying ulnaris and

matically relieved by decompressing the tunnel by making a

profundus muscles.

longitudinal incision through the flexor retinaculum.

The small muscles of the hand will be paralyzed, except

the muscles of the thenar eminence and the first two lum-

bricals, which are supplied by the median nerve. The

Ulnar Nerve Injuries

patient is unable to adduct and abduct the fingers and con-

The ulnar nerve (see text Fig. 17-20A), which arises from the

sequently is unable to grip a piece of paper placed between

medial cord of the brachial plexus (C8 and T1), gives off no

the fingers. Remember that the extensor digitorum can

cutaneous or motor branches in the axilla or in the arm. As

abduct the fingers to a small extent, but only when the

it enters the forearm from behind the medial epicondyle, it

metacarpophalangeal joints are hyperextended.

supplies the flexor carpi ulnaris and the medial half of the

It is impossible to adduct the thumb because the

flexor digitorum profundus. In the distal third of the fore-

adductor pollicis muscle is paralyzed. If the patient is

arm, it gives off its palmar and posterior cutaneous branches.

asked to grip a piece of paper between the thumb and the

The palmar cutaneous branch supplies the skin over the hy-

index finger, he or she does so by strongly contracting the

pothenar eminence; the posterior branch supplies the skin

flexor pollicis longus and flexing the terminal phalanx

over the medial third of the dorsum of the hand and the me-

(Froment’s sign).

dial one and a half fingers. Not uncommonly, the posterior

The metacarpophalangeal joints become hyperex-

branch supplies two and a half instead of one and a half

tended because of the paralysis of the lumbrical and

fingers. It does not supply the skin over the distal part of the

interosseous muscles, which normally flex these joints. Be-

dorsum of these fingers.

cause the first and second lumbricals are not paralyzed (they

The Spinal Nerves and Spinal Nerve Blocks

271

CD Figure 17-8

Ulnar nerve palsy.

are supplied by the median nerve), the hyperextension of

muscle is not paralyzed, and marked flexion of the

the metacarpophalangeal joints is most prominent in the

terminal phalanges occurs.

fourth and fifth fingers. The interphalangeal joints are

■ Sensory: The main ulnar nerve and its palmar cuta-

flexed, owing again to the paralysis of the lumbrical and in-

neous branch are usually severed; the posterior cuta-

terosseous muscles, which normally extend these joints

neous branch, which arises from the ulnar nerve trunk

through the extensor expansion. The flexion deformity at

about 2.5 in. (6.25 cm) above the pisiform bone, is usu-

the interphalangeal joints of the fourth and fifth fingers is

ally unaffected. The sensory loss will therefore be

obvious because the first and second lumbrical muscles of

confined to the palmar surface of the medial third of

the index and middle fingers are not paralyzed. In long-

the hand and the medial one and a half fingers and to

standing cases the hand assumes the characteristic “claw”

the dorsal aspects of the middle and distal phalanges of

deformity (main en griffe). Wasting of the paralyzed mus-

the same fingers.

cles results in flattening of the hypothenar eminence and

■ Vasomotor and trophic changes: These are the same as

loss of the convex curve to the medial border of the hand.

those described for injuries at the elbow. It is important

Examination of the dorsum of the hand will show hollow-

to remember that with ulnar nerve injuries, the higher

ing between the metacarpal bones caused by wasting of the

the lesion is, the less obvious is the clawing deformity of

dorsal interosseous muscles (CD Fig. 17-8).

the hand.

Unlike median nerve injuries, lesions of the ulnar nerve

Sensory

leave a relatively efficient hand. The sensation over the lateral

Loss of skin sensation will be observed over the anterior and

part of the hand is intact, and the pincer-like action of the

posterior surfaces of the medial third of the hand and the

thumb and index finger is reasonably good, although there is

medial one and a half fingers.

some weakness, owing to loss of the adductor pollicis.

Vasomotor Changes

Arterial Innervation and

The skin areas involved in sensory loss are warmer and drier

than normal because of the arteriolar dilatation and absence

Raynaud’s Disease

of sweating resulting from loss of sympathetic control.

The arteries of the upper limb are innervated by sympa-

thetic nerves. The preganglionic fibers originate from cell

Injuries to the Ulnar Nerve

bodies in the second to eighth thoracic segments of the

at the Wrist

spinal cord. They ascend in the sympathetic trunk and

■ Motor: The small muscles of the hand will be paralyzed

synapse in the middle cervical, inferior cervical, first tho-

and show wasting, except for the muscles of the thenar

racic, or stellate ganglia. The postganglionic fibers join the

eminence and the first two lumbricals, as described (see

nerves that form the brachial plexus and are distributed to

previous page). The clawhand is much more obvious in

the arteries within the branches of the plexus. For example,

wrist lesions because the flexor digitorum profundus

the digital arteries of the fingers are supplied by postgan-

272

Chapter 17

glionic sympathetic fibers that run in the digital nerves.

Vasospastic diseases involving digital arterioles, such as

Raynaud’s disease, may require a cervicodorsal pregan-

LUMBAR PLEXUS

glionic sympathectomy to prevent necrosis of the fingers.

The operation is followed by arterial vasodilatation, with

consequent increased blood flow to the upper limb.

CLINICAL NOTES

INTERCOSTAL

ON THE NERVES OF

NERVES

THE LOWER LIMB

Skin Innervation of the Chest

Tendon Reflexes of the

Wall and Referred Pain

Lower Limb

Above the level of the sternal angle, the cutaneous innerva-

Skeletal muscles receive a segmental innervation. Most

tion of the anterior chest wall is derived from the supraclav-

muscles are innervated by two, three, or four spinal nerves

icular nerves (C3 and 4). Below this level, the anterior and

and therefore by the same number of segments of the spinal

lateral cutaneous branches of the intercostal nerves supply

cord. The segmental innervation of the following muscles in

oblique bands of skin in regular sequence. The skin on

the lower limb should be known because it is possible to test

the posterior surface of the chest wall is supplied by the pos-

them by eliciting simple muscle reflexes in the patient:

terior rami of the spinal nerves. The arrangement of the

■ Patellar tendon reflex (knee jerk): L2, 3, and 4 (exten-

dermatomes is shown in CD Figs. 17-1 and 17-2.

sion of the knee joint on tapping the patellar tendon)

An intercostal nerve not only supplies areas of skin but

■ Achilles tendon reflex (ankle jerk): S1 and S2 (plantar

also supplies the ribs, costal cartilages, intercostal muscles,

flexion of the ankle joint on tapping the Achilles tendon)

and parietal pleura lining the intercostal space. Further-

more, the seventh to eleventh intercostal nerves leave the

thoracic wall and enter the anterior abdominal wall so that

Femoral Nerve Injury

they, in addition, supply dermatomes on the anterior

The femoral nerve (L2, 3, and 4) enters the thigh from be-

abdominal wall, muscles of the anterior abdominal wall,

hind the inguinal ligament, at a point midway between the

and parietal peritoneum. This latter fact is of great clinical

anterior superior iliac spine and the pubic tubercle; it lies

importance because it means that disease in the thoracic

about a fingerbreadth lateral to the femoral pulse. About 2

wall may be revealed as pain in a dermatome that extends

in. (5 cm) below the inguinal ligament, the nerve splits into

across the costal margin into the anterior abdominal wall.

its terminal branches (see text Fig. 17-29).

For example, a pulmonary thromboembolism or a pneu-

The femoral nerve can be injured in stab or gunshot

monia with pleurisy involving the costal parietal pleura

wounds, but a complete division of the nerve is rare. The

could give rise to abdominal pain and tenderness and rigid-

following clinical features are present when the nerve is

ity of the abdominal musculature. The abdominal pain in

completely divided:

these instances is called referred pain.

■ Motor: The quadriceps femoris muscle is paralyzed, and

the knee cannot be extended. In walking, this is compen-

Herpes Zoster

sated for to some extent by use of the adductor muscles.

Herpes zoster, or shingles, is a relatively common condition

■ Sensory: Skin sensation is lost over the anterior and me-

caused by the reactivation of the latent varicella-zoster virus

dial sides of the thigh, over the medial side of the lower

in a patient who has previously had chickenpox. The lesion

part of the leg, and along the medial border of the foot as

is seen as an inflammation and degeneration of the sensory

far as the ball of the big toe; this area is normally supplied

neuron in a cranial or spinal nerve with the formation of

by the saphenous nerve.

vesicles with inflammation of the skin. In the thorax the first

symptom is a band of dermatomal pain in the distribution

Sciatic Nerve Injury

of the sensory neuron in a thoracic spinal nerve, followed in

a few days by a skin eruption. The condition occurs most

The sciatic nerve (L4 and 5 and S1, 2, and 3) curves later-

frequently in patients older than 50 years.

ally and downward through the gluteal region, situated at

The Spinal Nerves and Spinal Nerve Blocks

273

first midway between the posterosuperior iliac spine and the

The result of operative repair of a sciatic nerve injury is

ischial tuberosity, and lower down, midway between the tip

poor. It is rare for active movement to return to the small

of the greater trochanter and the ischial tuberosity. The

muscles of the foot, and sensory recovery is rarely complete.

nerve then passes downward in the midline on the posterior

Loss of sensation in the sole of the foot makes the develop-

aspect of the thigh and divides into the common peroneal

ment of trophic ulcers inevitable.

and tibial nerves, at a variable site above the popliteal fossa

(see text Figs. 17-42 and 17-46).

Sciatica

Trauma to the Sciatic Nerve

Sciatica describes the condition in which patients have pain

along the sensory distribution of the sciatic nerve. Thus, the

The nerve is sometimes injured by penetrating wounds,

pain is experienced in the posterior aspect of the thigh, the

fractures of the pelvis, or dislocations of the hip joint. It is

posterior and lateral sides of the leg, and the lateral part of

most frequently injured by badly placed intramuscular in-

the foot. Sciatica can be caused by prolapse of an interver-

jections in the gluteal region. To avoid this injury, injec-

tebral disc with pressure on one or more roots of the lower

tions into the gluteus maximus or the gluteus medius should

lumbar and sacral spinal nerves, pressure on the sacral

be made well forward on the upper outer quadrant of the

plexus or sciatic nerve by an intrapelvic tumor, or inflam-

buttock. Most nerve lesions are incomplete, and in 90% of

mation of the sciatic nerve or its terminal branches.

injuries, the common peroneal part of the nerve is the most

affected. This can probably be explained by the fact that the

common peroneal nerve fibers lie most superficial in the

Common Peroneal Nerve Injury

sciatic nerve. The following clinical features are present:

The common peroneal nerve (see text Fig. 17-38) is in an

■ Motor: The hamstring muscles are paralyzed, but weak

exposed position as it leaves the popliteal fossa and winds

flexion of the knee is possible because of the action of the

around the neck of the fibula to enter the peroneus longus

sartorius (femoral nerve) and gracilis (obturator nerve).

muscle.

All the muscles below the knee are paralyzed, and the

It is commonly injured in fractures of the neck of the

weight of the foot causes it to assume the plantar-flexed

fibula and by pressure from casts or splints. The following

position, or foot drop (CD Fig. 17-9).

clinical features are present:

■ Sensory: Sensation is lost below the knee, except for a

■ Motor: The muscles of the anterior and lateral compart-

narrow area down the medial side of the lower part of the

ments of the leg are paralyzed, namely, the tibialis an-

leg and along the medial border of the foot as far as the

terior, the extensor digitorum longus and brevis, the

ball of the big toe, which is supplied by the saphenous

peroneus tertius, the extensor hallucis longus (supplied by

nerve (femoral nerve).

the deep peroneal nerve), and the peroneus longus and

brevis (supplied by the superficial peroneal nerve). As a

result, the opposing muscles, the plantar flexors of the an-

kle joint and the invertors of the subtalar and transverse

tarsal joints, cause the foot to be plantar flexed (foot drop)

and inverted, an attitude referred to as equinovarus.

■ Sensory: Loss of sensation occurs down the anterior and

lateral sides of the leg and dorsum of the foot and toes, in-

cluding the medial side of the big toe. The lateral border

of the foot and the lateral side of the little toe are virtually

unaffected

(sural nerve, mainly formed from tibial

nerve). The medial border of the foot as far as the ball of

the big toe is completely unaffected (saphenous nerve, a

branch of the femoral nerve).

When the injury occurs distal to the site of origin of the

lateral cutaneous nerve of the calf, the loss of sensibility is

confined to the area of the foot and toes.

Tibial Nerve Injury

The tibial nerve (see text Fig. 17-42) leaves the popliteal

CD Figure 17-9

Foot drop. With this condition, the individ-

fossa by passing deep to the gastrocnemius and soleus mus-

ual catches his or her toes on the ground when walking.

cles. Because of its deep and protected position, it is rarely

274

Chapter 17

injured. Complete division results in the following clinical

features:

Invasion of the Sacral Plexus

■ Motor: All the muscles in the back of the leg and the sole

by Malignant Tumors

of the foot are paralyzed. The opposing muscles dorsiflex

the foot at the ankle joint and evert the foot at the subta-

The nerves of the sacral plexus can become invaded by

lar and transverse tarsal joints, an attitude referred to as

malignant tumors extending from neighboring viscera.

calcaneovalgus.

A carcinoma of the rectum, for example, can cause severe

■ Sensory: Sensation is lost on the sole of the foot; later,

intractable pain down the lower limbs.

trophic ulcers develop.

Referred Pain from the

Obturator Nerve Injury

Obturator Nerve

The obturator nerve (L2, 3, and 4) enters the thigh as ante-

rior and posterior divisions through the upper part of the ob-

The obturator nerve lies on the lateral wall of the pelvis and

turator foramen. The anterior division descends in front of

supplies the parietal peritoneum. An inflamed appendix

the obturator externus and the adductor brevis, deep to the

hanging down into the pelvic cavity could cause irritation of

floor of the femoral triangle. The posterior division descends

the obturator nerve endings, leading to referred pain down

behind the adductor brevis and in front of the adductor

the inner side of the right thigh. Inflammation of the ovaries

magnus (see text Fig. 17-33).

can produce similar symptoms.

It is rarely injured in penetrating wounds, in anterior dis-

locations of the hip joint, or in abdominal herniae through

the obturator foramen. It may be pressed on by the fetal head

CLINICAL

during parturition. The following clinical features occur:

■ Motor: All the adductor muscles are paralyzed except

ANATOMY OF

the hamstring part of the adductor magnus, which is

supplied by the sciatic nerve.

SPINAL NERVE

■ Sensory: The cutaneous sensory loss is minimal on the

medial aspect of the thigh.

BLOCKS

Referred Pain from the Hip Joint

Brachial Plexus Block

The femoral nerve not only supplies the hip joint but, via

the intermediate and medial cutaneous nerves of the thigh,

In the neck, the brachial plexus occupies the lower part

also supplies the skin of the front and medial side of the

of the posterior triangle (CD Fig. 17-10). It lies below and

thigh. It is not surprising, therefore, for pain originating in

anterior to a line connecting the cricoid cartilage of

the hip joint to be referred to the front and medial side of the

the larynx to the midpoint of the clavicle. In the axilla, the

thigh. The posterior division of the obturator nerve supplies

brachial plexus and its branches are arranged within

both the hip and knee joints. This would explain why hip

the axillary sheath around the axillary artery, which can be

joint disease sometimes gives rise to pain in the knee joint.

palpated.

Four techniques can be used—interscalene block, supra-

clavicular block, infraclavicular block, and axillary block.

SACRAL PLEXUS

Interscalene Block

Procedure: At the level of the cricoid cartilage (C6) the

Pressure from the Fetal Head on

posterior border of the sternocleidomastoid muscle can

be palpated. With the head turned laterally and upward

the Sacral Plexus

from the side of the block, the palpating finger can feel

During the later stages of pregnancy, when the fetal head

the groove between the scalenus anterior and the

has descended into the pelvis, the mother often complains

scalenus medius muscles just lateral to the sternocleido-

of discomfort or aching pain extending down one of the

mastoid muscle (see CD Fig. 17-10). The blocking

lower limbs. The discomfort, caused by pressure from the

needle is inserted into the interval between the scalene

fetal head, is often relieved by changing position, such as

muscles, and the roots of the upper part of the brachial

lying on the side in bed.

plexus can be blocked.

Chapter 17

276

Supraclavicular Block

Musculocutaneous Nerve Block

Procedure: The trunks of the brachial plexus can be

blocked as they cross the first rib and enter the axilla (see

Area of anesthesia: The anterior and posterior surfaces of

CD Fig. 17-10). The third part of the subclavian artery is

the lateral border of the forearm down as far as the thenar

first palpated in the lower anterior corner of the posterior

eminence (see CD Figs. 17-1 and 17-2)

triangle of the neck. The posterior border of the stern-

Indications: Repair of lacerations on the lateral border of

ocleidomastoid muscle is then felt. A blocking needle is

the forearm

inserted at the level of the cricoid cartilage between the

Procedure: These include the following:

scalenus anterior and the scalenus medius muscles and

■ Brachial plexus approach: The musculocutaneous

directed caudally behind the subclavian artery toward

nerve trunk may be blocked with the rest of the brachial

the upper surface of the first rib (see CD Fig. 17-10). It is

plexus (see CD Fig. 17-10). The infraclavicular or axil-

here that the brachial plexus is very compact, consisting

lary approach is used; in the axillary approach great

of the upper middle and lower trunks.

care has to be taken to ensure that the anesthetic agent

Anatomy of complications: The subclavian artery lies

rises sufficiently high in the axillary sheath to block the

between the scalenus anterior and scalenus medius mus-

musculocutaneous nerve.

cles just behind the clavicle and may be pierced by the

■ Lateral cutaneous nerve of the forearm approach: The

needle. The cervical dome of parietal pleura is situated

musculocutaneous nerve may also be blocked as it

close to the brachial plexus, and a pneumothorax can be

emerges between the biceps and the brachialis muscles

caused if the needle enters the pleural cavity.

just above the lateral epicondyle of the humerus, where

it becomes the lateral cutaneous nerve of the forearm

(CD Fig. 17-11). The needle is inserted just lateral to the

Infraclavicular Block

tendon of the biceps muscle on a line between the two

Procedure: The middle of the clavicle is identified. A

epicondyles of the humerus.

blocking needle is inserted 1 in. (2.5 cm) inferior to it

and directed laterally in the direction of the head of the

Median Nerve Block

humerus and toward the subclavian artery. The anes-

thetic solution is infiltrated around the trunks of the

Area of anesthesia: The skin on the lateral half of the

brachial plexus (see CD Fig. 17-10).

palm, the palmar aspect of the lateral three and a half

Anatomy of complications: The close relationship of the

fingers, including the nail beds on the dorsum (see CD

axillary vessels to the brachial plexus within the axillary

Fig. 17-16)

sheath means that vessel puncture and hematoma for-

Indications: Repair of lacerations of the palm and fingers

mation may occur. Frequent aspirations are necessary

Procedures: These include the following:

before the anesthetic agent is injected.

■ Block at the elbow: With the elbow joint extended, the

brachial artery can easily be palpated in the cubital fossa

Axillary Block

on the medial side of the tendon of the biceps muscle.

The needle is inserted on the medial side of the brachial

Procedure: With the arm abducted to an angle greater

artery (CD Fig. 17-12).

than 90°, the axillary artery within the axillary sheath

■ Block at the wrist: Here the median nerve lies on

may be palpated high up in the axilla (see CD Fig. 17-

the medial side of the tendons of the flexor carpi radi-

10). The artery is compressed, and a blocking needle is

alis and to the lateral side of the flexor digitorum su-

inserted just proximal to the point of compression into

perficialis (CD Fig. 17-13); it usually lies posterior

the axillary sheath. The cords and branches of the

to the tendon of the palmaris longus muscle (some-

plexus lie within the sheath along with the artery. The

times absent). The nerve may be infiltrated here with

disadvantage of this approach is the difficulty in block-

local anesthetic just proximal to the flexor retinaculum

ing the musculocutaneous nerve. The object of com-

(i.e., just proximal to the distal transverse crease in front

pressing the artery distal to the point of injection is

of the wrist). The needle is inserted for 3/8 in. between

to close off the axillary sheath distally so that the

the tendons of flexor carpi radialis and the palmaris

anesthetic agent may rise in the sheath to the musculo-

longus.

cutaneous nerve.

Anatomy of complications: The close relationship of the

The palmar cutaneous branch of the median nerve

axillary vessels to the brachial plexus within the axillary

leaves the main trunk just proximal to the distal transverse

sheath means that vessel puncture and hematoma for-

crease of the palm, and, unless this nerve is also blocked,

mation may occur. Frequent aspirations are necessary

the sensation to the skin on the lateral part of the palm will

before the anesthetic agent is injected.

remain intact.

The Spinal Nerves and Spinal Nerve Blocks

277

deltoid muscle

brachialis

muscle

biceps brachii

triceps

muscle

triceps muscle

muscle

brachialis

muscle

lateral

cutaneous

musculocutaneous

nerve of the

nerve becoming

forearm

lateral cutaneous

nerve of

lateral

forearm

biceps

epicondyle

brachii

lateral

muscle

epicondyle

lateral

of humerus

cutaneous

nerve of

forearm

posterior

cutaneous

brachioradialis

nerve of

muscle

forearm

CD Figure 17-11

Lateral cutaneous nerve of the forearm block. A and B show the

musculocutaneous nerve becoming the lateral cutaneous nerve of the forearm. The nerve

is blocked just lateral to the tendon of the biceps brachii muscle on a line between the two

epicondyles of the humerus.

lateral to the tendons of the flexor carpi ulnaris muscle

Ulnar Nerve Block

and the pisiform bone (see CD Fig. 17-13). The ul-

nar artery lies on the lateral side of the ulnar nerve.

Area of anesthesia: The skin of the medial one third of

The needle is inserted just lateral to the flexor carpi ul-

the palmar and dorsal surfaces of the hand and the pal-

naris tendon at the level of the distal transverse crease of

mar and dorsal surfaces of the medial one and a half

the wrist.

fingers (see CD Fig. 17-16)

Indications: Repair of lacerations of the hand and fingers

Note that the dorsal cutaneous branch of the ulnar

Procedures: These involve the following:

nerve (see CD Fig. 17-16) leaves the main trunk about 2 in.

■ Block at the elbow: At the elbow, the ulnar nerve enters

(5 cm) proximal to the wrist; an ulnar nerve block at the

the forearm between the olecranon process of the ulna

wrist will therefore leave the skin sensation on the dorsum of

and the medial epicondyle of the humerus (CD Fig. 17-

the hand and fingers intact.

14). Here the nerve may be palpated and infiltrated with

Also, the superficially placed palmar cutaneous branch

an anesthetic agent.

of the ulnar nerve leaves the nerve trunk a variable distance

■ Block at the wrist: At the wrist, the ulnar nerve en-

proximal to the transverse crease of the wrist; unless this

ters the hand anterior to the flexor retinaculum and

nerve is also infiltrated with anesthetic, the ulnar block at

278

Chapter 17

biceps

brachii

brachialis

muscle

brachial

artery

cephalic

median

vein

biceps

nerve

brachii

bicipital

brachial

aponeurosis

artery

biceps

medial

brachii

epicondyle

tendon

brachial

basilic

lateral

artery

vein

epicondyle

median

nerve

cubital

vein

medial

epicondyle

of humerus

pronator

teres

muscle

CD Figure 17-12

A and B. Median nerve block at the elbow. The brachial artery is

identified in the cubital fossa, and the needle is inserted on the medial side of the artery.

the wrist will leave the sensory nerve supply to the medial

the level of the proximal transverse flexor crease on the

part of the palm intact.

lateral side of the radial artery, the nerve may be infil-

trated with an anesthetic solution. Since other terminal

branches of the radial nerve run in the subcutaneous tis-

Radial Nerve Block

sue on the dorsum of the wrist, a subcutaneous wheal of

Area of anesthesia: The skin of the back of the arm down

local anesthetic is necessary; this should run across the

as far as the elbow, the skin of the lower lateral surface of

lateral half of the dorsum of the wrist.

the arm down to the elbow, the skin down the middle of

the posterior surface of the forearm as far as the wrist, the

Digital Nerve Blocks

skin of the lateral half of the dorsal surface of the hand, and

the dorsal surface of the lateral three and a half fingers

Area of anesthesia: Skin of the fingers. Each finger is

proximal to the nail beds (see CD Figs. 17-1 and 17-2)

supplied by four digital nerves at the 2 o’clock, 5 o’clock,

Indications: Repair of lacerations of the hand:

7 o’clock, and 10 o’clock positions. The palmar digital

Procedures: These involve the following:

nerves are derived from the ulnar and median nerves; the

■

Block at the elbow: At the elbow, the radial nerve de-

dorsal digital nerves are derived from the ulnar and radial

scends anterior to the lateral epicondyle of the humerus

nerves (CD Fig.17-16).

in the interval between the brachialis and the brachiora-

The palmar digital nerves, which arise from the su-

dialis muscles (CD Fig.17-15). With the elbow joint

perficial terminal branch of the ulnar nerve in the hand,

extended, the lateral edge of the biceps tendon is easily

supply the palmar surface of the medial one and a half

palpated. The needle is inserted halfway between the

fingers, including their nail beds. The dorsal digital

tendon and the tip of the lateral epicondyle, and the local

nerves, which arise from the dorsal cutaneous branch of

anesthetic is injected at this point.

the ulnar nerve in the forearm, supply the dorsal surface

■

Block at the wrist: Just proximal to the wrist, the superfi-

of the proximal parts of the medial one and a half fingers

cial branch of the radial nerve lies lateral to the radial

(see CD Fig. 17-16).

artery. The nerve leaves the artery and passes laterally and

The palmar digital nerves, which arise from the me-

backward under the tendon of brachioradialis to reach

dian nerve in the palm, supply the palmar surface of the

the posterior surface of the wrist (see CD Fig. 17-15). At

lateral three and a half fingers, including their nail beds.

280

Chapter 17

biceps brachii tendon

radial

nerve

lateral

epicondyle

of humerus

superficial branch

CD Figure 17-15

A. Radial nerve

of radial nerve

block at the elbow. The needle is

inserted halfway between the

tendon of the biceps brachii and

the tip of the lateral epicondyle of

the humerus. B. Radial nerve

block at the wrist. The needle is

inserted into the subcutaneous

tissue on the dorsum of the hand,

tendon of

and a wheal of anesthetic is

brachioradialis

placed across the lateral half of

muscle

the dorsum of the wrist.

The dorsal digital nerves, which arise from the superficial

■ Metacarpal head block: The needle is inserted in the

branch of the radial nerve, supply the dorsal surface of

palm at the metacarpal head and directed slightly distally

the proximal parts of the lateral three and a half fingers

and medially and then slightly distally and laterally to

(see CD Fig. 17-16).

block the palmar digital nerves (see CD Fig. 17-17). The

Note that the origins of the dorsal digital nerves from

dorsal digital nerves, if they remain unblocked, are han-

the ulnar and radial nerves are subject to variation.

dled with an injection across the base of the dorsum of

Indications: Repair of lacerations involving individual

the proximal phalanx.

fingers; removal of nails

■ Ring block: Since the digital nerves lie in pairs on ei-

Procedures: These involve the following:

ther side of the proximal phalanges, they are easily

■

Web space method: At the web space, the digital nerves

blocked at the base of the digit (see CD Fig. 17-16).

are about to enter the fingers (CD Fig. 17-17). The nee-

The needle is inserted on both sides of the base of the

dle is inserted about 0.5 cm, and the nerves are infiltrated

proximal phalanx, and the anesthetic agent is infiltrated

with the anesthetic agent. A block on both sides of the fin-

around the nerves between the bone and the skin; this

ger adequately deals with the four digital nerves supplying

produces a half-ring block on either side of the finger

the finger. When blocking the digital nerves of the index

(see CD Fig. 17-17).

and little fingers, a subcutaneous wheal of anesthetic so-

lution must be deposited on the lateral side of the index

Thoracic Spinal Nerve Blocks

finger and the medial side of the little finger.

■ Dorsal metacarpal method: A skin wheal of anesthetic is

raised between the metacarpal bones on the dorsum of

Intercostal Nerve Block

the hand (see CD Fig. 17-17). The needle is inserted

through the wheal and advanced slowly forward between

Area of anesthesia: The skin and the parietal pleura cov-

the metacarpal bones, stopping just short of the palmar

ering the outer and inner surfaces of each intercostal

skin. The anesthetic solution will block the common

space respectively; the seventh to the eleventh intercostal

palmar and dorsal digital nerves.

nerves supply the skin and the parietal peritoneum

The Spinal Nerves and Spinal Nerve Blocks

281

dorsal

dorsal extensor

expansion

dorsal digital nerve

phalanx

long flexor

tendons

palmar digital nerve

palmar

radial

nerve

radial

ulnar

median

nerve

ulnar

nerve

median nerve

superficial

branch of

dorsal

radial

cutaneous

nerve

branch of

ulnar nerve

radial

ulnar

nerve

CD Figure 17-16

A. Transverse section of the finger showing the location of the dorsal

and palmar digital nerves. B. Palmar surface of hand and fingers showing the origin of the

palmar digital nerves. C. Palmar surface of the hand and fingers showing the areas of skin

supplied by the ulnar, median, and radial nerves. D. Dorsal surface of the hand and

fingers showing the origin of the dorsal digital nerves. E. Dorsal surface of the hand and

fingers showing the areas of skin supplied by the radial, ulnar, and median nerves.

covering the outer and inner surfaces of the abdominal

Procedure: To produce analgesia of the anterior and lat-

wall, respectively; therefore, these areas will also be anes-

eral thoracic and abdominal walls, the intercostal nerve

thetized. In addition, the periosteum of the adjacent ribs

should be blocked before the lateral cutaneous branch

is anesthetized.

arises at the midaxillary line. The ribs may be identified

Indications: Repair of lacerations of the thoracic and ab-

by counting up from the twelfth or down from the second

dominal walls; relief of pain in rib fractures and to allow

(opposite sternal angle). The needle is directed toward

pain-free respiratory movements

the rib near the lower border (CD Fig. 17-18), and the tip

282

Chapter 17

digital nerve

metacarpal bone

web space method

dorsal metacarpal method

CD Figure 17-17

Digital nerve blocks.

A. Web space method. The needle is

inserted about 0.5 cm into the web space. A

block on both sides of the finger anes-

thetizes the four digital nerves to the finger.

B. Dorsal metacarpal method. The needle is

directed forward between the metacarpal

bones, stopping just short of the palmar

skin. The four digital nerves to each finger

are blocked. C. Metacarpal head block. The

needle is inserted in the palm at the level of

the metacarpal head and directed slightly

distally and medially and then slightly

distally and laterally. D. Ring block. The nee-

dle is inserted on both sides of the base of

the proximal phalanx to produce a half-ring

metacarpal head block

ring block

block on either side of the finger.

comes to rest near the subcostal groove, where the local

always be performed before injecting the anesthetic. A

anesthetic is infiltrated around the nerve. Remember

small hematoma may result.

that the order of structures lying in the neurovascular

bundle from above downward is intercostal vein, artery,

Anterior Abdominal Nerve Blocks

and nerve, and that these structures are situated between

the posterior intercostal membrane of the internal inter-

Area of anesthesia: Skin of the anterior abdominal wall.

costal muscle and the parietal pleura. Furthermore,

The nerves of the anterior and lateral abdominal walls

laterally the nerve lies between the internal intercostal

are the anterior rami of the seventh through the twelfth

muscle and the subcostals and the innermost intercostals

thoracic nerves and the first lumbar nerve.

(i.e., transverse thoracic muscle).

Indications: Repair of lacerations of the anterior

Anatomy of complications: These include the following:

abdominal wall

■

Pneumothorax: This complication can occur if the nee-

Procedure: The anterior ends of the intercostal nerves

dle point misses the subcostal groove and penetrates too

T7 through T11 enter the abdominal wall by leaving the

deeply through the parietal pleura.

intercostal spaces and passing posterior to the costal car-

■ Hemorrhage: Puncture of the intercostal blood vessels.

tilages (CD Fig. 17-19). An abdominal field block is most

This is a common complication so that aspiration should

easily carried out along the lower border of the costal

The Spinal Nerves and Spinal Nerve Blocks

283

posterior ramus

2nd thoracic

internal intercostal

spinal nerve

muscle

artery

anterior ramus

intercostobrachial

vein

nerve

external

intercostal

muscle

intercostal nerve

nerve

cutaneous

branch

innermost

intercostal

muscle

lateral

cutaneous

branch

CD Figure 17-18

Intercostal nerve block. A. The distribution of two intercostal nerves

relative to the rib cage. B. Section through an intercostal space showing the positions of

the intercostal nerve, artery, and vein relative to the intercostal muscles. The needle is

directed toward the rib near the lower border, and the tip comes to rest near the subcostal

groove.

margin and then infiltrating the nerves as they emerge

The two nerves are easily blocked by inserting the anes-

between the xiphoid process and the tenth or eleventh rib

thetic needle 1 in. (2.5 cm) above the anterior superior iliac

along the costal margin.

spine on the spinoumbilical line (see CD Fig. 17-19).

Lumbar Spinal Nerve Blocks

Genitofemoral Nerve Block

Area of anesthesia: Small area of skin of the thigh below

the inguinal ligament and adjacent part of the scrotum or

Ilioinguinal and Iliohypogastric

labium majus

Indications: Repair of lacerations in the thigh and geni-

Nerve Blocks

tal area

Area of anesthesia: Skin of the lower part of the anterior

Procedure: The genitofemoral nerve (L1 and L2) runs

abdominal wall

downward under the inguinal ligament at a point

Indications: Repair of lacerations on the anterior ab-

halfway between the anterior superior iliac spine and the

dominal wall

symphysis pubis. The terminal branches are most easily

Procedure: The ilioinguinal nerve (L1) passes forward

blocked by infiltrating the subcutaneous tissue through a

around the anterior abdominal wall, through the in-

needle inserted through the skin lateral to the pubic

guinal canal, and emerges through the superficial in-

tubercle (see CD Fig. 17-19).

guinal ring to supply the skin of the groin and part of the

scrotum or labium majus. The iliohypogastric nerve (L1)

Femoral Nerve Block

passes around the abdominal wall and pierces the exter-

nal oblique aponeurosis above the superficial inguinal

Area of anesthesia: Skin of the front and medial side of

ring to supply the skin (see CD Fig. 17-19).

the thigh, extending down the medial side of the knee

284

Chapter 17

iliohypogastric

nerve

ilioinguinal nerve

anterior superior

iliac spine

genitofemoral nerve

pubic turbercle

CD Figure 17-19

Anterior abdominal

wall nerve blocks. A and B. T7

through T11 intercostal nerves are

costal margin

blocked (x) as they emerge from be-

neath the costal margin. The

iliohypogastric and ilioinguinal nerves

are blocked by inserting the needle

about 1 in. above the anterior superior

iliac spine on the spinoumbilical line

(x). The terminal branches of the

anterior superior

pubic tubercle

genitofemoral nerve are blocked by in-

iliac spine

serting the needle through the skin

just lateral to the pubic tubercle and

infiltrating the subcutaneous tissue

with anesthetic solution (x).

and leg, and along the medial border of the foot as far as

medial side of the knee after emerging between

the ball of the big toe

the tendons of sartorius and gracilis muscles (CD Fig.

Indications: Repair of lacerations of the thigh, medial

17-21).

side of the leg, and medial side of the foot

The nerve may be blocked by inserting the anesthetic

Procedure: The femoral nerve (L2 through L 4) enters

needle on the medial side of the knee joint either over the

the thigh beneath the inguinal ligament at a point mid-

medial femoral condyle or lower down over the condyle of

way between the anterior superior iliac spine and the pu-

the tibia (see CD Fig. 17-21). Care should be taken to avoid

bic tubercle (CD Fig. 17-20). Here it lies lateral to the

the great saphenous vein. The nerve may also be blocked at

femoral artery.

the ankle where it passes anterior to the medial malleolus

The nerve may be blocked by introducing the anes-

(see CD Fig. 17-21).

thetic needle just below the midpoint of the inguinal liga-

ment and lateral to the femoral artery (see CD Fig. 17-20).

Lateral Cutaneous Nerve of the

Saphenous Nerve Block

Thigh Block

Area of anesthesia: Skin of the medial side of the leg and

Area of anesthesia: Skin of the anterolateral surface of

the medial border of the foot down as far as the ball of the

the thigh down to the lateral side of the knee

big toe

Indications: Repair of lacerations on the anterolateral

Indications: Repair of lacerations on the medial side of

surface of the thigh

the leg and the medial side of the foot

Procedure: The lateral cutaneous nerve of the thigh

Procedure: The saphenous nerve is a continuation

(L2 and L3) enters the thigh behind (or through)

of the femoral nerve and becomes superficial on the

the lateral end of the inguinal ligament just medial to

The Spinal Nerves and Spinal Nerve Blocks

285

lateral cutaneous nerve

of the thigh

iliacus muscle

anterior superior

psoas muscle

iliac spine

inguinal ligament

femoral nerve

tensor fasciae latae muscle

sartorius muscle (cut)

femoral artery

femoral vein

nerve to sartorious muscle

nerves to rectus femoris

vastus lateralis, and

pubic tubercle

vastus intermedius

medial cutaneous

nerve to vastus

nerve of thigh

medialis muscle

adductor longus

saphenous nerve

muscle

intermediate

cutaneous

nerve of thigh

sartorius muscle (cut)

rectus femoris muscle

superior

iliac spine

pubic

tubercle

CD Figure 17-20

Femoral nerve block. The needle is directed posteriorly just below the

midpoint of the inguinal ligament and lateral to the femoral artery. In a lateral cutaneous

nerve of the thigh block, the needle is directed posteriorly just inferior to the inguinal liga-

ment about 0.5 in. (1.3 cm) medial to the anterior superior iliac spine.

the anterior superior iliac spine (see CD Fig. 17-20). It

then descends anterior or through the sartorius muscle

Sacral Spinal Nerve Blocks

and divides into terminal anterior and posterior

branches.

Tibial Nerve Block

The nerve may be blocked by inserting the anesthetic

needle just inferior to the inguinal ligament about 0.5 in.

Area of anesthesia: Skin of the sole of the foot (medial

(1.3 cm) medial to the anterior superior iliac spine.

and lateral plantar nerves)

286

Chapter 17

tibialis anterior muscle

common peroneal nerve

saphenous nerve

superficial peroneal nerve

deep peroneal nerve

gastrocnemius muscle

peroneus longus muscle

anterior tibial artery

soleus

peroneus brevis muscle

muscle

extensor hallucis

longus muscle

tibialis

medial femoral

tendon

interosseous membrane

condyle

extensor hallucis

extensor digitorum

longus tendon

longus muscle

saphenous

medial malleolus

nerve

lateral malleolus

dorsalis

tuberosity

deep peroneal nerve

pedis artery

of tibia

tibialis

anterior tendon

extensor hallucis

longus tendon

saphenous

superficial peroneal nerve

nerve

medial malleolus

lateral malleolus

tibialis anterior tendon

deep peroneal nerve

extensor digitorum

longus tendons

dorsalis pedis artery

extensor hallucis

longus tendon

CD Figure 17-21

Nerve blocks on the front of the lower part of the leg and dorsum of

foot. A. The saphenous nerve, the superficial peroneal nerve, and the deep peroneal nerve

in relation to other important anatomic structures. B. The surface landmarks in the ankle

region and on the dorsum of the foot necessary for performing superficial peroneal nerve

block, saphenous nerve block, and deep peroneal nerve block. C. The surface landmarks

used for performing saphenous nerve block on the medial side of the knee.

Indications: Repair of lacerations on the sole of foot

posterior tibial artery can be felt midway between the medial

Procedure: The tibial nerve (L4 and L5 and S1 through

malleolus and the heel. The nerve lies immediately poste-

S3) is the largest terminal branch of the sciatic nerve. At

rior to the artery, and the anesthetic needle can be inserted

the ankle, the nerve, accompanied by the posterior tibial

at this location (see CD Fig. 17-22).

artery, becomes superficial. It lies behind the medial

malleolus, between the tendons of the flexor digitorum

Sural Nerve Block

longus and the flexor hallucis longus muscles, and is

covered by the flexor retinaculum (CD Fig. 17-22).

Area of anesthesia: Skin of the lateral border of foot and

lateral side of the little toe

The tibial nerve may be blocked as it lies behind the

Indications: Repair of lacerations on the lateral side of

medial malleolus. By careful palpation, the pulsations of the

the foot and little toe

The Spinal Nerves and Spinal Nerve Blocks

287

flexor digitorum

longus muscle

tibial nerve

tibialis posterior muscle

tendo calcaneus

posterior tibial artery

flexor hallucis longus muscle

medial malleolus

flexor retinaculum

medial plantar nerve

lateral plantar nerve

medial malleolus

tibial nerve

posterior tibial artery

CD Figure 17-22

Tibial nerve block.

A. The tibial nerve and its relationships

as it passes behind the medial malleolus

of the tibia. B. The important surface

landmarks used when blocking the tibial

nerve at the ankle.

Procedure: The sural nerve is a branch of the tibial

the fibula, it is subcutaneous and can easily be rolled

nerve in the popliteal space. It descends superficially in

against the bone.

the calf accompanied by the small saphenous vein. It

The common peroneal nerve can be blocked by first pal-

courses behind the lateral malleolus and passes to

pating the nerve below the head of the fibula and infiltrating

its distribution along the lateral border of the foot and

the tissue around the nerve with a local anesthetic solution.

little toe (CD Fig. 17-23).

The sural nerve may be blocked by inserting the anes-

thetic needle midway between the lateral malleolus and the

Superficial Peroneal Nerve Block

tendo calcaneus (Achilles) and infiltrating the subcuta-

Area of anesthesia: Skin on the lower anterior and lateral

neous tissue with anesthetic solution (see CD Fig. 17-23).

sides of the leg and the dorsum of the foot and toes (ex-

cept the cleft between the first and second toes, which is

Common Peroneal Nerve Block

innervated by the deep peroneal nerve and the lateral

side of the little toe, which is supplied by the sural nerve)

Area of anesthesia: Skin on the anterior and lateral sides

Indications: Repair of lacerations in the area of its cuta-

of the leg and the dorsum of the foot and toes, including

neous distribution

the medial side of the big toe

Procedure: The superficial peroneal nerve is a branch of

Indications: Repair of lacerations on the anterior and lat-

the common peroneal nerve. In the lower third of the leg

eral sides of the leg and the dorsum of the foot and toes

it becomes superficial and its terminal branches pass to

Procedure: The common peroneal nerve (L4 and L5

their distribution on the dorsum of the foot and toes (see

and S1 and S2) is the smaller of the terminal branches of

CD Fig. 17-21).

the sciatic nerve. It winds laterally around the neck of the

fibula to pierce the peroneus longus muscle (see CD Fig.

The superficial peroneal nerve is easily blocked in the

17-23). As the nerve lies on the lateral side of the neck of

lower part of the leg by infiltrating the anesthetic in the

288

Chapter 17

tibial nerve

plantaris muscle (cut)

popliteus

biceps femoris

muscle

common peroneal nerve

tendon

lateral head of

soleus

gastrocnemius muscle (cut)

muscle

head of fibula

(cut)

head of fibula

tibialis posterior

flexor hallucis longus

common

muscle

peroneal

peroneus longus muscle

nerve

flexor digitorum longus

muscle

peroneus brevis muscle

medial malleous

lateral malleolus

flexor

sural nerve

retinaculum

tendo calcaneus

sural nerve

lateral malleoulus

CD Figure 17-23

A. The important anatomic relationships of the common peroneal

nerve at the back of the knee joint and the sural nerve behind the lateral malleolus of the

fibula. B. The surface landmarks used for performing a common peroneal nerve block at

the knee. C. The surface landmarks used for performing a sural nerve block at the ankle.

subcutaneous tissue along a transverse line connecting the

on the lateral side of the dorsalis pedis artery and is su-

medial and lateral malleoli (see CD Fig. 17-21).

perficially placed between the tendons of extensor digi-

torum longus and the extensor hallucis longus muscles

(see CD Fig. 17-21).

Deep Peroneal Nerve Block

Area of anesthesia: Skin in the cleft between the big and

First, the dorsalis pedis artery is palpated midway be-

second toes

tween the medial and lateral malleoli. With the foot actively

Indications: Repair of lacerations in the cleft between

dorsiflexed, the tendons of the extensor digitorum longus

the big and second toes

and extensor hallucis longus muscles can be seen. The

Procedure: The deep peroneal nerve is a terminal

nerve lies on the lateral side of the artery between these ten-

branch of the common peroneal nerve. It descends in

dons (see CD Fig. 17-21). The needle is then inserted over

the anterior compartment of the leg and at the ankle it

the nerve, and the surrounding tissues are infiltrated with

passes onto the dorsum of the foot. Here the nerve lies

anesthetic.

The Spinal Nerves and Spinal Nerve Blocks

289

cial peroneal nerve (except the cleft between the big toe

Toe Nerve Blocks

and second toe, which is supplied by the deep peroneal

nerve, and the lateral side of the little toe, which is sup-

Area of anesthesia. Skin of the toes. Each toe is supplied

plied by the sural nerve).

by four digital nerves at the 2 o’clock, 5 o’clock, 7 o’clock,

Indications: Repair of lacerations of the toes, removal of

and 10 o’clock positions. The plantar digital nerves are

foreign bodies, and removal of nails

derived from the medial and lateral plantar nerves (CD

Procedure: The nerves are easily blocked with small vol-

Fig. 17-24); the dorsal digital nerves are from the superfi-

umes of anesthetic solution injected subcutaneously and

saphenous

medial calcaneal

nerve

branch of tibial

medial

nerve

malleolus

medial malleolus

lateral malleolus

lateral plantar

superficial

medial

nerve

peroneal

plantar

nerve

sural nerve

deep

saphenous

peroneal

lateral

nerve

malleolus

medial calcaneal

branch of tibial

nerve

deep

peroneal

nerve

superficial

peroneal

nerve

sural

superficial

nerve

peroneal

nerve

CD Figure 17-24

Toe nerve blocks. A, B, C, and D. The sensory nerve supply to the foot

and toes; the heavy lines indicate the boundaries between the different areas of innerva-

tion. The plantar digital nerves are derived from the medial and lateral plantar nerves; the

dorsal digital nerves are from the superficial peroneal nerve (except the cleft between the

big and second toes, which are supplied by the deep peroneal nerve, and the lateral side

of the little toe, which is supplied by the sural nerve). E and F. The sites at the base of

each toe (x) where the anesthetic solution may be injected subcutaneously.

290

Chapter 17

dorsal nerve of clitoris

perineal nerve

CD Figure

17-25

Pudendal nerve blocks.

A. Transvaginal method. The needle is passed

ischial spine

through the vaginal mucous membrane toward

the ischial spine. On passing through the

ischial tuberosity

sacrospinous ligament the anesthetic solution

is infiltrated around the pudendal nerve.

pudendal nerve

B. Perineal method. The ischial tuberosity is

palpated subcutaneously through the buttock.

The needle is inserted on the medial side of the is-

chial tuberosity to a depth of about 1 in. from the

sacrospinous ligament

free surface of the tuberosity. The anesthetic is

infiltrated around the pudendal nerve.

circumferentially around the base of each toe (see CD

inserted through the vagina to palpate the ischial spine.

Fig. 17-24).

The needle of the syringe is then passed through the

vaginal mucous membrane toward the ischial spine. On

passing through the sacrospinous ligament there is a

Pudendal Nerve Block

feeling of “give.” The anesthetic solution is then infil-

Area of anesthesia: Skin of the perineum; it does not, how-

trated into the tissues around the pudendal nerve (see

ever, abolish sensation from the anterior part of the per-

CD Fig. 17-25).

ineum, which is innervated by terminal branches of the il-

■ Perineal method: The bony landmark is the ischial

ioinguinal nerve and genitofemoral nerve. Needless to say,

tuberosity (see CD Fig. 17-25). The tuberosity is palpated

it does not abolish pain from uterine contractions that as-

subcutaneously through the buttock, and the needle is

cend to the spinal cord via the sympathetic afferent nerves.

introduced into the pudendal canal along the medial

Indications: Forceps delivery and episiotomy repair

side of the tuberosity. The canal lies about 1 in. (2.5 cm)

Procedures: These involve the following:

deep to the free surface of the ischial tuberosity. The lo-

■

Transvaginal method: The bony landmark used is the

cal anesthetic is then infiltrated around the pudendal

ischial spine

(CD Fig. 17-25). The index finger is

nerve.

Clinical Problem Solving Questions

Read the following case histories/questions and give

diagnosis of dislocation of the right shoulder joint

the best answer for each.

was made.

1. The following statements concerning this patient are

A 60-year-old woman fell down the stairs and was admitted

consistent with the diagnosis except which?

to the emergency department with severe right shoulder

A. This patient had a subcoracoid dislocation of the

pain. On examination, the patient was sitting up with

right shoulder joint.

her right arm by her side and her right elbow joint

B. The head of the humerus was dislocated down-

supported by her left hand. Inspection of the right

ward through the weakest part of the capsule of the

shoulder showed loss of the normal rounded curvature

joint.

and evidence of a slight swelling below the right clavicle.

C. The pull of the pectoralis major and subscapularis

Any attempt at active or passive movement of the shoulder

muscles had displaced the upper end of the humerus

joint was stopped by severe pain in the shoulder. A

medially.

The Spinal Nerves and Spinal Nerve Blocks

291

D. The greater tuberosity of the humerus no longer

B. The muscles of the thenar eminence showed some

displaced the deltoid muscle laterally, and the curve

evidence of wasting as seen by flattening of the

of the shoulder was lost.

thenar eminence.

E. The integrity of the axillary nerve should always be

C. The muscles of the thenar eminence are supplied by

tested by touching the skin over the upper half of the

the recurrent muscular branch of the median nerve.

deltoid muscle.

D. The median nerve enters the palm through the

carpal tunnel.

A young housewife was on a ladder cleaning a window in her

E. The median nerve occupies a large space between

home, when she lost her balance and started to fall. To pro-

the tendons behind the flexor retinaculum.

tect herself, she held out her right hand, which smashed

F. This patient has carpal tunnel syndrome.

through the glass. On admission to the hospital, she was

bleeding profusely from a superficial laceration in front of her

A 6-year-old boy, running along a concrete path with a

right wrist. She had sensory loss over the palmar aspect of the

glass jam jar in his hand, slipped and fell. The glass from

medial one and a half fingers but normal sensation of the

the broken jar pierced the skin on the front of his left wrist.

back of these fingers over the middle and proximal phalanges.

On examination a small wound was present on the front of

She had difficulty in grasping a piece of paper between her

the left wrist and the palmaris longus tendon had been sev-

right index and middle fingers. All her long flexor tendons

ered. The thumb was laterally rotated and adducted, and

were intact.

the boy was unable to oppose his thumb to the other fin-

gers. There was loss of skin sensation over the lateral half

2. The following statements concerning this patient are

of the palm and the palmar aspect of the lateral three and

correct except which?

a half fingers.

A. The ulnar artery was cut in front of the flexor retinac-

ulum, and this accounted for the profuse bleeding.

4. The following facts concerning this patient are correct

B. The loss of skin sensation on the palmar aspect of

except which?

the medial one and a half fingers was caused by the

A. Sensory loss of the distal part of the dorsal surfaces of

severance of the median nerve as it crossed in front

the lateral three and a half fingers was experienced.

of the flexor retinaculum.

B. The median nerve lies superficial to the palmaris

C. The normal sensation on the back of the medial one

longus proximal to the flexor retinaculum and was

and a half fingers over the proximal phalanges was

severed by the piece of glass.

caused by the fact that the posterior cutaneous branch

C. The median nerve lies in the interval between the

of the ulnar nerve arises about 2.5 in. (6.25 cm) prox-

tendons of the flexor digitorum superficialis and the

imal to the flexor retinaculum and was spared.

flexor carpi radialis muscles just proximal to the

D. The inability to hold the piece of paper was caused

wrist joint.

by the paralysis of the second palmar interosseous

D. Adduction of the thumb was produced by the con-

muscle, which is supplied by the deep branch of the

traction of the adductor pollicis muscle, which is

ulnar nerve.

supplied by the ulnar nerve.

E. There was no sensory loss on the palm of the hand

E. The palmar cutaneous branch of the median nerve

because the palmar cutaneous branch of the ulnar

had been severed.

nerve was not cut.

A 52-year-old woman was admitted to the hospital with a

A 50-year-old woman complaining of severe “pins and nee-

diagnosis of right-sided pleurisy with pneumonia. It was

dles” in her right hand and lateral fingers visited her physi-

decided to remove a sample of pleural fluid from her

cian. She said that she had experienced difficulty in button-

pleural cavity. The resident inserted the needle close to the

ing up her clothes when dressing. On physical examination

lower border of the eighth rib in the anterior axillary line.

the patient pointed to her thumb and index, middle, and

The next morning he was surprised to hear that the patient

ring fingers as the areas where she felt discomfort. No ob-

had complained of altered skin sensation extending from

jective impairment of sensation was found in these areas.

the point where the needle was inserted downward and for-

The muscles of the thenar eminence appeared to be func-

ward to the midline of the abdominal wall above the um-

tioning normally, although there was some loss of power

bilicus.

compared with the activity of the muscles of the left thenar

5. The altered skin sensation in this patient after the nee-

eminence.

dle thoracostomy could be explained by which?

3. The following statements concerning this patient are

A. The needle was inserted too low down in the inter-

correct except which?

costal space.

A. Altered skin sensation was felt in the skin areas

B. The needle was inserted too close to the lower bor-

supplied by the digital branches of the median

der of the eighth rib and damaged the eighth inter-

nerve.

costal nerve.

292

Chapter 17

C. The needle had impaled the eighth rib.

B. The parietal peritoneum in this area is innervated by

D. The needle had penetrated too deeply and pierced

the tenth and eleventh intercostal nerves, which

the lung.

give rise to referred pain in the tenth and eleventh

E. There is a peritoneal abscess beneath the diaphragm

dermatomes on the side and back.

on the left side.

C. The parietal peritoneum on the central part of the

undersurface of the diaphragm is supplied by the

A 43-year-old man was involved in a violent quarrel with his

phrenic nerve.

wife over another woman. In a fit of rage, the wife picked up

D. The spinal segmental nerves within the phrenic

a carving knife and lunged forward at her husband, striking

nerve are C3, C4, and C5.

his anterior neck over the left clavicle. The husband col-

E. The pain was referred to the shoulder along the

lapsed on the kitchen floor, bleeding profusely from the

supraclavicular nerves (C3 and C4).

wound. The distraught wife called an ambulance.

An 8-year-old boy was admitted to the hospital with a tem-

6. On examination in the emergency department of the

perature of 101°F, a furred tongue, and pain in the right

hospital, the following conditions were found except

lower quadrant. On examination, the skin on the right lower

which?

quadrant was tender to the touch, and the abdominal mus-

A. A wound was seen about 1 in. (2.5 cm) wide over the

cles were contracted and rigid. A diagnosis of acute appen-

left clavicle.

dicitis was made.

B. Auscultation revealed diminished breath sounds

over the left hemithorax.

9. The symptoms and signs displayed by this patient can

C. The trachea was deflected to the left.

be explained by the following statements except which?

D. The left upper limb was lying stationary on the table,

A. An acutely inflamed appendix produces an inflam-

and active movement of the small muscles of the left

mation of the peritoneal coat covering it.

hand was absent.

B. Should the inflammatory process spread, for exam-

E. The patient was insensitive to pin prick along the lat-

ple, if the appendix should rupture, the parietal peri-

eral side of the left arm, forearm, and hand.

toneum would become involved.

C. The parietal peritoneum, the abdominal muscles,

A 72-year-old man complaining of burning pain on the

and the overlying skin are supplied by the same seg-

right side of his chest was seen by his physician. On exam-

mental spinal nerves.

ination the patient indicated that the pain passed forward

D. The segmental nerves supplying the right lower

over the right sixth intercostal space from the posterior ax-

quadrant of the abdominal wall are T7, T8, and T9.

illary line forward as far as the midline over the sternum.

E. The pain in the right lower quadrant and the regional

The physician noted that there were several watery blebs

contraction of the abdominal muscles are attempts by

on the skin in the painful area.

the body to keep the inflamed appendix immobile so

7. The following statements are correct except which?

that the inflammatory process remains localized.

A. This patient has herpes zoster.

A 45-year-old woman was shopping in a liquor store when

B. A virus descends along the cutaneous nerves, caus-

an armed robbery took place. A shoot-out occurred and a

ing dermatomal pain and the eruption of vesicles.

bullet ricocheted off the wall and entered her left side. For-

C. The sixth right intercostal nerve was involved.

tunately, the bullet did not enter the peritoneal cavity. One

D. The condition was confined to the anterior cuta-

year later, in addition to diminished skin sensation over the

neous branch of the sixth intercostal nerve.

left lumbar region and umbilicus, she noticed a bulging for-

ward of the left side of her anterior abdominal wall.

An obese 40-year-old woman was seen in the emergency de-

partment complaining of a severe pain over the right shoul-

10. The symptoms and signs displayed by this patient can

der and in her right side and back below the shoulder blade.

be explained by the following statements except which?

She said that she had experienced the pain on several occa-

A. The bullet cut the ninth and tenth intercostal nerves

sions before and that when she ate fatty foods it seemed to

just below the costal margin on the left side.

make the pain worse. Ultrasound demonstrated the pres-

B. The diminished skin sensation was caused by the

ence of gallstones. Her condition was diagnosed as

loss of the sensory nerve supply to the ninth and

cholelithiasis, and the pain was attributed to gallstone colic.

tenth thoracic dermatomes.

8. The symptoms and signs displayed by this patient can

C. Portions of the oblique, transversus, and rectus ab-

be explained by the following statement except which?

dominis muscles on the left side were paralyzed.

A. The fundus of the gallbladder lies against the ante-

D. Atrophy of the pyramidalis muscle resulted in loss of

rior abdominal wall next to the tip of the right ninth

support to the abdominal viscera, which then sagged

costal cartilage.

forward.

The Spinal Nerves and Spinal Nerve Blocks

293

After a major abdominal operation, a patient was given a

B. Skin sensation was lost over the anterior and medial

course of antibiotics by intramuscular injection. The nurse

sides of the thigh.

was instructed to give the injections into the right buttock.

C. Skin sensation was lost along the medial border of

Later, when the patient left the hospital, he developed sev-

the big toe.

eral symptoms and signs that suggested that the injections

D. Skin sensation was lost on the lower part of the leg

into the gluteus maximus muscle had been given over the

and the medial border of the foot as far as the ball of

course of the sciatic nerve and had caused a lesion of the

the big toe.

common peroneal nerve.

E. Weak extension of the knee was possible when walk-

ing because of the use of the adductor muscles.

11. The symptoms and signs displayed by this patient

included the following except which?

13.

A patient was seen in the emergency department with a

A. He experienced numbness and tingling sensations

laceration of the skin over the middle phalanx of the left

down the anterior and lateral sides of the right leg

index finger. What is the sensory nerve supply of that

and the dorsum of the foot.

finger? Where is it possible to perform a nerve block so

B. His right foot tended to catch on steps and on the

that the wound could be sutured?

edges of the carpet.

14.

A 37-year-old woman was involved in an automobile ac-

C. On testing, he had impaired skin sensation on the

cident and sustained a fracture of her sixth right rib. It

lateral side of the right thigh.

was decided to relieve her acute pain caused by the bro-

D. The patient tended to hold the foot plantar flexed

ken rib by performing an intercostal nerve block.

and slightly inverted.

Which intercostal nerve innervates the sixth rib? What

E. Dorsiflexion of the right ankle joint was weaker than

is the course taken by an intercostal nerve in an inter-

the same movement of the left ankle.

costal space? From what part of a spinal nerve is an in-

F. The everter muscles of the right midtarsal joints

tercostal nerve formed? Name the order of structures

were weaker than those of the opposite side.

forming the neurovascular bundle in an intercostal

space from above downward.

A 17-year-old girl was dealing drugs on a street corner

when she became involved in a fight. During the brawl she

15.

A 17-year-old boy received a knife wound on the lateral

received a deep knife wound to the front of her right thigh.

side of his right thigh. What is the sensory nerve supply

After a thorough examination in the emergency depart-

to this region of the thigh? Which important surface

ment of the local hospital, it was determined that the knife

landmarks would you use when blocking the nerves?

point had severed the trunk of the right femoral nerve just

16.

What is the sensory nerve supply to the skin on the dor-

below the inguinal ligament.

sum of the foot? Where would you block these nerves?

12. This patient had the following signs and symptoms

except which?

A. The right quadriceps femoris muscle failed to con-

tract when the patient was asked to extend her right

knee joint.

Answers and Explanations

1. E is the correct answer. The integrity of the axillary nerve

in front of the flexor retinaculum with the ulnar artery,

is tested by touching the skin over the lower half of the

which was also cut (see text Fig. 17-14).

deltoid muscle. The skin of the curve of the shoulder, in-

3. E is the correct answer. The median nerve occupies a

cluding the skin covering the upper half of the deltoid

small restricted space in the carpal tunnel (see text Fig.

muscle, is supplied by the supraclavicular nerves.

17-14).

2. B is the correct answer. The loss of skin sensation of the

4. B is the correct answer. The median nerve lies deep to

palmar aspect of the medial one and a half fingers was

the palmaris longus tendon proximal to the flexor reti-

caused by the severance of the ulnar nerve as it crossed

naculum (see text Fig. 17-12).

294

Chapter 17

B is the correct answer. The needle was inserted too

superficial radial nerve. The nerves are easily blocked

close to the lower border of the eighth rib and damaged

by injecting small volumes of anesthetic solution

the eighth intercostal nerve (see CD Fig. 17-18).

around the base of the finger (see CD Fig. 17-17).

E is the correct answer. The lower trunk of the brachial

14.

The periosteum of the sixth rib is innervated by the

plexus was cut by the knife. This would explain the loss

sixth intercostal nerve. (It is conceivable that in the

of movement of the small muscles of the left hand. It

individual who has a collateral branch of the fifth inter-

would also explain the loss of skin sensation that oc-

costal nerve, the periosteum of the sixth is also inner-

curred in the C8 and T1 dermatomes on the medial not

vated by this nerve.) Intercostal nerves are formed from

on the lateral side of the left forearm and hand. The knife

the anterior rami of T1 through T11 spinal nerves. An

had also pierced the left dome of the cervical pleura,

intercostal nerve passes forward around the chest wall

causing a left pneumothorax with left-sided diminished

first, between the posterior intercostal membrane and

breath sounds and a deflection of the trachea to the left.

the parietal pleura, then between the internal inter-

costal muscle and the innermost intercostal muscle

D is the correct answer. The skin over the sixth inter-

(part of the transversus thoracis). The nerve lies in the

costal space is innervated by the lateral cutaneous

subcostal groove of the rib of its own number. The in-

branch as well as the anterior cutaneous branch of the

tercostal vein, the intercostal artery, and the intercostal

sixth intercostal nerve.

nerve lie within the subcostal groove in that order from

B is the correct answer. The parietal peritoneum in the

above downward.

region of the fundus of the gallbladder is innervated by

15.

The sensory innervation of the skin on the lateral sur-

the eighth and ninth intercostal nerves, which give rise

face of the thigh is the lateral cutaneous nerve of the

to referred pain in the eighth and ninth thoracic der-

thigh, a branch of the lumbar plexus (L2 and L3). The

matomes on the side and back.

nerve may be blocked by inserting an anesthetic needle

D is the correct answer. The segmental nerves supply-

just inferior to the inguinal ligament about 0.5 in. (1.3

ing the right lower quadrant of the abdominal wall are

cm) medial to the anterior superior iliac spine.

T11, T12, and L1 (see CD Fig. 17-1).

16.

The sensory nerve supply to the skin on the dorsum of

10.

D is the correct answer. The pyramidalis muscle (if pre-

the foot is from the superficial peroneal nerve. The cleft

sent) is innervated by the twelfth thoracic nerve.

between the first and second toes is from the deep per-

oneal nerve.

11.

C is the correct answer. The skin on the lateral side of

the thigh is innervated by the lateral cutaneous nerve of

The superficial peroneal nerve can be blocked by infil-

the thigh (L2 and L3), a branch of the lumbar plexus

trating the anesthetic in the subcutaneous tissue along

(see CD Fig. 17-1).

a transverse line connecting the medial and lateral

malleoli (see CD Fig. 17-21). The deep peroneal nerve

12.

C is the correct answer. The skin covering the medial

is blocked by first palpating the dorsalis pedis artery as it

border of the big toe is innervated by the superficial per-

lies between the tendons of the extensor hallucis longus

oneal nerve (see CD Fig. 17-1).

and the extensor digitorum longus. The nerve lies on

13.

The index finger receives the following sensory inner-

the lateral side of the artery between these tendons. The

vation: anterior aspect, two digital branches of the me-

needle is then inserted over the nerve, and the sur-

dian nerve; posterior aspect, two digital branches of the

rounding tissue is infiltrated with anesthetic.

Chapter Outline

The Eye

296

Trauma and the Cornea

299

Corneal Ulcers

299

Eyelids

296

Pupil

300

Clinical Examination of the Eyelids

296

Flashlight Examination of the Pupil

300

Hordeolum (Stye)

296

Pupillary Reflexes

300

Chalazion

297

Retina

300

Edema of the Eyelids

297

Detachment of the Retina

300

Subtarsal Sulcus and Foreign Bodies

297

Central Retinal Artery Occlusion

300

Ptosis (Drooping of the Upper Lid)

297

Papilledema, the Central Vein, and Increased

Lacrimal Apparatus

297

Cerebrospinal Fluid Pressure

300

Inflammation of the Lacrimal Sac

297

Lens

300

Probing the Nasolacrimal Duct

298

Cataract

300

Eye Trauma

298

Examination of the Eye as Seen with the Direct

Blowout Fractures of the Maxilla

298

Ophthalmoscope

300

Movements of the Eye

298

The Ear

303

Clinical Testing for the Actions of the Superior and

External Ear

303

Inferior Recti and the Superior and Inferior

Tympanic Membrane Examination

303

Oblique Muscles

298

Middle Ear

303

Lesions of the Cranial Nerves that Control the Eye

Infections and Otitis Media

303

Movements

298

Complications of Otitis Media

303

Strabismus

298

Eye Structure

298

Clinical Problem Solving Questions

303

Sclera

298

The Lamina Cribrosa, the Cerebrospinal Fluid,

Answers and Explanations

305

and the Aqueous Humor Pressure

298

Cornea

298

Aging Changes in the Cornea

298

Astigmatism

299

and muscular attachments. It is performed for purposes

THE EYE

of inspection of the eye and removing a superficial con-

junctival foreign body. With the patient looking down-

ward, the upper lid is grasped by the central eyelashes

Eyelids

and pulled downward while a cotton-tipped applicator is

applied centrally to the skin on the upper surface of the

Clinical Examination of the Eyelids

upper lid. With the superior tarsal plate serving to stiffen

the upper lid, the upper lid is gently flipped upward over

Retraction of the eyelids: Both the upper and lower lids

the applicator tip so that the conjunctival surface is fully

can be retracted by applying the thumbs to the patient’s

exposed (see CD Fig. 18-1).

forehead and the cheek just above and below the orbital

margins. The lids are then gently retracted away from

Hordeolum (Stye)

the eyeball, and the lower lid may be easily everted (CD

Fig. 18-1).

An external hordeolum is an acute infection of a lash follicle

Eversion of the upper lid: Eversion of the upper lid is

or a sebaceous gland (of Zeis) or a ciliary sweat gland

more difficult than that of the lower lid because of its size

(of Moll); all drain externally to the skin surface of the lid.

The Eye and the Ear

297

eyebrow

orbital part of upper lid

tarsal part of upper lid

superior palpebral furrow

tarsal glands

beneath conjuctiva

lateral

punctum lacrimale

angle of eye

caruncula

lacrimalis

orifices of

tarsal glands

bulbar conjunctiva

palpebral conjunctiva

branches of posterior

conjunctival arteries

upper lid

tarsal glands

CD Figure 18-1

A. Complete eversion of the up-

ducts of

per eyelid of the right eye made possible by stiff-

tarsal glands

lateral

ness of the superior tarsal plate; the lower eyelid is

angle

pulled downward. Note the orifices of the tarsal

of eye

glands and the puncta lacrimalia. B. Posterior view

of the eyelids with the upper and lower lids nearly

closed. Note the tarsal glands with their short ducts

anterior margin of lid

and orifices. In this diagram the conjunctiva has

posterior margin of lid

been removed from the back of the eyelids to re-

lower lid

veal the tarsal glands in situ.

An internal hordeolum is an acute infection of a tarsal gland

described previously. Small particles often migrate and be-

(of Meibom). The tarsal glands drain onto the conjunctival

come lodged in the subtarsal sulcus (see text Fig. 18-1).

surface of the lid.

Corneal abrasions may occur as the result of the foreign

body being carried across the cornea with the movement of

Chalazion

the eyelids.

This is a localized, painless swelling of the lid resulting from

Ptosis (Drooping of the Upper Lid)

chronic inflammation of a tarsal gland. Since the gland lies

on the conjunctival surface of the tarsal plate, the swelling

In Horner’s syndrome, ptosis is caused by loss of sympathetic

should be incised through the conjunctival surface of the lid.

innervation of the smooth muscle component of the levator

palpebrae superioris muscle. In third cranial nerve dysfunc-

Edema of the Eyelids

tion, ptosis is due to paralysis of the striated muscle of the

levator palpebrae superioris.

The looseness of the subcutaneous tissue of the eyelids ex-

plains why edema fluid secondary to renal failure or insect

bites can rapidly accumulate, causing extensive swelling of

Lacrimal Apparatus

the lids.

Inflammation of the Lacrimal Sac

Subtarsal Sulcus and Foreign Bodies

This presents as a tender swelling above the upper margin of

Foreign bodies in the conjunctival sac produce severe pain

the medial palpebral ligament. Gentle pressure on the sac

and reflex tearing. The superior and inferior fornices can be

may result in a yellowish discharge emerging from the

examined for the foreign bodies by everting the eyelids as

puncta lacrimalia.

298

Chapter 18

Probing the Nasolacrimal Duct

oblique and the origin of the inferior oblique muscles lie me-

dial and anterior to their insertions. The ophthalmologist tests

Congenital or acquired blockage of the duct may occur.

the action of these muscles by asking the patient first to look

To relieve the blockage, a probe is passed downward starting

medially, thus placing these muscles in the optimum position

at the punctum lacrimalia of the upper eyelid. The probe is

to lower the cornea (superior oblique) or to raise it (inferior

first directed vertically upward and then medially into the

oblique). In other words, when you ask a patient to look me-

lacrimal sac. It is then turned downward at right angles in the

dially and downward at the tip of his nose, you are testing the

nasolacrimal duct to reach the inferior meatus in the nose.

superior oblique at its best position. Conversely, by asking the

The end of the probe should then be visible within the nose.

patient to look medially and upward, you are testing the infe-

Remember that the nasolacrimal duct inclines downward,

rior oblique at its best position.

backward, and laterally as it descends to the nose.

Because the lateral and medial recti are neutrally placed

relative to the axes of the eyeball, asking the patient to turn his

Eye Trauma

or her cornea directly laterally tests the lateral rectus, and

turning the cornea directly medially tests the medial rectus.

Although the eyeball is well protected by the surrounding

The cardinal positions of the eye and the actions of the

bony orbit, it is protected anteriorly only from large objects,

recti and oblique muscles are shown in CD Fig. 18-2.

such as tennis balls, which tend to strike the orbital margin

but not the globe. The bony orbit provides no protection

Lesions of the Cranial Nerves that

from small objects, such as golf balls, which can cause se-

Control the Eye Movements

vere damage to the eye. Careful examination of the eyeball

relative to the orbital margins shows that it is least protected

Lesions of the oculomotor, trochlear, and abducent nerves

from the lateral side.

are described on CD page 227.

Strabismus

Blowout Fractures of the Maxilla

Many cases of strabismus are nonparalytic and are caused by

Blowout fractures of the orbital floor involving the maxillary

an imbalance in the action of opposing muscles. This type

sinus commonly occur as a result of blunt force to the face.

of strabismus is known as concomitant strabismus and is

If the force is applied to the eye, the orbital fat explodes

common in infancy.

inferiorly into the maxillary sinus, fracturing the orbital

floor. Not only can blowout fractures cause displacement of

Eye Structure

the eyeball, with resulting symptoms of double vision

(diplopia), but also the fracture can injure the infraorbital

Sclera

nerve, producing loss of sensation of the skin of the cheek

and the gum on that side. Entrapment of the inferior rectus

muscle in the fracture may limit upward gaze.

The Lamina Cribrosa, the Cerebrospinal

Fluid, and the Aqueous Humor Pressure

Movements of the Eye

The lamina cribrosa is the area of the sclera that is pierced by

the nerve fibers of the optic nerve. It is a relatively weak area

Clinical Testing for the Actions of the

and can be made to bulge into the eyeball by a rise of cere-

Superior and Inferior Recti and the

brospinal fluid pressure in the tubular extension of the sub-

Superior and Inferior Oblique Muscles

arachnoid space, which surrounds the optic nerve.

If the intraocular pressure rises, due to blockage in the

Since the actions of the superior and inferior recti and the

drainage of aqueous humor, as in glaucoma, the lamina

superior and inferior oblique muscles are complicated

cribrosa will bulge outward, producing a cupped disc, as

when a patient is asked to look vertically upward or vertically

seen through the ophthalmoscope.

downward, the examiner tests the eye movements in which

the single action of each muscle predominates.

Cornea

The origins of the superior and inferior recti are situ-

ated about 23° medial to their insertion and, therefore,

Aging Changes in the Cornea

when the patient is asked to turn the cornea laterally, these

muscle are placed in the optimum position to raise the

With advancing years, the cornea becomes less translucent,

cornea (superior rectus) or lower it (inferior rectus). To test

and dust-like opacities may occur in the deeper parts of the

the superior rectus, have the patient look up and laterally; to

substantia propria. Arcus senilis appears as white arcs near

test the inferior rectus, have the patient look down and out.

the edge of the cornea and is caused by an extracellular

Using the same rationale, the examiner tests the superior

infiltration of lipid; it is present in almost every person over

and the inferior oblique muscles. The pulley of the superior

60 years old.

The Eye and the Ear

299

CD Figure 18-2

The cardinal positions of the right and left eyes and the actions of the

recti and oblique muscles principally responsible for the movements of the eyes. A. Right

eye, superior rectus muscle; left eye, inferior oblique muscle. B. Both eyes, superior recti

and inferior oblique muscles. C. Right eye, inferior oblique muscle; left eye, superior rec-

tus muscle. D. Right eye, lateral rectus muscle; left eye, medial rectus muscle. E. Primary

position, with the eyes fixed on a distant fixation point. F. Right eye, medial rectus muscle;

left eye, lateral rectus muscle. G. Right eye, inferior rectus muscle; left eye, superior

oblique muscle. H. Both eyes, inferior recti and superior oblique muscles. I. Right eye, su-

perior oblique muscle; left eye, inferior rectus muscle.

Astigmatism

Fortunately, the stratified squamous epithelium covering the

anterior surface of the cornea is capable of rapid regeneration

Often the cornea is not the section of a perfect sphere so that

after an abrasion.

the refractive power is not the same in all directions, a

Foreign bodies driven with great force may penetrate

condition known as astigmatism.

the cornea and enter the anterior chamber or even the

deepest parts of the eyeball.

Trauma and the Cornea

Corneal Ulcers

Because a portion of the cornea is exposed between the

eyelids, injuries from foreign bodies or abrasions are very

Corneal ulcers are caused by a bacterial invasion of the

common. Damage to the corneal epithelium causes consid-

cornea with the formation of a stromal abscess. The ability of

erable pain, reflex tearing, and vasodilatation of the conjunc-

the cornea to resist bacterial invasion depends on the cleans-

tival capillaries. Later, edema of the lids will be apparent.

ing action of the tears and their normal circulation and the

300

Chapter 18

integrity of the corneal epithelium. A breakdown of this

hole or tear, allows accumulation of fluid between the

mechanism can occur as the result of mild trauma, such as

pigment epithelium and the neural retina, causing the

that which occurs when soft corneal lenses are worn for an ex-

layers to separate or become detached.

cessive period of time, or in the presence of chronic disease.

Central Retinal Artery Occlusion

Pupil

At the point where the central artery pierces the lamina

cribrosa (CD Fig. 18-3), it is subject to atherosclerosis and

Flashlight Examination of the Pupil

can undergo complete or partial occlusion. Disease changes

in the arteriolar wall can be seen with the ophthalmoscope

Normally, the pupils should be of equal or nearly equal

where the arteries cross the veins as a nicking or narrowing

diameter (within 1 to 2 mm in diameter is normal). They

of the venous blood column.

should be round and react to light and accommodation.

In complete central artery occlusion there is a sudden

onset of unilateral blindness. In branch arteriole occlusion

Pupillary Reflexes

there is a partial loss of sight corresponding to the sector

The pupillary reflexes—that is, the reaction of the pupils to

supplied by the arteriole. Total arterial occlusion lasting

light and accommodation—depend on the integrity of ner-

longer than 1¹⁄2 hours can produce irreversible retinal

vous pathways. In the direct light reflex, the normal pupil

degeneration.

reflexly contracts when a light is shone into the patient’s eye.

The nervous impulses pass from the retina along the optic

Papilledema, the Central Vein, and

nerve to the optic chiasma and then along the optic tract.

Increased Cerebrospinal Fluid Pressure

Before reaching the lateral geniculate body, the fibers con-

Since the optic nerve is surrounded by the dura and arach-

cerned with this reflex leave the tract and pass to the oculo-

noid sheaths, an increase in the intracranial pressure is

motor nuclei on both sides via the pretectal nuclei. From

transmitted through the cerebrospinal fluid along the exten-

the parasympathetic part of the nucleus, efferent fibers leave

sion of the subarachnoid space to the lamina cribrosa of the

the midbrain in the oculomotor nerve and reach the ciliary

eyeball. Because the central artery and vein of the retina

ganglion via the nerve to the inferior oblique. Postgan-

cross the subarachnoid space to enter or leave the optic

glionic fibers pass to the constrictor pupillae muscles via the

nerve, they will be subject to a rise in cerebrospinal fluid

short ciliary nerves.

pressure. The thick-walled artery is unaffected, but the thin-

The consensual light reflex is tested by shining the

walled vein may be compressed, causing congestion of the

light in one eye and noting the contraction of the pupil in

retinal veins and edema of the retina; bulging of the disc

the opposite eye. This reflex is possible because the afferent

may also occur.

pathway just described travels to the parasympathetic nuclei

of both oculomotor nerves.

Lens

The accommodation reflex is the contraction of the

pupil that occurs when a person suddenly focuses on a near

Cataract

object after having focused on a distant object. The nervous

impulses pass from the retina via the optic nerve, the optic

In this condition the lens becomes opaque. Metabolic prod-

chiasma, the optic tract, the lateral geniculate body, the

ucts accumulate within the lens fibers. Senile cataract is the

optic radiation, and the cerebral cortex of the occipital lobe

most common form; its cause is unknown.

of the brain. The visual cortex is connected to the eye field

of the frontal cortex. From here, efferent pathways pass to

Examination of the Eye as Seen

the parasympathetic nucleus of the oculomotor nerve.

From there, the efferent impulses reach the constrictor

with the Direct Ophthalmoscope

pupillae via the oculomotor nerve, the ciliary ganglion, and

the short ciliary nerves.

Red reflex: On looking through the ophthalmoscope,

holding it about 1 ft away from the patient, the examiner

Retina

notes that the fundus appears red (see CD Fig. 18-3). The

fundus shows red because the light is being reflected

Detachment of the Retina

back from the blood in the choroidal blood vessels, with

The neural retina is firmly attached to the underlying

the intervening retina being transparent. An absent red

pigment epithelium at the optic disc and the ora serrata.

reflex means that either there is an opacity in the refrac-

Pathologic separation of the two layers of the retina may

tive media or the retina is not against the choroid. The

follow trauma to the eyeball or degeneration of the neural

possible opacities include a cataract, a vitreous hemor-

retina. Vitreous traction of the retina, or the presence of a

rhage, and a detached retina.

The Eye and the Ear

301

tributary of central vein of retina

optic disc

pigmentation

of retina

site of

fovea

centralis

branch of central artery of retina

CD Figure 18-3

The left ocular fundus as seen with an ophthalmoscope.

Fundus examination: Without pupillary dilatation, only

optic disc is a weak area, a rise in intraocular pressure can

about 15% of the fundus can be seen. With full pupillary

cause it to bulge outward, producing a cupped disc that

dilatation, about 50% of the fundus can be viewed, but

can be seen with the ophthalmoscope.

the area between the equator of the eyeball and the ora

Retinal arteries and veins: The arteries are bright red;

serrata cannot be seen.

the veins are darker red (see CD Fig. 18-3). The arteries

Optic disc: This structure is circular or oval with a vertical

are smaller than the veins (about a 3:4 ratio). The arter-

orientation (see CD Fig. 18-3). It is pink, with the tempo-

ies have thicker walls, which reflect the light as a shiny

ral side slightly lighter than the nasal side. The disc mea-

central reflex stripe. The walls of the arteries and the

sures about 1.5 mm in diameter and can be used as a unit

veins are transparent, so that the examiner observes a

of measurement. The center of the disc has a pale, almost

moving column of blood. The arteries usually cross the

white, depression called the physiologic cup. The edge of

veins on their superficial or vitreal surface, and normally

the disc is usually flat and sharply defined. In some indi-

the arteries do not compress or nick the veins at the site

viduals in whom the retina does not quite reach the mar-

of crossing. The branching of the vessels is variable.

gin of the disc, an arc of choroid pigment may be visible.

Macula: The macula area lies about two disc diameters

The bright red central artery of the retina becomes

on the lateral side of the optic disc (see CD Fig. 18-3).

visible on the disc surface emerging from the optic cup,

It is darker than the surrounding retina. The superior

where it divides into its superior and inferior branches.

and inferior temporal blood vessels arch above and below

The arteries do not normally pulsate. The darker red

the macular area, and no blood vessels are visible in

main tributaries of the central vein of the retina pass into

the center of the macula. The center of the macula

the cup and unite in the cup or deeper out of site within

shows a small, dark red area called the fovea centralis.

the optic nerve.

A small white-yellow light reflex can be detected at

In glaucoma, the increase in intraocular pressure

the center of the fovea, caused by the reflection of

leads to atrophy of the optic nerve and defects in the vi-

the ophthalmoscope light from the concavity of the

sual field. Since the lamina cribrosa of the sclera at the

fovea.

The Eye and the Ear

303

of the pharynx. Acute infection of the middle ear (otitis

THE EAR

media) produces bulging and redness of the tympanic

membrane.

External Ear

Complications of Otitis Media

Inadequate treatment of otitis media can result in the spread

Tympanic Membrane Examination

of the infection into the mastoid antrum and the mastoid air

Otoscopic examination of the tympanic membrane is facili-

cells (acute mastoiditis). Acute mastoiditis may be followed

tated by first straightening the external auditory meatus by

by the further spread of the organisms beyond the confines

gently pulling the auricle upward and backward in the adult

of the middle ear. The meninges and the temporal lobe of

(CD Fig. 18-4), and straight backward or backward and

the brain lie superiorly. A spread of the infection in this

downward in the infant. Normally, the tympanic membrane

direction could produce a meningitis and a cerebral abscess

is pearly gray and concave. Remember that in the adult the

in the temporal lobe. Beyond the medial wall of the middle

external meatus is about 1 in. (2.5 cm) long and is narrow-

ear lie the facial nerve and the internal ear. A spread of

est about 0.2 in. (5 mm) from the tympanic membrane.

the infection in this direction can cause a facial nerve palsy

and labyrinthitis with vertigo. The posterior wall of the

mastoid antrum is related to the sigmoid venous sinus. If

Middle Ear

the infection spreads in this direction, a thrombosis in

the sigmoid sinus may well take place. These various

Infections and Otitis Media

complications emphasize the importance of knowing the

Pathogenic organisms can gain entrance to the middle ear

anatomy of this region.

by ascending through the auditory tube from the nasal part

Clinical Problem Solving Questions

Read the following case histories/questions and give

A 33-year-old woman was riding her bicycle when she

the best answer for each.

swerved to avoid a pothole and lost her balance. She then

crashed and hit her head hard on the sidewalk. When she

A 49-year-old woman was found on ophthalmoscopic exam-

regained consciousness in the hospital, it was immediately

ination to have edema of both optic discs (bilateral pa-

noted that she had medial strabismus (squint) of her left

pilledema) and congestion of both retinal veins. The cause

eye.

of the condition was found to be a rapidly expanding in-

tracranial tumor.

2. Which eye muscle was paralyzed in this injury?

A. The medial rectus muscle

1. The following statements concerning this patient are

B. The inferior rectus muscle

correct except which?

C. The superior rectus muscle

A. An intracranial tumor causes a rise in cerebrospinal

D. The lateral rectus muscle

fluid pressure.

E. The superior obliques muscle

B. The optic nerves are surrounded by sheaths derived

from the pia mater, arachnoid mater, and dura mater.

3. An 18-year-old student went to the clinic complaining

C. The intracranial subarachnoid space extends for-

of an acute tender area on the middle of his right upper

ward around the optic nerve for about half its length.

eyelid. Examination revealed a localized red, indurated

D. The thin walls of the retinal vein will be compressed

area on the eyelid margin. Close inspection showed a

as the vein crosses the extension of the subarachnoid

yellowish spot in the center of the swelling. Gentle

space around the optic nerve.

eversion of the lid showed no evidence of swelling on its

E. Because both subarachnoid extensions are continu-

posterior surface. What is the diagnosis? Which

ous with the intracranial subarachnoid space, both

anatomic structure(s) is (are) involved in the inflamma-

eyes will exhibit papilledema and congestion of the

tory process? On which part of the eyelid does the

retinal veins.

abscess tend to point?

304

Chapter 18

A 13-year-old schoolboy was hit in the left eye by another

C. Saliva tended to accumulate in his right cheek.

boy during recess. During the next hour, both the eyelids

D. The saliva tended to dribble from the corner of his

of the victim swelled up until he could barely see. Ex-

mouth.

amination in the emergency department revealed a

E. All the muscles of the right side of his face were

bluish-red discoloration of both eyelids of his left eye with

paralyzed.

narrowing of the palpebral fissure. The discoloration ex-

A 3-year-old boy was playing with his friend when they

tended to the forehead and the left cheek. Careful sepa-

decided to see how many peas they could stick into

ration of the eyelids showed a localized hemorrhage of

each others ears. Later, the babysitter noticed that one

the inferolateral part of the bulbar conjunctiva (part of

of the boys had become completely deaf in his left ear.

the conjunctiva adherent to the sclera of the eyeball).

On examination in the emergency department of the

When the conjunctiva was gently moved with the tip of

local hospital, the physician’s assistant noticed what

the examiner’s little finger, the hemorrhage moved also.

appeared to be several peas deeply embedded in the left

When the patient was asked to look medially,

external auditory meatus. She decided to attempt the

the physician could clearly see the posterior limit of

removal of the peas through an otoscope. Which direc-

the conjunctival hemorrhage. Does this patient have a

tion should the auricle be pulled in a child to straighten

simple “black eye,” or is this a fracture of the anterior

the meatus and assist in the operation? How does this

cranial fossa of the skull? What role does the orbital

change in the adult?

septum play in enabling one to distinguish between

these lesions? Is the appearance of the conjunctival

Following a severe cold, a 10-year-old girl complained

hemorrhage important in making the diagnosis?

of severe right-sided earache. On examination by her

pediatrician, the tympanic membrane looked reddened

A 6-month-old girl was seen in the emergency depart-

and bulged laterally. A diagnosis of otitis media was

ment because her mother had noticed a yellow, sticky

made. A yellowish area was apparent close to the umbo

discharge from the baby’s left eye. On questioning, the

and it appeared that perforation of the tympanic mem-

mother said that she had first noticed the condition that

brane was about to take place. It was decided to do a

morning when her daughter woke up. She also said that

myringotomy (incise the tympanic membrane). Where

she had noticed that her daughter’s left eye watered

would you do a myringotomy? What structures do you

excessively when she cried ever since birth. The physi-

have to avoid in this operation? What are the features

cian confirmed the epiphora of the left eye and noted

normally seen on the tympanic membrane with an

the emergence of yellow pus into the lacus lacrimalis

otoscope?

from the puncta when gentle pressure was exerted over

the medial palpebral ligament. What is the diagnosis?

A 13-year-old boy was struck on his right ear by another

What is the most likely cause in a child of this age?

boy’s fist during a fight. By the time the boy was exam-

What are the posterior relations of the medial palpebral

ined, the ear was extremely swollen and bluish and very

ligament? Describe the anatomy of the drainage pas-

painful. Explain in anatomic terms where the blood

sages of the conjunctival sac and give the direction of

and edema fluid collect in such a case. Can the ear be

each of the tubes.

treated conservatively or should the hematoma be

drained? What is a cauliflower ear?

A 7-year-old boy with right-sided otitis media was treated with

antibiotics. The organisms did not respond to the treatment,

10.

A 45-year-old woman with a severe cold had to make a

and the infection spread to the mastoid antrum and the mas-

business trip by plane. On takeoff she noticed that her

toid air cells. The surgeon decided to perform a radical mas-

hearing became impaired and she experienced acute

toid operation. After the operation, it was noticed that the

pain in her right ear. She told the stewardess about her

boy’s face was distorted.

problem and asked for an aspirin. The stewardess

6. The following signs and symptoms suggest that the right

advised the patient to relax and swallow hard several

facial nerve had been damaged during the operation

times. On reaching the cruising altitude the right

except which?

ear suddenly popped and the deafness and pain

A. The mouth was drawn upward to the right.

disappeared. In anatomic terms explain this patient’s

B. He was unable to close his right eye.

condition.

The Eye and the Ear

305

Answers and Explanations

C is the correct answer. The intracranial subarachnoid

In a young child, the external auditory meatus may be

space extends forward through the optic canal around

straightened by pulling the auricle directly backward.

the optic nerve as far as the back of the eyeball (see text

In an adult, the meatus is straightened by pulling the

Fig. 18-9).

auricle backward and upward (see CD Fig. 18-4).

D is the correct answer. The left abducent nerve was

A myringotomy is performed through the lower quad-

damaged by the head trauma and resulted in paralysis

rants of the tympanic membrane to avoid damaging the

of the left lateral rectus muscle. As a consequence, the

chorda tympani nerve that crosses the tympanic mem-

medial rectus muscle was unapposed and turned the

brane on the medial side of the upper quadrants (see text

eye medially (medial strabismus).

Fig. 18-15A).The features seen on a normal tympanic

membrane with an otoscope with a good light include

The student had a hordeolum or stye in his right eye.

(1) the long process of the malleus with the umbo; (2) the

The usual cause is a staphylococcal infection of the eye-

anterior and posterior malleolar folds with the pars flac-

lash follicle, the sebaceous gland of Zeis, or the ciliary

cida; (3) the cone of light produced by light reflection on

gland of Moll. The suppurative infection tends to point

the concave tympanic membrane; (4) the tympanic

on the anterior part of the lid margin. Repeated multi-

membrane is pearl colored with no evidence of dilated

ple styes tend to occur as the result of spread of infec-

blood vessels; (5) sometimes when the tympanic mem-

tion along the eyelid margin.

brane is translucent, as in a young child, the long process

This schoolboy has a severe “black eye.” In this patient

of the incus and the promontory on the medial wall of

the contusion involved not only the eyelids but the skin

the middle ear can be seen (see CD Fig. 18-4).

of the cheek and forehead. In anterior cranial fossa frac-

In auricular hematomas the blood tends to accumulate

tures, the hemorrhage occurs into the orbital cavity and

between the perichondrium and the underlying carti-

is limited anteriorly by the attachment of the orbital

lage. The edema fluid has little room to spread since

septum to the orbital margin. In such cases the discol-

the skin is tightly bound down to the perichondrium;

oration tends to be circular. In fractures of the anterior

moreover, the pressure of the fluid causes extreme pain.

cranial fossa, because the bleeding is deeply placed, it

Failure to aspirate the hematoma may lead to necrosis

tends to be purplish from the start, whereas with a black

of the cartilage, since it has been deprived of its blood

eye the color is initially red.

supply due to separation of the perichondrium from the

This girl was suffering from chronic dacryocystitis sec-

cartilage. If cartilaginous necrosis takes place, fibrous

ondary to congenital obstruction of the nasolacrimal

replacement occurs followed by contraction and defor-

duct. The obstruction results from failure of the naso-

mity, the so-called cauliflower ear.

lacrimal duct to open up and drain into the inferior

10.

Inflammation of the mucous membrane of the pharynx

meatus of the nose. The posterior relation of the medial

tends to spread upward to the middle ear via the audi-

palpebral ligament is the lacrimal sac. The drainage

tory tube. The swelling of the mucous membrane lin-

passages start at the puncta on the tip of the lacrimal

ing the stiff wall of the tube results in blockage of the

papilla. The canaliculi first pass vertically in the eyelids

passageway. Very quickly, the trapped air in the middle

for about 2 mm and then turn sharply at right angles

ear becomes absorbed into the bloodstream, creating a

and run medially for about 8 mm to enter the lacrimal

vacuum. As a result, the tympanic membrane is pulled

sac. The lower end of the lacrimal sac is connected to

inward and causes deafness and acute pain. In a plane

the inferior meatus of the nose by the nasolacrimal

that is taking off and climbing quickly, the cabin pres-

duct, which is about 15 mm long. The duct passes

sures are subject to changes and this augments the

downward, backward, and laterally.

pressure differences on the two sides of the tympanic

A is the correct answer. The facial muscles on the left

membrane. Repeated swallowing causes the contrac-

side of the mouth on contraction pull the mouth up-

tion of the salpingopharyngeus muscle and often allows

ward and to the left because the muscles on the right

sufficient air into the tympanic cavity through the audi-

side were paralyzed.

tory tube, thus relieving the problem.

Chapter Outline

Abdominal Wall

312

Abdominal Stab Wounds

326

General Appearances of the Abdominal Wall

312

Abdominal Gun Shot Wounds

327

Infection of the Umbilicus

312

Tying the Umbilical Cord

327

Surgical Incisions and Lines of Cleavage

312

Patent Urachus

327

Caval Obstruction

312

Vitellointestinal Duct

327

Portal Vein Obstruction and Caput Medusae

312

Umbilical Vessel Catheterization

327

Indications for Umbilical Artery

Skin and Its Regional Lymph Nodes

312

Catheterization

327

Membranous Layer of the Superficial Fascia

Anatomy of Procedure

327

and a Healing Skin Wound

313

Anatomy of Complications

327

Indications for Umbilical Vein Catheterization

328

Membranous Layer of Superficial Fascia and the

Anatomy of Procedure

328

Extravasation of Urine

313

Anatomy of Complications

329

Hematoma of the Rectus Sheath

313

Peritoneum and Peritoneal Cavity

329

Abdominal Muscles, Abdominothoracic Rhythm,

Movement of Peritoneal Fluid

329

and Visceroptosis

313

Peritoneal Infection

329

Muscle Rigidity and Referred Pain

313

Greater Omentum and the Localization of

Surgery and Tendinous Intersections of the

Infection

329

Rectus Abdominis Muscle

314

Greater Omentum as a Hernial Plug

329

Fate of the Processus Vaginalis

314

Greater Omentum in Surgery

329

Abdominal Herniae

314

Indirect Inguinal Hernia

314

Torsion of the Greater Omentum

329

Direct Inguinal Hernia

315

Ascites

329

Femoral Hernia

316

Peritoneal Pain

330

Umbilical Herniae

319

From the Parietal Peritoneum

330

Epigastric Hernia

320

From the Visceral Peritoneum

331

Separation of the Recti Abdominis

320

Incisional Hernia

320

Peritoneal Dialysis

331

Hernia of the Linea Semilunaris

Internal Abdominal Hernia

331

(Spigelian Hernia)

320

Lumbar Hernia

320

Retroperitoneal Space

331

Internal Hernia

320

Trauma to Organs in the Retroperitoneal Space

331

Abdominal Pain

320

Abscess Formation

332

Somatic Abdominal Pain

320

Leaking Aortic Aneurysm

332

Visceral Abdominal Pain

320

Referred Abdominal Pain

321

The Alimentary Tract

332

Anterior Abdominal Nerve Block

322

Esophagus

332

Surgical Incisions

322

Narrow Areas of the Esophageal Lumen

332

Achalasia of the Cardia (Esophagogastric

Endoscopic Surgery

323

Junction)

332

Paracentesis of the Abdomen

323

Bleeding Esophageal Varices

332

Anatomy of Peritoneal Lavage

324

Anatomy of the Insertion of the

Midline Incision Technique

324

Sengstaken-Blakemore Balloon for

Paraumbilical Incision Technique

325

Esophageal Hemorrhage

332

Anatomy of the Complications of

Anatomy of Complications

332

Peritoneal Lavage

326

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

311

Stomach

332

Cancer of the Rectum

341

Nausea

332

Rectal Injuries

341

Vomiting

332

Anal Canal

341

Trauma to the Stomach

333

Internal Hemorrhoids (Piles)

341

Gastric Ulcer

334

External Hemorrhoids

342

Gastric Pain

334

Perianal Hematoma

343

Cancer of the Stomach

334

Anal Fissure

343

Gastroscopy

334

Perianal Abscesses

345

Nasogastric Intubation

334

Removal of Anorectal Foreign Bodies

345

Anatomic Structures that May Impede

Anal Sphincter Nerve Block and Anesthetizing

the Passage of the Nasogastric Tube

335

the Perianal Skin

345

Anatomy of Complications

335

Incontinence Associated with Rectal

Duodenum

335

Prolapse

345

Trauma to the Duodenum

335

Incontinence after Trauma

345

Duodenal Ulcer

335

Incontinence after Spinal Cord Injury

345

Duodenal Recesses

335

Rectal Examination

346

Important Duodenal Relations

335

Cancer and Lymph Drainage of the

Anal Canal

347

Jejunum and Ileum

335

Trauma to the Jejunum and Ileum

335

Ischiorectal Fossa

347

Recognition of the Jejunum and Ileum

335

The Ischiorectal Fossa and Infection

347

Tumors and Cysts of the Mesentery of the

Small Intestine

335

Congenital Anomalies of the Esophagus

347

Pain Fibers from the Jejunum and Ileum

336

Atresia of the Esophagus

347

Mesenteric Arterial Occlusion

336

Mesenteric Vein Thrombosis

336

Esophageal Stenosis

347

Appendix

336

Congenital Short Esophagus

347

Variability of Position of the Appendix

336

Congenital Anomalies of the Stomach

347

Pelvic Appendix

336

Congenital Hypertrophic Pyloric Stenosis

347

Predisposition of the Appendix to Infection

336

Predisposition of the Appendix to Perforation

336

Congenital Anomalies of the Small

Pain of Appendicitis

336

and Large Intestines

347

Colon and Cecum

336

Diverticula of the Intestine

347

Colonoscopy

336

Atresia and Stenosis of the Small Intestine

348

Trauma of the Cecum and Colon

338

Cancer of the Large Bowel

338

Duplication of the Digestive System

348

Diverticulosis

338

Arrested Rotation or Malrotation of the

Cecostomy and Colostomy

338

Midgut Loop

349

Volvulus

338

Intussusception

338

Complete Absence of Rotation or Incomplete

Rotation

349

Sigmoid Colon

339

Variations in the Length and Location of the

Malrotation of the Midgut Loop

349

Sigmoid Colon

339

Persistence of the Vitellointestinal Duct

349

Cancer of the Sigmoid Colon

339

Meckel’s Diverticulum

349

Volvulus

339

Diverticula

339

Undescended Cecum and Appendix

349

Sigmoidoscopy

339

Anomalies of the Appendix

349

Anatomic Facts Relative to

Sigmoidoscopy

339

Anomalies of the Colon

349

Anatomy of Complications of

Primary Megacolon (Hirschsprung Disease)

349

Sigmoidoscopy

339

Imperforate Anus

349

Colostomy

339

Rectum

340

Clinical Problem Solving Questions

350

Rectal Curves and Mucosal Folds

340

Blood Supply and Internal Hemorrhoids

340

Answers and Explanations

355

Partial and Complete Prolapse of the Rectum

340

312

Chapter 19

line will heal as a narrow scar, whereas one that crosses the

lines will heal as wide or heaped-up scars.

ABDOMINAL WALL

Caval Obstruction

General Appearances of the

If the superior or inferior vena cava is obstructed, the venous

blood causes distension of the veins running from the ante-

Abdominal Wall

rior chest wall to the thigh. The lateral thoracic vein anasto-

The normal abdominal wall is soft and pliable and under-

moses with the superficial epigastric vein, a tributary of the

goes inward and outward excursion with respiration. The

great saphenous vein of the leg. In these circumstances, a

contour is subject to considerable variation and depends on

tortuous varicose vein may extend from the axilla to the

the tone of its muscles and the amount of fat in the subcu-

lower abdomen (CD Fig. 19-1).

taneous tissue. Well-developed muscles or an abundance of

fat can prove to be a severe obstacle to the palpation of the

Portal Vein Obstruction and

abdominal viscera.

Caput Medusae

Infection of the Umbilicus

In cases of portal vein obstruction (CD Fig. 19-2), the super-

In the adult, the umbilicus often receives scant attention in

ficial veins around the umbilicus and the paraumbilical veins

the shower and is consequently a common site of infection.

become grossly distended. The distended subcutaneous veins

radiate out from the umbilicus, producing in severe cases the

clinical picture referred to as caput medusae.

Surgical Incisions and Lines

of Cleavage

Skin and Its Regional Lymph Nodes

If possible, all surgical incisions should be made in the lines

Knowledge of the areas of the skin that drain into a particu-

of cleavage where the bundles of collagen fibers in the

lar group of lymph nodes is clinically important (see text

dermis run in parallel rows. An incision along a cleavage

Fig. 19-3). For example, it is possible to find a swelling in the

lateral thoracic vein

portal vein in porta hepatis

lumbar veins

paraumbilical veins

CD Figure 19-1

Superficial veins of the

anterior abdominal wall. On the left are

anastomoses between systemic veins

and the portal vein via paraumbilical

veins. Arrows indicate the direction taken

varicosed vein

by venous blood when the portal vein is

obstructed. On the right is an enlarged

anastomosis between the lateral thoracic

vein and the superficial epigastric vein.

superficial epigastric vein

This occurs if either the superior or the

interior vena cava is obstructed.

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

313

into the lower part of the anterior abdominal wall deep to

the membranous layer of fascia. The urine is excluded from

the thigh because of the attachment of the fascia to the

fascia lata (see text Fig. 19-4).

Hematoma of the Rectus Sheath

Hematoma of the rectus sheath is uncommon but impor-

tant, since it is often overlooked. It occurs most often on the

right side below the level of the umbilicus. The source of

the bleeding is the inferior epigastric vein or, more rarely,

the inferior epigastric artery. These vessels may be stretched

during a severe bout of coughing or in the later months of

pregnancy, which may predispose to the condition. The

cause is usually blunt trauma to the abdominal wall, such as

a fall or a kick. The symptoms that follow the trauma in-

clude midline abdominal pain. An acutely tender mass

confined to one rectus sheath is diagnostic.

Abdominal Muscles, Abdominotho-

caput Medusae

racic Rhythm, and Visceroptosis

CD Figure 19-2

An example of caput Medusae in a case of

portal obstruction caused by cirrhosis of the liver.

The abdominal muscles contract and relax with respiration,

and the abdominal wall conforms to the volume of the

abdominal viscera. There is an abdominothoracic rhythm.

Normally, during inspiration, when the sternum moves for-

groin (enlarged superficial inguinal node) caused by an in-

ward and the chest expands, the anterior abdominal wall also

fection or malignant tumor of the skin of the lower part of

moves forward. If, when the chest expands, the anterior

the anterior abdominal wall or that of the buttock.

abdominal wall remains stationary or contracts inward, it is

highly probable that the parietal peritoneum is inflamed and

has caused a reflex contraction of the abdominal muscles.

Membranous Layer of the

The shape of the anterior abdominal wall depends on the

tone of its muscles. A middle-aged woman with poor abdom-

Superficial Fascia and a

inal muscles who has had multiple pregnancies is often inca-

pable of supporting her abdominal viscera. The lower part of

Healing Skin Wound

the anterior abdominal wall protrudes forward, a condition

When closing abdominal wounds, it is usual for a surgeon to

known as visceroptosis. This should not be confused with an

put in a continuous suture uniting the divided membranous

abdominal tumor such as an ovarian cyst or with the excessive

layer of superficial fascia. This strengthens the healing

accumulation of fat in the fatty layer of the superficial fascia.

wound, prevents stretching of the skin scar, and makes for a

more cosmetically acceptable result.

Muscle Rigidity and Referred Pain

Sometimes it is difficult for a physician to decide whether

Membranous Layer of Superficial

the muscles of the anterior abdominal wall of a patient are

rigid because of underlying inflammation of the parietal

Fascia and the Extravasation of

peritoneum or whether the patient is voluntarily contracting

the muscles because he or she resents being examined or be-

Urine

cause the physician’s hand is cold. This problem is usually

The membranous layer of the superficial fascia is important

easily solved by asking the patient, who is lying supine on

clinically because beneath it is a potential closed space that

the examination table, to rest the arms by the sides and draw

does not open into the thigh but is continuous with the su-

up the knees to flex the hip joints. It is practically impossible

perficial perineal pouch via the penis and scrotum. Rupture

for a patient to keep the abdominal musculature tensed

of the penile urethra may be followed by extravasation of

when the thighs are flexed. Needless to say, the examiner’s

urine into the scrotum, perineum, and penis and then up

hand should be warm.

314

Chapter 19

A pleurisy involving the lower costal parietal pleura

cannula are inserted through the scrotal skin (see CD

causes pain in the overlying skin that may radiate down into

Fig. 19-4). The following anatomic structures are traversed

the abdomen. Although it is unlikely to cause rigidity of the

by the cannula: skin, dartos muscle and membranous layer

abdominal muscles, it may cause confusion in making a

of fascia (Colles’ fascia), external spermatic fascia, cremas-

diagnosis unless these anatomic facts are remembered.

teric fascia, internal spermatic fascia, and parietal layer of

It is useful to remember the following:

the tunica vaginalis.

Dermatomes over:

■ The xiphoid process-T7

Abdominal Herniae

■ The umbilicus-T10

A hernia is the protrusion of part of the abdominal con-

■ The pubis-L1

tents beyond the normal confines of the abdominal wall

See text Figure 19-1.

(CD Fig. 19-5). It consists of three parts: the sac, the con-

tents of the sac, and the coverings of the sac. The hernial

sac is a pouch (diverticulum) of peritoneum and has a

Surgery and Tendinous

neck and a body. The hernial contents may consist of any

structure found within the abdominal cavity and may vary

Intersections of the Rectus

from a small piece of omentum to a large viscus such as

the kidney. The hernial coverings are formed from the

Abdominis Muscle

layers of the abdominal wall through which the hernial

Transverse tendinous intersections that divide the rectus

sac passes.

abdominis muscle into distinct segments are firmly attached

Abdominal herniae are of the following common types:

to the anterior wall of the rectus sheath, whereas the poste-

■ Inguinal (indirect or direct)

rior wall of the sheath is not attached. This information is of

■ Femoral

great value to the surgeon when entering the abdominal

■ Umbilical (congenital or acquired)

cavity through the anterior abdominal wall.

■ Epigastric

■ Separation of the recti abdominis

Fate of the Processus Vaginalis

■ Incisional hernia

■ Hernia of the linea semilunaris (Spigelian hernia)

The formation of the processus vaginalis and its passage

■ Lumbar hernia (Petit’s triangle hernia)

through the lower part of the anterior abdominal wall with

■ Internal hernia

the formation of the inguinal canal in both sexes were

described in text Chapter 19. Normally, the upper part be-

Indirect Inguinal Hernia

comes obliterated just before birth and the lower part re-

mains as the tunica vaginalis.

The indirect inguinal hernia is the most common form of

The processus is subject to the following common

hernia and is believed to be congenital in origin (CD Fig.

congenital anomalies:

19-6A). The hernial sac is the remains of the processus

vaginalis (an outpouching of peritoneum that in the fetus is

■ It may persist partially or in its entirety as a preformed her-

responsible for the formation of the inguinal canal). It fol-

nial sac for an indirect inguinal hernia (CD Fig. 19-3).

lows that the sac enters the inguinal canal through the deep

■ It may become very much narrowed, but its lumen re-

inguinal ring lateral to the inferior epigastric vessels (CD

mains in communication with the abdominal cavity.

Fig. 19-6). It may extend part of the way along the canal or

Peritoneal fluid accumulates in it, forming a congenital

the full length, as far as the superficial inguinal ring. If the

hydrocele (see CD Fig. 19-3).

processus vaginalis has undergone no obliteration, then the

■ The upper and lower ends of the processus may become

hernia is complete and extends through the superficial

obliterated, leaving a small intermediate cystic area

inguinal ring down into the scrotum or labium majus.

referred to as an encysted hydrocele of the cord (see CD

Under these circumstances the neck of the hernial sac lies

Fig. 19-3).

at the deep inguinal ring lateral to the inferior epigastric

The tunica vaginalis is closely related to the front and

vessels, and the body of the sac resides in the inguinal canal

sides of the testis. It is therefore not surprising to find that

and scrotum (or base of labium majus).

inflammation of the testis can cause an accumulation of

An indirect inguinal hernia is about 20 times more

fluid within the tunica vaginalis. This is referred to simply

common in males than in females, and nearly one third

as a hydrocele

(CD Fig. 19-4). Most hydroceles are

are bilateral. It is more common on the right (normally, the

idiopathic.

right processus vaginalis becomes obliterated after the left;

To remove excess fluid from the tunica vaginalis, a

the right testis descends later than the left). It is most

procedure termed tapping a hydrocele, a fine trocar and

common in children and young adults.

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

315

peritoneal cavity

vas deferens

cyst

persistent

processus

vaginalis

epididymis

testis

peritoneal fluid

coils of small intestine inside

persistent processus vaginalis, which

forms hernial sac

CD Figure

19-3

Common congenital

anomalies of the processus vaginalis.

A. Congenital hydrocele. B. Encysted hy-

drocele of the cord. C. Preformed hernial

sac for indirect inguinal hernia.

The indirect inguinal hernia can be summarized as

Direct Inguinal Hernia

follows:

The direct inguinal hernia makes up about 15% of all

■ It is the remains of the processus vaginalis and therefore

inguinal hernias. The sac of a direct hernia bulges directly

is congenital in origin.

anteriorly through the posterior wall of the inguinal canal

■ It is more common than a direct inguinal hernia.

medial to the inferior epigastric vessels (CD Fig. 19-6B).

■ It is much more common in males than in females.

Because of the presence of the strong conjoint tendon

■ It is more common on the right side.

(combined tendons of insertion of the internal oblique and

■ It is most common in children and young adults.

transversus muscles), this hernia is usually nothing more

■ The hernial sac enters the inguinal canal through the

than a generalized bulge; therefore, the neck of the hernial

deep inguinal ring and lateral to the inferior epigastric

sac is wide.

vessels. The neck of the sac is narrow.

Direct inguinal hernias are rare in women and most are

■ The hernial sac may extend through the superficial in-

bilateral. It is a disease of old men with weak abdominal

guinal ring above and medial to the pubic tubercle.

muscles.

(Femoral hernia is located below and lateral to the pubic

A direct inguinal hernia can be summarized as follows:

tubercle.)

■ The hernial sac may extend down into the scrotum or

■ It is common in old men with weak abdominal muscles

labium majus.

and is rare in women.

316

Chapter 19

acquired hydrocele

hydrocele fluid

scrotal skin

testis

dartos muscle

membranous layer of

superficial fascia

tunica vaginalis

external spermatic fascia

CD Figure 19-4

The tunica vaginalis dis-

tended with fluid (hydrocele). Also shown are

cremasteric fascia

the various anatomic layers traversed by a tro-

internal spermatic fascia

car and cannula when a hydrocele is tapped.

■ The hernial sac bulges forward through the posterior

wall of the inguinal canal medial to the inferior epigas-

neck of hernial sac

tric vessels.

peritoneum

■ The neck of the hernial sac is wide.

An inguinal hernia can be distinguished from a femoral

abdominal wall

hernia by the fact that the sac, as it emerges through the

superficial inguinal ring, lies above and medial to the pubic

tubercle, whereas that of a femoral hernia lies below and

body of hernial sac

lateral to the tubercle (CD Fig. 19-7).

hernial coverings

Femoral Hernia

loop of ileum

The hernial sac descends through the femoral canal within

the femoral sheath, creating a femoral hernia. The femoral

sheath is a protrusion of the fascial envelope lining the

abdominal walls and surrounds the femoral vessels and

lymphatics for about 1 in. (2.5 cm) below the inguinal

ligament (CD Fig. 19-8). The femoral artery, as it enters

the thigh below the inguinal ligament, occupies the lateral

hernial sac

compartment of the sheath. The femoral vein, which lies

CD Figure 19-5

Different parts of a hernia.

on its medial side and is separated from it by a fibrous

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

317

peritoneum

neck of hernia

inferior epigastric artery

extraperitoneal fat

deep inguinal ring

conjoint tendon

superficial inguinal ring

pubic tubercle

tunica vaginalis

hernial sac

remains of

processus vaginalis

inferior epigastric artery

neck of hernia

conjoint tendon

deep inguinal ring

superficial inguinal ring

CD Figure 19-6

A. Indirect inguinal hernia. B. Direct inguinal hernia. Note that the neck

of the indirect inguinal hernia lies lateral to the inferior epigastric artery, and the neck of

the direct inguinal hernia lies medial to the inferior epigastric artery.

septum, occupies the intermediate compartment. The

end, it expands to form a swelling in the upper part of the

lymph vessels, which are separated from the vein by a

thigh deep to the deep fascia (see CD Fig. 19-8). With

fibrous septum, occupy the most medial compartment.

further expansion, the hernial sac may turn upward to cross

The femoral canal, the compartment for the lymphatics,

the anterior surface of the inguinal ligament.

occupies the medial part of the sheath. It is about 0.5 in.

The neck of the sac always lies below and lateral to the

(1.3 cm) long, and its upper opening is referred to as the

pubic tubercle (see CD Fig. 19-7), which serves to distin-

femoral ring. The femoral septum, which is a condensa-

guish it from an inguinal hernia. The neck of the sac is

tion of extraperitoneal tissue, plugs the opening of the

narrow and lies at the femoral ring. The ring is related

femoral ring.

anteriorly to the inguinal ligament, posteriorly to the

A femoral hernia is more common in women than in

pectineal ligament and the pubis, medially to the sharp

men (possibly because of a wider pelvis and femoral canal).

free edge of the lacunar ligament, and laterally to the

The hernial sac passes down the femoral canal, pushing the

femoral vein. Because of the presence of these anatomic

femoral septum before it. On escaping through the lower

structures, the neck of the sac is unable to expand. Once

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

319

an abdominal viscus has passed through the neck into

Umbilical Herniae

the body of the sac, it may be difficult to push it up and

Congenital umbilical hernia, or exomphalos (omphalo-

return it to the abdominal cavity (irreducible hernia).

cele), is caused by a failure of part of the midgut to return to

Furthermore, after straining or coughing, a piece of

the abdominal cavity from the extraembryonic coelom dur-

bowel may be forced through the neck and its blood

ing fetal life. The hernial sac and its relationship to the um-

vessels may be compressed by the femoral ring, seriously

bilical cord are shown in CD Fig. 19-9.

impairing its blood supply

(strangulated hernia). A

Acquired infantile umbilical hernia is a small hernia

femoral hernia is a dangerous disease and should always be

that sometimes occurs in children and is caused by a weak-

treated surgically.

ness in the scar of the umbilicus in the linea alba (see CD

A femoral hernia can be summarized as follows:

Fig. 19-9). Most become smaller and disappear without

■ A protrusion of abdominal parietal peritoneum down

treatment as the abdominal cavity enlarges.

through the femoral canal forms the hernial sac.

Acquired umbilical hernia of adults is more correctly

■ It is more common in women than in men.

referred to as a paraumbilical hernia. The hernial sac does

■ The neck of the hernial sac lies below and lateral to the

not protrude through the umbilical scar, but through the

pubic tubercle.

linea alba in the region of the umbilicus (see CD Fig. 19-9).

■ The neck of the hernial sac lies at the femoral ring and at

Paraumbilical herniae gradually increase in size and hang

that point is related anteriorly to the inguinal ligament,

downward. The neck of the sac may be narrow, but the body

posteriorly to the pectineal ligament and the pubis, later-

of the sac often contains coils of small and large intestine

ally to the femoral vein, and medially to the sharp free

and omentum. Paraumbilical herniae are much more com-

edge of the lacunar ligament.

mon in women than in men.

linea alba

Wharton's jelly

peritoneum

amnion

umbilical cord

hernial sac

linea alba

weak scar of

rectus muscle

linea alba

umbilicus

CD Figure 19-9

A. Congenital

umbilical hernia. B. Infantile

umbilical hernia. C. Paraumbili-

cal hernia. D. Epigastric hernia.

E. Separation of recti abdominis.

320

Chapter 19

Epigastric Hernia

Internal Hernia

Epigastric hernia occurs through the widest part of the linea

Occasionally, a loop of intestine enters a peritoneal recess

alba, anywhere between the xiphoid process and the um-

(e.g., the lesser sac or the duodenal recesses) and becomes

bilicus. The hernia is usually small and starts off as a small

strangulated at the edges of the recess.

protrusion of extraperitoneal fat between the fibers of the

linea alba. During the following months or years the fat is

Abdominal Pain

forced farther through the linea alba and eventually drags

behind it a small peritoneal sac. The body of the sac often

Abdominal pain is one of the most important problems facing

contains a small piece of greater omentum. It is common in

the physician. This section provides an anatomic basis for the

middle-aged manual workers.

different forms of abdominal pain found in clinical practice.

Three distinct forms of pain exist: somatic, visceral, and

Separation of the Recti Abdominis

referred pain.

Separation of the recti abdominis occurs in elderly multi-

Somatic Abdominal Pain

parous women with weak abdominal muscles (see CD Fig.

19-9). In this condition, the aponeuroses forming the rectus

Somatic abdominal pain in the abdominal wall can arise

sheath become excessively stretched. When the patient

from the skin, fascia, muscles, and parietal peritoneum. It

coughs or strains, the recti separate widely, and a large

can be severe and precisely localized. When the origin is on

hernial sac, containing abdominal viscera, bulges forward

one side of the midline, the pain is also lateralized. The

between the medial margins of the recti. This can be

somatic pain impulses from the abdomen reach the central

corrected by wearing a suitable abdominal belt.

nervous system in the following segmental spinal nerves:

■ Central part of the diaphragm: phrenic nerve (C3, 4,

Incisional Hernia

and 5)

■ Peripheral part of the diaphragm: intercostal nerves

A postoperative incisional hernia is most likely to occur in

(T7-11)

patients in whom it was necessary to cut one of the segmen-

■ Anterior abdominal wall: thoracic nerves (T7-12) and

tal nerves supplying the muscles of the anterior abdominal

the first lumbar nerve

wall; postoperative wound infection with death (necrosis) of

■ Pelvic wall: obturator nerve (L2, 3, and 4)

the abdominal musculature is also a common cause. The

neck of the sac is usually large, and adhesion and strangula-

The inflamed parietal peritoneum is extremely sensitive,

tion of its contents are rare complications. In very obese

and because the full thickness of the abdominal wall is inner-

individuals the extent of the abdominal wall weakness is

vated by the same nerves, it is not surprising to find cutaneous

often difficult to assess.

hypersensitivity (hyperesthesia) and tenderness. Local re-

flexes involving the same nerves bring about a protective phe-

Hernia of the Linea Semilunaris

nomenon in which the abdominal muscles increase in tone.

This increased tone or rigidity, sometimes called guarding, is

(Spigelian Hernia)

an attempt to rest and localize the inflammatory process.

The uncommon hernia of the linea semilunaris occurs

Rebound tenderness occurs when the parietal peri-

through the aponeurosis of the transversus abdominis just

toneum is inflamed. Any movement of that inflamed peri-

lateral to the lateral edge of the rectus sheath. It usually

toneum, even when that movement is elicited by removing

occurs just below the level of the umbilicus. The neck of the

the examining hand from a site distant from the inflamed

sac is narrow, so that adhesion and strangulation of its

peritoneum, brings about tenderness.

contents are common complications.

Examples of acute, severe, localized pain originating in

the parietal peritoneum are seen in the later stages of ap-

Lumbar Hernia

pendicitis. Cutaneous hyperesthesia, tenderness, and mus-

cular spasm or rigidity occur in the lower right quadrant of

The lumbar hernia occurs through the lumbar triangle and

the anterior abdominal wall. A perforated peptic ulcer, in

is rare. The lumbar triangle (Petit’s triangle) is a weak area

which the parietal peritoneum is chemically irritated, pro-

in the posterior part of the abdominal wall. It is bounded

duces the same symptoms and signs but involves the right

anteriorly by the posterior margin of the external oblique

upper and lower quadrants.

muscle, posteriorly by the anterior border of the latissimus

dorsi muscle, and inferiorly by the iliac crest. The floor of

Visceral Abdominal Pain

the triangle is formed by the internal oblique and the

transversus abdominis muscles. The neck of the hernia is

Visceral abdominal pain arises in abdominal organs, visceral

usually large, and the incidence of strangulation is low.

peritoneum, and the mesenteries. The causes of visceral pain

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

321

include stretching of a viscus or mesentery, distension of a

cord. Both somatic and visceral structures can produce re-

hollow viscus, impaired blood supply (ischemia) to a viscus,

ferred pain.

and chemical damage (e.g., acid gastric juice) to a viscus or its

In the case of referred somatic pain, the possible expla-

covering peritoneum. Pain arising from an abdominal viscus

nation is that the nerve fibers from the diseased structure

is dull and poorly localized. Visceral pain is referred to the

and the area where the pain is felt ascend in the central

midline, probably because the viscera develop embryologi-

nervous system along a common pathway, and the cerebral

cally as midline structures and receive a bilateral nerve

cortex is incapable of distinguishing between the sites.

supply; many viscera later move laterally as development pro-

Examples of referred somatic pain follow. Pleurisy involving

ceeds, taking their nerve supply with them.

the lower part of the costal parietal pleura can give rise to

Colic is a form of visceral pain produced by the violent

referred pain in the abdomen because the lower parietal

contraction of smooth muscle; it is commonly caused by

pleura receives its sensory innervation from the lower five

luminal obstruction as in intestinal obstruction, in the

intercostal nerves, which also innervate the skin and mus-

passage of a gallstone in the biliary ducts, or in the passage

cles of the anterior abdominal wall.

of a stone in the ureters.

Visceral pain from the stomach is commonly referred to

Many visceral afferent fibers that enter the spinal cord

the epigastrium (CD Fig. 19-10). The afferent pain fibers

participate in reflex activity. Reflex sweating, salivation,

from the stomach ascend in company with the sympathetic

nausea, vomiting, and increased heart rate may accompany

nerves and pass through the celiac plexus and the greater

visceral pain.

splanchnic nerves. The sensory fibers enter the spinal cord

The sensations that arise in viscera reach the central

at segments T5-9 and give rise to referred pain in der-

nervous system in afferent nerves that accompany the

matomes T5-9 on the lower chest and abdominal walls.

sympathetic nerves and enter the spinal cord through

Visceral pain from the appendix (see CD Fig. 19-10),

the posterior roots. The significance of this pathway is

which is produced by distension of its lumen or spasm of its

better understood in the following discussion on referred

smooth muscle coat, travels in nerve fibers that accompany

visceral pain.

sympathetic nerves through the superior mesenteric plexus

and the lesser splanchnic nerve to the spinal cord (T10

segment). The vague referred pain is felt in the region of the

Referred Abdominal Pain

umbilicus (T10 dermatome). Later, if the inflammatory

Referred abdominal pain is the feeling of pain at a location

process involves the parietal peritoneum, the severe somatic

other than the site of origin of the stimulus but in an area

pain dominates the clinical picture and is localized

supplied by the same or adjacent segments of the spinal

precisely in the right lower quadrant.

gallbladder,

diaphragm

esophagus

heart

gallbladder

stomach

appendix

kidney

ureter

urinary bladder

CD Figure 19-10

Some important skin areas involved in referred pain.

322

Chapter 19

Visceral pain from the gallbladder, as occurs in pa-

extensive operations in which a large exposure is re-

tients with cholecystitis or gallstone colic, travels in nerve

quired, the incision can run the full length of the rectus

fibers that accompany sympathetic nerves. They pass

sheath. The anterior wall of the rectus sheath is exposed

through the celiac plexus and greater splanchnic nerves to

and incised about 1 in. (2.5 cm) from the midline. The

the spinal cord (segments T5-9). The vague referred pain

medial edge of the incision is dissected medially, free-

is felt in the dermatomes (T5-9) on the lower chest and

ing the anterior wall of the sheath from the tendinous

upper abdominal walls (see CD Fig. 19-10). If the inflam-

intersections of the rectus muscle. The rectus abdo-

matory process spreads to involve the parietal peritoneum

minis muscle is retracted laterally with its nerve supply

of the anterior abdominal wall or peripheral diaphragm,

intact, and the posterior wall of the sheath is exposed.

the severe somatic pain is felt in the right upper quadrant

The posterior wall is then incised, together with the

and through to the back below the inferior angle of the

fascia transversalis and the peritoneum. The wound is

scapula. Involvement of the central diaphragmatic parietal

closed in layers.

peritoneum, which is innervated by the phrenic nerve (C3,

■ Pararectus incision: The anterior wall of the rectus

4, and 5), can give rise to referred pain over the shoulder

sheath is incised medially and parallel to the lateral mar-

because the skin in this area is innervated by the supra-

gin of the rectus muscle. The rectus is freed and retracted

clavicular nerves (C3 and 4).

medially, exposing the segmental nerves entering its pos-

terior surface. If the opening into the abdominal cavity is

to be small, these nerves may be retracted upward and

Anterior Abdominal Nerve Block

downward. The posterior wall of the sheath is then in-

See CD Chapter 17.

cised, as in the paramedian incision. The great disadvan-

tage of this incision is that the opening is small, and any

longitudinal extension requires that one or more seg-

Surgical Incisions

mental nerves to the rectus abdominis be divided, with

resultant postoperative rectus muscle weakness.

The length and direction of surgical incisions through the

■ Midline incision: This incision is made through the

anterior abdominal wall to expose the underlying viscera are

linea alba. The fascia transversalis, the extraperitoneal

largely governed by the position and direction of the nerves

connective tissue, and the peritoneum are then incised.

of the abdominal wall, the direction of the muscle fibers,

It is easier to perform above the umbilicus because the

and the arrangement of the aponeuroses forming the rectus

linea alba is wider in that region. It is a rapid method of

sheath. Ideally, the incision should be made in the direction

gaining entrance to the abdomen and has the obvious

of the lines of cleavage in the skin so that a hairline scar is

advantage that it does not damage muscles or their nerve

produced. The surgeon usually has to compromise, placing

and blood supplies. Midline incision has the additional

the safety of the patient first and the cosmetic result second.

advantage that it may be converted into a T-shaped inci-

Incisions that necessitate the division of one of the main

sion for greater exposure. The anterior and posterior

segmental nerves lying within the abdominal wall result in

walls of the rectus sheath are then cut across transversely,

paralysis of part of the anterior abdominal musculature and

and the rectus muscle is retracted laterally.

a segment of the rectus abdominis. The consequent weak-

■ Transrectus incision: The technique of making and

ness of the abdominal musculature causes an unsightly

closing this incision is the same as that used in the para-

bulging forward of the abdominal wall and visceroptosis;

median incision, except that the rectus abdominis mus-

extreme cases may require a surgical belt for support.

cle is incised longitudinally and not retracted laterally

If the incision can be made in the line of the muscle

from the midline. This incision has the great disadvan-

fibers or aponeurotic fibers as each layer is traversed, on

tage of sectioning the nerve supply to that part of the

closing the incision the fibers fall back into position and

muscle that lies medial to the muscle incision.

function normally.

■ Transverse incision: This can be made above or below

Incisions through the rectus sheath are widely used,

the umbilicus and can be small or so large that it ex-

provided that the rectus abdominis muscle and its nerve

tends from flank to flank. It can be made through the

supply are kept intact. On closure of the incisions, the ante-

rectus sheath and the rectus abdominis muscles and

rior and posterior walls of the sheath are sutured separately,

through the oblique and transversus abdominis muscles

and the rectus muscle springs back into position between

laterally. It is rare to damage more than one segmental

the suture lines. The result is a very strong repair, with min-

nerve so that postoperative abdominal weakness is

imum interference with function.

minimal. The incision gives good exposure and is well

The following incisions are commonly used:

tolerated by the patient. Closure of the wound is made

■ Paramedian incision: This may be supraumbilical, for

in layers. It is unnecessary to suture the cut ends of the

exposure of the upper part of the abdominal cavity, or

rectus muscles, provided that the sheaths are carefully

infraumbilical, for the lower abdomen and pelvis. In

repaired.

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

323

■ Muscle splitting, or McBurney’s incision: This is

chiefly used for cecostomy and appendectomy. It gives a

Endoscopic Surgery

limited exposure only, and should any doubt arise about

Endoscopic surgery on the gallbladder, bile ducts, and ap-

the diagnosis, an infraumbilical right paramedian inci-

pendix has become a common procedure. It involves the

sion should be used instead. An oblique skin incision is

passage of the endoscope into the peritoneal cavity through

made in the right iliac region about 2 in. (5 cm) above

small incisions in the anterior abdominal wall. The

and medial to the anterior superior iliac spine. The ex-

anatomic structures traversed by the instruments are similar

ternal and internal oblique and transversus muscles are

to those enumerated for peritoneal lavage. Great care must

incised or split in the line of their fibers and retracted to

be taken to preserve the integrity of the segmental nerves as

expose the fascia transversalis and the peritoneum. The

they course down from the costal margin to supply the

latter are now incised and the abdominal cavity is

abdominal musculature.

opened. The incision is closed in layers, with no postop-

The advantages of this surgical technique are that the

erative weakness.

anatomic and physiologic features of the anterior abdominal

■ Abdominothoracic incision: This is used to expose the

wall are disrupted only minimally and, consequently, con-

lower end of the esophagus, as, for example, in esopha-

valescence is brief. The great disadvantages are that the

gogastric resection for carcinoma of this region. An upper

surgical field is small and the surgeon is limited in the extent

oblique or paramedian abdominal incision is extended

of the operation (CD Fig. 19-11).

upward and laterally into the seventh, eighth, or ninth

intercostal space, the costal arch is transected, and the

diaphragm is incised. Wide exposure of the upper ab-

Paracentesis of the Abdomen

domen and thorax is then obtained by the use of a rib-

Paracentesis of the abdomen may be necessary to withdraw

spreading retractor.

excessive collections of peritoneal fluid, as in ascites

On completion of the operation, the diaphragm is re-

secondary to cirrhosis of the liver or malignant ascites

paired with nonabsorbable sutures, the costal margin is

secondary to advanced ovarian cancer. Under a local anes-

reconstructed, and the abdominal and thoracic wounds

thetic, a needle or catheter is inserted through the anterior

are closed.

abdominal wall. The underlying coils of intestine are not

CD Figure 19-11

Inguinal canal anatomy as viewed during laparoscopic exploration of the

peritoneal cavity. A. The normal anatomy of the inguinal region from within the peritoneal

cavity. Black arrow indicates the closed deep inguinal ring; white arrow, the inferior epigas-

tric vessels. B. An indirect inguinal hernia. Curved black arrow indicates the mouth of the

hernial sac; white arrow, the inferior epigastric vessels. (Courtesy of N.S. Adzick.)

324

Chapter 19

costal margin

superior

epigastric

artery

umbilicus

inferior

epigastric

superior

artery

iliac spine

CD Figure 19-12

Common sites used in abdom-

deep circumflex

inal paracentesis. Note the position of the supe-

iliac artery

rior and inferior epigastric arteries in the rectus

sheath and the deep circumflex iliac arteries.

damaged because they are mobile and are pushed away by

Fig. 19-14). It is generally employed as a diagnostic tech-

the cannula.

nique in certain cases of blunt abdominal trauma. In non-

If the cannula is inserted in the midline (CD Figs. 19-

trauma situations, peritoneal lavage has been used to

12 and 19-13), it will pass through the following anatomic

confirm the diagnosis of acute pancreatitis and primary

structures: skin, superficial fascia, deep fascia (very thin),

peritonitis, to correct hypothermia, and to conduct dialysis.

linea alba (virtually bloodless), fascia transversalis, extraperi-

The patient is placed in the supine position and the uri-

toneal connective tissue (fatty), and parietal peritoneum.

nary bladder is emptied by catheterization. In small chil-

If the cannula is inserted in the flank (see CD Figs. 19-

dren the bladder is an abdominal organ; in adults, the full

12 and 19-13) lateral to the inferior epigastric artery and above

bladder may rise out of the pelvis and reach as high as the

the deep circumflex artery, it will pass through the following:

umbilicus. The stomach is emptied by a nasogastric tube

skin, superficial fascia, deep fascia (very thin), aponeurosis or

because a distended stomach may extend to the anterior ab-

muscle of external oblique, internal oblique muscle, trans-

dominal wall. The skin is anesthetized and a 2.25 in. (3-cm)

versus abdominis muscle, fascia transversalis, extraperitoneal

vertical incision is made.

connective tissue (fatty), and parietal peritoneum.

Midline Incision Technique

Anatomy of Peritoneal Lavage

The following anatomic structures are penetrated, in order,

Peritoneal lavage is used to sample the intraperitoneal space

to reach the parietal peritoneum (CD Fig. 19-14): skin, fatty

for evidence of damage to viscera and blood vessels (CD

layer of superficial fascia, membranous layer of superficial

rectus abdominis

in sheath

skin

supericial fascia

linea

external oblique

alba

internal oblique

transversus abdominis

fascia transversalis

coils of

extraperitoneal fat

small intestine

parietal peritoneum

peritoneal cavity

CD Figure 19-13

Paracentesis of the abdominal cavity in midline (1) and laterally (2).

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

325

costal margin

superior epigastric

artery

umbilicus

inferior epigastric

artery

anterior superior

iliac spine

fatty layer of

rectus abdominis

superficial fascia

muscle

catheter

skin

membranous layer of

linea alba

superficial fascia

fascia transversalis

parietal

extraperitoneal fat

peritoneum

retracted rectus

anterior wall of

abdominis muscle

rectus sheath

umbilicus

inferior epigastric artery

linea alba

fascia transversalis

peritoneum

posterior wall

extraperitoneal fat

of rectus sheath

CD Figure 19-14

Peritoneal lavage. A. The two common sites used in this procedure. Note

the positions of the superior and inferior epigastric arteries in the rectus sheath. B. Cross

section of the anterior abdominal wall in the midline. Note the structures pierced by the

catheter. C. Cross section of the anterior abdominal wall just lateral to the umbilicus. Note

the structures pierced by the catheter. The rectus muscle has been retracted laterally.

fascia, thin layer of deep fascia, linea alba, fascia transver-

fatty layer of superficial fascia, membranous layer of superfi-

salis, extraperitoneal fat, and parietal peritoneum.

cial fascia, thin layer of deep fascia, anterior wall of rectus

sheath, the rectus abdominis muscle is retracted, posterior

wall of the rectus sheath, fascia transversalis, extraperitoneal

Paraumbilical Incision Technique

fat, and parietal peritoneum.

The following anatomic structures are penetrated, in order,

It is important that all the small blood vessels in the

to reach the parietal peritoneum (see CD Fig. 19-14): skin,

superficial fascia be secured, because bleeding into the

326

Chapter 19

structures present in the normal umbilicus

umbilicus

patent urachus

umbilical vein

bladder

midgut loop

site of future

umbilicus

umbilical cord

vitelline duct

allantois

urinary bladder

fecal fistula

fibrous band

Meckel's diverticulum

CD Figure 19-15

Umbilicus and

vitelline cyst

fibrous band and a Meckel's diverticulum

some common congenital defects.

peritoneal cavity might produce a false-positive result.

■ Perforation of a full bladder

These vessels are the terminal branches of the superficial

■ Wound infection

and deep epigastric arteries and veins.

Abdominal Stab Wounds

Anatomy of the Complications of

Abdominal stab wounds may or may not penetrate the

Peritoneal Lavage

parietal peritoneum and violate the peritoneal cavity, and

■

In the midline technique, the incision or trochar may

consequently may or may not significantly damage the

miss the linea alba and enter the rectus sheath and

abdominal viscera. The structures in the various layers

traverse the vascular rectus abdominis muscle and en-

through which an abdominal stab wound penetrates will

counter branches of the epigastric vessels. Bleeding from

depend on the anatomic location.

this source could produce a false-positive result.

Lateral to the rectus sheath (see CD Fig. 19-13) are the

■

Perforation of the gut by the scalpel or trocar

following: skin, fatty layer of superficial fascia, membranous

■

Perforation of the mesenteric blood vessels or vessels on

layer of superficial fascia, thin layer of deep fascia, external

the posterior abdominal wall or pelvic walls

oblique muscle or aponeurosis, internal oblique muscle or

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

327

aponeurosis, transversus abdominis muscle or aponeurosis,

lointestinal duct can result in an umbilical fecal fistula (see

fascia transversalis, extraperitoneal connective tissue (often

CD Fig. 19-15). If the duct remains as a fibrous band, a loop

fatty), and parietal peritoneum.

of bowel can become wrapped around it, causing intestinal

Anterior to the rectus sheath (see CD. Fig. 19-13) are

obstruction (see CD Fig. 19-15).

the following: skin; fatty layer of superficial fascia; membra-

Meckel’s diverticulum is a congenital anomaly repre-

nous layer of superficial fascia; thin layer of deep fascia;

senting a persistent portion of the vitellointestinal duct. It

anterior wall of rectus sheath; rectus abdominis muscle,

occurs in 2% of patients (see CD Fig. 19-15), is located

with segmental nerves and epigastric vessels lying behind

about 2 ft (61 cm) from the ileocolic junction, and is about

the muscle; posterior wall of rectus sheath; fascia transver-

2 in. (5 cm) long. It can become ulcerated or cause intesti-

salis; extraperitoneal connective tissue (often fatty); and

nal obstruction.

parietal peritoneum.

In the midline (see CD Fig. 19-13) are the following:

Umbilical Vessel Catheterization

skin, fatty layer of superficial fascia, membranous layer of

superficial fascia, thin layer of deep fascia, linea alba, fascia

The umbilical cord is surrounded by the fetal membrane,

transversalis, extraperitoneal connective tissue (often fatty),

amnion, and contains Wharton’s jelly. Embedded in this

and parietal peritoneum.

jelly are the remains of the vitellointestinal duct and the

In a stab wound, peritoneal lavage may be used to

allantois, and the single umbilical vein and the two

determine whether any damage to viscera or vasculature has

umbilical arteries (CD Fig. 19-16). The vein is a larger thin-

occurred.

walled vessel and is located at the 12 o’clock position when

facing the umbilicus; the two arteries, which lie adjacent to

one another and are located at the 4 and 8 o’clock positions

Abdominal Gunshot Wounds

when facing the umbilicus, are smaller and thick walled.

Gunshot wounds are much more serious than stab wounds;

in most patients, the peritoneal cavity has been entered, and

Indications for Umbilical Artery

significant visceral damage has ensued.

Catheterization

1. Administration of fluids or blood for resuscitation

Tying the Umbilical Cord

purposes

At birth, the cord is tied off close to the umbilicus. About 2

2. Arterial blood gas and blood pressure monitoring. The

in. (5 cm) of cord is left between the umbilicus and the lig-

umbilical arteries may be cannulated most easily dur-

ature, since a piece of intestine may be present as an um-

ing the first few hours after birth, but they may be

bilical hernia in the remains of the extraembryonic coelom.

cannulated up to 6 days after delivery.

After application of the ligature, the umbilical vessels con-

strict and thrombose. Later, the stump of the cord is shed

Anatomy of Procedure

and the umbilical scar tissue becomes retracted and as-

One of the small, thick-walled arteries is identified in the

sumes the shape of the umbilicus, or navel.

Wharton’s jelly in the umbilical stump. Because the umbil-

ical arteries are branches of the internal iliac arteries in the

Patent Urachus

pelvis, the catheter is introduced and advanced slowly in the

direction of the feet. The catheter can be inserted for about

The urachus is the remains of the allantois of the fetus and

2.75 in. (7 cm) in a premature infant and 4.75 in. (12 cm)

normally persists as a fibrous cord that runs from the apex

in a full-term infant. The course of the catheter can be con-

of the bladder to the umbilicus. Occasionally, the cavity of

firmed on a radiograph and is as follows: (1) umbilical artery

the allantois persists, and urine passes from the bladder

(directed downward into the pelvis), (2) internal iliac artery

through the umbilicus. In newborns, it usually reveals

(acute turn into this artery), and (3) common iliac artery and

itself when a congenital urethral obstruction is present.

the aorta.

More often, it remains undiscovered until old age, when

enlargement of the prostate may obstruct the urethra (see

Anatomy of Complications

CD Fig. 19-15).

■ Catheter perforates arterial wall at a point where the

artery turns downward toward the pelvis at the anterior

Vitellointestinal Duct

abdominal wall.

The vitelline duct in the early embryo connects the devel-

■ Catheter enters the thin-walled wider umbilical vein

oping gut to the yolk sac. Normally, as development

instead of the thick-walled smaller artery.

proceeds, the duct is obliterated, severs its connection with

■ Catheter enters the thin-walled persistent urachus (urine

the small intestine, and disappears. Persistence of the vitel-

is returned into catheter).

328

Chapter 19

inferior vena cava

ductus venosus

liver

branch of portal vein

at porta hepatis

umbilical vein

single umbilical vein

note direction of bend

of blood vessels

abdominal

aorta

catheters

common

iliac artery

two umbilical

arteries

stump of

external

umbilical cord

iliac artery

left internal

iliac artery

left umbilical

artery

right umbilical

artery

CD Figure 19-16

Catheterization of the umbilical blood vessels. Arrangement of the single

umbilical vein and the two umbilical arteries in the umbilical cord and the paths taken by the

catheter in the umbilical vein and the umbilical artery.

■ Vasospasm of the umbilical and the iliac arteries causing

2. Exchange transfusions; the umbilical vein may be

blanching of the leg

cannulated up to 7 days after birth.

■ Perforation of arteries distal to the umbilical artery, for

Anatomy of Procedure

example, the iliac arteries or even the aorta

■ Other complications include thrombosis, emboli, and

The umbilical vein is located in the cord stump at the 12 o’-

infection of the umbilical stump.

clock position (see CD Fig. 19-16), as described previously,

and is easily recognized because of its thin wall and large

Indications for Umbilical Vein

lumen. The catheter is advanced gently and is directed

Catheterization

toward the head, because the vein runs in the free margin of

the falciform ligament to join the ductus venosus at the

1. Administration of fluids or blood for resuscitation

porta hepatis. The catheter may be advanced about 2 in.

purposes

(5 cm) in a full-term infant. The course of the catheter may

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

329

be confirmed by radiography and is as follows: (1) the um-

matic peritoneum.) The skin of the shoulder is supplied by

bilical vein, (2) the ductus venosus, and (3) the inferior vena

the supraclavicular nerves (C3 and 4), which have the

cava (4 to 4.75 in.; 10 to 12 cm).

same segmental origin as the phrenic nerve, which sup-

plies the peritoneum in the center of the undersurface of

Anatomy of Complications

the diaphragm.

To avoid the accumulation of infected fluid in the sub-

■ Catheter may perforate the venous wall. This is most

phrenic spaces and to delay the absorption of toxins from in-

likely to occur where the vein turns cranially at the

traperitoneal infections, it is common nursing practice to sit

abdominal wall.

a patient up in bed with the back at an angle of 45°. In this

■ Other complications include liver necrosis, hemorrhage,

position, the infected peritoneal fluid tends to gravitate

and infection.

downward into the pelvic cavity, where the rate of toxin ab-

sorption is slow (see CD Fig. 19-17).

PERITONEUM AND

Greater Omentum and the

PERITONEAL

Localization of Infection

The greater omentum is often referred to by the surgeons as

CAVITY

the abdominal policeman. The lower and the right and left

margins are free, and it moves about the peritoneal cavity in

response to the peristaltic movements of the neighboring

Movement of Peritoneal Fluid

gut. In the first 2 years of life it is poorly developed and thus

The peritoneal cavity is divided into an upper part within

is less protective in a young child. Later, however, in an

the abdomen and a lower part in the pelvis. The abdominal

acutely inflamed appendix, for example, the inflammatory

part is further subdivided by the many peritoneal reflections

exudate causes the omentum to adhere to the appendix and

into important recesses and spaces, which, in turn, are con-

wrap itself around the infected organ (CD Fig. 19-18). By

tinued into the paracolic gutters (CD Fig. 19-17). The at-

this means, the infection is often localized to a small area of

tachment of the transverse mesocolon and the mesentery of

the peritoneal cavity, thus saving the patient from a serious

the small intestine to the posterior abdominal wall provides

diffuse peritonitis.

natural peritoneal barriers that may hinder the movement of

infected peritoneal fluid from the upper part to the lower

Greater Omentum as a Hernial Plug

part of the peritoneal cavity.

It is interesting to note that when the patient is in the

The greater omentum has been found to plug the neck of

supine position the right subphrenic peritoneal space and

a hernial sac and prevent the entrance of coils of small

the pelvic cavity are the lowest areas of the peritoneal cavity

intestine.

and the region of the pelvic brim is the highest area (see CD

Fig. 19-17).

Greater Omentum in Surgery

Surgeons sometimes use the omentum to buttress an

Peritoneal Infection

intestinal anastomosis or in the closure of a perforated

Infection may gain entrance to the peritoneal cavity through

gastric or duodenal ulcer.

several routes: from the interior of the gastrointestinal tract

and gallbladder, through the anterior abdominal wall, via

Torsion of the Greater Omentum

the uterine tubes in females (gonococcal peritonitis in

adults and pneumococcal peritonitis in children occur

The greater omentum may undergo torsion, and if

through this route), and from the blood.

extensive, the blood supply to a part of it may be cut off,

Collection of infected peritoneal fluid in one of the

causing necrosis.

subphrenic spaces is often accompanied by infection of

the pleural cavity. It is common to find a localized

Ascites

empyema in a patient with a subphrenic abscess. It is be-

lieved that the infection spreads from the peritoneum to

Ascites is essentially an excessive accumulation of peritoneal

the pleura via the diaphragmatic lymph vessels. A patient

fluid within the peritoneal cavity. Ascites can occur

with a subphrenic abscess may complain of pain over the

secondary to hepatic cirrhosis (portal venous congestion),

shoulder. (This also holds true for collections of blood

malignant disease (e.g., cancer of the ovary), or congestive

under the diaphragm, which irritate the parietal diaphrag-

heart failure (systemic venous congestion). In a thin patient,

330

Chapter 19

anterior and posterior

anterior left subphrenic space

right subphrenic spaces

phrenicocolic

ligament

right

paracolic

gutter

left

paracolic gutter

pelvic brim

right posterior subphrenic space

pelvic cavity

CD Figure 19-17

Direction of flow of the peritoneal fluid. 1. Normal flow upward to the

subphrenic spaces. 2. Flow of inflammatory exudate in peritonitis. 3. The two sites where

inflammatory exudate tends to collect when the patient is nursed in the supine position.

4. Accumulation of inflammatory exudate in the pelvis when the patient is nursed in the

inclined position.

as much as 1,500 mL has to accumulate before ascites can

first lumbar nerve. Abdominal pain originating from the

be recognized clinically. In obese individuals, a far greater

parietal peritoneum is therefore of the somatic type, can be

amount has to collect before it can be detected.

precisely localized, and is usually severe (see Abdominal

Pain).

An inflamed parietal peritoneum is extremely sensi-

Peritoneal Pain

tive to stretching. This fact is made use of clinically in

diagnosing peritonitis. Pressure is applied to the ab-

From the Parietal Peritoneum

dominal wall with a single finger over the site of the in-

The parietal peritoneum lining the anterior abdominal

flammation. The pressure is then removed by suddenly

wall is supplied by the lower six thoracic nerves and the

withdrawing the finger. The abdominal wall rebounds,

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

331

CD Figure 19-18

A. The normal greater

omentum. B. The greater omentum

wrapped around an inflamed appendix.

C. Greater omentum adherent to the

base of a gastric ulcer. One important

function of the greater omentum is to

attempt to limit the spread of intraperi-

toneal infections.

resulting in extreme local pain, which is known as re-

the same as peritoneal lavage. The products of metabolism,

bound tenderness.

such as urea, diffuse through the peritoneal lining cells from

It should always be remembered that the parietal peri-

the blood vessels into the dialysate and are removed from

toneum in the pelvis is innervated by the obturator nerve

the patient.

and can be palpated by means of a rectal or vaginal exami-

nation. An inflamed appendix may hang down into the

Internal Abdominal Hernia

pelvis and irritate the parietal peritoneum. A pelvic exami-

nation can detect extreme tenderness of the parietal peri-

Occasionally, a loop of intestine enters a peritoneal pouch

toneum on the right side.

or recess (e.g., the lesser sac or the duodenal recesses) and

becomes strangulated at the edges of the recess. Remember

From the Visceral Peritoneum

that important structures form the boundaries of the

entrance into the lesser sac and that the inferior mesenteric

The visceral peritoneum, including the mesenteries, is in-

vein often lies in the anterior wall of the paraduodenal

nervated by autonomic afferent nerves. Stretch caused by

recess.

overdistension of a viscus or pulling on a mesentery gives

rise to the sensation of pain. The sites of origin of visceral

pain are shown in CD Fig. 19-10.

Because the gastrointestinal tract arises embryologically

RETROPERITONEAL

as a midline structure and receives a bilateral nerve

supply, pain is referred to the midline. Pain arising from an

SPACE

abdominal viscus is dull and poorly localized (see Abdomi-

nal Pain).

Trauma to Organs in the

Peritoneal Dialysis

Retroperitoneal Space

Because the peritoneum is a semipermeable membrane, it

allows rapid bidirectional transfer of substances across itself.

Palpation of the anterior abdominal wall in the lumbar

Because the surface area of the peritoneum is enormous,

and iliac regions may give rise to signs indicative of peri-

this transfer property has been made use of in patients with

toneal irritation (the peritoneum forms the anterior bound-

acute renal insufficiency. The efficiency of this method is

ary of the space; see text Fig.

19-30). In other words,

only a fraction of that achieved by hemodialysis.

tenderness and muscle spasm (rigidity) may be present.

A watery solution, the dialysate, is introduced through a

Palpation of the back in the interval between the twelfth

catheter through a small midline incision through the ante-

rib and the vertebral column may reveal tenderness sug-

rior abdominal wall below the umbilicus. The technique is

gestive of kidney disease.

332

Chapter 19

Abdominal radiographs may reveal air in the extraperi-

portal hypertension develops, resulting in dilatation and

toneal tissues, indicating perforation of a viscus (e.g., as-

varicosity of the portal-systemic anastomoses. Varicosed

cending or descending colon). Computed tomography

esophageal veins may rupture, causing severe vomiting of

scans can often accurately define the extent of the injury to

blood (hematemesis).

the extraperitoneal organs.

Anatomy of the Insertion of the

Sengstaken-Blakemore Balloon

Abscess Formation

for Esophageal Hemorrhage

Infection originating in retroperitoneal organs, such as the

kidneys, lymph nodes, and retrocecal appendix, may extend

The Sengstaken-Blakemore balloon is used for the control

widely into the retroperitoneal space.

of massive esophageal hemorrhage from esophageal varices.

A gastric balloon anchors the tube against the esophageal--

gastric junction. An esophageal balloon occludes the

Leaking Aortic Aneurysm

esophageal varices by counterpressure. The tube is inserted

The blood may first be confined to the retroperitoneal space

through the nose or by using the oral route.

before rupturing into the peritoneal cavity.

The lubricated tube is passed down into the stom-

ach, and the gastric balloon is inflated. In the average

adult the distance between the external orifices of the

nose and the stomach is 17.2 in. (44 cm), and the dis-

THE ALIMENTARY

tance between the incisor teeth and the stomach is 16 in.

(41 cm).

TRACT

Anatomy of the Complications

■ Difficulty in passing the tube through the nose

Esophagus

■ Damage to the esophagus from overinflation of the

esophageal tube

Narrow Areas of the Esophageal

■ Pressure on neighboring mediastinal structures as

Lumen

the esophagus is expanded by the balloon within its

lumen

The esophagus is narrowed at three sites: at the beginning,

■ Persistent hiccups caused by irritation of the diaphragm

behind the cricoid cartilage of the larynx; where the left

by the distended esophagus and irritation of the stomach

bronchus and the arch of the aorta cross the front of

by the blood

the esophagus; and where the esophagus enters the stomach.

These three sites may offer resistance to the passage of a tube

down the esophagus into the stomach (CD Fig. 19-19).

Stomach

Achalasia of the Cardia

Nausea

(Esophagogastric Junction)

Nausea is a very common symptom and may occur as the

The cause of achalasia is unknown, but it is associated with

result of drugs, such as anesthetics and apomorphine,

a degeneration of the parasympathetic plexus (Auerbach’s

pregnancy, motion sickness, and chemotherapy. It often

plexus) in the wall of the esophagus. The primary site of the

precedes vomiting. Nausea is the recognition that the vom-

disorder may be in the innervation of the cardioesophageal

iting center in the medulla oblongata is being stimulated by

sphincter by the vagus nerves. Dysphagia (difficulty in swal-

afferent impulses derived from the stomach and intestines,

lowing) and regurgitation are common symptoms that are

or in the case of motion sickness, impulses derived from the

later accompanied by proximal dilatation and distal narrow-

semicircular canals of the inner ear. It is well known that

ing of the esophagus.

certain offensive odors can initiate nausea and vomiting and

this is presumably due to the direct stimulation of the

Bleeding Esophageal Varices

vomiting center by nerve impulses from the cerebral cortex.

At the lower third of the esophagus is an important

Vomiting

portal-systemic venous anastomosis. Here, the esophageal

tributaries of the left gastric vein (which drains into the por-

Vomiting is the process by which the stomach and upper

tal vein) anastomose with the esophageal tributaries of the

intestinal tract empties itself of its contents. It is caused by

azygos veins (systemic veins). Should the portal vein be-

the presence in the upper gastrointestinal tract of some sub-

come obstructed, as, for example, in cirrhosis of the liver,

stance, chemical, bacterial, or viral, that excessively irritates

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

333

external naris

incisor tooth

cervical constriction

7.2 in. (18 cm)

6 in. (15 cm)

bronchoaortic constriction

11.2 in. (28 cm)

10 in. (25 cm)

tube

diaphragmatic constriction

17.2 in. (44 cm)

16 in. (41 cm)

CD Figure 19-19

The approxi-

mate respective distances from

the incisor teeth (black) and the

nostrils (red) to the normal three

duodenum

constrictions of the esophagus.

23.2-27.2 in. (59-69 cm)

To assist in the passage of a

22-26 in. (56-66 cm)

tube to the duodenum, the dis-

tances to the first part of the

duodenum are also included.

the gut wall and results in overdistension of the upper part

the expulsive phase a deep breath is taken and the larynx is

of the gastrointestinal tract. The act of vomiting is preceded

raised to close the inlet; the nasopharynx is also closed by the

by excessive salivation (presumably an attempt to dilute the

raising of the soft palate. This is quickly followed by the mas-

irritant). This is followed by stimulation of the sympathetic

sive coordinated contraction of the diaphragm and abdomi-

system resulting in dilatation of the pupils, an increase in

nal muscles exerting intense squeezing pressure on the

the heart rate, facial pallor (due to vasoconstriction of the

stomach. Suddenly the gastroesophageal sphincter relaxes

blood vessels), cold sweating, fatigue, and drowsiness. Nerve

and the stomach contents are ejected through the esopha-

impulses travel to the vomiting center from the gastroin-

gus and the mouth. The act of vomiting usually makes the

testinal tract via the vagi and sympathetic afferent fibers.

patient feel better, but it may be repeated if the irritant has

Once the nerve stimulation of the vomiting center reaches

not been expelled or the drug action persists.

a certain level, the vomiting act takes place.

The act of vomiting has two phases. The retching phase

Trauma to the Stomach

is nonproductive and involves one or two rounds of the

coordinated contraction of the diaphragm, the anterior

Apart from its attachment to the esophagus at the cardiac

abdominal wall muscles, and the muscles of inspiration. In

orifice and its continuity with the duodenum at the

334

Chapter 19

Gastric Pain

pylorus, the stomach is relatively mobile. It is protected on

the left by the lower part of the rib cage. These factors

The sensation of pain in the stomach is caused by the stretch-

greatly protect the stomach from blunt trauma to the

ing or spasmodic contraction of the smooth muscle in its walls

abdomen. However, its large size makes it vulnerable to

and is referred to the epigastrium. It is believed that the pain-

gunshot wounds.

transmitting fibers leave the stomach in company with the

sympathetic nerves. They pass through the celiac ganglia and

Gastric Ulcer

reach the spinal cord via the greater splanchnic nerves.

The mucous membrane of the body of the stomach and, to

Cancer of the Stomach

a lesser extent, that of the fundus produce acid and pepsin.

The secretion of the antrum and pyloric canal is mucous

Because the lymphatic vessels of the mucous membrane

and weakly alkaline (CD Fig. 19-20). The secretion of acid

and submucosa of the stomach are in continuity, it is possi-

and pepsin is controlled by two mechanisms: nervous and

ble for cancer cells to travel to different parts of the stomach,

hormonal. The vagus nerves are responsible for the nervous

some distance away from the primary site. Cancer cells also

control, and the hormone gastrin, produced by the antral

often pass through or bypass the local lymph nodes and are

mucosa, is responsible for the hormonal control. In the

held up in the regional nodes. For these reasons, malignant

surgical treatment of chronic gastric and duodenal ulcers,

disease of the stomach is treated by total gastrectomy, which

attempts are made to reduce the amount of acid secretion by

includes the removal of the lower end of the esophagus and

sectioning the vagus nerves (vagotomy) and by removing

the first part of the duodenum; the spleen and the gastros-

the gastrin-bearing area of mucosa, the antrum (partial

plenic and splenicorenal ligaments and their associated

gastrectomy).

lymph nodes; the splenic vessels; the tail and body of the

Gastric ulcers occur in the alkaline-producing mucosa

pancreas and their associated nodes; the nodes along

of the stomach, usually on or close to the lesser curvature.

the lesser curvature of the stomach; and the nodes along the

A chronic ulcer invades the muscular coats and, in time,

greater curvature, along with the greater omentum. This

involves the peritoneum so that the stomach adheres to

radical operation is a desperate attempt to remove the stom-

neighboring structures. An ulcer situated on the posterior

ach en bloc and, with it, its lymphatic field. The continuity

wall of the stomach may perforate into the lesser sac or be-

of the gut is restored by anastomosing the esophagus with

come adherent to the pancreas. Erosion of the pancreas

the jejunum.

produces pain referred to the back. The splenic artery runs

along the upper border of the pancreas, and erosion of this

Gastroscopy

artery may produce fatal hemorrhage. A penetrating ulcer

of the anterior stomach wall may result in the escape of

Gastroscopy is the viewing of the mucous membrane of the

stomach contents into the greater sac, producing diffuse

stomach through an illuminated tube fitted with a lens

peritonitis. The anterior stomach wall may, however, ad-

system. The patient is anesthetized and the gastroscope is

here to the liver, and the chronic ulcer may penetrate the

passed into the stomach, which is then inflated with air.

liver substance.

With a flexible fiberoptic instrument, direct visualization of

different parts of the gastric mucous membrane is possible.

It is also possible to perform a mucosal biopsy through a

gastroscope.

Nasogastric Intubation

Nasogastric intubation is a common procedure and is per-

formed to empty the stomach, to decompress the stomach in

cases of intestinal obstruction, or before operations on the

gastrointestinal tract; it may also be performed to obtain a

sample of gastric juice for biochemical analysis.

1. The patient is placed in the semiupright position or left

lateral position to avoid aspiration.

2. The well-lubricated tube is inserted through the wider

nostril and is directed backward along the nasal floor.

3. Once the tube has passed the soft palate and entered

CD Figure 19-20

Areas of the stomach that produce acid

the oral pharynx, decreased resistance is felt, and the

and pepsin (stippled) and alkali and gastrin (diagonal lines).

conscious patient will feel like gagging.

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

335

4. Some important distances in the adult may be useful.

the escaping fluid into the right lateral paracolic gutter and

From the nostril

(external nares) to the cardiac

thus down to the right iliac fossa. The differential diagnosis

orifice of the stomach is about 17.2 in. (44 cm), and

between a perforated duodenal ulcer and a perforated

from the cardiac orifice to the pylorus of the stomach is

appendix may be difficult.

4.8 to 5.6 in. (12 to 14 cm). The curved course taken by

An ulcer of the posterior wall of the first part of the

the tube from the cardiac orifice to the pylorus is

duodenum may penetrate the wall and erode the relatively

usually longer, 6.0 to 10.0 in. (15 to 25 cm) (see CD

large gastroduodenal artery, causing a severe hemorrhage.

Fig. 19-19).

The gastroduodenal artery is a branch of the hepatic

artery, a branch of the celiac trunk (see text Fig. 19-38).

Anatomic Structures that May Impede the

Passage of the Nasogastric Tube

Duodenal Recesses

■ Deviated nasal septum, making the passage of the tube

The importance of the duodenal recesses and the occur-

difficult on the narrower side

rence of herniae of the intestine were already alluded to in

■ Three sites of esophageal narrowing may offer resistance

this chapter.

to the nasogastric tube—at the beginning of the esopha-

gus behind the cricoid cartilage (7.2 in.; 18 cm), where

Important Duodenal Relations

the left bronchus and the arch of the aorta cross the front

The relation to the duodenum of the gallbladder, the trans-

of the esophagus (11.2 in.; 28 cm), and where the esoph-

verse colon, and the right kidney should be remembered.

agus enters the stomach (17.2 in.; 44 cm). The upper

Cases have been reported in which a large gallstone

esophageal narrowing may be overcome by gently grasp-

ulcerated through the gallbladder wall into the duodenum.

ing the wings of the thyroid cartilage and pulling the

Operations on the colon and right kidney have resulted in

larynx forward. This maneuver opens the normally

damage to the duodenum.

collapsed esophagus and permits the tube to pass down

without further delay.

Jejunum and Ileum

Anatomy of Complications

Trauma to the Jejunum and Ileum

■ The nasogastric tube enters the larynx instead of the

esophagus.

Because of its extent and position, the small intestine is

■ Rough insertion of the tube into the nose will cause nasal

commonly damaged by trauma. The extreme mobility and

bleeding from the mucous membrane.

elasticity permit the coils to move freely over one another in

■ Penetration of the wall of the esophagus or stomach.

instances of blunt trauma. Small, penetrating injuries may

Always aspirate tube for gastric contents to confirm

self-seal as a result of the mucosa plugging up the hole and the

successful entrance into stomach.

contraction of the smooth muscle wall. Material from large

wounds leaks freely into the peritoneal cavity. The presence

of the vertebral column and the prominent anterior margin of

Duodenum

the first sacral vertebra may provide a firm background for

intestinal crushing in cases of midline crush injuries.

Trauma to the Duodenum

Small-bowel contents have nearly a neutral pH and

produce only slight chemical irritation to the peritoneum.

Apart from the first inch, the duodenum is rigidly fixed to

the posterior abdominal wall by peritoneum and therefore

Recognition of the Jejunum and Ileum

cannot move away from crush injuries. In severe crush

injuries to the anterior abdominal wall, the third part of the

A physician should be able to distinguish between the large

duodenum may be severely crushed or torn against the third

and small intestine. He or she may be called on to examine

lumbar vertebra.

a case of postoperative burst abdomen, where coils of gut are

lying free in the bed. The macroscopic differences are de-

Duodenal Ulcer

scribed on text page 738.

As the stomach empties its contents into the duodenum, the

Tumors and Cysts of the Mesentery of

acid chyme is squirted against the anterolateral wall of

the Small Intestine

the first part of the duodenum. This is thought to be an

important factor in the production of a duodenal ulcer at

The line of attachment of the small intestine to the posterior

this site. An ulcer of the anterior wall of the first inch of the

abdominal wall should be remembered. It extends from a

duodenum may perforate into the upper part of the greater

point just to the left of the midline about 2 in. (5 cm) below

sac, above the transverse colon. The transverse colon directs

the transpyloric plane (L1) downward to the right iliac fossa.

336

Chapter 19

Predisposition of the Appendix

A tumor or cyst of the mesentery, when palpated through

the anterior abdominal wall, is more mobile in a direction

to Infection

at right angles to the line of attachment than along the line

of attachment.

The following factors contribute to the appendix’s predilec-

tion to infection:

Pain Fibers from the Jejunum

■ It is a long, narrow, blind-ended tube, which encourages

and Ileum

stasis of large-bowel contents.

■ It has a large amount of lymphoid tissue in its wall.

Pain fibers traverse the superior mesenteric sympathetic

■ The lumen has a tendency to become obstructed by

plexus and pass to the spinal cord via the splanchnic nerves.

hardened intestinal contents (enteroliths), which leads to

Referred pain from this segment of the gastrointestinal tract

further stagnation of its contents.

is felt in the dermatomes supplied by the ninth, tenth, and

eleventh thoracic nerves. Strangulation of a coil of small

Predisposition of the Appendix

intestine in an inguinal hernia first gives rise to pain in the

to Perforation

region of the umbilicus. Only later, when the parietal

peritoneum of the hernial sac becomes inflamed, does the

The appendix is supplied by a long small artery that does not

pain become more intense and localized to the inguinal

anastomose with other arteries. The blind end of the appen-

region (see Abdominal Pain).

dix is supplied by the terminal branches of the appendicular

artery. Inflammatory edema of the appendicular wall com-

Mesenteric Arterial Occlusion

presses the blood supply to the appendix and often leads to

thrombosis of the appendicular artery. These conditions

The superior mesenteric artery, a branch of the abdominal

commonly result in necrosis or gangrene of the appendicu-

aorta, supplies an extensive territory of the gut, from halfway

lar wall, with perforation.

down the second part of the duodenum to the left colic

Perforation of the appendix or transmigration of bacte-

flexure. Occlusion of the artery or one of its branches results

ria through the inflamed appendicular wall results in infec-

in death of all or part of this segment of the gut. The occlu-

tion of the peritoneum of the greater sac. The part that the

sion may occur as the result of an embolus, a thrombus, an

greater omentum may play in arresting the spread of the

aortic dissection, or an abdominal aneurysm.

peritoneal infection is described on CD page 329.

Mesenteric Vein Thrombosis

Pain of Appendicitis

The superior mesenteric vein, which drains the same area of

Visceral pain in the appendix is produced by distention of its

the gut supplied by the superior mesenteric artery, may

lumen or spasm of its muscle. The afferent pain fibers enter

undergo thrombosis after stasis of the venous bed. Cirrhosis

the spinal cord at the level of the tenth thoracic segment,

of the liver with portal hypertension may predispose to this

and a vague referred pain is felt in the region of the

condition.

umbilicus. Later, the pain shifts to where the inflamed

appendix irritates the parietal peritoneum. Here the pain is

Appendix

precise, severe, and localized.

Variability of Position of the Appendix

Colon and Cecum

The inconstancy of the position of the appendix should be

Colonoscopy

borne in mind when attempting to diagnose appendicitis.

A retrocecal appendix, for example, may lie behind a

Since colorectal cancer is a leading cause of death in the

cecum distended with gas, and thus it may be difficult to

Western world, colonoscopy is now being extensively used

elicit tenderness on palpation in the right iliac region.

for early detection of malignant tumors. In this procedure,

Irritation of the psoas muscle, conversely, may cause the

the mucous membrane of the colon can be directly visual-

patient to keep the right hip joint flexed.

ized through an elongated flexible tube, or endoscope.

Following a thorough washing out of the large bowel, the

Pelvic Appendix

patient is sedated, and the tube is gently inserted into the

An appendix hanging down in the pelvis may result in

anal canal. The interior of the large bowel can be observed

absent abdominal tenderness in the right lower quadrant,

from the anus to the cecum (CD Fig. 19-21). Photographs

but deep tenderness may be experienced just above the

of suspicious areas, such as polyps, can be taken and biopsy

symphysis pubis. Rectal or vaginal examination may reveal

specimens can be removed for pathologic examination.

tenderness of the peritoneum in the pelvis on the right side.

Although a relatively expensive procedure, it provides a

338

Chapter 19

Cecostomy and Colostomy

more complete screening examination for colorectal cancer

than combined fecal occult blood testing and the examina-

Because of the anatomic mobility of the cecum, transverse

tion of the distal colon with sigmoidoscopy.

colon, and sigmoid colon, they may be brought to the

surface through a small opening in the anterior abdominal

Trauma of the Cecum and Colon

wall. If the cecum or transverse colon is then opened,

Blunt or penetrating injuries to the colon occur. Blunt

the bowel contents may be allowed to drain by this

injuries most commonly occur where mobile parts of the

route. These procedures are referred to as cecostomy or

colon (transverse and sigmoid) join the fixed parts (ascend-

colostomy, respectively, and are used to relieve large-bowel

ing and descending).

obstructions.

Penetrating injuries following stab wounds are common.

Volvulus

The multiple anatomic relationships of the different parts of

the colon explain why isolated colonic trauma is unusual.

Because of its extreme mobility, the sigmoid colon some-

times rotates around its mesentery. This may correct itself

Cancer of the Large Bowel

spontaneously or the rotation may continue until the blood

Cancer of the large bowel is relatively common in persons

supply of the gut is cut off completely.

older than 50 years. The growth is restricted to the bowel

Intussusception

wall for a considerable time before it spreads via the

lymphatics. Bloodstream spread via the portal circulation to

Intussusception is the telescoping of a proximal segment of

the liver occurs late. If a diagnosis is made early and a partial

the bowel into the lumen of an adjoining distal segment.

colectomy is performed, accompanied by removal of the

Needless to say, there is a grave risk of cutting off the blood

lymph vessels and lymph nodes draining the area, then a

supply to the gut and developing gangrene. It is common in

cure can be anticipated.

children. Ileocolic, colocolic, and ileoileal forms do occur,

but ileocolic is the most common.

Diverticulosis

The high incidence in children may be caused by the

Diverticulosis of the colon is a common clinical condition.

relatively large size of the large bowel compared with

It consists of a herniation of the lining mucosa through the

the small intestine at this time of life. Another factor may be

circular muscle between the teniae coli and occurs at points

the possible swelling of Peyer’s patches secondary to infec-

where the circular muscle is weakest—that is, where the

tion. In the latter case, the swollen patch protrudes into the

blood vessels pierce the muscle (CD Fig. 19-22). The com-

lumen and violent peristalsis of the ileal wall tries to pass it

mon site for herniation is shown in CD Fig. 19-22.

distally along the gut lumen.

teniae coli

appendices epiploicae

colic artery

diverticulum

CD Figure 19-22

Blood supply to the

colon (A) and formation of the diverticu-

marginal

lum (B). Note the passage of the mucosal

artery

diverticulum through the muscle coat

along the course of the artery.

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

339

■ The sigmoidoscope is gently inserted into the anus and

Sigmoid Colon

anal canal in the direction of the umbilicus to ensure that

the instrument passes along the long axis of the canal.

Variation in the Length and Location

Gentle but firm pressure is applied to overcome the re-

of the Sigmoid Colon

sistance of the anal sphincters (see text Fig. 19-68).

■ After a distance of about 1.5 in. (4 cm), the instrument

The sigmoid colon shows great variation in length and may

enters the ampulla of the rectum. At this point, the tip of

measure as much as 36 in. (91 cm). In the young child,

the sigmoidoscope should be directed posteriorly in the

because the pelvis is small, this segment of the colon may lie

midline to follow the sacral curve of the rectum (see CD

mainly in the abdomen.

Fig. 19-23).

■ Slow advancement is made under direct vision. Some

Cancer of the Sigmoid Colon

slight side-to-side movement may be necessary to bypass

The sigmoid colon is a common site for cancer of the large

the transverse rectal folds.

bowel. Because the lymphatic vessels of this segment of the

■ At approximately 6.5 in. (16.25 cm) from the anal mar-

colon drain ultimately into the inferior mesenteric nodes, it

gin, the rectosigmoid junction will be reached. The sig-

follows that an extensive resection of the gut and its associated

moid colon here bends forward and to the left, and the

lymphatic field is necessary to extirpate the growth and its lo-

lumen appears to end in a blind cul-de-sac. To negotiate

cal lymphatic metastases. The colon is removed from the left

this angulation, the tip of the sigmoidoscope must be

colic flexure to the distal end of the sigmoid colon, and the

directed anteriorly and to the patient’s left side. This

transverse colon is anastomosed to the rectum.

maneuver can cause some discomfort in the anal canal

from distortion of the anal sphincters by the shaft of the

Volvulus

sigmoidoscope. Another possibility is that the point of

the instrument may stretch the wall of the colon, giving

Because of its extreme mobility, the sigmoid colon some-

rise to colicky pain in the lower abdomen.

times rotates around its mesentery. This may correct itself

■ Once the instrument has entered the sigmoid colon, it

spontaneously, or the rotation may continue until the blood

should be possible to pass it smoothly along its full extent

supply of the gut is cut off completely. The rotation com-

and, using the full length of the sigmoidoscope, enter the

monly occurs in a counterclockwise direction and is

descending colon.

referred to as volvulus.

■ The sigmoidoscope may now be slowly withdrawn, care-

fully inspecting the mucous membrane. The normal

Diverticula

rectal and colonic mucous membrane is smooth and

Diverticula of the mucous membrane along the course of

glistening and pale pink with an orange tinge, and blood

the arteries supplying the sigmoid colon is a common clini-

vessels in the submucosa can be clearly seen. The mu-

cal condition and is described on page 338. In patients with

cous membrane is supple and moves easily over the end

diverticulitis or ulcerative colitis, the sigmoid colon may

of the sigmoidoscope.

become adherent to the bladder, rectum, ileum, or ureter

Anatomy of Complications

and produce an internal fistula.

of Sigmoidoscopy

Sigmoidoscopy

Perforation of the bowel at the rectosigmoid junction can

Because the sigmoid colon lies only a short distance from

occur. This is almost invariably caused by the operator fail-

the anus (6.5 in. [17 cm]) it is possible to examine the

ing to negotiate carefully the curve between the rectum and

mucous membrane under direct vision for pathologic

the sigmoid colon. In some patients, the curve is in the form

conditions. A flexible tube fitted with lenses and illuminated

of an acute angulation, which may frustrate the overzealous

internally is introduced through the anus and carefully

advancement of the sigmoidoscope. Perforation of the sig-

passed up through the anal canal, rectum, sigmoid colon,

moid colon results in the escape of colonic contents into the

and descending colon. This examination, called sigmoi-

peritoneal cavity.

doscopy, can be carried out without an anesthetic in an out-

patient clinic. Biopsy specimens of the mucous membrane

Colostomy

can be obtained through this instrument.

The sigmoid colon is often selected as a site for performing

a colostomy in patients with carcinoma of the rectum. Its

Anatomic Facts Relative to Sigmoidoscopy

mobility allows the surgeon to bring out a loop of colon,

■ The patient is placed in the left lateral position with

with its blood supply intact, through a small incision in the

the left knee flexed and the right knee extended (CD

left iliac region of the anterior abdominal wall. Its mobility

Fig. 19-23). Alternatively, the patient is placed kneeling

also makes it suitable for implantation of the ureters after

in the knee-chest position.

surgical removal of the bladder.

340

Chapter 19

umbilicus

sigmoid

colon

area of

referred

discomfort or

pain as instrument

enters sigmoid

6.5 in.

colon

1 1/2

inches

CD Figure 19-23

Sigmoidoscopy. A. Patient in the left lateral position with the left knee

flexed and the right knee extended. B. Sagittal section of the male pelvis showing the

positions (1, 2, and 3) of the tube of the sigmoidoscope relative to the patient as it ascends

the anal canal and rectum. The area of discomfort or pain experienced by the patient as the

tube is negotiated around the bend into the sigmoid colon is referred to the skin of the

anterior abdominal wall below the umbilicus.

branch divides into an anterior and a posterior branch. The

Rectum

tributaries of the superior rectal vein are arranged in a simi-

lar manner, so that it is not surprising to find that internal he-

Rectal Curves and Mucosal Folds

morrhoids are arranged in three groups (see CD p. 341): two

on the right side of the lower rectum and anal canal and one

The anteroposterior flexure of the rectum, as it follows the

on the left.

curvature of the sacrum and coccyx, and the lateral flexures

must be remembered when one is passing a sigmoidoscope

Partial and Complete Prolapse of

to avoid causing the patient unnecessary discomfort.

the Rectum

The crescentic transverse mucosal folds of the rectum

must also be borne in mind when passing an instrument

Partial and complete prolapses of the rectum through the

into the rectum. It is thought that these folds serve to support

anus are relatively common clinical conditions. In partial

the weight of the feces and to prevent excessive distension of

prolapse, the rectal mucous membrane and submucous

the rectal ampulla.

coat protrude for a short distance outside the anus (CD Fig.

19-24). In complete prolapse, the whole thickness of the

Blood Supply and Internal

rectal wall protrudes through the anus. In both conditions,

Hemorrhoids

many causative factors may be involved. However, damage

The chief arterial supply to the rectum is from the superior

to the levatores ani muscles as the result of childbirth and

rectal artery, a continuation of the inferior mesenteric artery.

poor muscle tone in the aged are important contributing

In front of the third sacral vertebra, the artery divides into

factors. A complete rectal prolapse may be regarded as a

right and left branches. Halfway down the rectum, the right

sliding hernia through the pelvic diaphragm.

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

341

involve the ureter. An anterior penetration in the male may

mucous membrane

peritoneum

involve the prostate, seminal vesicles, or bladder; in the

female, the vagina and uterus may be invaded.

levator ani

It is clear from the anatomic features of the rectum and

rectum

its lymph drainage that a wide resection of the rectum with

its lymphatic field offers the best chance of cure. When the

tumor has spread to contiguous organs and is of a low

internal anal

sphincter

grade of malignancy, some form of pelvic evisceration may

be justifiable.

external anal

It is most important for a medical student to remember

sphincter

that the interior of the lower part of the rectum can be exam-

ined by a gloved index finger introduced through the anal

canal. The anal canal is about 1.5 in. (4 cm) long so that the

anus

pulp of the index finger can easily feel the mucous membrane

prolapse

lining the lower end of the rectum. Most cancers of the rec-

of mucous

tum can be diagnosed by this means. This examination can

membrane

be extended in both sexes by placing the other hand on the

lower part of the anterior abdominal wall. With the bladder

empty, the anterior rectal wall can be examined bimanually.

rectum

In the female, the placing of one finger in the vagina and an-

other in the rectum may enable the physician to make a thor-

ough examination of the lower part of the anterior rectal wall.

external anal

sphincter

Rectal Injuries

The management of penetrating rectal injuries will be de-

termined by the site of penetration relative to the peritoneal

covering. The upper third of the rectum is covered on the

peritoneum

anterior and lateral surfaces by peritoneum, the middle

internal anal

sphincter

third is covered only on its anterior surface, and the lower

third is devoid of a peritoneal covering (CD Fig. 19-25). The

complete

prolapse

treatment of penetration of the intraperitoneal portion of the

of rectal wall

rectum is identical to that of the colon, because the peri-

toneal cavity has been violated. In the case of penetration of

CD Figure 19-24

Coronal section of the rectum and anal

canal. A. Incomplete rectal (mucosal) prolapse. B. Complete

the extraperitoneal portion, the rectum is treated by divert-

rectal prolapse.

ing the feces through a temporary abdominal colostomy,

administering antibiotics, and repairing and draining the

tissue in front of the sacrum.

Cancer of the Rectum

Cancer (carcinoma) of the rectum is a common clinical

Anal Canal

finding that remains localized to the rectal wall for a

considerable time. At first, it tends to spread locally in the

Internal Hemorrhoids (Piles)

lymphatics around the circumference of the bowel. Later, it

spreads upward and laterally along the lymph vessels,

Internal hemorrhoids are varicosities of the tributaries of the

following the superior rectal and middle rectal arteries.

superior rectal (hemorrhoidal) vein and are covered by

Venous spread occurs late, and because the superior rectal

mucous membranes (CD Fig. 19-26). The tributaries of the

vein is a tributary of the portal vein, the liver is a common

vein, which lie in the anal columns at the 3, 7, and 11 o’-

site for secondary deposits.

clock positions when the patient is viewed in the lithotomy

Once the malignant tumor has extended beyond the

position,^* are particularly liable to become varicosed.

confines of the rectal wall, knowledge of the anatomic rela-

Anatomically, a hemorrhoid is therefore a fold of mucous

tions of the rectum will enable a physician to assess the

structures and organs likely to be involved. In both sexes,

a posterior penetration involves the sacral plexus and

^*The patient is in the supine position with both hip joints flexed

can cause severe intractable pain down the leg in the distri-

and abducted; the feet are held in position by stirrups. The position

bution of the sciatic nerve. A lateral penetration may

is commonly used for pelvic examinations of the female.

342

Chapter 19

sigmoid colon

coil of ileum

peritoneum

rectouterine pouch

cavity of uterus

uterovesical pouch

rectum

bladder

anococcygeal body

cervix

anal canal

anus

urogenital diaphragm

urethra

vagina

perineal body

CD Figure 19-25

Sagittal section of the female pelvis.

membrane and submucosa containing a varicosed tributary

muscular coat of the rectal wall during defecation. Chronic

of the superior rectal vein and a terminal branch of the su-

constipation, associated with prolonged straining at stool, is

perior rectal artery. Internal hemorrhoids are initially con-

a common predisposing factor. Pregnancy hemorrhoids are

tained within the anal canal (first degree). As they enlarge,

common owing to pressure on the superior rectal veins by

they extrude from the canal on defecation but return at the

the gravid uterus. Portal hypertension as a result of cirrhosis

end of the act (second degree). With further elongation,

of the liver can also cause hemorrhoids. The possibility that

they prolapse on defecation and remain outside the anus

cancerous tumors of the rectum are blocking the superior

(third degree).

rectal vein must never be overlooked.

Because internal hemorrhoids occur in the upper half

of the anal canal, where the mucous membrane is inner-

External Hemorrhoids

vated by autonomic afferent nerves, they are painless and

are sensitive only to stretch. This may explain why large in-

External hemorrhoids are varicosities of the tributaries of

ternal hemorrhoids give rise to an aching sensation rather

the inferior rectal (hemorrhoidal) vein as they run laterally

than acute pain.

from the anal margin. They are covered by skin (see

The causes of internal hemorrhoids are many. They fre-

CD Fig. 19-26) and are commonly associated with well-

quently occur in members of the same family, which sug-

established internal hemorrhoids.

gests a congenital weakness of the vein walls. Varicose veins

External hemorrhoids are covered by the mucous

of the legs and hemorrhoids often go together. The superior

membrane of the lower half of the anal canal or the skin,

rectal vein is the most dependent part of the portal circula-

and they are innervated by the inferior rectal nerves. They

tion and is valveless. The weight of the column of venous

are sensitive to pain, temperature, touch, and pressure,

blood is thus greatest in the veins in the upper half of the

which explains why external hemorrhoids tend to be

anal canal. Here, the loose connective tissue of the submu-

painful. Thrombosis of an external hemorrhoid is common.

cosa gives little support to the walls of the veins. Moreover,

Its cause is unknown, although coughing or straining may

the venous return is interrupted by the contraction of the

produce distension of the hemorrhoid followed by stasis.

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

343

tributary of superior rectal vein

internal anal sphincter

external anal sphincter

anal columns

inferior

rectal vein

internal hemorrhoid

mucous membrane

skin

external hemorrhoid

perianal hematoma

anal valves

11 o'clock

3 o'clock

7 o'clock

CD Figure 19-26

A. Normal tributary of the superior rectal vein within the anal column.

B. Varicosed tributary of the superior rectal vein forming the internal hemorrhoid. Dotted

lines indicate degrees of severity of condition. C. Positions of three internal hemorrhoids as

seen through a proctoscope with the patient in the lithotomy position.

The presence of a small, acutely tender swelling at the anal

Anal Fissure

margin is immediately recognized by the patient.

The lower ends of the anal columns are connected by

small folds called anal valves (CD Fig. 19-26A). In people

Perianal Hematoma

suffering from chronic constipation, the anal valves may be

A perianal hematoma is a small collection of blood beneath

torn down to the anus as the result of the edge of the fecal

the perianal skin (see CD Fig. 19-26). It is caused by a

mass catching on the fold of mucous membrane. The

rupture of a small subcutaneous vein, possibly an external

elongated ulcer so formed, known as an anal fissure (CD

hemorrhoid, and is extremely painful.

Fig. 19-27), is extremely painful. The fissure occurs most

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

345

Perianal Abscesses

Anal Sphincter Nerve Block and

Anesthetizing the Perianal Skin

Perianal abscesses are produced by fecal trauma to the anal

mucosa (see CD Fig. 19-27). Infection may gain entrance to

By blocking the branches of the inferior rectal nerve and

the submucosa through a small mucosal lesion, or the ab-

the perineal branch of the fourth sacral nerve, the anal

scess may complicate an anal fissure or the infection of an

sphincters will be relaxed and the perianal skin anes-

anal mucosal gland. The abscess may be localized to the

thetized.

submucosa (submucous abscess), may occur beneath the

The procedure is as follows:

perianal skin (subcutaneous abscess), or may occupy the is-

1. An intradermal wheal is produced by injecting a small

chiorectal fossa (ischiorectal abscess). Large ischiorectal ab-

amount of anesthetic solution behind the anus in the

scesses sometimes extend posteriorly around the side of the

midline.

anal canal to invade the ischiorectal fossa of the opposite

2. A gloved index finger is inserted into the anal canal to

side (horseshoe abscess). An abscess may be found in the

serve as a guide.

space between the ampulla of the rectum and the upper sur-

3. A long needle attached to a syringe filled with

face of the levator ani (pelvirectal abscess). Anatomically,

anesthetic solution is inserted through the cuta-

these abscesses are closely related to the different parts of the

neous wheal into the sphincter muscles along the

external sphincter and levator ani muscles, as seen in CD

posterior and lateral surfaces of the anal canal. The

Fig. 19-27.

procedure is repeated on the opposite side. The pur-

Anal fistulae develop as the result of spread or inade-

pose of the finger in the anal canal is to guide the

quate treatment of anal abscesses. The fistula opens at one

needle and to prevent penetration of the anal mucous

end at the lumen of the anal canal or lower rectum and at

membrane.

the other end on the skin surface close to the anus (see CD

Fig. 19-27). If the abscess opens onto only one surface, it is

known as a sinus, not a fistula. The high-level fistulae are

Incontinence Associated with

rare and run from the rectum to the perianal skin. They are

Rectal Prolapse

located above the anorectal ring; as a result, fecal material

constantly soils the clothes. The low-level fistulae occur

Fecal incontinence can accompany severe rectal prolapse

below the level of the anorectal ring, as shown in CD

of long duration. It is thought that the prolonged and

Fig. 19-27.

excessive stretching of the anal sphincters is the cause of

The most important part of the sphincteric mechanism

the condition. The condition can be treated by restoring

of the anal canal is the anorectal ring. It consists of the deep

the anorectal angle by tightening the puborectalis part of the

part of the external sphincter, the internal sphincter, and the

levator ani muscles and the external anal sphincters behind

puborectalis part of the levator ani. Surgical operations on

the anorectal junction.

the anal canal that result in damage to the anorectal ring

will produce fecal incontinence.

Incontinence after Trauma

Removal of Anorectal Foreign Bodies

Trauma, such as childbirth, or damage to the sphincters

during surgery or perianal abscesses or fistulae can be

Normally, the anal canal is kept closed by the tone of the

responsible for incontinence after trauma.

internal and external anal sphincters and the tone of the

puborectalis part of the levator ani muscles. The rectal

contents are supported by the levator ani muscles, possibly

Incontinence after Spinal Cord Injury

assisted by the transverse rectal mucosal folds. For these

After severe spinal cord injuries, the patient is not aware

reasons, the removal of a large foreign body, such as a vase

of rectal distension. Moreover, the parasympathetic

or electric light bulb, from the rectum may be a formida-

influence on the peristaltic activity of the descending

ble problem.

colon, sigmoid colon, and rectum is lost. In addition,

The following procedure is usually successful:

control over the abdominal musculature and sphincters

1. The foreign body must first be fixed so that the sphinc-

of the anal canal may be severely impaired. The rectum,

teric tone, together with external attempts to grab the

now an isolated structure, responds by contracting

object, do not displace the object farther up the

when the pressure within its lumen rises. This local re-

rectum.

flex response is much more efficient if the sacral segments

2. Large, irregular, or fragile foreign bodies may not be re-

of the spinal cord are spared. At best, however, the force

moved so easily, and it may be necessary to paralyze the

of the contractions of the rectal wall is small, and

anal sphincter by giving the patient a general anesthetic

constipation and impaction of feces are the usual

or by performing an anal sphincter nerve block.

outcome.

346

Chapter 19

Rectal Examination

■ Opposite the proximal phalanx are the perineal body,

the urogenital diaphragm, and the bulb of the penis.

The following structures can be palpated by the gloved in-

dex finger inserted into the anal canal and rectum in the

In the female:

normal patient.

■ Opposite the terminal phalanx are the rectouterine

Anteriorly

pouch, the vagina, and the cervix (CD Fig. 19-25).

In the male:

■ Opposite the middle phalanx are the urogenital di-

aphragm and the vagina.

■ Opposite the terminal phalanx are the contents of the

■ Opposite the proximal phalanx are the perineal body

rectovesical pouch, the posterior surface of the bladder,

and the lower part of the vagina.

the seminal vesicles, and the vasa deferentia (CD Fig.

19-28).

Posteriorly

■ Opposite the middle phalanx are the rectoprostatic

The sacrum, coccyx, and anococcygeal body can be felt.

fascia and the prostate.

Laterally

seminal vesicle

bladder

prostate

external os of uterus

head of baby

anterior lip of cervix

CD Figure 19-28

A. Rectal ex-

amination in a pregnant woman

showing how it is possible to

palpate the cervix through the

anterior rectal wall. B. Rectal ex-

amination in the male showing

how it is possible to palpate the

prostate and the seminal vesicles

through the anterior rectal wall.

site for episiotomy

C. Position of the episiotomy inci-

sion in a woman during the sec-

ond stage of labor. The baby’s

head is presenting at the vaginal

orifice.

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

347

The ischiorectal fossae and ischial spines can be

palpated.

Congenital Short Esophagus

Abnormal shortness of the esophagus is caused by an

Cancer and the Lymph Drainage of the

esophageal hiatus hernia in the diaphragm. Stomach con-

Anal Canal

tents flow into the esophagus, resulting in esophagitis.

The upper half of the mucous membrane of the anal canal

is drained upward to lymph nodes along the course of the

superior rectal artery. The lower half of the mucous

CONGENITAL

membrane is drained downward to the medial group of

superficial inguinal nodes. Many patients have thought they

ANOMALIES OF

had an inguinal hernia, and the physician has found a

cancer of the lower half of the anal canal, with secondary

deposits in the inguinal lymph nodes.

THE STOMACH

Congenital Hypertrophic

ISCHIORECTAL

Pyloric Stenosis

FOSSA

Hypertrophic pyloric stenosis is a relatively common emer-

gency in infants between the ages of 3 and 6 weeks. The

child ejects the stomach contents with considerable force.

The Ischiorectal Fossa

The exact cause of the stenosis is unknown, although

evidence suggests that the number of autonomic ganglion

and Infection

cells in the stomach wall is fewer than normal. This

The ischiorectal fossae (ischioanal fossae) are filled with fat

possibility leads to prenatal neuromuscular incoordination

that is poorly vascularized. The close proximity to the anal

and localized muscular hypertrophy and hyperplasia of

canal makes them particularly vulnerable to infection.

the pyloric sphincter. It is much more common in male

Infection commonly tracks laterally from the anal mucosa

children.

through the external anal sphincter. Infection of the peri-

anal hair follicles or sweat glands may also be the cause of

infection in the fossae. Rarely, a perirectal abscess bursts

CONGENITAL

downward through the levator ani muscle. An ischiorectal

abscess may involve the opposite fossa by the spread of in-

fection across the midline behind the anal canal.

ANOMALIES OF

THE SMALL AND

CONGENITAL

LARGE INTESTINES

ANOMALIES OF

THE ESOPHAGUS

Diverticula of the Intestine

All coats of the intestinal wall are found in the wall of a con-

genital diverticulum. In the duodenum, diverticula are

Atresia of the Esophagus

found on the medial wall of the second and third parts (CD

Atresia of the esophagus, with and without fistula, with the

Fig. 19-29). Usually, these are symptomless. Jejunal diver-

trachea is considered in detail on CD Chapter 3.

ticula occasionally occur and usually give rise to no symp-

toms. For Meckel’s diverticulum of the ileum, see CD page

327. A diverticulum of the cecum is commonly situated on

Esophageal Stenosis

the medial side of the cecum close to the ileocecal valve. It

Esophageal stenosis is a narrowing of the lumen of the

may be subject to acute inflammation and then is confused

esophagus, which commonly occurs in the lower part. It is

with appendicitis. Diverticula of the colon are acquired, not

treated by dilatation.

congenital (see CD p. 338).

348

Chapter 19

CD Figure 19-29

Some common congen-

ital anomalies of the intestinal tract.

1-3. Congenital atresias of the small intes-

tine. 4. Diverticulum of the duodenum or

jejunum. 5. Mesenteric cyst of the small in-

testine. 6. Absence of the appendix. 7. Dou-

ble appendix. 8. Malrotation of the gut, with

the appendix lying in the left iliac fossa. For

Meckel’s diverticulum, see CD Fig. 19-15.

obstruction occurs at multiple sites. The cause is possibly

Atresia and Stenosis of the

the failure of the lumen to become recanalized after it has

been blocked by epithelial proliferation of the cells of the

Small Intestine

mucous membrane. Other causes have been suggested,

such as vascular damage associated with twisting or volvulus

The most common site of an atretic or stenotic obstruction

of the intestine. Persistent bile-stained vomiting occurs from

is in the duodenum. During the development of the

birth. Surgical relief of the obstruction should be carried out

duodenum, the lining cells proliferate at such a rate that the

as soon as possible.

lumen becomes completely obliterated. Later, as a result of

degeneration of these cells, the gut becomes recanalized.

Failure of recanalization could produce atresia or stenosis.

Duplication of the Digestive System

Different forms of duodenal atresia and stenosis are shown

in CD Fig. 19-29. Vomiting is the most common presenting

In duplication of the digestive system, the normal degener-

symptom, and the vomitus usually is bile stained. Surgical

ation of the mucous membrane cells, which have prolifer-

treatment during the first few days of life is essential.

ated to temporarily block the lumen, occurs at two sites

The next most common sites are the ileum and je-

simultaneously instead of at one. In this way, two lumina are

junum, respectively (see CD Fig. 19-29). Frequently, the

formed side by side. The additional segment of bowel

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

349

should be removed as soon as possible, since it may cause

2% of individuals. The diverticulum is important clinically,

obstruction or be the site of hemorrhage or perforation.

since it may possess a small area of gastric mucosa, and

bleeding may occur from a “gastric” ulcer in its mucous

membrane. Moreover, the pain from this ulcer may be con-

Arrested Rotation or Malrotation

fused with the pain from appendicitis. Should a fibrous

band connect the diverticulum to the umbilicus, a loop of

of the Midgut Loop

small bowel may become wrapped around it, causing in-

testinal obstruction.

Complete Absence of Rotation or

Undescended Cecum and Appendix

Incomplete Rotation

In cases of undescended cecum and appendix, an inflam-

Complete absence of rotation is rare. In cases of incomplete

mation of the appendix would give rise to tenderness in the

rotation, no further rotation occurs after the initial counter-

right hypochondrium, which may lead to a mistaken diag-

clockwise rotation of 90° in the umbilical cord. Thus, the

nosis of inflammation of the gallbladder.

duodenum, jejunum, and ileum remain on the right side of

the abdomen, and the cecum and colon are on the left side

of the abdomen (see CD Fig. 19-29). In other cases, a coun-

Anomalies of the Appendix

terclockwise rotation of 180° occurs, and although the duo-

Agenesis of the appendix (failure to develop) is extremely

denum may take up its correct position posterior to the

rare; however, a few examples of double appendix have

superior mesenteric artery, the cecum comes to lie anterior

been reported (see CD Fig. 19-29). The possibility of left-

and to the left of the duodenum. Abnormal adhesions form,

sided appendix in individuals with transposition of thoracic

which run across the anterior surface of the duodenum and

and abdominal viscera or in cases of arrested rotation of

cause obstruction to its second part.

the midgut should always be remembered (see CD Fig.

19-29).

Malrotation of the Midgut Loop

Anomalies of the Colon

Counterclockwise rotation of 90° followed by clockwise ro-

tation of 90° or 180° may occur. In these cases, the duode-

The congenital anomaly of undescended cecum or failure

num comes to lie anterior to the superior mesenteric artery,

of rotation of the gut so that the cecum lies in the left iliac

and the colon may come to lie anterior to the mesentery of

fossa may give rise to confusion in diagnosis. The pain of ap-

the small intestine. Repeated vomiting is usually the pre-

pendicitis, for example, although initially starting in the um-

senting symptom and is caused by duodenal obstruction.

bilical region, may shift not to the right iliac fossa but to the

Surgical correction of the incomplete rotation or malrota-

right upper quadrant or to the left lower quadrant.

tion of the gut is performed, and all adhesions are divided.

Primary Megacolon

Persistence of the

(Hirschsprung Disease)

Vitellointestinal Duct

Hirschsprung disease shows a familial tendency and is more

The vitelline duct in the early embryo connects the devel-

common in males than in females. Symptoms usually appear

oping gut to the yolk sac (see text Fig. 19-78). Normally, as

during the first few days after birth. The child fails to pass

development proceeds, the duct is obliterated, severs its con-

meconium, and the abdomen becomes enormously dis-

nection with the intestine, and disappears. Persistence of the

tended. The sigmoid colon is greatly distended and hyper-

vitellointestinal duct can result in an umbilical fistula (see

trophied, while the rectum and anal canal are constricted

CD Fig. 19-15). If the duct remains as a fibrous band, a loop

(CD Fig. 19-30). It is the constricted segment of the bowel

of small intestine can become wrapped around it, causing

that causes the obstruction, and histologic examination re-

intestinal obstruction (see CD Fig. 19-15).

veals a complete failure of development of the parasympa-

thetic ganglion cells in this region. The treatment is opera-

tive excision of the aganglionic segment of the bowel.

Meckel’s Diverticulum

Meckel’s diverticulum, a congenital anomaly, represents a

Imperforate Anus

persistent portion of the vitellointestinal duct (see CD Fig.

19-15). The diverticulum is located on the antimesenteric

About 1 child in 4,000 is born with imperforate anus caused

border of the ileum about 2 ft (61 cm) from the ileocecal

by an imperfect fusion of the entodermal cloaca with the

junction. It is about 2 in. (5 cm) long and occurs in about

proctodeum (see text Fig. 19-77).

350

Chapter 19

distended and hypertrophied

sigmoid colon

constricted rectum

and anal canal

commonest area to find absence

of parasympathetic

ganglion cells

CD Figure 19-30

Main characteristics of primary megacolon (Hirschsprung disease).

Clinical Problem Solving Questions

Read the following case histories/questions and give

his perineum, scrotum, and penis. He was unable to

the best answer for each.

urinate normally, passing only a few drops of blood-

stained urine. The lower part of the anterior abdominal

An 8-year-old boy was admitted to the hospital with a tem-

wall was also swollen, but his thighs were normal.

perature of 101°F, a furred tongue, and pain in the right

2. The symptoms and signs displayed by this patient can

lower quadrant. On examination, the skin on the right

be explained by the following statements except which?

lower quadrant was tender to the touch, and the abdominal

A. The patient’s fall ruptured the urethra in the per-

muscles were contracted and rigid. A diagnosis of acute ap-

ineum.

pendicitis was made.

B. When the patient attempted to micturate, the urine

1. The symptoms and signs displayed by this patient can

extravasated beneath Colles’ fascia.

be explained by the following statements except which?

C. The urine passed over the scrotum and penis under

A. An acutely inflamed appendix produces an inflam-

the membranous layer of superficial fascia.

mation of the peritoneal coat covering it.

D. The urine passed upward beneath the membranous

B. Should the inflammatory process spread, for exam-

layer of superficial fascia on the anterior abdominal

ple, if the appendix should rupture, the parietal peri-

wall.

toneum would become involved.

E. The urine could not extend posteriorly because of the

C. The parietal peritoneum, the abdominal muscles,

attachment of Colles’ fascia to the tip of the coccyx.

and the overlying skin are supplied by the same seg-

F. The urine did not extend into the thigh because of

mental spinal nerves.

the attachment of the membranous layer of superfi-

D. The segmental nerves supplying the right lower

cial fascia to the fascia lata, just below the inguinal

quadrant of the abdominal wall are T7, T8, and T9.

ligament.

E. The pain in the right lower quadrant and the re-

A 45-year-old woman was shopping in a liquor store when

gional contraction of the abdominal muscles is an

an armed robbery took place. A shootout occurred and a

attempt by the body to keep the inflamed appendix

bullet ricocheted off the wall and entered her left side. For-

immobile so that the inflammatory process remains

tunately, the bullet did not enter the peritoneal cavity.

localized.

One year later, in addition to diminished skin sensation

A workman engaged in demolishing a building lost his

over the left lumbar region and umbilicus, she noticed a

balance and fell astride a girder on the floor below. On

bulging forward of the left side of her anterior abdominal

examination, he was found to have extensive swelling of

wall.

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

351

3. The symptoms and signs displayed by this patient can

6. The symptoms and signs displayed by this patient can

be explained by the following statements except which?

A. The bullet cut the ninth and tenth intercostal nerves

A. The excessive exertion caused a rise in intraabdom-

just below the costal margin on the left side.

inal pressure.

B. The diminished skin sensation was caused by the

B. A hernial sac formed of parietal peritoneum was

loss of the sensory nerve supply to the ninth and

forced downward.

tenth thoracic dermatomes.

C. The peritoneum was forced through the right

C. Portions of the oblique, transversus, and rectus

femoral canal.

abdominis muscles on the left side were paralyzed.

D. The patient had a right-sided femoral hernia.

D. Atrophy of the pyramidalis muscle resulted in loss of

E. The neck of a femoral hernial sac is situated below

support to the abdominal viscera, which then sagged

and medial to the pubic tubercle.

forward.

A 55-year-old man was admitted to the hospital with a large

A 9-week-old boy was admitted to the hospital with a

hard, fixed, intraabdominal mass. On examination of the ab-

swelling in the right groin that extended down into the up-

domen, the mass was situated on the transpyloric plane. The

per part of the scrotum. When he cried, the swelling en-

inguinal lymph nodes were normal.

larged. On careful palpation it was possible to reduce the

7. The symptoms and signs displayed by this patient can

size of the swelling, and this procedure was accompanied by

be explained by the following statements except which?

a gurgling noise.

A. Radiologic examination of the stomach showed

4. The symptoms and signs displayed by this patient can

nothing abnormal.

be explained by the following statements except which?

B. The right testicle was enlarged and was much

A. The swelling was situated above and medial to the

harder than normal.

pubic tubercle on the right side.

C. A diagnosis of malignant disease of the right testis

B. The child had a right indirect inguinal hernia.

was made.

C. The processus vaginalis in its upper part had failed

D. The malignant tumor had metastasized to the lum-

to become obliterated before birth.

bar lymph nodes lying on the transpyloric plane on

D. The hernial sac in an indirect inguinal hernia

the posterior abdominal wall, which is the normal

emerges from the superficial inguinal ring.

lymphatic drainage of the testis.

E. The superficial inguinal ring lies above and medial

E. In malignant disease of the testis the superficial

to the pubic tubercle.

inguinal lymph nodes only become involved if the

F. The contents of the hernial sac consisted only of the

tumor spreads to involve the scrotal skin.

greater omentum.

F. The normal testis is tethered to the skin of the

scrotum.

A 75-year-old man with chronic bronchitis noticed that a

bulge was developing in his left groin. On examination, an

A 25-year-old man involved in purchasing drugs was knifed

elongated swelling was seen above the medial end of the left

in the abdomen in the left upper quadrant. On examination

inguinal ligament. When the patient coughed, the swelling

in the emergency department, it was difficult to determine

enlarged but did not descend into the scrotum. The patient

whether the knife had penetrated the peritoneal cavity. It

had weak abdominal muscles.

was decided to do a midline peritoneal lavage below the

umbilicus to see if there was any free blood in the peritoneal

5. The symptoms and signs displayed by this patient can

cavity.

be explained by the following statements except which?

A. The inguinal swelling was a direct inguinal hernia.

8. The following layers of tissue were penetrated by the

B. The cause of the hernia was weak abdominal

trocar and cannula to enter the peritoneal cavity except

muscles.

which?

C. The hernial sac was wide and in direct communica-

A. Skin

tion with the peritoneal cavity.

B. Fatty and membranous layers of superficial fascia

D. A rise in intraabdominal pressure on coughing

C. Rectus sheath and rectus abdominis muscle

caused the hernial swelling to expand.

D. Deep fascia

E. The swelling occured lateral to the inferior epigas-

E. Fascia transversalis

tric artery.

F. Extraperitoneal tissue and parietal peritoneum

A 40-year-old woman noticed a painful swelling in her right

A 45-year-old man was admitted to the emergency

groin after helping her husband move some heavy furniture.

department complaining of severe pain in the right lower

On examination, a small tender swelling was noted in the

quadrant of the anterior abdominal wall. He had repeatedly

right groin.

vomited, and his temperature and pulse rate were elevated.

352

Chapter 19

His history indicated that he had acute appendicitis and that

E. The lesser sac of peritoneum

the pain had suddenly increased. On examination, the mus-

F. The splenic artery

cles of the lower part of the anterior abdominal wall in the

A 58-year-old man was in a restaurant when he suddenly

right lower quadrant showed rigidity. The diagnosis of peri-

started to vomit blood. He was taken unconscious to the

tonitis after perforation of the appendix was made.

emergency department of a local hospital. On examination,

9. The symptoms and signs displayed by this patient can

he had all the signs of severe hypovolemic shock. On palpa-

be explained by the following statements except which?

tion of the anterior abdominal wall, the right lobe of the

A. The perforation of the appendix had resulted in the

liver was felt three fingerbreadths below the costal margin.

spread of the infection from the appendix to involve

Several enlarged superficial veins could be seen around the

the parietal peritoneum.

umbilicus. His wife said that he had vomited blood 3

B. The parietal peritoneum in the right iliac region,

months previously and had nearly died. She admitted that

the muscles of the anterior abdominal wall, and the

he was a chronic alcoholic. The diagnosis was cirrhosis of

overlying skin are all supplied by the segmental

the liver secondary to chronic alcoholism.

nerves T12 and L1.

12. The symptoms and signs displayed by this patient can

C. Irritation of the parietal peritoneum reflexly increases

be explained by the following statements except which?

the tone of the abdominal muscles, causing rigidity.

A. The normal flow of portal blood through the liver is

D. The greater omentum tends to become stuck down

impaired by cirrhosis of the liver.

to the appendix and restricts the spread of infection.

B. The portal-systemic anastomoses become enlarged

E. The pain was intensified after perforation of the ap-

in this condition.

pendix because of stimulation of the autonomic

C. At the lower end of the esophagus, a branch from the

pain endings in the parietal peritoneum.

right gastric vein anastomoses with an esophageal

tributary of the azygos vein.

A 63-year-old man with a long history of a duodenal ulcer

D. Rupture of a varicosed esophageal vein could pro-

was seen in the emergency department after vomiting

duce a severe hemorrhage so that the patient would

blood-stained fluid and exhibiting all the signs and symp-

vomit up blood.

toms of severe hypovolemic shock.

E. With portal hypertension the paraumbilical veins

10. The following statements concerning duodenal ulcers

linking the superficial veins of the skin (systemic

could apply to the patient’s condition except which?

veins) to the portal vein become congested and

A. Hemorrhage from a duodenal ulcer often reveals it-

visible.

self by the passage of black stools on defecation.

A 48-year-old woman with a history of repeated vomiting

B. The pyloric sphincter prevents most of the blood

was admitted to the hospital with a diagnosis of large bowel

from the duodenal lumen from passing up into the

obstruction. To decompress the stomach a nasogastric tube

stomach.

was passed.

C. The gastroduodenal artery lies behind the first part of

the duodenum and was probably eroded by the ulcer.

13. When passing a nasogastric tube some important

D. The gastroduodenal artery is a small branch of the

anatomic facts should be considered except which?

hepatic artery.

A. The well-lubricated tube is inserted through the

E. The duodenal ulcer was most likely to be situated on

wider nostril.

the posterior wall of the first part of the duodenum.

B. The tube is directed backward along the nasal floor

and not upward because it may become caught on

A 47-year-old woman was operated on for the treatment of a

the nasal choanae.

chronic gastric ulcer that had not responded to medical treat-

C. The distance between the nostril and the cardiac

ment. At operation for partial gastrectomy, it was found that

orifice of the stomach is about 23 in. (57.5 cm).

the posterior wall of the stomach was stuck down to the pos-

D. The distance between the cardiac orifice and the py-

terior abdominal wall. The surgeon had to proceed with great

lorus is 4.8 to 5.6 in. (12 to 14 cm).

care to avoid damaging important structures lying on the pos-

E. Esophageal narrowing may offer resistance to the

terior abdominal wall.

tube behind the cricoid cartilage, 7.2 in. (18 cm)

11. The following structures located on the posterior ab-

from the nostril.

dominal wall were possibly involved in the disease

F. The left bronchus and the arch of the aorta cross in

process except which?

front of the esophagus and may impede the descent

A. The right kidney

of the tube, 11.2 in. (28 cm) from the nostril.

B. The pancreas

G. Where the esophagus enters the stomach there is a

C. The left suprarenal gland

slight resistance to the descent of the tube.

D. The left kidney

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

353

14. The following statements concerning an indirect

in the sitting position on the leg of an upturned bar stool.

inguinal hernia are correct except which?

While under observation he developed the signs and symp-

A. It is the most common form of abdominal hernia.

toms of peritonitis.

B. The neck of the hernial sac lies medial to the infe-

17. The signs and symptoms displayed by this patient could

rior epigastric artery.

be explained by the following anatomic statements ex-

C. The sac is the remains of the processus vaginalis.

cept which?

D. The hernial sac can extend into the scrotum.

A. The patient had impaled his rectum on the leg of

E. At the superficial inguinal ring, the hernial sac lies

the upturned bar stool.

above and medial to the pubic tubercle.

B. At operation, a laceration of the anterior wall of the

A mother took her 20-day-old baby boy to a pediatrician be-

middle of the rectum was found.

cause he had started to vomit after his feeds. The baby was

C. The leg of the bar stool had entered the rectovesical

breast-fed. For the first 15 days after birth, the baby had

pouch.

taken his feeds very well and had slept contentedly in his

D. The rectal contents had contaminated the peri-

crib following the normal after-feed burp. However, in the

toneal cavity and were responsible for the develop-

previous 5 days, the baby had begun to vomit toward the end

ment of peritonitis.

of each feed, shooting the milk out of his mouth for a dis-

E. The anterior surface of the middle third of the rec-

tance of 1 to 2 ft. After carefully questioning the mother and

tum has no peritoneal covering.

after a physical examination of the boy, the pediatrician

A 46-year-old man had been treating himself for hemor-

made the diagnosis of congenital hypertrophic pyloric

rhoids for the past 3 years. He had noticed that his feces were

stenosis.

often slightly blood stained. For the past 12 months, he had

15. He was able to ascertain the following additional signs

noticed that when he had his bowels open, he always felt that

and symptoms except which?

more was to come. Sometimes he went to the toilet several

A. Once the milk had been vomited, the child imme-

times a day but was only able to pass flatus and blood-stained

diately would feed again, only to repeat the same

mucus. Recently, pain had developed down the outside of

performance.

his right leg. Digital examination of the rectum revealed a

B. On gentle palpation of the anterior abdominal wall,

large, hard-based ulcer on the posterior wall of the rectum

a small firm swelling was felt just below and medial

with extensive induration of the pararectal tissues. A diagno-

to the tip of the left eighth costal cartilage.

sis of advanced carcinoma of the rectum was made.

C. On observing the anterior abdominal wall, an occa-

18. The following statements about this patient are proba-

sional wave of gastric peristalsis was seen traveling

bly correct except which?

across the epigastrium from left to right.

A. Some of the bleeding was from the carcinomatous

D. The stools were small in quantity and infrequent.

ulcer of the rectum as well as from the hemorrhoids.

E. The child showed signs of dehydration as evidenced

B. The lymphatic drainage of the rectum takes place

by a depressed anterior fontanelle of the skull.

first into the pararectal lymph nodes.

A 6-year-old girl was examined by a pediatrician because she

C. Carcinoma of the rectum never metastasizes to the

had a history of recurrent pain in the region of the umbili-

liver.

cus. The pain was dull and aching in nature and lasted for

D. Examination of the right leg revealed some weak-

about 1 week. It had recurred on four occasions in the pre-

ness of the muscles supplied by the sciatic nerve.

vious 2 years. Then 2 days before the examination, the child

E. The carcinoma had extended posteriorly to involve

had severe rectal bleeding and had fainted.

the sacral plexus.

F. The patient indicated that the leg pain was felt in

16. On examination of the child, the pediatrician found the

skin areas supplied by branches of the sciatic nerve.

following signs and symptoms consistent with the diag-

nosis of Meckel’s diverticulum except which?

A 72-year-old woman was suspected of having a tumor of the

A. Tenderness of the anterior abdominal wall in the

sigmoid colon. The physician decided to confirm the diag-

right iliac region

nosis by performing a sigmoidoscopy.

B. Anemia

19. The following anatomic statements are correct con-

C. Stools streaked with dark red blood

cerning the procedure of sigmoidoscopy except which?

D. Pyrexia of 102°F

A. After inserting the instrument into the anus, the

A 30-year-old man involved in a barroom brawl was seen in

lighted end enters the ampulla of the rectum after a

the emergency department. He was found to have a blood-

distance of about 1.5 in. (4 cm).

stained tear on the seat of his trousers and lacerations of the

B. Some side-to-side movement may be necessary to

anal margin. During the fight he was knocked down and fell

avoid the transverse rectal folds.

354

Chapter 19

C. The rectosigmoid junction will be reached approxi-

D. The swellings bulged downward when the patient

mately 6.5 in. (16.25 cm) from the anal margin.

was asked to strain.

D. To negotiate the rectosigmoid junction, the tip of

E. Large, congested veins were seen in the swellings.

the sigmoidoscope should be directed anteriorly and

F. The swellings remained outside the anus after defe-

to the patient’s left.

cation.

E. Stretching of the colonic wall may give rise to col-

G. Abrasion of the mucous membrane was responsible

icky pain in the upper part of the abdomen in the re-

for the bleeding.

gion of the xiphoid process.

A 42-year-old woman visited her physician because she ex-

A 3-week-old boy was taken to a pediatrician because of re-

perienced an agonizing pain in the rectum, which occurred

peated vomiting and reluctance to feed. On questioning,

on defecation. She had first noticed the pain a week before

the mother said the child had started to vomit on the first

when she tried to defecate. The pain lasted for about an

day of life and has vomited at least once a day since then.

hour, then passed off, only to return with the next bowel

Early on, the mother had been reassured and told that the

movement. She said that she suffered from constipation and

baby was taking his feedings too quickly and that the vom-

admitted that sometimes her stools were streaked with

iting eventually would cease. While initially accepting this

blood. After a careful examination, a diagnosis of anal fissure

reassurance, the mother now noticed that the child did not

was made.

seem hungry at feeding time; moreover, she could see that

22. The following statements concerning this case are cor-

the abdomen was becoming distended. She added that the

rect except which?

child definitely was constipated; very occasionally, hard

A. Examination of the anal canal was difficult because

meconium was passed. After a thorough physical examina-

any attempt to insert a gloved finger into the canal

tion of the child, the pediatrician made the diagnosis of

caused severe pain.

primary megacolon (Hirschsprung disease).

B. The anus was kept tightly closed by the spasm of the

20. The examination of the child revealed the following

external anal sphincter.

possible signs except which?

C. Gentle eversion of the anal margin under local anes-

A. The abdomen was found to be distended.

thesia revealed the lower edge of a linear tear in the

B. A rectal examination with the gloved little finger re-

posterior wall of the anal canal; a small tag of skin

sulted in the passage of a large amount of flatus and

projected from the lower end of the tear.

the abdominal distension became visibly less.

D. The forward edge of a hard fecal mass may have

C. A low barium enema followed by an X-ray examina-

caught one of the anal valves and torn it downward

tion showed a normal rectum.

as it descended.

D. On the radiograph, above the rectum, a narrowed

E. Anal fissures tend to occur on the anterior and pos-

part of the colon led to a funnel-shaped expansion,

terior walls of the anal canal because the mucous

which in turn led to a greatly dilated descending

membrane is poorly supported in this region by the

colon and transverse colon.

superficial external sphincter muscle.

E. On placing a stethoscope on the abdominal

F. The mucous membrane of the lower half of the anal

wall, the physician could not hear sounds of peri-

canal is innervated by autonomic afferent nerves

stalsis.

and is sensitive only to stretch.

A 53-year-old man complained that for the past 4 years he

A 41-year-old woman was seen in the emergency depart-

had frequently passed blood-stained stools. Recently, he had

ment complaining of a painful swelling in the region of the

noticed that his “bowel” protruded from his anus after defe-

anus. On examination, a hot, red, tender swelling was found

cation, and this caused him considerable discomfort.

on the right side of the anal margin. A diagnosis of

ischiorectal abscess was made.

21. The following symptoms and signs in this patient were

consistent with a diagnosis of third-degree internal he-

23. The following statements concerning this case are prob-

morrhoids except which?

ably correct except which?

A. The patient suffered from intense perianal irritation

A. An ischiorectal abscess is a common complication

caused by the mucous secretions from the prolapsed

of anal fissure.

mucous membrane.

B. The fat in the ischiorectal fossa is prone to infection

B. Proctoscopic examination revealed three pink

that might extend laterally through the base of the

swellings of mucous membrane at the level of the

anal fissure.

anal valves.

C. The fat in the ischiorectal fossa has a profuse blood

C. The swellings were situated at the 1, 4, and 9 o’-

supply.

clock positions with the patient in the lithotomy

D. A surgical incision of the abscess should provide

position.

adequate drainage of the pus.

The Abdominal Wall, the Peritoneal Cavity, the Retroperitoneal Space, and the Alimentary Tract

355

E. The surgeon should avoid the inferior rectal nerve

26. Following a terrorist bomb attack, a young child was

and vessels that cross the ischiorectal fossa from the

seen in the emergency department with a gaping hole

lateral to the medial side.

in the anterior abdominal wall, and coils of gut were

exposed on the surface. How would you determine by

24. The differential diagnosis between a perforated duode-

inspection whether the gut was small or large intes-

nal ulcer and a perforated appendix may prove difficult.

tine?

Can you explain this in anatomic terms?

25. The pain of acute appendicitis is commonly first felt in

the umbilical region and later in the right iliac region.

Can you explain this in anatomic terms?

Answers and Explanations

D is the correct answer. The segmental nerves supply-

12.

C is the correct answer. At the lower end of the esoph-

ing the right lower quadrant of the abdominal wall are

agus, a branch from the left gastric vein anastomoses

T11, T12, and L1.

with an esophageal tributary of the azygos vein.

E is the correct answer. The urine could not ex-

13.

C is the correct answer. The distance between the nos-

tend posteriorly because of the attachment of the

tril and the cardiac orifice of the stomach is about 17.2

Colles’ fascia to the posterior edge of the perineal

in. (44 cm).

membrane.

14.

B is the correct answer. The neck of the hernial sac in

D is the correct answer. The pyramidalis muscle (if pre-

an indirect inguinal hernia lies lateral to the inferior

sent) is innervated by the twelfth thoracic nerve.

epigastric artery (see CD Fig. 19-6).

F is the correct answer. The contents of this hernial sac

15.

B is the correct answer. In congenital hypertrophic py-

included coils of small intestine, which were responsi-

loric stenosis, there is a localized muscular hypertrophy

ble for the gurgling noises that occurred as the hernia

and hyperplasia of the pyloric sphincter, which is larger

was reduced.

than normal and can usually be palpated just below and

medial to the tip of the right ninth costal cartilage.

E is the correct answer. The swelling occurs medial to

the inferior epigastric artery (see CD Fig. 19-6).

16.

D is the correct answer. In many cases of Meckel’s di-

E is the correct answer. The neck of a femoral hernial

verticulum, a small area of ectopic gastric mucosa is

sac is situated below and lateral to the pubic tubercle

present, which is capable of producing hydrochloric

(see CD Fig. 19-7).

acid and pepsin. In the adjoining mucous membrane,

this child had a chronic ulcer that was responsible for

F is the correct answer. The normal testis is freely

the umbilical pain. Sudden severe hemorrhage from

mobile within the scrotum and is not tethered to the

an artery in the floor of the ulcer was the cause of the

subcutaneous tissue or skin.

rectal bleeding and fainting attack. The condition is

C is the correct answer. The linea alba lies in the mid-

not associated with pyrexia. After restoration of the

line; the rectus sheath lies lateral to the linea alba.

blood volume and hemoglobin to a normal level, a

child with this condition should be operated on and

E is the correct answer. In the parietal peritoneum

the diverticulum should be widely excised. The cut

lining the anterior abdominal wall in the right

ends of the ileum then are joined by an end-to-end

iliac fossa, the sensation of pain originates in the nerve

anastomosis.

endings of somatic spinal nerves (T12 and L1).

17.

E is the correct answer. The upper third of the rectum

10.

D is the correct answer. The gastroduodenal artery is a

has peritoneum on its anterior and lateral surfaces; the

large branch of the hepatic artery.

middle third has peritoneum on its anterior surface;

11.

A is the correct answer. The right kidney does not lie

and the lower third has no peritoneal covering (see text

behind the stomach (see text Fig. 19-38)

Fig. 19-64).

356

Chapter 19

18. C is the correct answer. Advanced carcinoma of the rec-

23.

C is the correct answer. The fat in the ischiorectal fossa

tum not only extends to the pararectal and inferior

has a poor blood supply.

mesenteric nodes but may also spread via the superior

24.

A small perforation of the first part of the duodenum

rectal, inferior mesenteric, splenic, and portal veins to

may result in the contents of the duodenum running

the liver.

down the right paracolic gutter to the right iliac fossa.

19. E is the correct answer. Colicky pain from the colon is

The signs then closely resemble those of a perforated

referred to the lower part of the anterior abdominal wall

appendix.

above the symphysis pubis (see CD Fig. 19-23).

25.

The initial pain of acute appendicitis is a vague dis-

20. E is the correct answer. In patients with primary mega-

comfort and is referred to the umbilical region. The af-

colon, the muscle of the colon immediately proximal to

ferent nerve fibers from the appendix accompany the

the obstruction is hypertrophied as the result of at-

sympathetic nerves to the superior mesenteric plexus.

tempting to force the meconium and feces onward.

They enter the thorax via the splanchnic nerves and en-

Usually very active peristalsis is heard on listening to the

ter the spinal cord at the level of the tenth thoracic seg-

abdomen with a stethoscope.

ment. The tenth thoracic intercostal nerve supplies the

skin of the umbilicus, and for this reason pain is com-

21. C is the correct answer. The swellings of internal he-

monly referred to the umbilicus. Once the inflamma-

morrhoids are situated at the 3, 7, and 11 o’clock po-

tory process has extended beyond the confines of the

sitions with the patient in the lithotomy position.

appendix and has involved the parietal peritoneum, a

These swellings are caused by a dilatation of the three

severe localized pain is felt in the right iliac region. The

main tributaries of the superior rectal vein (see CD

parietal peritoneum, the overlying muscles of the ante-

Fig. 19-26).

rior abdominal wall, and the covering skin are all sup-

22. F is the correct answer. The mucous membrane of the

plied by the first lumbar nerve.

lower half of the anal canal is innervated by the inferior

26.

A list of naked-eye differences between the small and

rectal nerve and is very sensitive to pain, temperature,

large intestine are given on text page 751.

touch, and pressure.

Chapter Outline

The Liver

358

Accessory Bile Duct

361

Liver Supports and Surgery

358

Congenital Choledochal Cyst

361

Liver Trauma

358

The Pancreas

362

Liver Biopsy

358

Diagnosis of Pancreatic Disease

362

Subphrenic Spaces

359

Trauma of the Pancreas

362

Portal-Systemic Anastomoses

359

Cancer of the Head of the Pancreas

and the Bile Duct

362

Portal Hypertension

359

The Pancreatic Tail and Splenectomy

362

Blood Flow in the Portal Vein and

Malignant Disease

359

Congenital Anomalies of the Pancreas

362

Gallstones

359

Anular Pancreas

362

Biliary Colic

359

Ectopic Pancreas

363

Acute Cholecystitis

359

Congenital Fibrocystic Disease

363

Cholecystectomy and the Arterial Supply to the

The Spleen

363

Gallbladder

359

Splenic Enlargement

363

Gangrene of the Gallbladder

359

Trauma to the Spleen

363

Congenital Anomalies of the Gallbladder

359

Congenital Anomalies of the Spleen

363

Biliary Atresia

359

Supernumerary Spleens

363

Absence of the Gallbladder

361

Clinical Problem Solving Questions

363

Double Gallbladder

361

Absence of the Cystic Duct

361

Answers and Explanations

364

the thorax or upper abdomen are common causes of liver

THE LIVER

injury. Blunt traumatic injuries from automobile accidents

are also common, and severe hemorrhage accompanies

tears of this organ.

Liver Supports and Surgery

Because anatomic research has shown that the bile

ducts, hepatic arteries, and portal vein are distributed in a

The liver is held in position in the upper part of the abdom-

segmental manner, appropriate ligation of these structures

inal cavity by the attachment of the hepatic veins to the in-

allows the surgeon to remove large portions of the liver in

ferior vena cava. The peritoneal ligaments and the tone of

patients with severe traumatic lacerations of the liver or with

the abdominal muscles play a minor role in its support. This

a liver tumor. (Even large, localized carcinomatous metasta-

fact is important surgically because even if the peritoneal

tic tumors have been successfully removed.)

ligaments are cut, the liver can be only slightly rotated.

Liver Biopsy

Liver Trauma

Liver biopsy is a common diagnostic procedure. With the

The liver is a soft, friable structure enclosed in a fibrous cap-

patient holding his or her breath in full expiration—to re-

sule. Its close relationship to the lower ribs must be empha-

duce the size of the costodiaphragmatic recess and the like-

sized. Fractures of the lower ribs or penetrating wounds of

lihood of damage to the lung—a needle is inserted through

The Viscera Associated with the Alimentary Tract: The Liver, the Pancreas, and the Spleen

359

the right eighth or ninth intercostal space in the midaxillary

determines whether infected bile is likely to enter the pan-

line. The needle passes through the diaphragm into the

creatic duct.

liver, and a small specimen of liver tissue is removed for

Gallstones have been known to ulcerate through the

microscopic examination.

gallbladder wall into the transverse colon or the duodenum.

In the former case, they are passed naturally per the rectum,

but in the latter case, they may be held up at the ileocecal

Subphrenic Spaces

junction, producing intestinal obstruction.

The important subphrenic spaces and their relationship to

the liver are described on text page 713. Under normal

Acute Cholecystitis

conditions these are potential spaces only, and the peri-

toneal surfaces are in contact. An abnormal accumulation

Acute cholecystitis produces discomfort in the right upper

of gas or fluid is necessary for separation of the peritoneal

quadrant or epigastrium. Inflammation of the gallbladder

surfaces. The anterior surface of the liver is normally dull

may cause irritation of the subdiaphragmatic parietal peri-

on percussion. Perforation of a gastric ulcer is often ac-

toneum, which is supplied in part by the phrenic nerve (C3,

companied by a loss of liver dullness caused by the accu-

4, and 5). This may give rise to referred pain over the shoul-

mulation of gas over the anterior surface of the liver and in

der, because the skin in this area is supplied by the supra-

the subphrenic spaces.

clavicular nerves (C3 and 4).

Portal-Systemic Anastomoses

Cholecystectomy and the Arterial

See CD Chapter 8.

Supply to the Gallbladder

Before attempting a cholecystectomy operation, the surgeon

Portal Hypertension

must be aware of the many variations in the arterial supply

to the gallbladder and the relationship of the vessels to the

See CD Chapter 8.

bile ducts (CD Fig. 20-1). Unfortunately, there have been

several reported cases in which the common hepatic duct or

Blood Flow in the Portal Vein and

the main bile duct has been included in the arterial ligature

with disastrous consequences.

Malignant Disease

See CD Chapter 8.

Gangrene of the Gallbladder

Unlike the appendix, which has a single arterial supply, the

Gallstones

gallbladder rarely becomes gangrenous. In addition to the

cystic artery, the gallbladder also receives small vessels from

Gallstones are usually asymptomatic; however, they can

the visceral surface of the liver.

give rise to gallstone colic or produce acute cholecystitis.

Biliary Colic

CONGENITAL

Biliary colic is usually caused by spasm of the smooth

muscle of the wall of the gallbladder in an attempt to ex-

ANOMALIES OF

pel a gallstone. Afferent nerve fibers ascend through the

celiac plexus and the greater splanchnic nerves to the tho-

THE GALLBLADDER

racic segments of the spinal cord. Referred pain is felt in

the right upper quadrant or the epigastrium (T7, 8, and 9

dermatomes).

Biliary Atresia

Obstruction of the biliary ducts with a gallstone or by

compression by a tumor of the pancreas results in backup of

Failure of the bile ducts to canalize during development

bile in the ducts and development of jaundice. The im-

causes atresia. The various forms of atresia are shown in CD

paction of a stone in the ampulla of Vater may result in the

Fig. 20-2. Jaundice appears soon after birth; clay-colored

passage of infected bile into the pancreatic duct, producing

stools and very dark colored urine are also present. Surgical

pancreatitis. The anatomic arrangement of the terminal part

correction of the atresia should be attempted when possible.

of the bile duct and the main pancreatic duct is subject to

If the atresia cannot be corrected, the child will die of liver

considerable variation. The type of duct system present

failure.

The Viscera Associated with the Alimentary Tract: The Liver, the Pancreas, and the Spleen

361

duct. The gallbladder drains directly into the bile duct. The

Absence of the Gallbladder

condition may not be recognized when performing a chole-

cystectomy, and the bile duct may be seriously damaged by

Occasionally, the outgrowth of cells from the hepatic bud

the surgeon (see CD Fig. 20-3).

fails to develop. In these cases, there is no gallbladder and

no cystic duct (CD Fig. 20-3).

Accessory Bile Duct

Double Gallbladder

A small accessory bile duct may open directly from the liver

into the gallbladder, which may cause leakage of bile into

Rarely, the outgrowth of cells from the hepatic bud bifur-

the peritoneal cavity after cholecystectomy if it is not recog-

cates so that two gallbladders are formed (see CD Fig. 20-3).

nized at the time of surgery (see CD Fig. 20-3).

Absence of the Cystic Duct

Congenital Choledochal Cyst

In absence of the cystic duct, the entire outgrowth of cells

Rarely, a choledochal cyst develops because of an area of

from the hepatic bud develops into the gallbladder and fails

weakness in the wall of the bile duct. A cyst can contain 1 to

to leave the narrow stem that would normally form the cystic

2 L of bile. The anomaly is important in that it may press

congenital absence of gallbladder

double gallbladder

absence of cystic duct

abnormally long cystic duct

CD Figure 20-3

Some common congeni-

accessory bile duct

choledochal cyst

tal anomalies of the gallbladder.

362

Chapter 20

on the bile duct and cause obstructive jaundice (see CD

Fig. 20-3).

Cancer of the Head of the Pancreas

and the Bile Duct

Because of the close relation of the head of the pancreas to

THE PANCREAS

the bile duct, cancer of the head of the pancreas often

causes obstructive jaundice.

Diagnosis of Pancreatic Disease

The Pancreatic Tail and Splenectomy

The deep location of the pancreas sometimes gives rise to

The presence of the tail of the pancreas in the splenicorenal

problems of diagnosis for the following reasons:

ligament sometimes results in its damage during splenec-

■

Pain from the pancreas is commonly referred to the back.

tomy. The damaged pancreas releases enzymes that start to

■

Because the pancreas lies behind the stomach and trans-

digest surrounding tissues, with serious consequences.

verse colon, disease of the gland can be confused with

that of the stomach or transverse colon.

■ Inflammation of the pancreas can spread to the peri-

CONGENITAL

toneum, forming the posterior wall of the lesser sac. This

in turn can lead to adhesions and the closing off of the

ANOMALIES OF

lesser sac to form a pseudocyst.

THE PANCREAS

Trauma of the Pancreas

The pancreas is deeply placed within the abdomen and is

Anular Pancreas

well protected by the costal margin and the anterior ab-

dominal wall. However, blunt trauma, such as in a sports in-

In anular pancreas, the ventral pancreatic bud becomes

jury when a sudden blow to the abdomen occurs, can com-

fixed so that, when the stomach and duodenum rotate, the

press and tear the pancreas against the vertebral column.

ventral bud is pulled around the right side of the duode-

The pancreas is most commonly damaged by gunshot or

num to fuse with the dorsal bud of the pancreas, thus en-

stab wounds.

circling the duodenum (CD Fig. 20-4). This may cause

Damaged pancreatic tissue releases activated pancre-

obstruction of the duodenum, and vomiting may start a

atic enzymes that produce the signs and symptoms of acute

few hours after birth. Early surgical relief of the obstruction

peritonitis.

is necessary.

dorsal pancreatic bud

duodenum

ventral pancreatic bud

dorsal bud

narrowed lumen of duodenum

CD Figure 20-4

Formation of the anular

fixed ventral pancreatic bud

pancreas, producing duodenal obstruction.

Note the narrowing of the duodenum.

The Viscera Associated with the Alimentary Tract: The Liver, the Pancreas, and the Spleen

363

The spleen is situated at the beginning of the splenic

Ectopic Pancreas

vein, and in cases of portal hypertension it often enlarges

from venous congestion.

Ectopic pancreatic tissue may be found in the submucosa of

the stomach, duodenum, small intestine

(including

Meckel’s diverticulum), and gallbladder and in the spleen.

Trauma to the Spleen

It is important in that it may protrude into the lumen of the

Although anatomically the spleen gives the appearance of

gut and be responsible for causing intussusception.

being well protected, automobile accidents of the crushing

or run-over type commonly produce laceration of the

Congenital Fibrocystic Disease

spleen. Penetrating wounds of the lower left thorax can also

damage the spleen.

Basically, congenital fibrocystic disease in the pancreas is

caused by an abnormality in the secretion of mucus. The mu-

cus produced is excessively viscid and obstructs the pancre-

atic duct, which leads to pancreatitis with subsequent fibrosis.

CONGENITAL

The condition also involves the lungs, kidneys, and liver.

ANOMALIES OF

THE SPLEEN

Splenic Enlargement

Supernumerary Spleens

A pathologically enlarged spleen extends downward and

In 10% of people, one or more supernumerary spleens may

medially. The left colic flexure and the phrenicocolic liga-

be present, either in the gastrosplenic omentum or in the

ment prevent a direct downward enlargement of the organ.

splenicorenal ligament. Their clinical importance is that

As the enlarged spleen projects below the left costal margin,

they may hypertrophy after removal of the major spleen and

its notched anterior border can be recognized by palpation

be responsible for a recurrence of symptoms of the disease

through the anterior abdominal wall.

for which splenectomy was initially performed.

Clinical Problem Solving Questions

Read the following case histories/questions and give

C. Referred pain is felt in the right upper quadrant or

the best answer for each.

the epigastrium.

D. T7 through T9 dermatomes are involved.

A 55-year-old woman with a history of flatulent dyspepsia

E. The violent contractions of the gallbladder wall are

suddenly experienced an excruciating colicky pain across

attempts to expel the gallstones.

the upper part of the abdomen. On examination in the

emergency department, she was found to have some rigidity

On examination of the abdomen of a 31-year-old woman, a

and tenderness in the right upper quadrant. A diagnosis of

large swelling was found to extend downward and medially

biliary colic was made.

below the left costal margin. On percussion, a continuous

band of dullness was noted to extend upward from the left of

1. The following statements would explain this patient’s

the umbilicus to the left axillary region. On palpation, a

symptoms except which?

notch was felt along the anterior border of the swelling. A di-

A. The pain of gallstone colic is caused by spasm of the

agnosis of splenic enlargement was made.

smooth muscle in the wall of the gallbladder and

distension of the bile ducts by the stones.

2. The signs displayed by this patient can be explained by

B. The pain fibers from the gallbladder and bile ducts

the following statements except which?

ascend through the superior mesenteric plexus and

A. The spleen has a notched anterior border caused by

the greater splanchnic nerves to enter the thoracic

incomplete fusion of its parts during development.

segments of the spinal cord.

364

Chapter 20

B. Because of the presence of the left colic flexure and

across the upper part of the abdomen. On examination

the phrenicocolic ligament, the spleen is unable to

after the attack, some rigidity and tenderness was noted

expand vertically downward.

in the right hypochondrium. Two days later the patient

C. A pathologically enlarged spleen extends downward

became jaundiced, and it was noticed that the degree of

and forward, toward the umbilicus.

jaundice varied from day to day. The diagnosis of biliary

D. The spleen is situated in the upper left quadrant of

colic was made. Why should a person passing a gall-

the abdomen beneath the diaphragm.

stone experience pain? Why is the pain experienced in

E. The long axis of the spleen lies along the twelfth rib.

the area described above? Why does the jaundice vary

in intensity?

3. A 19-year-old football player was accidently kicked on

the left side of his chest. On returning to the locker

A 65-year-old woman was admitted to the hospital with

room he said he felt faint and collapsed to the floor. On

progressive jaundice of three months’ duration and

examination in the emergency department, he was

weight loss. She had not experienced any colicky pain.

found to be in hypovolemic shock. He had tenderness

On examination, a soft swelling could be felt in the ab-

and guarding in the left upper quadrant of his ab-

domen in the region of the tip of the right ninth costal

domen. He also had extreme local tenderness over his

cartilage. A diagnosis of cancer of the head of the pan-

left tenth rib in the midaxillary line. A diagnosis of a

creas was made. What anatomic structure is responsible

ruptured spleen and the possibility of a fractured tenth

for the swelling?

rib was made. Explain the tenderness and guarding in

A patient with thrombocytopenic purpura was advised

the abdomen in this patient.

to have a splenectomy to stop the episodes of bleeding

A 40 year-old obese woman complaining of indigestion was

from the gums and gastrointestinal tract. The operation

admitted to the hospital for investigation. She had a past

was successful. Eighteen months later the clinical fea-

history of gallstones and transient attacks of jaundice.

tures returned. Can you explain in anatomic terms the

Large gallstones have been known to erode through the

recurrence of the bleeding after the condition had ap-

posterior wall of the gallbladder and enter the intestinal

parently been cured by splenectomy?

tract.

Following a splenectomy, it was noticed that pancreatic

4. Which part of the intestinal tract is likely to initially

juice was exuding through the patient’s abdominal

contain the stone?

wound. Is the pancreas likely to be damaged during

A. The sigmoid colon

splenectomy? Which part of the pancreas?

B. The descending colon

The anatomic arrangement of the terminal part of the

C. The transverse colon

bile duct and the main pancreatic duct is subject to

D. The ascending colon

considerable variation. Which variations are likely to be

E. The jejunum

associated with a pancreatitis should a gallstone be-

5. A 50-year-old woman with a history of flatulent dyspep-

come impacted at the lower end of the bile duct?

sia suddenly experienced an excruciating colicky pain

Answers and Explanations

1. B is the correct answer. The pain fibers from the gall-

quadrant and reflex guarding of the muscles in the

bladder and bile ducts ascend through the celiac plexus.

same area.

2. E is the correct answer. The long axis of the spleen lies

4. C is the correct answer. The transverse colon is in close

along the tenth rib (see text Fig. 20-27).

posterior relation to the gallbladder.

3. Initially in this patient, the spleen underwent a

5. The pain is due to the spastic contraction of the muscle

subcapsular hemorrhage, and later, in the locker

of the gallbladder attempting to flush the stone down

room, the capsule gave way, allowing the blood to

the bile ducts and to the distension of the ducts by the

escape into the peritoneal cavity. The presence of

stone. The afferent pain fibers from the gallbladder and

blood in the peritoneal cavity irritated the parietal

bile ducts enter the spinal cord between segments T5

peritoneum, causing tenderness in the left upper

and T9. Pain is referred to the epigastrium via the sev-

The Viscera Associated with the Alimentary Tract: The Liver, the Pancreas, and the Spleen

365

enth to the ninth intercostal nerves. A variable amount

8. The tail of the pancreas lies within the splenicorenal

of bile gets past the stone.

ligament, and its tip is related to the hilus of the spleen.

The surgeon has to take extreme care not to damage the

6. A small carcinoma of the head of the pancreas was

tail of the pancreas during a splenectomy.

found at operation to be compressing the bile duct.

Back pressure along the bile ducts produced dilatation

9. Any variation in which the bile duct and the pancreatic

of the gallbladder, which could be felt in the region of

duct open by a common orifice into the duodenum is

the tip of the right ninth costal cartilage.

likely to cause this problem (see text Fig. 20-26). Gall-

7. About 10% of persons have accessory spleens. These

stones are usually associated with infected bile. A stone

should always be looked for when performing a

impacted at the orifice into the duodenum will allow

splenectomy for such conditions as thrombocytopenic

reflux of infected bile along the main pancreatic duct,

purpura. If an accessory spleen is missed, it will enlarge

and pancreatitis will occur.

and take over the functions of the main spleen.

Chapter Outline

The Kidneys

370

Bladder Distension

375

Renal Mobility

370

Urinary Retention

375

Kidney Trauma

370

Suprapubic Aspiration

375

Kidney Tumors

371

Cystoscopy

375

Renal Pain

371

Bladder Injuries

375

Transplanted Kidneys

371

Difficulty with Micturition after Spinal Cord Injury

375

The Male Urethra

377

The Ureters

371

Urethral Infections

377

Traumatic Ureteral Injuries

371

Injuries to the Penis

377

Ureteric Stones

372

Rupture of the Urethra

377

Renal Colic

372

Catheterization

377

Congenital Anomalies of the Kidneys

372

Anatomy of the Procedure of Catheterization

377

Polycystic Kidney

372

The Female Urethra

378

Pelvic Kidney

372

Urethral Infections

378

Horseshoe Kidney

372

Urethral Injuries

378

Unilateral Double Kidney

373

Catheterization

378

Rosette Kidney

373

Congenital Anomalies of the Bladder

378

Supernumerary Renal Arteries

373

Exstrophy of the Bladder (Ectopia Vesicae)

378

Congenital Anomalies of the Ureters

374

Congenital Anomalies of the Urethra

378

Double Pelvis

374

Meatal Stenosis

378

Bifid Ureter

374

Hypospadias

378

Megaloureter

374

Epispadias

378

Postcaval Ureter

375

Clinical Problem Solving Questions

380

The Urinary Bladder

375

Palpation of the Urinary Bladder

375

Answers and Explanations

382

poorly developed abdominal musculature. Should the

THE KIDNEYS

amount of perirenal fat be reduced, the mobility of the kidney

may become excessive and produce symptoms of renal colic

caused by kinking of the ureter. Excessive mobility of the kid-

Renal Mobility

ney leaves the suprarenal gland undisturbed because the latter

occupies a separate compartment in the renal fascia.

The kidneys are maintained in their normal position by in-

traabdominal pressure and by their connections with the

perirenal fat and renal fascia. Each kidney moves slightly with

Kidney Trauma

respiration. The right kidney lies at a slightly lower level than

the left kidney, and the lower pole may be palpated in the right

The kidneys are well protected by the lower ribs, the lumbar

lumbar region at the end of deep inspiration in a person with

muscles, and the vertebral column. However, a severe blunt

The Kidneys, the Ureters, the Bladder, and the Urethra

371

injury applied to the abdomen may crush the kidney against

subcostal nerve (T12) to the flank and the anterior abdom-

the last rib and the vertebral column. Depending on the

inal wall.

severity of the blow, the injury varies from a mild bruising to

a complete laceration of the organ. Penetrating injuries are

Transplanted Kidneys

usually caused by stab wounds or gunshot wounds and often

involve other viscera. Because 25% of the cardiac outflow

The iliac fossa on the posterior abdominal wall is the usual site

passes through the kidneys, renal injury can result in rapid

chosen for transplantation of the kidney. The fossa is exposed

blood loss. A summary of the injuries to the kidneys is shown

through an incision in the anterior abdominal wall just above

in CD Fig. 21-1.

the inguinal ligament. The iliac fossa in front of the iliacus

muscle is approached retroperitoneally. The kidney is posi-

tioned and the vascular anastomosis constructed. The renal

Kidney Tumors

artery is anastomosed end to end to the internal iliac artery and

Malignant tumors of the kidney have a strong tendency to

the renal vein is anastomosed end to side to the external iliac

spread along the renal vein. The left renal vein receives the

vein (CD Fig. 21-2). Anastomosis of the branches of the inter-

left testicular vein in the male, and this may rarely become

nal iliac arteries on the two sides is sufficient so that the pelvic

blocked, producing left-sided varicocele.

viscera on the side of the renal arterial anastomosis are not at

risk. Ureterocystostomy is then performed by opening the

bladder and providing a wide entrance of the ureter through

Renal Pain

the bladder wall.

Renal pain varies from a dull ache to a severe pain in the

flank that may radiate downward into the lower abdomen.

Renal pain can result from stretching of the kidney capsule

THE URETERS

or spasm of the smooth muscle in the renal pelvis. The

afferent nerve fibers pass through the renal plexus around

the renal artery and ascend to the spinal cord through

Traumatic Ureteral Injuries

the lowest splanchnic nerve in the thorax and the sympa-

thetic trunk. They enter the spinal cord at the level of T12.

Because of its protected position and small size, injuries to

Pain is commonly referred along the distribution of the

the ureter are rare. Most injuries are caused by gunshot

CD Figure 21-1

Injuries to the kidney. A. Contu-

sion, with hemorrhage confined to the cortex be-

neath the intact fibrous capsule. B. Tearing of the

capsule and cortex with bleeding occurring into

the perirenal fat. C. Tearing of the capsule, the

cortex, and the medulla. Note the escape of blood

into the calyces and therefore the urine. Urine as

well as blood may extravasate into the perirenal

and pararenal fat and into the peritoneal cavity.

D. Shattered kidney with extensive hemorrhage

and extravasation of blood and urine into the

perirenal and pararenal fat; blood also enters the

calyces and appears in the urine. E. Injury to the

renal pedicle involving the renal vessels and pos-

sibly the renal pelvis.

372

Chapter 21

inferior vena cava

abdominal aorta

transplanted

kidney

common iliac

artery

internal iliac artery

external iliac artery

external iliac vein

CD Figure 21-2

The transplanted kidney.

wounds and, in a few individuals, penetrating stab wounds.

Because the ureters are retroperitoneal in position, urine

CONGENITAL

may escape into the retroperitoneal tissues on the posterior

abdominal wall.

ANOMALIES OF

Ureteric Stones

THE KIDNEYS

There are three sites of anatomic narrowing of the ureter

where stones may be arrested, namely, the pelviureteral

Polycystic Kidney

junction, the pelvic brim, and where the ureter enters the

bladder. Most stones, although radiopaque, are small

A hereditary disease, polycystic kidney can be transmitted by

enough to be impossible to see definitely along the course of

either parent. It may by associated with congenital cysts of

the ureter on plain radiographic examination. An intra-

the liver, pancreas, and lung. Both kidneys are enormously

venous pyelogram is usually necessary. The ureter runs down

enlarged and riddled with cysts. Polycystic kidney is thought

in front of the tips of the transverse processes of the lumbar

to be caused by a failure of union between the developing

vertebrae, crosses the region of the sacroiliac joint, swings out

convoluted tubules and collecting tubules. The accumula-

to the ischial spine, and then turns medially to the bladder.

tion of urine in the proximal tubules results in the formation

of retention cysts.

Renal Colic

Pelvic Kidney

The renal pelvis and the ureter send their afferent nerves into

the spinal cord at segments T11 and 12 and L1 and 2. In renal

In pelvic kidney, the kidney is arrested in some part of its

colic, strong peristaltic waves of contraction pass down the

normal ascent; it usually is found at the brim of the pelvis

ureter in an attempt to pass the stone onward. The spasm of the

(CD Fig. 21-3). Such a kidney may present with no signs

smooth muscle causes an agonizing colicky pain, which is re-

or symptoms and may function normally. However,

ferred to the skin areas that are supplied by these segments of

should an ectopic kidney become inflamed, it may—be-

the spinal cord, namely, the flank, loin, and groin.

cause of its unusual position—give rise to a mistaken

When a stone enters the low part of the ureter, the pain

diagnosis.

is felt at a lower level and is often referred to the testis or the

tip of the penis in the male and the labium majus in the fe-

Horseshoe Kidney

male. Sometimes ureteral pain is referred along the femoral

branch of the genitofemoral nerve (L1 and 2) so that pain is

When the caudal ends of both kidneys fuse as they de-

experienced in the front of the thigh. The pain is often so se-

velop, the result is horseshoe kidney (see CD Fig. 21-3).

vere that afferent pain impulses spread within the central

Both kidneys commence to ascend from the pelvis, but

nervous system, giving rise to nausea.

the interconnecting bridge becomes trapped behind the

The Kidneys, the Ureters, the Bladder, and the Urethra

373

aorta

inferior

mesenteric

horseshoe kidney

pelvic kidney

unilateral double kidney

aberrant renal arteries

rosette kidney (cake kidney)

aberrant renal artery causing

CD Figure 21-3

Some common congenital

urinary obstruction

anomalies of the kidney.

inferior mesenteric artery so that the kidneys come to rest

the ureter may result in stasis of the urine and may require

in the low lumbar region. Both ureters are kinked as they

surgical treatment.

pass inferiorly over the bridge of renal tissue, producing

urinary stasis, which may result in infection and stone

Rosette Kidney

formation. Surgical division of the bridge corrects the

condition.

Both kidneys may fuse together at their hila, and they usu-

ally remain in the pelvis. The two kidneys together form a

rosette (see CD Fig. 21-3). This is the result of the early

Unilateral Double Kidney

fusion of the two ureteric buds in the pelvis.

The kidney on one side may be double, with separate

ureters and blood vessels. In unilateral double kidney, the

Supernumerary Renal Arteries

ureteric bud on one side crosses the midline as it ascends,

and its upper pole fuses with the lower pole of the normally

Supernumerary renal arteries are relatively common. They

placed kidney (see CD Fig. 21-3). Here again, angulation of

represent persistent fetal renal arteries, which grow in

374

Chapter 21

sequence from the aorta to supply the kidney as it ascends

lower groups of calyces. The cause is a premature division of

from the pelvis. Their occurrence is clinically important be-

the ureteric bud near its termination.

cause a supernumerary artery may cross the pelviureteral

junction and obstruct the outflow of urine, producing dila-

Bifid Ureter

tion of the calyces and pelvis, a condition known as

hydronephrosis (see CD Fig. 21-3).

In bifid ureter, the ureters may join in the lower third of

their course, may open through a common orifice into the

bladder, or may open independently into the bladder (see

CD Fig. 21-4). In the latter case, one ureter crosses its fellow

CONGENITAL

and may produce urinary obstruction. The cause of bifid

ureter is a premature division of the ureteric bud.

ANOMALIES OF

Cases of double pelvis and double ureters may be found

by chance on radiologic investigation of the urinary tract.

They are more liable to become infected or to be the seat of

THE URETERS

calculus formation than is a normal ureter.

Double Pelvis

Megaloureter

Double pelvis of the ureter is usually unilateral (CD Fig.

Megaloureter may be unilateral or bilateral and shows com-

21-4). The upper pelvis is small and drains the upper group

plete absence of motility (see CD Fig. 21-4). The cause is

of calyces; the larger lower pelvis drains the middle and

unknown. Because of the urinary stasis, the ureter is prone

double pelvis

bifid ureter

megaloureter

CD Figure 21-4

Some common conge-

ectopic ureteric orifice

postcaval ureter

nital anomalies of the ureter.

The Kidneys, the Ureters, the Bladder, and the Urethra

375

to infection. Plastic surgery is required to improve the rate of

anterior abdominal wall. In cases of acute retention of

drainage.

urine, when catheterization has failed, it is possible to pass

a needle into the bladder through the anterior abdominal

wall above the symphysis pubis, without entering the peri-

Postcaval Ureter

toneal cavity. This is a simple method of draining off the

The right ureter may ascend posterior to the inferior vena

urine in an emergency.

cava and may be obstructed by it (see CD Fig. 21-4). Surgi-

cal rerouting of the ureter with reimplantation of the distal

Cystoscopy

end into the bladder is the treatment of choice.

The mucous membrane of the bladder, the two ureteric ori-

fices, and the urethral meatus can easily be observed by

THE URINARY

means of a cystoscope. With the bladder distended with

fluid, an illuminated tube fitted with lenses is introduced

into the bladder through the urethra. Over the trigone, the

BLADDER

mucous membrane is pink and smooth. If the bladder is par-

tially emptied, the mucous membrane over the trigone re-

mains smooth, but it is thrown into folds elsewhere. The

Palpation of the Urinary Bladder

ureteric orifices are slit-like and eject a drop of urine at in-

The full bladder in the adult projects up into the abdomen

tervals of about 1 minute. The interureteric ridge and the

and may be palpated through the anterior abdominal wall

uvula vesicae can easily be recognized.

above the symphysis pubis.

Bimanual palpation of the empty bladder with or with-

Bladder Injuries

out a general anesthetic is an important method of examin-

ing the bladder. In the male, one hand is placed on the

The bladder may rupture intraperitoneally or extraperi-

anterior abdominal wall above the symphysis pubis, and the

toneally. Intraperitoneal rupture usually involves the supe-

gloved index finger of the other hand is inserted into the rec-

rior wall of the bladder and occurs most commonly when

tum. From their knowledge of anatomy, students can see

the bladder is full and has extended up into the abdomen.

that the bladder wall can be palpated between the examin-

Urine and blood escape freely into the peritoneal cavity.

ing fingers. In the female, an abdominovaginal examination

Extraperitoneal rupture involves the anterior part of the

can be similarly made. In the child, the bladder is in a

bladder wall below the level of the peritoneal reflection; it

higher position than in the adult because of the relatively

most commonly occurs in fractures of the pelvis when

smaller size of the pelvis.

bony fragments pierce the bladder wall. Lower abdominal

pain and blood in the urine (hematuria) are found in most

patients.

Bladder Distension

In young children, the bladder is an abdominal organ,

The normal adult bladder has a capacity of about 500 mL.

so abdominal trauma can injure the empty bladder.

In the presence of urinary obstruction in males, the bladder

may become greatly distended without permanent damage

to the bladder wall; in such cases, it is routinely possible to

Difficulty with Micturition after

drain 1,000 to 1,200 mL of urine through a catheter.

Spinal Cord Injury

Urinary Retention

After injuries to the spinal cord, the nervous control of mic-

turition is disrupted.

In adult males, urinary retention is commonly caused by

The normal bladder is innervated as follows:

obstruction to the urethra by a benign or malignant

enlargement of the prostate. An acute urethritis or prostati-

■ Sympathetic outflow is from the first and second lumbar

tis can also be responsible. Acute retention occurs much less

segments of the spinal cord. The sympathetic nerves (see

frequently in females. The only anatomic cause of urinary

the footnote on text p. 819) inhibit contraction of the de-

retention in females is acute inflammation around the

trusor muscle of the bladder wall and stimulate closure of

urethra (e.g., from herpes).

the sphincter vesicae.

■ Parasympathetic outflow is from the second, third, and

fourth sacral segments of the spinal cord. The parasym-

Suprapubic Aspiration

pathetic nerves stimulate the contraction of the detrusor

As the bladder fills, the superior wall rises out of the pelvis

muscle of the bladder wall and inhibit the action of the

and peels the peritoneum off the posterior surface of the

sphincter vesicae.

376

Chapter 21

■ Sensory nerve fibers enter the spinal cord at the above

■ The automatic reflex bladder (CD Fig. 21-5) occurs af-

segments. The normal process of micturition is described

ter the patient has recovered from spinal shock, provided

on text page 819.

that the cord lesion lies above the level of the parasympa-

thetic outflow (S2, 3, and 4). It is the type of bladder nor-

Disruption of the process of micturition by spinal cord

mally found in infancy. The bladder fills and empties

injuries may produce the following types of bladder:

reflexly. Stretch receptors in the bladder wall are stimu-

■

The atonic bladder occurs during the phase of spinal

lated as the bladder fills, and the afferent impulses pass to

shock, immediately after the injury, and may last for a

the spinal cord (segments S2, 3, and 4). Efferent impulses

few days to several weeks. The bladder wall muscle is re-

pass down to the bladder muscle, which contracts; the

laxed, the sphincter vesicae tightly contracted, and the

sphincter vesicae and the urethral sphincter both relax.

sphincter urethrae relaxed. The bladder becomes greatly

This simple reflex occurs every 1 to 4 hours.

distended and finally overflows. Depending on the level

■ The autonomous bladder (see CD Fig. 21-5) is the con-

of the cord injury, the patient either is or is not aware that

dition that occurs if the sacral segments of the spinal cord

the bladder is full.

are destroyed. The sacral segments of the spinal cord are

bladder wall

spinal cord

sphincter vesicae

prostate

sphincter urethrae

CD Figure 21-5

A. Nervous control

of the bladder after section of the

spinal cord in the upper thoracic

region. Destruction of the sacral

segments of the spinal cord. B. The

afferent sensory fibers from the blad-

der entering the central nervous sys-

tem and the parasympathetic efferent

fibers passing to the bladder are

shown; the sympathetic fibers have

been omitted for clarity.

The Kidneys, the Ureters, the Bladder, and the Urethra

377

situated in the upper part of the lumbar region of the ver-

passes forward over the scrotum beneath the membranous

tebral column. The bladder is without any external reflex

layer of the superficial fascia, as described on CD page 313.

control. The bladder wall is flaccid, and the capacity of

If the membranous part of the urethra is ruptured, urine

the bladder is greatly increased. It merely fills to capacity

escapes into the deep perineal pouch and can extravasate

and overflows; continual dribbling is the result. The blad-

upward around the prostate and bladder or downward into

der may be partially emptied by manual compression of

the superficial perineal pouch.

the lower part of the anterior abdominal wall, but infec-

tion of the urine and backpressure effects on the ureters

Catheterization

and kidneys are inevitable.

The following anatomic facts should be remembered before

passing a catheter or other instrument along the male

urethra:

THE MALE

■ The external orifice at the glans penis is the narrowest

part of the entire urethra.

URETHRA

■ Within the glans, the urethra dilates to form the fossa ter-

minalis (navicular fossa).

■ Near the posterior end of the fossa, a fold of mucous

Urethral Infections

membrane projects into the lumen from the roof (CD

The most dependent part of the male urethra is that which

Fig. 21-6).

lies within the bulb. Here, it is subject to chronic inflam-

■ The membranous part of the urethra is narrow and fixed.

mation and stricture formation.

■ The prostatic part of the urethra is the widest and most di-

The many glands that open into the urethra—includ-

latable part of the urethra.

ing those of the prostate, the bulbourethral glands, and

■ By holding the penis upward, the S-shaped curve to the

many small penile urethral glands—are commonly the site

urethra is converted into a J-shaped curve.

of chronic gonococcal infection.

If the point of the catheter passes through the external

orifice and is then directed toward the urethral floor until it

Injuries to the Penis

has passed the mucosal fold, it should easily pass along a

normal urethra into the bladder.

Injuries to the penis may occur as the result of blunt trauma,

penetrating trauma, or strangulation. Amputation of the en-

Anatomy of the Procedure

tire penis should be repaired by anastomosis using micro-

of Catheterization

surgical techniques to restore continuity of the main blood

vessels.

The procedure is as follows:

1. The patient lies in a supine position.

Rupture of the Urethra

2. With gentle traction, the penis is held erect at right

Rupture of the urethra may complicate a severe blow on the

angles to the anterior abdominal wall. The lubricated

perineum. The common site of rupture is within the bulb of

catheter is passed through the narrow external urethral

the penis, just below the perineal membrane. The urine

meatus. The catheter should pass easily along the pe-

extravasates into the superficial perineal pouch and then

nile urethra. On reaching the membranous part of the

external urethral

orifice

fossa terminalis

fold of mucous membrane

corona

corpus spongiosum

lacunae

skin

openings of

CD Figure 21-6

The penile urethra slit open to

urethral

show the folds of mucous membrane and glandular

glands

orifices in the roof of the urethra.

378

Chapter 21

urethra, a slight resistance is felt because of the tone of

Because of the urinary incontinence and almost certain

the urethral sphincter and the surrounding rigid per-

occurrence of ascending urinary infection, surgical recon-

ineal membrane.

struction of the bladder is attempted.

3. The penis is then lowered toward the thighs, and the

catheter is gently pushed through the sphincter.

CONGENITAL

4. Passage of the catheter through the prostatic urethra

and bladder neck should not present any difficulty.

ANOMALIES OF

THE URETHRA

THE FEMALE

URETHRA

Meatal Stenosis

The external urinary meatus normally is the narrowest part

Urethral Infections

of the male urethra, but occasionally the opening is exces-

sively small and may cause back pressure effect on the entire

The short length of the female urethra predisposes to as-

urinary system. In severe cases, dilatation of the orifice by in-

cending infection; consequently, cystitis is more common

cision is necessary.

in females than in males.

Hypospadias

Urethral Injuries

Hypospadias is the most common congenital anomaly affect-

Because of the short length of the urethra, injuries are rare. In

ing the male urethra. The external meatus is situated on the

fractures of the pelvis, the urethra may be damaged by shear-

ventral or undersurface of the penis anywhere between the

ing forces as it emerges from the fixed urogenital diaphragm.

glans and the perineum. Five degrees of severity may occur,

the first of which is the most common: (1) glandular, (2) coro-

Catheterization

nal, (3) penile, (4) penoscrotal, and (5) perineal (CD Fig. 21-

8). In all except the first type, the penis is curved in a down-

Because the female urethra is shorter, wider, and more

ward or ventral direction, a condition referred to as chordee.

dilatable, catheterization is much easier than in males.

Types 1 and 2 are caused by a failure of the bud of

Moreover, the urethra is straight, and only minor resistance

ectodermal cells from the tip of the glans to grow into the

is felt as the catheter passes through the urethral sphincter.

substance of the glans and join the entodermal cells lining

the penile urethra. Types 3, 4, and 5 are caused by a failure

of the genital folds to unite on the undersurface of the de-

CONGENITAL

veloping penis and convert the urethral groove into the

penile urethra. In the penoscrotal variety, the genital

swellings fail to fuse completely, so that the meatal orifice

ANOMALIES OF

occurs in the midline of the scrotum. Type 1 requires no

treatment; for the remainder, plastic surgery is necessary.

THE BLADDER

Epispadias

Exstrophy of the Bladder

Epispadias is a relatively rare condition and is more com-

monly found in the male. In the male, the external meatus

(Ectopia Vesicae)

is situated on the dorsal or upper surface of the penis

Exstrophy of the bladder occurs three times more com-

between the glans and the anterior abdominal wall (CD Fig.

monly in males than in females. The posterior bladder wall

21-9). The most severe type is associated with exstrophy of

protrudes through a defect in the anterior abdominal wall

the bladder. In the female, the urethra is split dorsally and is

below the umbilicus (CD Fig. 21-7). The condition is

associated with a double clitoris. It is thought that epispadias

caused by a failure of the embryonic mesenchyme to invade

is caused by failure of the embryonic mesenchyme to

the embryonic disc caudal to the cloacal membrane (CD

develop in the lower part of the anterior abdominal wall, so

Fig.

21-7). The absence of intervening mesenchyme

that when the cloacal membrane breaks down, the urogen-

between the ectoderm and entoderm produces an unstable

ital sinus opens onto the surface of the cranial aspect of the

state, which is followed by breakdown of this area.

penis. Plastic surgery is the required treatment.

380

Chapter 21

exstrophy of bladder

penile

urethra

glans

scrotum

CD Figure 21-9

Types of epispadias.

anus

CD Figure 21-8

Types of hypospadias: (1) glandular,

(2) coronal, (3) penile, (4) penoscrotal, and (5) perineal.

Ventral flexion (chordee) of the penis also is present.

Clinical Problem Solving Questions

Read the following case histories/questions and give

F. Both kidneys lie on the posterior abdominal wall

the best answer for each.

and are at the same vertebral level.

A 16-year-old boy received a severe kick in the right

A 19-year-old boy was involved in a gang fight. It started

flank while playing football at school. On examination

as an argument but quickly worsened into a street brawl

in the emergency department, his right flank was se-

with the use of knives. He was examined in the emer-

verely bruised, and his right costovertebral angle was ex-

gency department and found to have a bleeding stab

tremely tender on palpation. A specimen of urine

wound in his left flank. A urine specimen revealed

showed microscopic hematuria. A diagnosis of damage

frank blood.

to the right kidney was made.

2. Stab wounds of the kidneys involve other abdominal or-

1. The following statements concerning blunt trauma to

gans in a high percentage of cases. Of the organs listed,

the kidney are correct except which?

which one is least likely to be damaged in this patient?

A. The kidney tends to be crushed between the twelfth

A. Stomach

rib and the vertebral column.

B. Spleen

B. The kidney can be injured by fractures of the twelfth

C. Inferior vena cava

rib (right kidney) or eleventh and twelfth ribs (left

D. Left colic flexure

kidney).

E. Left suprarenal gland

C. In most patients the kidney damage is mild and re-

F. Coils of jejunum

sults in nothing more than microscopic hematuria,

G. Body of the pancreas

as in this patient.

D. In severe kidney lacerations, extensive hemorrhage

An inebriated 40-year-old man was involved in a fight

and extravasation of blood and urine into the

over a woman. The woman’s husband gave the man a se-

pararenal fat occurs.

vere blow to the lower part of the anterior abdominal

E. In severe kidney lacerations, a mass caused by ex-

wall, whereupon he doubled up with pain and collapsed

travasated blood and urine behind the peritoneum

on the floor. On admission to the emergency department

may be palpated, especially on the right side.

of the local hospital, the man was in a state of shock and

The Kidneys, the Ureters, the Bladder, and the Urethra

381

complaining of severe pain in the lower abdominal

The following statements concerning this case are cor-

region. He was unable to pass urine since the fight. A di-

rect except which?

agnosis of ruptured urinary bladder was made.

A. Rupture of the bulbous part of the urethra had taken

place.

The following statements concerning this patient are

B. The urine had escaped from the urethra and ex-

correct except which?

travasated into the superficial perineal pouch.

A. Rectal examination revealed a bulging backward of

C. The urine had passed forward over the scrotum and

the rectovesical fossa.

penis to enter the anterior abdominal wall.

B. Although the patient had consumed a considerable

D. The urine had extended posteriorly into the is-

volume of liquor, dullness was not present on per-

chiorectal fossae.

cussion of the anterior abdominal wall above the

E. The urine was located beneath the membranous

symphysis pubis.

layer of superficial fascia.

C. The urine accumulated in the rectovesical pouch.

D. A full bladder is more likely to be ruptured by a blow

A 34-year-old man was suffering from postoperative re-

to the anterior abdominal wall than an empty

tention of urine after an appendectomy. The patient’s

bladder.

urinary tract was otherwise normal. Because the patient

E. In the adult, as the normal bladder fills, its superior

was in considerable discomfort, the resident decided to

wall extends upward into the abdomen, leaving the

pass a catheter.

covering of parietal peritoneum behind.

The following statements concerning the catheteriza-

A 39-year-old woman was admitted to the local hospital

tion of a male patient are correct except which?

after experiencing a gunshot wound to the lower part of

A. Because the external urethral orifice is the narrow-

her back. Radiographic examination revealed that the

est part of the urethra, once the tip of the catheter

bullet was lodged in the vertebral canal at the level of

has passed this point, further passage should be

the third lumbar vertebra. A comprehensive neurologic

easy.

examination indicated that a complete lesion of the

B. Near the posterior end of the fossa terminalis, a fold

cauda equina had occurred.

of mucous membrane projects from the roof and

may catch the end of the catheter.

The following statements concerning this patient are

C. The membranous part of the urethra is narrow and

likely to be true except which?

fixed and may produce some resistance to the pas-

A. The cauda equina, which consists of anterior and

sage of the catheter.

posterior nerve roots below the level of the first lum-

D. The prostatic part of the urethra is the widest and

bar segment, was sectioned at the level of the third

most easily dilated part of the urethra and should

lumbar vertebra.

cause no difficulty to the passage of the catheter.

B. The preganglionic sympathetic nerve fibers to the

E. The bladder neck is surrounded by the sphincter

vesical sphincter that descend in the anterior roots of

vesicae and always strongly resists the passage of the

the fourth and fifth lumbar nerves were sectioned.

tip of the catheter.

C. The preganglionic parasympathetic fibers to the

detrusor muscle that descend in the anterior roots

An explorer in the Amazon jungle was found alive af-

of the second, third, and fourth sacral nerves were

ter having lost contact with the outside world for 6

sectioned.

months. On physical examination, he was found to be

D. The patient would have an autonomous bladder.

in an emaciated condition. On palpation of the ab-

E. The bladder would fill to capacity and then overflow.

domen, a rounded, smooth swelling appeared in the

F. Micturition could be activated by powerful contrac-

right loin at the end of inspiration. On expiration, the

tion of the abdominal muscles and manual pressure

swelling moved upward and could no longer be felt.

on the anterior abdominal wall in the suprapubic

What anatomic structure could produce such a

region.

swelling?

A 15-year-old boy was taking part in a bicycle race

An intravenous pyelogram revealed that a patient’s left

when, on approaching a steep hill, he stood up on the

kidney was in its normal position, but the right kidney

pedals to increase the speed. His right foot slipped off

was situated in front of the right sacroiliac joint. Can

the pedal and he fell violently, his perineum hitting

you explain this on embryologic grounds?

the bar of the bicycle. Several hours later he was ad-

mitted to the hospital unable to micturate. On exami-

An examination of a patient revealed that she had a

nation, he was found to have extensive swelling of the

horseshoe kidney. What anatomic structure prevents a

penis and scrotum. A diagnosis of ruptured urethra

horseshoe kidney from ascending to a level above the

was made.

umbilicus?

382

Chapter 21

10. An intravenous pyelogram revealed that the calyces

13. Renal pain is a common symptom faced by medical

and pelvis of a patient’s right kidney were grossly dilated

professionals. Describe the course taken by pain nerve

(a condition known as hydronephrosis). What embry-

fibers from the kidneys. In which regions of the body is

ologic anomaly may be responsible for this condition?

pain commonly referred to?

11. A 55-year-old woman was found rolling on her kitchen

14. In relation to abdominal trauma, can you explain the

floor, crying out from agonizing pain in her abdomen.

differences between the bladder position in a child

The pain came in waves and extended from the right

compared with that of an adult? Does the degree of fill-

loin to the groin and to the front of the right thigh. An

ing of the adult bladder affect the signs and symptoms

anteroposterior radiograph of the abdomen revealed a

presented by the patient with a ruptured bladder? Can

calculus in the right ureter. What causes the pain when

you explain how it is possible to pass an aspirating

a ureteral calculus is present? Why is the pain felt in

needle through the anterior abdominal wall into the

such an extensive area? Where does one look for the

full bladder in an adult without entering the peritoneal

course of the ureter in a radiograph? Where along the

cavity?

ureter is a calculus likely to be held up?

15. Why is acute cystitis more common in females than in

12. Which congenital anomaly of the ureter is likely to

males? In anatomic terms explain stress incontinence.

present as a case of urinary incontinence?

Answers and Explanations

F is the correct answer. Because of the large size of the

contracted diaphragm has pushed it down to its lowest

right lobe of the liver, the right kidney lies at a lower

level. When the diaphragm relaxes on expiration, the

level than the left kidney.

kidney returns to its original position.

C is the correct answer. The inferior vena cava lies at

Both kidneys originate in the pelvis and with develop-

some distance from the left flank.

ment rise up on the posterior abdominal wall until the

hili lie opposite the second lumbar vertebra. Occasion-

E is the correct answer. In the adult, as the normal blad-

ally, one of the kidneys fails to reach its normal position.

der fills, its superior wall bulges upward into the

abdomen, peeling off the peritoneum from the poste-

The bridge of renal tissue, which unites the lower poles

rior surface of the anterior abdominal wall (see text

of the two kidneys to form the horseshoe, becomes

Fig. 21-17).

trapped behind the inferior mesenteric artery (see CD

Fig. 21-3). The artery arrests the ascent of the kidneys.

B is the correct answer. The preganglionic sympathetic

nerve fibers to the vesical sphincter descend in the an-

10.

An aberrant renal artery may cross the pelviureteric junc-

terior roots of the first and second lumbar nerves and

tion and obstruct the flow of urine (see CD Fig. 21-3).

were left intact.

11.

Spasm of the smooth muscle in the wall of the pelvis

D is the correct answer. The superficial perineal pouch

and ureter occurs as it attempts to move the calculus

is closed off posteriorly by the attachment of the mem-

down the urinary tract. Afferent pain nerve fibers enter

branous layer of superficial fascia to the posterior mar-

the spinal cord in the first and second lumbar segments.

gin of the urogenital diaphragm (see text Fig. 21-15).

The anterior rami of the first lumbar nerves are distrib-

Because of this attachment, the extravasated urine can-

uted in the skin in the lumbar region and groin as the

not enter the ischiorectal fossae.

iliohypogastric and ilioinguinal nerves. The pain expe-

rienced in the front of the thigh was referred along the

E is the correct answer. The bladder neck does not

femoral branch of the genitofemoral nerve (L1and 2).

cause obstruction to the passage of the catheter. In this

One could look for the course of the ureter in front of

patient, the sphincter may provide some minor resis-

the tips of the transverse processes of the lumbar verte-

tance that is easily overcome.

brae, in front of the sacroiliac joint, and in the region of

The right kidney was felt. It is the only normal kidney

the spine of the ischium. A calculus is likely to be held

that can be palpated. The lower pole may be felt in a

up at the pelviureteric junction, where the ureter

thin person at the end of inspiration, when the

crosses the pelvic brim and where it enters the bladder.

The Kidneys, the Ureters, the Bladder, and the Urethra

383

12.

The congenital anomaly is a case of bifid ureters in

When the bladder is empty, the anterior wall of the

which one ureter opens into the urinary tract below the

bladder lies behind the symphysis pubis. Trauma to the

bladder sphincter in the male, or into the vagina in the

lower abdomen in these circumstances may not dam-

female (see CD Fig. 21-4).

age the bladder. However, if the pubic bones are frac-

tured, the anterior wall of the bladder may be damaged

13.

Renal pain may result from stretching the renal capsule

by bone fragments, and urine escapes below the reflec-

or spasm of the smooth muscle in the pelvis or the

tion of the peritoneum and does not enter the peri-

ureter. The afferent nerve fibers pass through the renal

toneal cavity. Lower abdominal pain and hematuria are

plexus around the renal artery and ascend to the spinal

present in the majority of such patients.

cord through the lowest thoracic splanchnic nerve and

It is possible to pass an aspirating needle through

the sympathetic trunk. They enter the twelfth thoracic

the lower part of the anterior abdominal wall into the

spinal nerve through the white rami communicantes

full bladder in an adult without entering the peritoneal

and the twelfth thoracic segment of the spinal cord

cavity. This can be explained because as the bladder

through the posterior root of the spinal nerve. The pain

fills, the superior wall rises and strips the peritoneum

fibers are then believed to ascend to the brain in the lat-

off the lower part of the anterior abdominal wall.

eral spinal thalamic tracts. The pain is referred along

Thus, the aspirating needle will enter the bladder be-

the distribution of the subcostal nerve (T12) to the flank

low the peritoneal reflection and avoid the peritoneal

and the anterior abdominal wall.

cavity.

14.

In young children, the empty bladder lies in the ab-

domen; later, as the pelvis enlarges, the bladder sinks to

15.

Acute cystitis is much more common in females than

become a pelvic organ.

males because the urethra is much shorter. In females

In adults, the full bladder lies behind the lower part

the urethra measures 1.5 in. long, whereas in males the

of the anterior abdominal wall. Severe trauma to the

urethra measures about 8 in. long, and thus bacteria

lower abdomen in patients with a full bladder may

have a shorter distance to travel in the female.

cause the superior wall of the bladder to rupture into

Stress incontinence usually follows a difficult

the peritoneal cavity. The blood and urine irritates the

childbirth, where there has been injury to the pelvic

peritoneum, causing lower abdominal tenderness and

floor. This results in an alteration in the position of the

later muscle rigidity.

bladder neck relative to the urethra.

Chapter Outline

The Scrotum

388

The Bulbourethral Glands

391

Lymph Drainage of the Scrotum

388

Infection of the Bulbourethral Glands

391

Hydrocele

388

The Penis

391

The Testis and the Epididymis

388

Circumcision

391

Varicocele

388

Urethral Infection

391

Malignant Tumor of the Testis

389

Catheterization

391

Torsion of the Testis

389

Blunt Trauma to the Penis

391

Congenital Anomalies of the Testis

389

Penetrating Trauma to the Penis

391

Appendix of the Testis and Appendix of the

Strangulation of the Penis

391

Epididymis

389

Phimosis

392

The Vas Deferens

390

Erection and Ejaculation after Spinal Cord Injuries

392

Vasectomy

390

Congenital Anomalies of the Penis

392

The Prostate

390

Meatal Stenosis

392

Prostate Examination

390

Hypospadias

392

Prostate Activity and Disease

390

Epispadias

392

Benign Enlargement of the Prostate

390

Clinical Problem Solving Questions

392

Prostate Cancer and the Prostatic Venous Plexus

390

Answers and Explanations

393

THE TESTIS AND

THE SCROTUM

THE EPIDIDYMIS

Lymph Drainage of the Scrotum

It is important to remember that the lymph drainage of the

Varicocele

scrotal wall, including the fascia and tunica vaginalis, is into

the superficial inguinal nodes. The lymph drainage of the

A varicocele is a condition in which the veins of the

testis and epididymis (which develop on the posterior ab-

pampiniform plexus are elongated and dilated. It is a com-

dominal wall) is into the lumbar or paraaortic nodes at the

mon disorder in adolescents and young adults, with most oc-

level of the first lumbar vertebra.

curring on the left side. This is thought to be because the

right testicular vein joins the low-pressure inferior vena

cava, whereas the left vein joins the left renal vein, in which

Hydrocele

the venous pressure is higher. Rarely, malignant disease of

This is an accumulation of fluid within the tunica

the left kidney extends along the renal vein and blocks the

vaginalis. Most hydroceles are idiopathic, but some may be

exit of the testicular vein. A rapidly developing left-sided

caused by spread of infection from the testis or epididymis.

varicocele should therefore always lead one to examine the

Tapping a hydrocele is described on CD page 314.

left kidney.

The Male Genital Organs, the Penis, and the Scrotum

389

■ Imperfect descent (cryptorchidism):

Malignant Tumor of the Testis

Incomplete descent (CD Fig. 22-1), in which the

testis, although traveling down its normal path, fails to

A malignant tumor of the testis spreads upward via the lymph

reach the floor of the scrotum. It may be found within the

vessels to the lumbar (paraaortic) lymph nodes at the level of

abdomen, within the inguinal canal, at the superficial

the first lumbar vertebra. It is only later, when the tumor

inguinal ring, or high up in the scrotum.

spreads locally to involve the tissues and skin of the scrotum,

Maldescent (CD Fig. 22-2), in which the testis

that the superficial inguinal lymph nodes are involved.

travels down an abnormal path and fails to reach the

scrotum. It may be found in the superficial fascia of the

Torsion of the Testis

anterior abdominal wall above the inguinal ligament, in

front of the pubis, in the perineum, or in the thigh.

Torsion of the testes is a rotation of the testis around the sper-

matic cord within the scrotum. It is often associated with an

It is necessary for the testes to leave the abdominal cav-

excessively large tunica vaginalis. Torsion commonly occurs

ity because the temperature there retards the normal process

in active young men and children and is accompanied by

of spermatogenesis. If an incompletely descended testis is

severe pain. If not treated quickly, the testicular artery may

brought down into the scrotum by surgery before puberty, it

be occluded, followed by necrosis of the testis.

will develop and function normally. A maldescended testis,

although often developing normally, is susceptible to trau-

matic injury and, for this reason, should be placed in the

scrotum. Many authorities believe that the incidence of tu-

CONGENITAL

mor formation is greater in testes that have not descended

into the scrotum.

ANOMALIES OF

THE TESTIS

Appendix of the Testis and

The testis may be subject to the following congenital

Appendix of the Epididymis

anomalies:

These are embryologic remnants found at the upper poles of

■ Anterior inversion, in which the epididymis lies anteri-

these organs that may become cystic. The appendix of the

orly and the testis and the tunica vaginalis lie posteriorly

testis is derived from the paramesonephric ducts, and the ap-

■ Polar inversion, in which the testis and epididymis are

pendix of the epididymis is a remnant of the mesonephric

completely inverted

tubules.

CD Figure 22-1

Four degrees of incomplete descent

of the testis. 1. In the abdominal cavity close to the

deep inguinal ring. 2. In the inguinal canal. 3. At

the superficial inguinal ring. 4. In the upper part of

scrotum.

390

Chapter 22

estrogens circulating in the bloodstream. The secretions of

the prostate are poured into the urethra during ejaculation

and are added to the seminal fluid. Acid phosphatase is an

important enzyme present in the secretion in large

amounts. When the glandular cells producing this enzyme

cannot discharge their secretion into the ducts, as in carci-

noma of the prostate, the serum acid phosphatase level of

the blood rises.

It has been shown that trace amounts of proteins

produced specifically by prostatic epithelial cells are found

in peripheral blood. In certain prostatic diseases, notably

cancer of the prostate, this protein appears in the blood in

increased amounts. The specific protein level can be mea-

sured by a simple laboratory test called the PSA (prostatic-

specific antigen) test.

Benign Enlargement of the Prostate

Benign enlargement of the prostate is common in men

older than 50 years. The cause is possibly an imbalance in

CD Figure 22-2

Four types of maldescent of the testis. 1. In

the hormonal control of the gland. The median lobe of the

the superficial fascia of the anterior abdominal wall, above

gland enlarges upward and encroaches within the sphinc-

the superficial inguinal ring. 2. At the root of the penis. 3. In

ter vesicae, located at the neck of the bladder. The leakage

the perineum. 4. In the thigh.

of urine into the prostatic urethra causes an intense reflex

desire to micturate. The enlargement of the median and

lateral lobes of the gland produces elongation and lateral

compression and distortion of the urethra so that the pa-

THE VAS DEFERENS

tient experiences difficulty in passing urine and the stream

is weak. Backpressure effects on the ureters and both

kidneys are a common complication. The enlargement

Vasectomy

of the uvula vesicae (owing to the enlarged median lobe)

Bilateral vasectomy is a simple operation performed to pro-

results in the formation of a pouch of stagnant urine

duce infertility. Under local anesthesia, a small incision is

behind the urethral orifice within the bladder (CD Fig.

made in the upper part of the scrotal wall, and the vas def-

22-3). The stagnant urine frequently becomes infected,

erens is divided between ligatures. Spermatozoa may be pre-

and the inflamed bladder (cystitis) adds to the patient’s

sent in the first few postoperative ejaculations, but that is

symptoms.

simply an emptying process. Now only the secretions of the

In all operations on the prostate, the surgeon regards

seminal vesicles and prostate constitute the seminal fluid,

the prostatic venous plexus with respect. The veins have thin

which can be ejaculated as before.

walls, are valveless, and are drained by several large trunks

directly into the internal iliac veins. Damage to these veins

can result in a severe hemorrhage.

THE PROSTATE

Prostate Cancer and the Prostatic

Prostate Examination

Venous Plexus

The prostate can be examined clinically by palpation by per-

Many connections between the prostatic venous plexus and

forming a rectal examination (see CD Chapter 19). The ex-

the vertebral veins exist. During coughing and sneezing or

aminer’s gloved finger can feel the posterior surface of the

abdominal straining, it is possible for prostatic venous blood

prostate through the anterior rectal wall.

to flow in a reverse direction and enter the vertebral veins.

This explains the frequent occurrence of skeletal metastases

in the lower vertebral column and pelvic bones of patients

Prostate Activity and Disease

with carcinoma of the prostate. Cancer cells enter the skull

It is now generally believed that the normal glandular

via this route by floating up the valveless prostatic and verte-

activity of the prostate is controlled by the androgens and

bral veins.

The Male Genital Organs, the Penis, and the Scrotum

391

enlarged median lobe of prostate

bladder wall

pouch of stagnant urine

sphincter vesicae

ejaculatory duct

posterior lobe

CD Figure 22-3

Sagittal section of a prostate that

had undergone benign enlargement of the median

lobe. Note the bladder pouch filled with stagnant

urethra

urine behind the prostate.

these reasons, prophylactic circumcision is commonly prac-

THE

ticed. For Jews, it is a religious rite.

BULBOURETHRAL

Urethral Infection

See CD Chapter 21.

GLANDS

Catheterization

Infection of the Bulbourethral

See CD Chapter 21.

Glands

Blunt Trauma to the Penis

The bulbourethral glands are the common sites for chronic

This may cause penile fracture when it is in the erect state.

venereal infection (e.g., gonorrhoea). The organisms reach

A transverse laceration of the fibrous envelopes of the erec-

the gland by ascending from the bulbous part of the urethra

tile tissue of the penis occurs followed by the formation of a

along the duct of the gland.

large hematoma; the base of the penis is the common site of

injury. Rupture of the penile urethra may also occur and is

accompanied by a bloody urethral discharge.

THE PENIS

Penetrating Trauma to the Penis

This may injure the skin, fascia, erectile tissue, and urethra.

Circumcision

Amputation of the entire penis should be repaired by anas-

Circumcision is the operation of removing the greater part

tomosis using microsurgical techniques to restore continu-

of the prepuce, or foreskin. In many newborn males, the

ity of the main blood vessels.

prepuce cannot be retracted over the glans. This can result

in infection of the secretions beneath the prepuce, leading

Strangulation of the Penis

to inflammation, swelling, and fibrosis of the prepuce. Re-

peated inflammation leads to constriction of the orifice of

Strangulation of the penis by means of a ring or ligature may

the prepuce (phimosis) with obstruction to urination. It is

cause ischemia of the entire penis. It is imperative that the

now generally believed that chronic inflammation of the

constriction be removed without delay to avoid compromis-

prepuce predisposes to carcinoma of the glans penis. For

ing the blood supply.

392

Chapter 22

damage to the spinal cord results in loss of ejaculation.

Phimosis

Later, reflex ejaculation may be possible in patients with

spinal cord transections in the thoracic or cervical regions.

In this condition the opening in the prepuce is narrowed so

that it is impossible to retract the prepuce over the glans pe-

nis. Occasionally the narrowing is so extreme that the uri-

nary flow is obstructed. The usual cause of the condition is

CONGENITAL

infection under the prepuce, causing fibrosis and subse-

quent contraction of the prepuce.

ANOMALIES OF

Erection and Ejaculation after

THE PENIS

Spinal Cord Injuries

Meatal Stenosis

Erection of the penis is controlled by the parasympathetic

nerves that originate from the second, third, and fourth

See CD Chapter 21.

sacral segments of the spinal cord. Bilateral damage to the

reticulospinal nerve tracts in the spinal cord will result in

Hypospadias

loss of erection. Later, when the effects of spinal shock have

disappeared, spontaneous or reflex erection may occur if the

See CD Chapter 21.

sacral segments of the spinal cord are intact.

Ejaculation is controlled by sympathetic nerves

Epispadias

that originate in the first and second lumbar segments of

the spinal cord. As in the case of erection, severe bilateral

See CD Chapter 21.

Clinical Problem Solving Questions

Read the following case histories/questions and give

While bathing her 5-month-old boy, a mother no-

the best answer for each.

ticed that his penis tended to curve downward. She

decided to seek advice from a pediatrician.

A 55-year-old man was admitted to the hospital with a large

hard, fixed, intraabdominal mass. On examination of the ab-

2. The pediatrician examined the child and made the

domen, the mass was situated on the transpyloric plane and

following possible correct observations and statements

appeared to be attached to the posterior abdominal wall.

except which?

The inguinal lymph nodes were normal.

A. The penis had a definite downward curvature

1. The symptoms and signs displayed by this patient can

(chordee).

be explained by the following statements except which?

B. Both testes were in the scrotum.

A. Radiologic examination of the stomach showed

C. The external urethral meatus opened halfway along

nothing abnormal.

the undersurface of the penis.

B. The right testicle was enlarged and was much

D. The fusion of the genital folds on the ventral or un-

harder than normal.

dersurface of the shaft of the penis was incomplete

C. A diagnosis of malignant disease of the right testis

so that the urethra opened on the ventral surface.

was made.

E. The condition is a rare congenital anomaly.

D. The malignant tumor had metastasized to the lum-

bar lymph nodes lying on the transpyloric plane on

3. The pediatrician made the following possible correct

the posterior abdominal wall, which is the normal

statements to the mother regarding the diagnosis and

lymphatic drainage of the testis.

treatment except which?

E. In malignant disease of the testis the superficial

A. The child had hypospadias associated with chordee.

inguinal lymph nodes only become involved if the

B. The proximal portion of the penile urethra had

tumor spreads to involve the scrotal skin.

developed normally but was incomplete.

F. The normal testis is tethered to the skin of the

C. The bud of cells (ectodermal) on the tip of the glans

scrotum.

penis had failed to grow into the substance of the

The Male Genital Organs, the Penis, and the Scrotum

393

glans and join with the cells (entodermal cells) of

left thigh. What is the diagnosis? Is surgical treatment

the penile urethra.

required?

D. The treatment is the surgical correction of the

A 25-year-old man developed a swelling above the me-

chordee, which is followed by the plastic recon-

dial end of the right inguinal ligament. It was associated

struction of the penile urethra.

with a dull, aching pain, bit it did not expand on cough-

E. In view of the delicate tissues involved, the treat-

ing. On palpation, the swelling appeared to fluctuate,

ment should be delayed until the child is at least 10

and on grasping the right testis through the scrotal wall

years old.

and gently pulling it inferiorly, the swelling moved me-

A 65-year-old man with a history of prostatic disease was

dially along the inguinal canal. What was the swelling?

found on radiographic examination of his skeleton to

Why did it move with the testis?

have extensive carcinomatous metastases in his skull

A patient suffering from tuberculosis of the left epi-

and lumbar vertebrae. His PAS levels in his blood were

didymis was found to have an ulcer on the posterior sur-

very much higher than normal. Using your knowledge

face of the scrotum. Which group of lymph nodes

of anatomy, can you suggest a possible route taken by

would you examine for local spread of the disease?

the cancer cells as they migrated from the prostate to (1)

the lumbar vertebrae and (2) the skull?

10.

A resident was asked to examine the vas deferens of a pa-

tient. Where would you examine the vas deferens and

An 88-year-old man had a history of prostatic disease.

what does a normal vas feel like?

His latest symptoms included difficulty in starting to

micturate, a poor urinary stream, and difficulty in stop-

11.

In a patient with a history of venereal disease, a large,

ping the flow of urine. Which lobe or lobes of the

fluctuant swelling developed in front of the left testis.

prostate are related to the sphincter vesicae? The en-

From your knowledge of anatomy, and given that there

largement of which lobe is likely to interfere with the

is fluid present in the scrotum, where in the scrotum is

sphincter’s function?

the fluid likely to collect?

A 6-year-old boy was examined by a pediatrician and

12.

A 50-year-old man was found on examination to have a

found to have no testicle present in the right side of his

small cystic swelling above his right testis. What

scrotum. On careful palpation, a deep, firm ovoid struc-

anatomic structure is likely to be involved? Can you ex-

ture could be felt above the medial part of the inguinal

plain the presence of this structure embryologically?

ligament. What is the diagnosis? Is surgical treatment

13.

A 25-year-old man was found, during a physical exami-

necessary?

nation, to have an abnormal scrotum. On feeling the

An 18-year-old boy, at a medical examination for ad-

scrotum with the palm of the hand, it felt like a bag of

mission to the army, was found to have no testis in the

worms. This situation was caused by an enlargement of

left side of the scrotum. Nothing abnormal could be

the pampiniform plexus on the left side. The physician

palpated in the inguinal canal, but a small, firm ovoid

examined the scrotum and then the left kidney. Can

structure could be felt in front of the upper part of the

you explain why he should examine the left kidney?

Answers and Explanations

1. F is the correct answer. The normal testis is freely mo-

4. The prostatic venous plexus is drained into the internal

bile within the scrotum and is not tethered to the sub-

iliac veins. Large valveless veins also connect the plexus

cutaneous tissue or skin.

to the valveless vertebral veins. On coughing or sneez-

ing, the blood may be forced from the prostatic plexus

2. E is the correct answer. The condition is one of the

in the pelvis into the vertebral veins. Dislodged prosta-

most common congenital anomalies affecting the male

tic cancer cells may be carried along this route to the

urethra.

vertebral column. They may also pass up the vertebral

3. E is the correct answer. The surgical treatment should

plexus to enter the veins of the skull.

start at about the age of 2 years and be complete before

the child goes to school. Little boys like to look the same

5. The median (middle) lobe of the prostate is located be-

as other little boys.

tween the prostatic urethra and the ejaculatory ducts,

394

Chapter 22

just inferior to the sphincter vesicae. Benign hypertro-

tunica vaginalis, the cyst was pulled medially by the

phy of the median lobe results in its upward expansion

fibrous strand.

within the sphincter vesicae. The sphincter can no

The skin of the scrotum, the fascia, and the tunica vagi-

longer function effectively, and urine continues to drib-

nalis drain their lymph into the superficial inguinal

ble into the urethra, giving the patient an intense desire

lymph nodes.

to continue to micturate.

10.

Palpate the upper part of the scrotum between finger

The boy had an incompletely descended testis on the

and thumb, and you can roll the vas deferens as a cord-

right side. The right testis was situated in the inguinal

like structure. It has a smooth external wall and is firm

canal. Spontaneous descent of the testis usually occurs

in consistency. Remember there are two sides and to

without treatment. The injection of gonadotropic hor-

always compare the two.

mone can be used to speed up the descent. However, if

the descent has not occurred by the age of 10 years, sur-

11.

The tunica vaginalis covers the front and sides of the

gical treatment is necessary to place the testis in the

testis, and the visceral layer is in direct contact with the

scrotum. The high temperature of the abdominal cavity

tunica albuginea of the testis. Infection causes an ex-

and inguinal canal inhibits normal spermatogenesis.

cessive production and accumulation of fluid within

the tunica, a condition known as hydrocele.

The boy had a maldescended testis on the left side.

Instead of following the gubernaculum down into the

12.

The patient has a cyst of the appendix of the testis, a

scrotum, it passed laterally and came to rest in the su-

structure that is derived embryologically from the para-

perficial fascia in the upper part of the left thigh. A

mesonephric duct.

maldescended testis is very prone to injury and should

13.

The left pampiniform plexus is drained by the left

be placed in the scrotum by surgical means.

testicular vein, which is drained into the left renal vein.

The patient had a right encysted hydrocele of the sper-

A malignant tumor of the left kidney could spread along

matic cord. This is a cyst in the remnant of the upper

the left renal vein, blocking the exit of the left testicular

part of the processus vaginalis and is connected to the

vein and causing congestion and varicosity of the left

tunica vaginalis by a fibrous strand (a further remnant

pampiniform plexus. This is a rare cause. The majority

of the processus). On pulling down the testis and the

of varicoceles are idiopathic.

Chapter Outline

The Vulva

397

The Anatomy of Emergency Cesarean

Section

403

Vulval Infection

397

The Anatomy of the Technique

403

The Vulva and Pregnancy

397

Prolapse of the Uterus

403

The Urethra

397

Urethral Infection

397

Hysterectomy and Damage to the Ureter

404

Urethral Injuries

397

Congenital Anomalies of the Uterus

404

Catheterization

397

Agenesis of the Uterus

404

The Ovary

397

Infantile Uterus

404

Position of the Ovary

397

Failure of Fusion of the Paramesonephric Ducts

404

Cysts of the Ovary

397

The Placenta

404

Congenital Anomalies of the Ovary

397

The Placenta and Bleeding in Late Pregnancy

404

Ovarian Dysgenesis

397

Placenta Previa

404

Imperfect Descent of the Ovary

397

Placental Abruption

405

The Uterine Tube

397

The Vagina

405

The Uterine Tube as a Conduit for Infection

397

Vaginal Examination

405

Pelvic Inflammatory Disease

397

Prolapse of the Vagina

406

Ectopic Pregnancy

398

Culdocentesis

406

Anatomic Structures through which the

Tubal Ligation

398

Needle Passes

406

The Uterus

398

Anatomic Features of the Complications of

Rectal Examination

398

Culdocentesis

406

Bimanual Pelvic Examination of the Uterus

398

Vaginal Trauma

406

Congenital Anomalies of the Vagina

406

Basic Anatomy of a Normal Pregnancy

399

Vaginal Agenesis

406

Ultrasound Anatomy of the Developing Fetus

400

Double Vagina

406

Anatomy of Childbirth

400

Imperforate Vagina and Imperforate Hymen

406

Labor Pains

400

Visceral Pelvic Fascia

406

Labor

400

Visceral Pelvic Fascia and Infection

406

The Uterus in Pregnancy

401

The Pelvic Peritoneum

406

The Role of the Uterus in the Onset of Labor

401

The Rectouterine Pouch and Disease

406

Injury to the Perineum during Childbirth

402

Varicosed Veins and Hemorrhoids in Pregnancy

403

Clinical Problem Solving Questions

407

Answers and Explanations

408

The Perineum, the Female Genital Organs, and Childbirth

397

broad ligament is lax, and the ovaries may prolapse into the

rectouterine pouch (pouch of Douglas). In these circum-

THE VULVA

stances, the ovary may be tender and cause discomfort on

sexual intercourse (dyspareunia). An ovary situated in the

rectouterine pouch may be palpated through the posterior

Vulval Infection

fornix of the vagina.

In the region of the vulva, the presence of numerous glands

and ducts opening onto the surface makes this area prone to

Cysts of the Ovary

infection (see text Fig. 23-7). The sebaceous glands of the

Follicular cysts are common and originate in unruptured

labia majora, the ducts of the greater vestibular glands, the

graafian follicles; they rarely exceed 0.6 in. (1.5 cm) in di-

vagina (with its indirect communication with the peritoneal

ameter. Luteal cysts are formed in the corpus luteum.

cavity), the urethra, and the paraurethral glands can all be-

Fluid is retained, and the corpus luteum cannot become

come infected. The vagina itself has no glands and is lined

fibrosed. Luteal cysts rarely exceed 1.2 in. (3 cm) in

with stratified squamous epithelium. Provided that the pH

diameter.

of its interior is kept low, it is capable of resisting infection to

a remarkable degree.

Congenital Anomalies of the Ovary

The Vulva and Pregnancy

Ovarian Dysgenesis

An important sign in the diagnosis of pregnancy is the ap-

Complete failure of both ovaries to develop is found in

pearance of a bluish discoloration of the vulva and vagina as

Turner’s syndrome. The classic features of this syndrome

a result of venous congestion. It appears at the eighth to

are webbed neck, short stocky build, increased carrying an-

twelfth week and increases as the pregnancy progresses.

gle of the elbows, lack of secondary sex characteristics, and

amenorrhea.

THE URETHRA

Imperfect Descent of the Ovary

The ovary may fail to descend into the pelvis or very rarely

Urethral Infection

may be drawn downward with the round ligament of the

uterus into the inguinal canal or even into the labium

The short length of the female urethra predisposes to as-

majus.

cending infection; consequently, cystitis is more common

in females than in males.

THE UTERINE

Urethral Injuries

Because of the short length of the urethra, injuries are rare. In

TUBE

fractures of the pelvis, the urethra may be damaged by shear-

ing forces as it emerges from the fixed urogenital diaphragm.

The Uterine Tube as a Conduit

for Infection

Catheterization

The uterine tube lies in the upper free border of the broad

Because the female urethra is shorter, wider, and more di-

ligament (see text Fig. 23-10) and is a direct route of com-

latable, catheterization is much easier than in males. More-

munication from the vulva through the vagina and uterine

over, the urethra is straight, and only minor resistance is felt

cavity to the peritoneal cavity.

as the catheter passes through the urethral sphincter.

Pelvic Inflammatory Disease

THE OVARY

The pathogenic organism(s) enter the body through sexual

contact and ascend through the uterus and enter the uter-

ine tubes. Salpingitis may follow, with leakage of pus into

Position of the Ovary

the peritoneal cavity, causing pelvic peritonitis. A pelvic

The ovary is kept in position by the broad ligament and the

abscess usually follows, or the infection spreads farther,

mesovarium (see text Fig. 23-10). After pregnancy, the

causing general peritonitis.

398

Chapter 23

thin-walled uterine tube

fundus of uterus

thick decidua lining

CD Figure 23-1

An ectopic pregnancy

mucous plug

body of uterus

located where the ampulla of the uterine

tube narrows down to join the isthmus.

Note the thin tubal wall compared to the

thick decidua that lines the body of the

uterus.

Anteriorly: The anterior structures include the

Ectopic Pregnancy

following:

Implantation and growth of a fertilized ovum may occur out-

1. Opposite the terminal phalanx are the rectouterine

side the uterine cavity in the wall of the uterine tube (CD Fig.

pouch of Douglas, the vagina, and the cervix.

23-1). This is a variety of ectopic pregnancy. There being no

2. Opposite the middle phalanx are the urogenital di-

decidua formation in the tube, the eroding action of the tro-

aphragm and the vagina.

phoblast quickly destroys the wall of the tube. Tubal abortion

or rupture of the tube, with the effusion of a large quantity of

3. Opposite the proximal phalanx are the perineal body

blood into the peritoneal cavity, is the common result.

and the lower part of the vagina.

The blood pours down into the rectouterine pouch

Posteriorly: The posterior structures include the

(pouch of Douglas) or into the uterovesical pouch. The blood

following:

may quickly ascend into the general peritoneal cavity, giving

rise to severe abdominal pain, tenderness, and guarding. Irri-

1. The sacrum, coccyx, and anococcygeal body

tation of the subdiaphragmatic peritoneum (supplied by

Laterally: The lateral structures include the following:

phrenic nerves C3, C4, and C5) may give rise to referred pain

to the shoulder skin (supraclavicular nerves C3 and C4).

1. The ischiorectal fossae and ischial spines

Tubal Ligation

Bimanual Pelvic Examination of

Ligation and division of the uterine tubes is a method of ob-

the Uterus

taining permanent birth control and is usually restricted to

women who already have children. The ova that are dis-

A great deal of useful clinical information can be obtained

charged from the ovarian follicles degenerate in the tube

about the state of the uterus, uterine tubes, and ovaries from

proximal to the obstruction. If, later, the woman wishes to

a bimanual examination. The examination is easiest in

have an additional child, restoration of the continuity of the

parous women who are able to relax while the examination is

uterine tubes can be attempted, and, in about 20% of

in progress. In patients in whom it causes distress, the exami-

women, fertilization occurs.

nation may be performed under an anesthetic. With the blad-

der empty, the vaginal portion of the cervix is first palpated

with the index finger of the right hand. The external os is cir-

THE UTERUS

cular in the nulliparous woman but has anterior and posterior

lips in the multiparous woman. The cervix normally has the

consistency of the end of the nose, but in the pregnant uterus

Rectal Examination

it is soft and vascular and has the consistency of the lips. The

The following structures can be palpated by the gloved in-

left hand is then placed gently on the anterior abdominal wall

dex finger inserted into the anal canal and rectum in the

above the symphysis pubis, and the fundus and body of the

healthy patient (CD Fig. 23-2 and see CD Fig. 23-8).

uterus may be palpated between the abdominal and vaginal

The Perineum, the Female Genital Organs, and Childbirth

399

external os of uterus

head of baby

anterior lip of cervix

CD Figure 23-2

A. Rectal exami-

nation in a pregnant woman

showing how it is possible to

palpate the cervix through the

site for episiotomy

anterior rectal wall. B. Position of

the episiotomy incision in a

woman during the second stage

of labor. The baby’s head is pre-

senting at the vaginal orifice.

fingers situated in the anterior fornix. The size, shape, and

23-3). The ascent of the fundus is fairly uniform. At 12

mobility of the uterus can then be ascertained.

weeks, it lies just above the symphysis pubis; at 20 weeks, it

In most women, the uterus is anteverted and anteflexed.

lies about halfway between the symphysis pubis and the um-

A retroverted, retroflexed uterus can be palpated through

bilicus; at 24 weeks, it is level with the umbilicus; at 32

the posterior vaginal fornix.

weeks, it lies halfway between the umbilicus and the

xiphoid process; at 36 weeks, it has reached the xiphoid

process; and at 40 weeks; in the first pregnancy, the fetus

sinks downward as the presenting part enters the pelvic cav-

BASIC ANATOMY OF

ity and the fundus again takes up the position halfway be-

tween the xiphoid and the umbilicus. In multipara, the pre-

A NORMAL

senting part of the fetus descends at a later date.

Further evidence of fetal growth can be determined by

PREGNANCY

the mother first recognizing movements of the fetus (quick-

ening), which usually occurs between the sixteenth and twen-

As the fetus enlarges, the uterus increases in size, and

tieth weeks of pregnancy. Fetal heart sounds may be heard as

the fundus gradually rises out of the pelvic cavity (CD Fig.

early as the twelfth week, when a Doppler stethoscope is used.

400

Chapter 23

part of the anterior abdominal wall and the lower part of the

32 weeks

back (dermatomes T10 through T12).

24 weeks

Labor

Labor, or parturition, is the series of processes by which the

baby, the fetal membranes, and the placenta are expelled

from the genital tract of the mother. Forceful uterine con-

tractions occurring at regular intervals indicate the onset of

symphysis pubis

labor. The first stage is dilatation of the cervix. The second

stage is expulsion of the fetus. The third stage begins im-

mediately following the delivery of the baby and ends with

expulsion of the placenta and fetal membranes.

Duration of labor: This depends on (1) the strength and

36 weeks

frequency of the uterine contractions and (2) the resis-

40 weeks

tance offered to the passage of the baby by the bony pelvis

32 weeks

28 weeks

and the soft tissues of the lower part of the genital tract,

24 weeks

namely, the cervix, the vagina, the pelvic floor, and the

20 weeks

perineum. The approximate length of each stage is as fol-

lows: first stage, 9 1/2 hours; second stage, 50 minutes;

12 weeks

and third stage, 10 minutes. In multigravida the duration

of the first and second stages is shorter because of the re-

CD Figure 23-3

The height of the fundus of the uterus at

duced resistance offered by the maternal soft tissues.

various weeks of pregnancy. A. As seen in sagittal section.

Processes of Labor: During the first stage of labor, the

B. As felt through the anterior abdominal wall.

liquor amnii and the fetal membranes are forced down

into the cervical canal as a hydrostatic wedge, and the

cervix slowly dilates (CD Fig. 23-4). The pulling away of

the membranes from the uterine wall in the region of the

Ultrasound Anatomy of the

internal os of the cervix causes a little bleeding, and this,

together with the cervical plug of mucus that fills the

Developing Fetus

canal of the cervix, forms the so-called bloody show. The

rupture of the membranes and the escape of the liquor

With sequential longitudinal and transverse scans of the

amnii usually occur when the first stage of labor is well

uterus, the developing fetus, amniotic fluid, and placenta

advanced. The escape of the liquor amnii allow the

can be studied. The gestational sac can be recognized at

uterus to exert pressure directly on the baby and force it

about 5 weeks after the first day of the last menstrual period.

down.

By 6 to 7 weeks the fetal pole (extreme end or ends of fetus)

can be visualized, and the beating heart can be seen. Later,

During the second stage of labor, the combined actions

the fetal head, trunk, and limbs can be identified (see text

of the very strong uterine contractions and the reflex and

Fig. 23-30).

voluntary contractions of the abdominal muscles force the

baby through the maternal passages (CD Fig. 23-5).

The pelvic floor, formed by the levatores ani and coc-

Anatomy of Childbirth

cygeus muscles, serves an important function during the

second stage of labor. From their origin on the two sides of

Labor Pains

the pelvis, the muscle fibers slope downward and backward

The underlying cause of labor pains is believed to be the

in the midline, producing a gutter that slopes downward

anoxia of the uterine muscle brought about by the uterine

and forward. To begin with, the long axis of the baby’s

contractions. Afferent pain fibers from the fundus and body

head is transversely positioned at the pelvic inlet. When

of the uterus ascend to the spinal cord through the hypogas-

the head reaches the pelvic floor, the gutter shape of the

tric plexuses, entering the cord through the posterior roots of

floor tends to cause the baby’s head to rotate, so that its

the tenth, eleventh, and twelfth thoracic spinal nerves. Sen-

long axis comes to lie in the anteroposterior position, with

sory fibers from the cervix run in the pelvic splanchnic

the occiput anteriorly in the majority. The occipital part of

nerves and enter the spinal cord through the posterior roots

the head now moves downward and forward along the gut-

of the second, third, and fourth sacral nerves. Contraction

ter until it lies under the pubic arch. As the baby’s head

pains from the fundus and body are referred to the lower

passes through the lower part of the birth canal, the small

The Perineum, the Female Genital Organs, and Childbirth

401

uterus

placenta

umbilical cord

amnion and chorion

cervix

vagina

CD Figure 23-4

A. The relation of the

amniotic fluid

fetus to the uterus, placenta, and the

fetal membranes at the fortieth week of

pregnancy. B and C. The cervix dilat-

ing during the first stage of labor as the

result of the fetal membranes being

forced down into the cervical canal as a

hydrostatic

hydrostatic wedge. The bloody show

wedge (bag

consists of the mucous plug from the

of water)

cervical canal mixed with the small

cervical canal

bloody show^{amount of bleeding that occurs follow-}

ing separation of the fetal membrane

mucous plug

from the uterine wall in the region of

vagina

the internal os.

gap that exists in the anterior part of the pelvic floor be-

the afterbirth. The uterine muscle becomes firmly con-

comes enormously enlarged, so that the head may slip

tracted and little bleeding occurs.

through into the perineum. Once the baby has passed

through the perineum, the levatores ani muscles recoil and

The Uterus in Pregnancy

take up their previous position.

The third stage of labor then commences, and the

During pregnancy, the uterus becomes greatly enlarged as

uterus contracts downward so that the fundus lies at the

a result of the increasing production of estrogens and prog-

level of the umbilicus. Rhythmic uterine contractions con-

esterone, first by the corpus luteum of the ovary and later

tinue, as in the second stage, but they are painless. Separa-

by the placenta. At first it remains as a pelvic organ, but by

tion of the placenta from the uterine wall takes place. As the

the third month the fundus rises out of the pelvis, and by

uterus diminishes in size, there is a decrease in the surface

the ninth month it has reached the xiphoid process (see

area at the site of placental attachment. The placenta, being

CD Fig. 23-3). The increase in size is largely a result of

unable to accommodate itself to the decreased area, begins

hypertrophy of the smooth muscle fibers of the my-

to fold up and is squeezed off the uterine wall (CD Fig. 23-

ometrium, although some hyperplasia takes place.

6). Separation takes place at the spongy layer of the decidua,

and some bleeding occurs. In a similar manner, the fetal

Role of the Uterus in the Onset

membranes and the remains of the decidua are squeezed

from the remainder of the uterine wall. As the placenta is fi-

of Labor

nally expelled from the uterus by the uterine contractions,

the membranes that are attached to it are dragged after it

Normally labor takes place at the end of the tenth lunar

and peeled off from the inner surface of the uterus. The ex-

month, at which time the pregnancy is said to be at term.

pelled placenta and fetal membranes are often referred to as

The cause of the onset of labor is not definitely known. By

402

Chapter 23

CD Figure 23-5

Stages in rotation of

the baby’s head during the second

stage of labor. The shape of the pelvic

floor plays an important part in this

process.

the end of pregnancy, the contractility of the uterus has

The uterine muscular activity is largely independent

been fully developed in response to estrogen, and it is par-

of the extrinsic innervation. In women in labor, spinal

ticularly sensitive to the actions of oxytocin at this time. It is

anesthesia does not interfere with the normal uterine con-

possible that the onset of labor is triggered by the sudden

tractions. Severe emotional disturbance, however, can

withdrawal of progesterone. Once the presenting part (usu-

cause premature parturition.

ally the fetal head) starts to stretch the cervix, it is thought

that a nervous reflex mechanism is initiated and increases

Injury to the Perineum during

the force of the contractions of the uterine body.

Childbirth

fetal

The perineal body is a wedge of fibromuscular tissue that

membranes

lies between the lower part of the vagina and the anal canal.

placenta

bladder

It is held in position by the insertion of the perineal muscles

uterus

and by the attachment of the levatores ani muscles. In the

female, it is a much larger structure than in the male, and it

serves to support the posterior wall of the vagina. Damage by

vagina

laceration during childbirth can be followed by permanent

weakness of the pelvic floor.

Few women escape some injury to the birth canal dur-

ing delivery. In most, this is little more than an abrasion of

the posterior vaginal wall. Spontaneous delivery of the child

with the patient unattended can result in a severe tear of the

umbilical cord

lower third of the posterior wall of the vagina, the perineal

body, and overlying skin. In severe tears, the lacerations may

CD Figure 23-6

The third stage of labor showing the sep-

arated placenta with the attached fetal membranes about to

extend backward into the anal canal and damage the exter-

be expelled through the vagina.

nal sphincter. In these cases, it is imperative that an accurate

The Perineum, the Female Genital Organs, and Childbirth

403

repair of the walls of the anal canal, vagina, and perineal

two hemostats; an incision is then made between the

body be undertaken as soon as possible.

hemostats.

In the management of childbirth, when it is obvious to

3. The bladder is identified, and a cut is made in the floor

the obstetrician that the perineum will tear before the

of the uterovesical pouch. The bladder is then sepa-

baby’s head emerges through the vaginal orifice, a planned

rated from the lower part of the body of the uterus and

surgical incision is made through the perineal skin in a

depressed downward into the pelvis.

posterolateral direction to avoid the anal sphincters. This

procedure is known as an episiotomy (see CD Fig. 23-2).

4. The uterus is palpated to identify the presenting part of

Breech deliveries and forceps deliveries are usually pre-

the fetus.

ceded by an episiotomy.

5. A transverse incision about 1 in. (2.5 cm) long is made

into the exposed lower segment of the body of the

Varicosed Veins and Hemorrhoids

uterus. Care is taken that the uterine wall is not imme-

diately penetrated and the fetus injured.

in Pregnancy

6. When the uterine cavity is entered, the amniotic cavity

Varicosed veins and hemorrhoids are common conditions

is opened, and amniotic fluid spurts. The uterine inci-

in pregnancy. The following factors probably contribute to

sion is then enlarged sufficiently to deliver the head and

their cause: pressure of the gravid uterus on the inferior vena

trunk of the fetus. When possible, the large tributaries

cava and the inferior mesenteric vein, impairing venous re-

and branches of the uterine vessels in the myometrial

turn, and increased progesterone levels in the blood, leading

wall are avoided. Great care has to be taken to avoid the

to relaxation of the smooth muscle in the walls of the veins

large uterine arteries that course along the lateral mar-

and venous dilatation.

gin of the uterus.

7. Once the fetus is delivered, the umbilical cord is

clamped and divided.

THE ANATOMY OF

8. The contracting uterus will cause the placenta to bulge

through the uterine incision. The placenta and fetal

EMERGENCY

membranes are then delivered.

9. The uterine incision is closed with a full-thickness con-

CESAREAN SECTION

tinuous suture. The peritoneum over the bladder and

lower part of the uterine body is then repaired to restore

An emergency cesarean section is rarely performed. How-

the integrity of the uterovesical pouch. Finally, the ab-

ever, a physician may need to perform this surgery in cases

dominal wall incision is closed in layers.

in which the mother may die after suffering a severe trau-

matic incident. Following maternal death, placental circu-

lation ceases, and the child must be delivered within 10

minutes; after a delay of more than 20 minutes, neonatal

PROLAPSE OF

survival is rare.

THE UTERUS

The Anatomy of the Technique

The great importance of the tone of the levatores ani muscles

in supporting the uterus has already been emphasized. The

1. The bladder is emptied, and an indwelling catheter is

importance of the transverse cervical, pubocervical, and

left in position. This allows the empty bladder to sink

sacrocervical ligaments in positioning the cervix within the

down away from the operating field.

pelvic cavity has been considered. Damage to these structures

2. A midline skin incision is made that extends from just

during childbirth or general poor body muscular tone may re-

below the umbilicus to just above the symphysis pubis.

sult in downward displacement of the uterus called uterine

The following structures are then incised: superficial

prolapse. It most commonly reveals itself after menopause,

fascia, fatty layer, and membranous layer; deep fascia

when the visceral pelvic fascia tends to atrophy along with the

(thin layer); linear alba; fascia transversalis; extraperi-

pelvic organs. In advanced cases, the cervix descends the

toneal fatty layer; and parietal peritoneum. To avoid

length of the vagina and may protrude through the orifice.

damaging loops of the small intestine or the greater

Because of the attachment of the cervix to the vaginal

omentum, which might be lying beneath the parietal

vault, it follows that prolapse of the uterus is always accom-

peritoneum, a fold of peritoneum is raised between

panied by some prolapse of the vagina.

404

Chapter 23

HYSTERECTOMY

THE PLACENTA

AND DAMAGE TO

The Placenta and Bleeding in

THE URETER

Late Pregnancy

During the surgical procedure of hysterectomy, great care

The common causes of substantial vaginal bleeding in the

must be exercised to not damage the ureters. When the sur-

third trimester are placenta previa and placental abruption.

geon is looking for the uterine artery on each side at the base

of the broad ligament (see text Fig. 23-10), it is essential that

Placenta Previa

he or she first identifies the ureter before clamping and ty-

ing off the artery. The uterine artery passes forward from the

Placenta previa occurs in about 1 of every 200 pregnancies.

internal iliac artery and crosses the ureter at right angles to

It is more common in multiparous women and in those who

reach the cervix at the level of the internal os.

have had surgery on the lower part of the uterus. Normally,

the placenta is situated in the upper half of the uterus.

Should implantation occur in the lower half of the body of

the uterus, the condition is called placenta previa.

CONGENITAL

Three types of placenta previa may be recognized

(CD Fig. 23-7): central placenta

previa, in which the

ANOMALIES OF

Type 1

THE UTERUS

Agenesis of the Uterus

Rarely the uterus will be absent as the result of a failure of

the paramesonephric ducts to develop.

Infantile Uterus

Some adults may have an infantile uterus, a condition in

which the uterus is much smaller than normal and resem-

bles that present before puberty. Amenorrhea is present, but

lateral placenta previa

the vagina and ovaries may be normal.

Failure of Fusion of the

Type 2

Type 3

Paramesonephric Ducts

Failure of the paramesonephric ducts to fuse may cause a

variety of uterine defects: (1) The uterus may be dupli-

cated with two bodies and two cervices; (2) there may be a

complete septum through the uterus, making two uterine

cavities and two cervices; (3) there may be two separate

uterine bodies with one cervix; (4) one paramesonephric

duct may fail to develop, leaving one uterine tube and half

of the body of the uterus. Clinically, the main problems

with a double uterus may be seen when pregnancy occurs.

marginal placenta previa

central placenta previa

Abortion is frequent, and the nonpregnant half of the

uterus may cause obstruction at labor.

CD Figure 23-7

The different types of placenta previa.

The Perineum, the Female Genital Organs, and Childbirth

405

entire internal os is covered by placental tissue; marginal

compromised by the placental separation and the

placenta previa, when the edge of the placenta is en-

increased pressure on the placenta by the increased uterine

croaching on the internal os; and a low-lying lateral pla-

tone.

centa previa, when the placenta lies low down in the

uterus, lateral to the internal os. Severe, painless hemor-

rhage occurring from the twenty-eighth week onward is the

clinical sign of placenta previa and is caused by expansion

THE VAGINA

of the lower half of the uterine wall at this time and by its

tearing away from the placenta.

Vaginal Examination

Placental Abruption

The anatomic relations of the vagina are of great clinical

importance. Many pathologic conditions occurring in the

Placental abruption is the premature separation of the pla-

female pelvis may be diagnosed using a simple vaginal

centa in which normal implantation has occurred. It occurs

examination.

in about 1% of pregnancies. It is more common in multi-

The following structures can be palpated through the

parous women and in women with hypertension in preg-

vaginal walls from above downward:

nancy. As the placenta separates, hemorrhage occurs; the

blood clot dissects the fetal membranes away from the uter-

■ Anteriorly: The bladder and the urethra (CD Fig. 23-8)

ine wall. The blood usually escapes through the cervix or

■ Posteriorly: Loops of ileum and the sigmoid colon in

ruptures into the amniotic cavity. The blood irritates the

the rectouterine peritoneal pouch (pouch of Douglas),

myometrium, and uterine muscle tone is increased, which

the rectal ampulla, and the perineal body (see CD Fig.

results in contractions. The placental circulation is

23-8)

sigmoid colon

coil of ileum

peritoneum

rectouterine pouch

cavity of uterus

uterovesical pouch

rectum

bladder

anococcygeal body

cervix

anal canal

anus

urogenital diaphragm

urethra

vagina

perineal body

CD Figure 23-8

Sagittal section of the female pelvis.

406

Chapter 23

■ Laterally: The ureters, the pelvic fascia and the ante-

Congenital Anomalies of the

rior fibers of the levatores ani muscles, and the uro-

genital diaphragm

Vagina

Prolapse of the Vagina

Vaginal Agenesis

The vaginal vault is supported by the same structures that

If the paramesonephric ducts fail to develop, the wall of the

support the uterine cervix. Prolapse of the uterus is

urogenital sinus will fail to form the vaginal plate. In these

necessarily associated with some degree of sagging of the

patients, there is an absence of the vagina, uterus, and uter-

vaginal walls. However, if the supports of the bladder, ure-

ine tubes. Plastic surgical construction of a vagina should be

thra, or anterior rectal wall are damaged in childbirth,

attempted.

prolapse of the vaginal walls occurs, with the uterus re-

maining in its correct position.

Double Vagina

Sagging of the bladder results in the bulging of the an-

terior wall of the vagina, a condition known as a cystocele.

A double vagina is caused by incomplete canalization of the

When the ampulla of the rectum sags against the posterior

vaginal plate.

vaginal wall, the bulge is called a rectocele.

Imperforate Vagina and Imperforate

Culdocentesis

Hymen

The closeness of the peritoneal cavity to the posterior vagi-

Imperforate vagina is caused by a failure of the cells to de-

nal fornix enables the physician to drain a pelvic abscess

generate in the center of the vaginal plate. Imperforate hy-

through the vagina without performing a major operation.

men is caused by a failure of the cells of the lower part of

It is also possible to identify blood or pus in the peritoneal

the vaginal plate and wall of the urogenital sinus to degen-

cavity by the passage of a needle through the posterior

erate. These conditions lead to retention of the menstrual

fornix.

flow, a clinical condition called hematocolpos. Surgical

incision of the obstruction, followed by dilatation, relieves

the condition.

Anatomic Structures through which

the Needle Passes

The needle passes through the mucous membrane of the

THE VISCERAL

vagina, muscular coat of the vagina, connective tissue coat

of the vagina, visceral layer of pelvic fascia, and visceral layer

PELVIC FASCIA

of peritoneum.

Anatomic Features of the

Visceral Pelvic Fascia and Infection

Complications of Culdocentesis

Clinically, the pelvic fascia in the region of the uterine

Complications are as follows: (1) The loops of ileum and

cervix is often referred to as the parametrium. It is a com-

the sigmoid colon, structures that are normally present

mon site for the spread of acute infections from the uterus

within the pouch of Douglas, could be impaled by the

and vagina, and here the infection often becomes chronic

needle. However, the presence of blood or pus within the

(pelvic inflammatory disease).

pouch tends to deflect the viscera superiorly. (2) Occa-

sionally, when the uterus is somewhat retroflexed, the

needle may enter the posterior wall of the body of the

THE PELVIC

uterus.

PERITONEUM

Vaginal Trauma

Coital injury, picket fence-type of impalement injury, and

The Rectouterine Pouch and Disease

vaginal perforation caused by water under pressure, as oc-

curs in water skiing, are common injuries. Lacerations of

Since the rectouterine pouch (pouch of Douglas) is the

the vaginal wall involving the posterior fornix may violate

most dependent part of the entire peritoneal cavity (see CD

the pouch of Douglas of the peritoneal cavity and cause pro-

Fig. 23-8) (when the patient is in the standing position), it

lapse of the small intestine into the vagina.

frequently becomes the site for the accumulation of blood

The Perineum, the Female Genital Organs, and Childbirth

407

(from a ruptured ectopic pregnancy) or pus (from a rup-

A needle may be passed into the pouch through the

tured pelvic appendicitis or in gonococcal peritonitis).

posterior fornix in the procedure known as culdocentesis

Because the pouch lies directly behind the posterior

(see CD p. 406). Surgically, the pouch may be entered in

fornix of the vagina, it is commonly violated by misguided

posterior colpotomy.

nonsterile instruments, which pierce the wall of the poste-

The interior of the female pelvic peritoneal cavity may

rior fornix in a failed attempt at an illegal abortion. Pelvic

be viewed for evidence of disease through an endoscope;

peritonitis, often with fatal consequences, is the almost

the instrument is introduced through a small colpotomy

certain result.

incision.

Clinical Problem Solving Questions

Read the following case histories/questions and give

E. Tubal rupture occurs as a result of the eroding

the best answer for each.

action of the trophoblast.

F. Once a tubal pregnancy dies the decidual lining of

The following anatomic statements concerning uterine

the uterus begins to be shed because of lack of

prolapse are correct except which?

hormonal support, and this causes vaginal bleed-

A. The most important support to the uterus is the tone

ing.

of the levatores ani muscles.

G. The dough-like mass is produced by the accumula-

B. The transverse cervical, pubocervical, and sacrocer-

tion of blood in the pouch of Douglas.

vical ligaments play an important role in supporting

A 35-year-old woman was seen by her gynecologist

the uterus.

complaining of a swelling in the genital region. On

C. Damage to the levatores ani and the cervical liga-

examination, a tense cystic swelling was found be-

ments during childbirth can be responsible for pro-

neath the posterior two thirds of the right labium ma-

lapse of the uterus.

jus and minus. A diagnosis of a cyst of the right greater

D. Prolapse most commonly reveals itself before

vestibular gland (Bartholin’s cyst) was made.

menopause.

E. Prolapse of the uterus is always accompanied by

The following statements concerning this case are

some prolapse of the vagina.

probably correct except which?

A. The cyst of the greater vestibular gland is produced

A 25-year-old woman was seen in the emergency de-

by the retention of secretion caused by the blockage

partment complaining of severe pain in the right iliac

of the duct.

region. Just before admission she had fainted. On phys-

B. Infection of the duct by the gonococcus is a com-

ical examination, her abdominal wall was extremely

mon cause of the blockage.

tender on palpation in the lower right quadrant, and

C. Infection of the cyst may occur, forming a painful

some rigidity and guarding of the lower abdominal

abscess.

muscles were noticed. A vaginal examination revealed

D. The lymphatic drainage of this area is into the lateral

a rather soft cervix with a circular external os. A tender

group of superficial inguinal nodes.

“dough-like” mass could be felt through the posterior

E. A small tender swelling was detected below and me-

fornix. The patient had missed her last period.

dial to the inguinal ligament.

The following statements concerning this patient are

In anatomic terms explain the procedure of

correct except which?

culdocentesis.

A. A diagnosis of ruptured ectopic pregnancy was

made.

A 23-year-old woman was seen in the emergency de-

B. Tubal pregnancies commonly occur where the am-

partment with severe vaginal bleeding. She was 35

pulla narrows to join the isthmus.

weeks pregnant. On questioning she stated that she

C. Each uterine tube is situated in the base of the broad

had slight bleeding a week previously but this had

ligament.

stopped spontaneously. There was absolutely no pain

D. An ectopic tubal pregnancy almost invariably results

associated with the bleeding. On examining the ab-

in rupture of the tube with severe intraperitoneal

domen, it was found that the fetal head was high, and

hemorrhage.

it was not possible to make it enter the pelvis. The

408

Chapter 23

uterus had a normal consistency and was not tender.

was found on the medial aspect of the right labium

On examination of the genital organs, no cause for the

majus. A diagnosis of squamous cell carcinoma of the

bleeding could be determined. A diagnosis of placenta

skin was made. What is the lymphatic drainage of this

previa was made. What is placenta previa? What is the

region, and which group of lymph nodes would you

cause of the bleeding? Why is the bleeding painless?

therefore examine for evidence of metastases?

What is believed to be the cause of pain in labor? De-

11.

A mother took her 15-year-old daughter to a physician

scribe the pathways taken by the afferent pain fibers in

because she had failed to start to menstruate. On exam-

labor and explain the distribution of the areas of re-

ination the child was noted to be short and stocky with

ferred pain.

a webbed neck. She had an abnormally large carrying

angle of the elbow (cubitus valgus), a broad chest with

The postnatal vaginal examination of a young woman

lack of breast development, and an absence of pubic

revealed that the fundus and body of the uterus could

and axillary hair. No further abnormalities were found

be palpated in the rectouterine pouch (pouch of Dou-

on physical examination. What is your diagnosis? What

glas). What is the normal position of the uterus?

investigations would you undertake to confirm your di-

A multiparous 57-year-old woman visited her physi-

agnosis? How would you treat this patient?

cian complaining of a “bearing-down” feeling in the

12.

During the third stage of labor, the placenta and fetal

pelvis and of low backache, both of which were worse

membranes are expelled from the uterus. The obstetri-

when she was tired. On vaginal examination, the

cian or midwife must carefully examine the placenta

external os of the cervix was found to be located just

and the membranes to make sure that no part of them

within the vaginal orifice. A diagnosis of uterine

has been retained in the uterus. What is the approxi-

prolapse was made. What are the main supports of

mate diameter and thickness of a normal placenta?

the uterus?

Describe the appearance of the maternal and fetal sur-

During the vaginal examination of a multiparous

faces of a full-term placenta. Is it possible to separate the

woman, she was asked to strain downward. The anterior

amnion from the chorion?

wall of the vagina was found to sag downward. A diag-

13.

A 12-year-old girl was taken to a pediatrician because

nosis of prolapsed anterior vaginal wall was made. What

she experienced cyclic monthly pain, but there was no

structures lie anterior to the vagina and will sag down-

actual menstrual flow. On physical examination of the

ward with the vaginal wall?

vulva, the hymen was seen as a bulging septum. No

10.

A 65-year-old woman went to her physician complain-

vaginal orifice could be detected. What is your diagno-

ing of irritation, discharge, and bleeding of the genital

sis? How would you explain this condition embryologi-

region. On physical examination, a hard-based ulcer

cally? How would you treat this patient?

Answers and Explanations

1. D is the correct answer. Prolapse of the uterus most of-

5. Normally the placenta is situated in the upper half of

ten reveals itself after menopause, when the pelvic fas-

the uterus. Should implantation occur in the lower half

cia tends to atrophy.

of the body of the uterus, the condition is called pla-

centa previa. As the lower half of the body of the uterus

2. C is the correct answer. Each uterine tube is situated in

dilates toward the end of pregnancy, the placenta is sep-

the upper free margin of the broad ligament (see text

arated from the uterine wall and hemorrhage occurs.

Fig. 23-10).

The bleeding is painless since the blood escapes

3. D is the correct answer. The lymphatic drainage of

through the cervix, and the uterus does not contract and

this area is into the medial group of superficial in-

is not distended.

guinal nodes situated below the inguinal ligament.

6. The cause of labor pains has been fully discussed in this

The spread of infection can result in an enlargement

chapter, as have the path taken by the afferent pain

of one of the nodes, as in this case, which becomes

fibers from the uterus and the areas of the body to which

tender to palpation.

labor pains are referred.

4. See discussion of culdocentesis in this chapter.

The Perineum, the Female Genital Organs, and Childbirth

409

The long axis of a normal uterus usually lies at right an-

trogen and progesterone in this case will bring about

gles to the long axis of the vagina (anteverted); the body

the development of normal female secondary sexual

of the uterus is also bent forward on the cervix at the in-

characteristics and cyclic menstrual function.

ternal os (anteflexion).

12.

The normal placenta is flattened and circular in

The uterus is mainly supported by the tone of the leva-

shape, with a diameter of about 8 in. (20 cm) and a

tores ani muscles and the ligaments of the visceral layer

thickness of about 1 in. (2.5 cm). The maternal sur-

of pelvic fascia, namely, the transverse cervical, sacro-

face is dark red in color and oozes blood from the torn

cervical, and pubocervical ligaments.

maternal vessels. It has a sponge-like consistency. The

outer surface is rough, and the margins of the lobules

The urethra lies directly in contact with the lower half

or cotyledons may be recognized. The fetal surface is

of the anterior vaginal wall, and the bladder lies in con-

smooth and shining and is covered by amnion, which

tact with the upper half of the vaginal wall. The bulging

is fused with the underlying chorion. The umbilical

downward of the bladder with the anterior vaginal wall

cord is attached near its center, and the umbilical ves-

is referred to as a cystocele.

sels radiate out under the amnion from the point of at-

10.

The vulva is drained into the medial group of horizon-

tachment. The amnion may be peeled from the

tal superficial inguinal nodes.

chorion up to the umbilical cord. This procedure

should always be carried out following delivery to de-

11.

This case is a typical example of Turner’s syndrome, in

termine if the chorion is complete and to make sure

which there is complete failure of both ovaries to de-

that some part has not been retained in the uterus ad-

velop. In Turner’s syndrome the cells have only 45

herent to the decidua.

chromosomes because one X chromosome is missing

(XO). In this case the clinical signs and symptoms make

13.

This girl has an imperforate hymen. The pelvic dis-

the diagnosis obvious. A simple buccal smear and the

comfort and the absence of menstrual flow are due to

finding of absent nuclear sex chromatin make the diag-

the accumulation of blood and old menstrual secre-

nosis absolute. In difficult cases, where the diagnosis is

tions (hematocolpos) above the intact hymen. This

in doubt, culdoscopy shows the absence of ovaries in

condition is caused by a failure of the cells of the lower

the pelvis. Since these individuals are females in ap-

part of the vaginal plate and the wall of the urogenital

pearance and psychological outlook, they should be

sinus to degenerate. Surgical incision of the hymen,

brought up as females. The cyclic administration of es-

followed by dilatation, cures the condition.

Chapter Outline

Endocrine Glands in the Head and Neck

414

Hypoparathyroidism

418

Congenital Anomalies of the Parathyroid

Pituitary Gland (Hypophysis Cerebri)

414

Glands

418

Pituitary Enlargement and the Optic Chiasma

414

Absence and Hypoplasia of the Parathyroid

Gigantism and Acromegaly

414

Glands

418

Dwarfism

415

Ectopic Parathyroid Glands

418

Diabetes Insipidus

415

Endocrine Glands in the Abdomen

Pineal Gland

415

and Pelvis

419

Pineal Calcification

415

Pineal Tumors and Reproductive Function

415

Suprarenal Glands

419

Cushing’s Syndrome

419

Thyroid Gland

415

Addison’s Disease

419

Swellings of the Thyroid Gland and Movement

Pheochromocytoma

419

on Swallowing

415

Surgical Significance of the Renal Fascia

419

The Thyroid Gland and the Airway

415

Suprarenal Susceptibility to Trauma at Birth

419

Retrosternal Goiter

415

Thyroid Arteries and Important Nerves

415

Islets of Langerhans of the Pancreas

419

Thyroidectomy and the Parathyroid Glands

415

Islets of Langerhans and Diabetes Mellitus

419

Hyperthyroidism

416

Interstitial Cells of the Testis

419

Hypothyroidism

416

Testosterone Deficiency

419

Thyroid Tumors

417

Congenital Anomalies of the Thyroid Gland

417

Ovaries

420

Agenesis of the Thyroid

417

Menopause

420

Incomplete Descent of the Thyroid

417

Hypogonadism

420

Ectopic Thyroid Tissue

418

Placenta

420

Persistent Thyroglossal Duct

418

Hydatidiform Mole

420

Thyroglossal Cyst

418

Thyroglossal Sinus (Fistula)

418

Clinical Problem Solving Questions

420

Parathyroid Glands

418

Thyroidectomy and the Parathyroid Glands

418

Answers and Explanations

422

Hyperparathyroidism

418

A pituitary tumor classically pushes the diaphragma sellae

ENDOCRINE

upward and causes pressure on the optic chiasma. This re-

sults in interference with the function of the nerve fibers

crossing in the chiasma (from the inner quadrants of the

GLANDS IN THE

retina), and the patient presents with bitemporal hemi-

anopia (see text Fig. 15-1B). Further expansion of the pitu-

HEAD AND NECK

itary tumor causes erosion of the body of the sphenoid bone.

Gigantism and Acromegaly

Pituitary Gland (Hypophysis Cerebri)

Excessive production of the growth hormone by the soma-

totrope cells of the pars anterior or by tumors of these cells

Pituitary Enlargement and the

can produce abnormal growth of the skeleton. Gigantism

Optic Chiasma

occurs in the young before the epiphyses in long bones fuse

Since the pituitary is located in the bony sella turcica, en-

with the diaphysis. The growth hormone stimulates the car-

largement causes it to expand superiorly (see text Fig. 24-2).

tilage cells of the epiphyseal cartilage to continue laying

The Endocrine Glands

415

down new matrix, so that fusion of the epiphyses with the

the midbrain, producing hydrocephalus. Occasionally, the

shaft of long bones is delayed and the bones lengthen enor-

tumor destroys the pineal gland and causes precocious

mously. In this way, giants 9 ft tall have been produced be-

puberty.

fore the epiphyseal cartilage finally stops growing.

Acromegaly is a form of abnormal skeletal and soft tis-

sue growth that occurs after adolescence, following the fu-

Thyroid Gland

sion of the epiphyses in long bones with the diaphysis. In

this disease, the individual cannot grow taller, but over-

Swellings of the Thyroid Gland and

growth occurs in the bones and soft tissues of the forehead,

Movement on Swallowing

nose, lower jaw, hands, and feet. In the fully developed syn-

The thyroid gland is invested in a sheath derived from the

drome, the prominent supraorbital ridges and mandible, the

pretracheal fascia

(see text Fig.

24-10). This tethers

very large nose, and the very large, thick hands and feet

the gland to the larynx and the trachea and explains

make the diagnosis relatively easy.

why the thyroid gland follows the movements of the lar-

ynx in swallowing. This information is important be-

Dwarfism

cause any pathologic neck swelling that is part of the

A deficiency in the growth hormone secreted by the soma-

thyroid gland will move upward when the patient is asked

totrope cells of the pars anterior during childhood leads to

to swallow.

pituitary dwarfism. Growth does not stop entirely, and the

different parts of the body are in relatively normal propor-

The Thyroid Gland and the Airway

tions. The person is of normal intelligence, but the facial

The close relationship between the trachea and the lobes

skin is often wrinkled and sexual maturation is delayed.

of the thyroid gland commonly results in pressure on the

Diabetes Insipidus

trachea in patients with pathologic enlargement of the

thyroid.

This syndrome results from a lesion of the supraoptic and

paraventricular nuclei of the hypothalamus and a failure of

Retrosternal Goiter

these cells to synthesize the antidiuretic hormone, or from

destruction of the hypothalamohypophysial tract. There are

The attachment of the sternothyroid muscles to the thyroid

many causes of this syndrome, including cerebral tumors,

cartilage effectively binds down the thyroid gland to the lar-

cerebral abscesses, surgical or radiation damage, and head

ynx and limits upward expansion of the gland. There being

injuries.

no limitation to downward expansion, it is not uncommon

Characteristically, the patient passes large volumes of

for a pathologically enlarged thyroid gland to extend down-

urine (polyuria) of low specific gravity. The absence of an-

ward behind the sternum. A retrosternal goiter (any abnor-

tidiuretic hormone results in a failure to conserve water,

mal enlargement of the thyroid gland) can compress the

which is not reabsorbed in the collecting tubules of the kid-

trachea and cause dangerous dyspnea; it can also cause se-

neys. As a result, the patient is extremely thirsty (polydipsia)

vere venous compression.

and drinks large quantities of fluids. The condition must be

distinguished from diabetes mellitus, in which there is

Thyroid Arteries and Important Nerves

glucosuria.

It should be remembered that the two main arteries supply-

ing the thyroid gland are closely related to important nerves

Pineal Gland

that can be damaged during thyroidectomy operations (CD

Fig. 24-1). The superior thyroid artery on each side is re-

Pineal Calcification

lated to the external laryngeal nerve, which supplies the

cricothyroid muscle. The terminal branches of the inferior

With age, the pineal gland accumulates magnesium phos-

thyroid artery on each side are related to the recurrent la-

phate and carbonate within the glial cells and connective

ryngeal nerve. Damage to the external laryngeal nerve

tissue. These deposits are useful to radiologists, because

results in an inability to tense the vocal folds and in hoarse-

they serve as a landmark and assist in determining whether

ness. For the results of damage to the recurrent laryngeal

the pineal gland has been displaced laterally by a space-

nerve, see CD page 24.

occupying lesion within the skull.

Pineal Tumors and Reproductive

Thyroidectomy and The Parathyroid

Function

Glands

Pineal tumors may have an antigonadotropic effect. As they

The parathyroid glands are usually four in number and are

increase in size, they may obstruct the cerebral aqueduct of

closely related to the posterior surface of the thyroid gland

416

Chapter 24

internal carotid artery

right vagus nerve

external carotid artery

inferior contrictor

of pharynx

internal laryngeal nerve

left vagus nerve

external laryngeal

nerve

superior thyroid

left common

artery and vein

carotid artery

right lobe of

thyroid gland

esophagus

superior right

parathyroid gland

inferior

thyroid artery

inferior right

left recurrent

parathyroid gland

laryngeal nerve

right recurrent

laryngeal nerve

left subclavian

artery and vein

right subclavian

artery and vein

CD Figure 24-1

The pharynx, esoph-

agus, and trachea as seen from the

right

vagus nerve

posterior aspect. Note the positions of

aorta

the thyroid and parathyroid glands

superior

and the relationships of the large

vena cava

blood vessels and nerves. The dotted

lines indicate the level of the cricothy-

left vargus nerve

roid membrane.

(see CD Fig. 24-1). In partial thyroidectomy, the posterior

The hair thins, and the eyes may protrude (exophthalmos).

part of the thyroid gland is left undisturbed so that the

The heart rate is increased and frequent bowel movements

parathyroid glands are not damaged. The development of

may occur; the menstrual periods may be missed or scanty.

the inferior parathyroid glands is closely associated with the

Three forms of therapy are available for the treatment of

thymus. For this reason it is not uncommon for the surgeon

hyperthyroidism: (1) surgical excision of thyroid tissue, (2)

to find the inferior parathyroid glands in the superior medi-

antithyroid drugs, and (3) radioactive iodine.

astinum because they have been pulled down into the tho-

rax by the thymus.

Hypothyroidism

Hypothyroidism occurs in two forms: cretinism in infants

Hyperthyroidism

and myxedema in adults.

In hyperthyroidism

(thyrotoxicosis, Grave’s disease),

Cretinism can occur as a result of a failure in the de-

which is common in middle-aged women, the thyroid

velopment of the thyroid gland. The child is born with a

gland is diffusely enlarged. The walls of the thyroid folli-

normal appearance, caused by the mother’s thyroid hor-

cles are much infolded, and the epithelial cells lining the

mones having crossed the placenta. Soon after birth, the

follicular walls are taller than normal. Production of the

child shows signs of retarded mental and physical growth. If

thyroid hormones is greatly increased, and the colloid

cretinism is diagnosed early and the child is given adequate,

present is usually reduced in volume. The serum thyroid-

lifelong thyroid hormone therapy, he or she will develop

stimulating hormone level is normal or below normal. In

normally and live a normal life.

most patients, there is a thyroid-stimulating immunoglob-

Myxedema may be caused in adults by many condi-

ulin in the blood that is capable of stimulating increased

tions ranging from spontaneous degeneration of the thyroid

thyroid activity.

gland to hypopituitarism or hypothalamic failure. Excessive

The symptoms of hyperthyroidism are caused by

treatment of hyperthyroidism with drugs or surgery is an-

the excessive stimulation of the tissues by the thyroid hor-

other possible cause. The majority of the patients are fe-

mones. There is excessive sweating and loss of weight;

male. The symptoms include the slowing of mental and

increased nervousness, with fine tremor of the extended

physical processes of the individual. There is an increase in

fingers; intolerance to heat; and muscular weakness.

body weight and a preference for a warm environment.

418

Chapter 24

found just beneath the foramen cecum may be sufficiently

of an infection of a cyst. All remnants of the thyroglossal

large to obstruct swallowing in the infant.

duct should be removed surgically.

Ectopic Thyroid Tissue

Parathyroid Glands

Ectopic thyroid tissue is occasionally found in the thorax in

relation to the trachea or bronchi or even the esophagus. It

Thyroidectomy and the Parathyroid

is assumed that this thyroid tissue arises from entodermal

Glands

cells displaced during the formation of the laryngotracheal

tube or from entodermal cells of the developing esophagus.

See previous section of this CD chapter.

Persistent Thyroglossal Duct

Hyperparathyroidism

Conditions related to a persistence of the thyroglossal duct

This condition is caused by a benign adenoma or hyperpla-

usually appear in childhood, in adolescence, or in young

sia of the parathyroid glands. As a result, there is an excessive

adulthood.

secretion of the parathyroid hormone, and the blood cal-

cium level rises to as much as 15 mg/100 mL from the

Thyroglossal Cyst

normal level of 10 mg/100 mL. The raised levels of blood

calcium in this disease may cause the repeated occurrence

Cysts may occur at any point along the thyroglossal tract (see

of renal stones as the result of the spilling over of the cal-

CD Fig. 24-2 and CD Fig. 24-4). They occur most com-

cium salts into the urine. The high blood calcium levels also

monly in the region below the hyoid bone. Such a cyst oc-

affect the central and peripheral nervous systems. Neuro-

cupies the midline and develops as a result of persistence of

logic abnormalities include emotional instability, memory

a small amount of epithelium that continues to secrete mu-

loss, and muscular weakness. The treatment is surgical

cus. As the cyst enlarges, it is prone to infection and so it

removal of the diseased gland.

should be removed surgically. Since remnants of the duct

often traverse the body of the hyoid bone, this may have to

Hypoparathyroidism

be excised also to prevent recurrence.

This condition is most commonly caused by injury to or re-

Thyroglossal Sinus (Fistula)

moval of the glands during surgical procedures on the

thyroid gland.

Occasionally, a thyroglossal cyst ruptures spontaneously,

The main symptoms and signs of low blood calcium are

producing a sinus (see CD Fig. 24-2). Usually, this is a result

numbness and tingling in the fingers and toes and cramps of

the muscles in the hands and feet. These cramps are called

carpopedal spasms. The spasm, or tetany, of muscles may

also involve the facial or laryngeal muscles. The central ner-

vous system may also be involved, as evidenced by signs of

mental confusion and loss of memory.

The condition is treated by giving the patient calcium

gluconate and large quantities of vitamin D by mouth.

Congenital Anomalies of the

Parathyroid Glands

Absence and Hypoplasia of the

Parathyroid Glands

Agenesis or incomplete development of the parathyroid

glands has been demonstrated in individuals with idiopathic

hypoparathyroidism.

Ectopic Parathyroid Glands

The close relationship between the parathyroids III and the

developing thymus explains the frequent finding of parathy-

CD Figure 24-4

A thyroglossal cyst. (Courtesy of

roid tissue in the superior mediastinum of the thorax (see

L. Thompson.)

text Fig. 24-14). If the parathyroid glands remain attached to

The Endocrine Glands

419

the thymus, they may be pulled inferiorly into the lower part

Suprarenal Susceptibility to Trauma

of the neck or thoracic cavity. Moreover, this also explains

at Birth

the variable position of the inferior parathyroid glands in re-

lation to the lower poles of the lateral lobes of the thyroid

At birth, the suprarenal glands are relatively large because of

gland.

the presence of the fetal cortex; later, when this part of the

cortex involutes, the gland becomes reduced in size. During

the process of involution, the cortex is friable and suscepti-

ble to damage and severe hemorrhage.

ENDOCRINE

Islets of Langerhans of the

GLANDS IN THE

Pancreas

ABDOMEN AND

Islets of Langerhans and Diabetes

Mellitus

PELVIS

In diabetes mellitus, the beta cells of the islets of Langerhans

lose their ability to secrete insulin or the target cells of the tis-

Suprarenal Glands

sues become insensitive to circulating insulin. In juvenile di-

abetes, there is total absence of insulin, but when the onset

Cushing’s Syndrome

of diabetes occurs in adulthood, the plasma levels of insulin

Suprarenal cortical hyperplasia is the most common cause

may be normal or only slightly below normal. The exact

of Cushing’s syndrome, the clinical manifestations of which

cause of diabetes mellitus is not known. Genetic, metabolic,

include moon-shaped face, truncal obesity, abnormal hairi-

and autoimmune factors, as well as viral infections, are

ness (hirsutism), and hypertension; if the syndrome occurs

thought to play an important causative role in many patients.

later in life, it may result from an adenoma or carcinoma of

In all patients with diabetes mellitus, the blood glucose

the cortex.

level is above normal (hyperglycemia). Once the blood glu-

cose level reaches a certain threshold value, approximately

Addison’s Disease

180 mg/100 mL, the glucose spills over into the urine (glu-

cosuria). The osmotic pressure exerted by the high concen-

Adrenocortical insufficiency (Addison’s disease), which is

tration of glucose in the urine inhibits the reabsorption of

characterized clinically by increased pigmentation, muscu-

water in the kidney tubules, causing excessive urination

lar weakness, weight loss, and hypotension, may be caused

(polyuria). The patient becomes thirsty and dehydration

by tuberculous destruction or bilateral atrophy of both

may occur. There is an upset in the carbohydrate, fat, and

cortices.

protein metabolism in these patients that leads to loss of

weight and lack of energy.

Pheochromocytoma

The treatment of patients with diabetes mellitus in-

cludes giving sufficient insulin and a special diet so that the

Pheochromocytoma, a tumor of the medulla, produces a

carbohydrate metabolism returns to normal. In those pa-

paroxysmal or sustained hypertension. The symptoms and

tients with the less severe type of diabetes, the hyperglycemia

signs result from the production of a large amount of cate-

often can be treated with a low-calorie, low-carbohydrate diet

cholamines, which are then poured into the bloodstream.

without the administration of insulin.

Because of their position on the posterior abdominal

wall, few tumors of the suprarenal glands can be palpated.

Computed tomography (CT) scans can be used to visualize

Interstitial Cells of the Testis

the glandular enlargement; however, when interpreting CT

scans, remember the close relationship of the suprarenal

Testosterone Deficiency

glands to the crura of the diaphragm.

The function of the testes is the production of spermatozoa

and the secretion of the male sex hormones, particularly

Surgical Significance of the

testosterone, by the interstitial cells. The two functions may

Renal Fascia

be interfered with simultaneously by a severe acute infec-

The suprarenal glands, together with the kidneys, are en-

tion or by the occlusion of the blood supply during a repair

closed within the renal fascia; the suprarenal glands, how-

operation for inguinal hernia. Total absence of testosterone

ever, lie in a separate compartment, which allows the two

follows surgical castration, which may be necessary follow-

organs to be separated easily at operation.

ing severe trauma to the perineum. Testosterone deficiency

420

Chapter 24

is not present in patients with incompletely descended or

fat, or shrink, because of atrophy of the glandular ducts. The

maldescended testes. If testosterone deficiency occurs be-

patient usually gains weight from a diffuse deposition of fat.

fore puberty, the accessory organs of reproduction do not

The patient often complains of pains in the joints, fatigue,

develop; the penis, scrotum, seminal vesicles, and prostate

and insomnia. Anxiety, depression, and emotional instabil-

remain small. The secondary sexual characteristics do not

ity may also be present.

appear. There is no growth of the hair on the face or trunk

The lack of estrogen also increases protein catabolism.

or in the axillae. The pubic hair is of the female distribution

This change reveals itself by an alteration in the texture of

and develops in response to the suprarenal androgens. The

the hair and nails, wrinkling of the skin, and osteoporosis.

larynx fails to enlarge, and the voice remains high pitched

In the great majority of women, the symptoms of the

and infantile. The muscles are poorly developed. There is

menopause are slight, but for some, the body changes and

delay in the fusion of the epiphyses in the long bones with

emotional disturbances are very severe, requiring consider-

the diaphysis. Excessive fat deposits may occur in the pec-

able patience and understanding from the husband and

toral region, abdomen, and buttocks, and on the hips.

relatives.

Testosterone deficiency after puberty causes the acces-

sory sex organs to atrophy and the secondary sexual charac-

Hypogonadism

teristics to regress. Those organs and structures that do not

require testosterone for their maintenance are unaffected,

Ovarian hypofunction may be associated with lesions of the

however. Thus, the penis remains of normal size, the voice

hypothalamus that impair the release of the gonadotropic-

remains unchanged, and facial hair growth may be affected

releasing hormone. Via a similar mechanism, emotional

only slightly. Sexual desire and erection may be absent.

strain, such as leaving home and attending college, may

change the afferent nervous input of the hypothalamus,

causing amenorrhea. Hypopituitarism with a failure of folli-

Ovaries

cle-stimulating hormone and luteinizing hormone secre-

tion caused by a pituitary tumor may also cause ovarian

Menopause

hypofunction. Removal of the ovaries in the adult results in

a premature, artificial menopause.

Menopause is the period of life when the ovaries normally

cease to respond to the gonadotropic hormones of the ante-

rior lobe of the pituitary. Menopause occurs on average be-

tween ages 45 and 50. The ovaries become smaller, and the

Placenta

graafian follicles atrophy and are replaced by fibrous tissue.

Hydatidiform Mole

The tunica albuginea thickens. The corpora lutea and the

ovarian hormones are no longer produced.

Excessive proliferation of the trophoblast during the early

As a result of the cessation of the production of ovarian

stages of placenta formation may lead to the condition of hy-

estrogens and progesterone, menstruation ceases and the

datidiform mole. The uterus may become filled with vesic-

genital organs atrophy to some extent. Vasomotor changes,

ular structures, which may be the size of grapes, and the

in the form of hot flashes, occur in the skin of the face, neck,

fetus dies. Very large quantities of chorionic gonadotropin

and chest. The vaginal mucous membrane thins and atro-

are produced by the trophoblast, and the hormone appears

phies. The breasts may enlarge, because of the deposition of

in the urine.

Clinical Problem Solving Questions

Read the following case histories/questions and give

symptoms. Six months later, the patient started to com-

the best answer for each.

plain of frequency of micturition and was passing very

large quantities of pale urine. She also said that she al-

1. On examination, a patient is found to have a bitempo-

ways seemed thirsty and would often drink 10 glasses of

ral hemianopia. An enlargement of which anatomic

water in one morning. Using your knowledge of

structure is likely to cause this condition?

anatomy and physiology, do you think there is any con-

nection between the urinary symptoms and her auto-

2. A 40-year-old woman was involved in an automobile

mobile accident?

accident in which she sustained severe head injuries.

Following a slow but uneventful recovery, she was re-

3. A 17-year-old boy is taken by his parents to a pediatri-

leased from the hospital without any residual signs or

cian because the parents are concerned about his

The Endocrine Glands

421

excessive height and his complaints of fatigue and gen-

B. Each lobe of the thyroid gland is closely related to

eral lassitude. His standing height is 84 in. Questioning

the sides of the trachea.

reveals that the boy has grown very rapidly since his thir-

C. The isthmus of the thyroid gland was found to cross in

teenth birthday. As a young child, he excelled in com-

front of the third, fourth, and fifth rings of the trachea.

petitive sports, but for the past 3 years, he has experi-

D. The sudden increase in the size of the swelling can

enced weakness and fatigue and has ceased to compete.

be explained by a hemorrhage into the adenoma.

His nose is broad, and his mandible and facial features

E. The swelling was located superficial to the left ster-

appear larger than normal. He has large hands and feet

nothyroid muscle.

and takes a size 18 shoe. There is no family history of

F. The breathlessness was caused by the adenoma press-

unusual tallness. The patient is of normal intelligence,

ing on the trachea, partially occluding the lumen.

and the size of his external genitalia is normal for his

A 35-year-old woman had a partial thyroidectomy for

age. His secondary sexual characteristics are normal.

the treatment of thyrotoxicosis. During the operation a

Using your knowledge of anatomy and physiology,

ligature slipped off the right superior thyroid artery. To

make a diagnosis. Which cell groups are likely to have

stop the hemorrhage, the surgeon blindly grabbed for

undergone pathologic changes? How do you account

the artery with artery forceps. The operation was com-

for the excessive tallness and the presence of a large

pleted without further incident. The following morning

mandible, hands, and feet in the same individual?

the patient spoke with a husky voice.

A 25-year-old woman has been in labor for several

The following statements about this patient would ex-

hours. Her uterine contractions are weak, and her labor

plain the husky voice except which?

is not progressing. The obstetrician decides to give her

A. Laryngoscopic examination revealed that the right vo-

some Pitocin, a synthetic oxytocin hormone. What is

cal cord was slack, causing the huskiness of the voice.

the effect of oxytocin on the uterus? In which part of the

B. The vocal cord is tensed by the contraction of the

pituitary is this hormone normally released into the

cricothyroid muscle.

bloodstream?

C. The cricothyroid muscle tilts back the cricoid carti-

A 45-year-old woman visits her physician for a medical

lage and pulls forward the thyroid cartilage.

checkup. The woman has no complaints, but her hus-

D. The cricothyroid muscle is innervated by the recur-

band has noted the following changes in her appear-

rent laryngeal nerve.

ance during the previous year: She has gained a con-

E. The superior thyroid artery is closely related to the

siderable amount of weight and is becoming mentally

external laryngeal nerve.

and physically slow, often falling asleep while talking to

Following a total thyroidectomy for carcinoma of the

friends. Her face is puffy, and her hair is dry and has de-

thyroid gland, a 55-year-old man noticed tingling and

veloped a tendency to fall out. The lateral third of her

numbness of the fingers, toes, and lips. Painful cramps

eyebrows is missing. Her skin is pale and dry, and her

of the hands and feet were also experienced. Strong

voice is becoming deep and her articulation slow. She

muscle spasms producing adduction of the thumb, flex-

frequently complains of the cold when others feel

ion of the wrist and metacarpophalangeal joints, and

warm. Using your knowledge anatomy and physiology,

plantar flexion of the feet also occurred. Laboratory ex-

what do you think is wrong with this patient? What do

amination of the blood revealed a blood calcium level

you think would be the appropriate treatment?

of 4 mg/100 mL. Which organ was damaged during the

A 25-year-old woman complaining of a swelling on the

total thyroidectomy?

front of the neck and breathlessness visited her physi-

cian. On examination, a small, solitary swelling of firm

An 18-year-old woman went to her physician because

consistency was found to the left of the midline of the

she had noticed a swelling in the midline of her neck.

neck below the thyroid cartilage of the larynx. The

She said she had first noticed this swelling 3 years pre-

swelling was not attached to the skin but moved upward

viously, and it had gradually increased in size. On phys-

on swallowing. About 2 weeks previously the swelling

ical examination, a small swelling was found in the

had suddenly increased in size and had become tender

midline of the neck; it measured about 0.5 in. (1.25 cm)

to touch; following this increase in size the patient be-

in diameter. It was situated just below the body of the

came breathless.

hyoid bone, was soft and fluctuant, and moved upward

on swallowing. Nothing else abnormal was discovered.

The following statements concerning this case would

suggest a diagnosis of adenoma of the thyroid gland ex-

The physician made the diagnosis of thyroglossal cyst

cept which?

based on the following symptoms and signs except

A. The pretracheal layer of deep cervical fascia binds

which?

the thyroid gland to the larynx, which moves upward

A. The swelling was not hard.

on swallowing.

B. The swelling was fluctuant.

422

Chapter 24

C. The swelling was located in the midline of the

nary content of catecholamines. What hormones are

neck.

secreted by the cells of the suprarenal medulla, and

D. It moved upward on swallowing, which indicated

what is their action?

that it was tethered to tissue associated with the

12.

A 51-year-old man is concerned because he has noticed

thyroid gland.

during the past few weeks that he has started to urinate

E. A thyroglossal cyst is always found below the hyoid

more frequently and is always hungry and thirsty. He is

bone.

also worried because he has been treated for skin infec-

10.

A 38-year-old man is admitted to the hospital for labo-

tions on six occasions during the past year. The fasting

ratory tests. When seen by his physician, he complains

blood glucose level is measured, and a glucose toler-

of increasing tiredness and muscular weakness over the

ance test is performed. The results show that the patient

previous year. He has experienced five attacks of nausea

has diabetes mellitus. What is the normal fasting blood

and vomiting, and diarrhea during this period. His rea-

glucose level? Why does glucose appear in the urine in

son for visiting his physician is that his friends have no-

diabetes mellitus? What is the underlying cause of dia-

ticed that his skin is becoming darker. After a complete

betes mellitus?

physical examination, a diagnosis of Addison’s disease is

made, and it is confirmed by laboratory tests. What is

13.

A 21-year-old man sustains a severe injury to the per-

the cause of Addison’s disease? The secretions of which

ineum following an explosion of a road-side bomb

hormones are defective in this disease? What is respon-

by a terrorist. The surgeon is forced to amputate the

sible for the weakness and increased pigmentation of

scrotum and remove both testes. Using your knowl-

the skin in this condition?

edge of physiology, describe the changes that will take

place because of the absence of testosterone. Is testos-

11.

A 29-year-old man recently experienced what he de-

terone produced in patients with bilateral undescended

scribes as severe pounding palpitations. The attacks

testicles?

had lasted about 20 minutes each and had been ac-

companied by severe sweating, headache, and pale-

14.

What are the clinical signs and symptoms of meno-

ness and coldness of the skin. While in the hospital

pause? What is responsible for menopause? Is it caused

clinic he has another attack. His pulse rate is 120 beats

by a cessation of the activity of the hypothalamus, a ces-

per minute, and his blood pressure is 240/140 mm Hg.

sation of the activity of the pars anterior, or a failure of

A preliminary diagnosis of pheochromocytoma is

the ovary to respond to hormonal stimulation from the

made, which is later confirmed by analysis of the uri-

pituitary?

Answers and Explanations

1. Bitemporal hemianopia is a loss of both temporal fields

the absorption of water in the distal convoluted tubules

of vision and is due to the interruption of the optic nerve

and collecting tubules of the kidney.

fibers derived from the medial halves of both retinae.

3. This patient has the signs and symptoms of gigantism

Pressure on the optic chiasma by a tumor of the pituitary

and acromegaly caused by the excessive secretion of

gland is the most common cause of the condition.

growth hormone by the acidophil cells of the anterior

lobe of the pituitary gland. The condition started before

2. Yes, there is a connection between the accident and the

the epiphyses of the long bones fused with the diaph-

urinary symptoms. This patient is suffering from dia-

ysis, hence the gigantism, and continued growth after

betes insipidus caused by traumatic damage either to

the fusion had taken place, hence the acromegalic

the posterior lobe of the pituitary gland or to the

changes.

supraoptic or paraventricular nuclei of the hypothala-

mus. In any event, production of vasopressin was inhib-

4. Oxytocin stimulates the smooth muscle of the uterus to

ited. It should be pointed out that a lesion of the poste-

contract. Normally, it plays an important role in labor

rior lobe of the pituitary is usually not followed by

and delivery. During the third stage of labor, when the

diabetes insipidus, since the vasopressin (antidiuretic

placenta and the fetal membranes have been delivered,

hormone) produced by the neurons of the supraoptic

it stimulates the uterine muscle to contract and pre-

and paraventricular nuclei escapes directly into the

vents excessive bleeding. In this patient the obstetrician

bloodstream. The action of vasopressin is to increase

was supplementing the patient’s own oxytocin with

The Endocrine Glands

423

synthetic hormone to increase the force of the uterine

the pars anterior of the pituitary, which results in atro-

contractions.

phy of the suprarenal cortex. Cortisol and aldosterone

are the two hormones that are lacking in this disease.

Oxytocin is produced by the nerve cells in the hypothal-

The weakness is caused by the absence of cortisol se-

amus. The hormone reaches the posterior lobe of the pi-

cretion, which causes a fall in the level of blood glu-

tuitary via the hypothalamohypophysial tract, where it is

cose. The increased melanin pigmentation in the skin

stored and later released from the nerve endings.

and buccal mucous membrane is caused by the in-

This patient has the signs and symptoms of hypothy-

creased secretion of ACTH from the pars anterior of the

roidism and myxedema. After confirming the diagnosis

pituitary. (The increased pigmentation does not occur

by estimating the PBI (protein-bound iodine concen-

in patients in whom the disease is caused by hypopitu-

tration) and serum T4 levels, which are low in this dis-

itarism.) ACTH stimulates the melanocytes in the skin

ease, the doctor should prescribe daily doses of thyroid

to increase their production of melanin.

hormone, and this treatment should be continued

11.

The epithelial cells of the suprarenal medulla synthe-

indefinitely.

size and secrete norepinephrine and epinephrine.

E is the correct answer. The thyroid gland lies deep to

12.

The normal fasting blood glucose level is about 110

the sternothyroid muscle (see text Fig. 24-10).

mg/100 mL. Once the blood glucose level in diabetes

mellitus reaches a certain threshold value, approxi-

D is the correct answer. The cricothyroid muscle of the

mately 180 mg/100 mL, the glucose spills out into the

larynx is innervated by the external laryngeal nerve,

urine. The exact cause of diabetes mellitus is not

which was damaged in this patient.

known. Genetic, metabolic, and autoimmune factors,

The patient is suffering from parathyroid tetany due to

as well as viral infections, are thought to play an impor-

accidental removal of one or more of the parathyroid

tant causative role in many patients. Excessive glucagon

glands during the operation of total thyroidectomy.

secretion combined with insulin deficiency has been

Sometimes the condition occurs following interference

suggested as a contributing cause of the high levels of

with the blood supply to these glands. The function of

blood glucose. It should be remembered that insulin

the parathyroid gland is to secrete a hormone that

stimulates the uptake and storage of glucose in the liver

regulates calcium metabolism and plasma calcium

and muscle, whereas glucagon inhibits this process.

concentration. A low level of plasma calcium results in

13.

Because the testes were removed after puberty, many of

increased neuromuscular excitability and the clinical

the accessory sex organs of this patient will atrophy and

syndrome known as tetany.

the secondary sexual characteristics will regress. Testos-

E is the correct answer. A thyroglossal cyst occurs most

terone is produced in individuals with undescended

commonly in the midline of the neck below the hyoid

testes because the interstitial cells are not as sensitive to

bone and above the isthmus of the thyroid gland. It

heat as are the germinal epithelium of the seminiferous

should be emphasized that it can occur anywhere along

tubules.

the path of the thyroglossal tract, even as far superiorly

14.

A summary of the clinical signs and symptoms of

as the foramen cecum of the tongue. As the cyst en-

menopause are given on CD page 420. At menopause,

larges it is prone to infection, so it should be removed

the few remaining graafian follicles of the ovary cease to

surgically.

be sensitive to stimulation by the gonadotropic hor-

10.

Addison’s disease occurs as a result of the destruction of

mones of the pars anterior of the pituitary, even though

the suprarenal cortex by tuberculosis or idiopathic

the blood levels of these hormones rise after menopause.

atrophy; it may also occur secondary to a failure of elab-

The hypothalamus-pituitary- ovary hormonal mecha-

oration of adrenocorticotropic hormone (ACTH) from

nism thus ceases to operate.

Appendix Outline

Respiratory System

426

Table VII. Summary of the Movements of the

Knee Joint and the Muscles Producing

Table I. Important Airway Distances (Adult)

426

Those Movements

434

Table II. Important Data Concerning the Trachea

426

Table VIII. Summary of the Movements of the Ankle

Musculoskeletal System

427

Joint and the Muscles Producing Those

Table III. Summary of the Movements of the

Movements

435

Shoulder Joint and the Muscles Producing

Digestive System

436

Those Movements

427

Table IX. Lengths and Capacities

436

Table IV. Summary of the Movements of the

Urinary System

436

Elbow Joint and the Muscles Producing

Those Movements

429

Table X. Lengths and Capacities

436

Table V. Summary of the Movements of the

Reproductive System

436

Wrist Joint and the Muscles Producing

Table XI. Dimensions

436

Those Movements

430

Embryology

437

Table VI. Summary of the Movements of the

Hip Joint and the Muscles Producing

Table XII. The Size and Weight of the Developing

Those Movements

432

Human Embryo and Fetus

437

Respiratory System

Important Airway Distances

Important Data Concerning

Table I

Table II

(Adult)^a

the Trachea^a

Distances

Length (approx.)

Diameter (approx.)

Airway

(approx.)

Adults

4.5 in. (11.4 cm)

1 in. (2.5 cm)

Incisor teeth to the vocal cords

5.9 in. (15 cm)

Infants

1.6-2 in. (4-5 cm)

As small as 3 mm^b

Incisor teeth to the carina

7.9 in. (20 cm)

External nares to the carina

11.8 in. (30 cm)

^a Extension of the head and neck, as when maintaining

an airway in an anesthetized patient, may stretch the

trachea and increase its length by 25%. In the adult,

^a Average figures given

1-2 cm.

the carina may descend by as much as 3 cm on deep

inspiration. At the carina, the right bronchus leaves the

trachea at an angle of 25° from the vertical and the left

bronchus leaves the trachea at an angle of 45° from

the vertical. In children younger than 3 years, both

bronchi arise from the trachea at equal angles.

^b As children grow, the diameter in millimeters

corresponds approximately to their age in years.

Appendix

427

Musculoskeletal System

Summary of the Movements of the Shoulder Joint and the Muscles Producing

Table III

Those Movements^a

Segmental

Movements

Muscles

Origin

Insertion

Nerve Supply

Nerve^b

Flexion

Deltoid (anterior

Clavicle

Middle of lateral

Axillary nerve

C5, 6

fibers)

surface of shaft

of humerus

Pectoralis major

Clavicle

Lateral lip bicipital

Medial and lateral

C5, 6

(clavicular

groove of humerus

pectoral nerves

part)

from brachial

plexus

Biceps brachii

Long head

Supraglenoid

Tuberosity of

Musculocutaneous

C5, 6

tubercle of scapula

radius, deep fascia

nerve

of forearm

Short head

Coracoid process

of scapula

Coraco-

Coracoid process

Medial aspect of

Musculocutaneous

C5, 6, 7

brachialis

of scapula

shaft of humerus

nerve

Extension

Deltoid

Spine of scapula

Middle of lateral

Axillary nerve

C5, 6

(posterior

surface of shaft

fibers)

of humerus

Latissimus dorsi

Iliac crest, lumbar

Floor of bicipital

Thoracodorsal

C6, 7, 8

fascia, spines of

groove of

nerve

lower six thoracic

humerus

vertebrae, lower

three or four ribs,

and inferior angle

of scapula

Teres major

Lower third lateral

Medial lip of

Lower subscapular

C6, 7

border of scapula

bicipital groove

nerve

of humerus

Abduction

Middle fibers

Acromion process

Middle of lateral

Axillary nerve

C5, 6

of deltoid

of scapula

surface of shaft

of humerus

Supraspinatus

Supraspinous fossa

Greater tuberosity

Suprascapular

C4, 5, 6

of scapula

of humerus

nerve

Adduction

Pectoralis major

Sternum and upper

Lateral lip of

Medial and lateral

C7, 8; T1

(sternal part)

six costal

bicipital groove

pectoral nerves

cartilages

of humerus

Latissimus dorsi

Iliac crest, lumbar

Floor of bicipital

Thoracodorsal

C6, 7, 8

fascia, spines of

groove of humerus

nerve

lower six thoracic

vertebrae, lower

three or four ribs,

inferior angle of

scapula

428

Appendix

Table III

(continued)

Segmental

Movements

Muscles

Origin

Insertion

Nerve Supply

Nerve^b

Teres major

Lower third lateral

Medial lip of

Lower subscapular

C6, 7

border of scapula

bicipital groove

nerve

of humerus

Teres minor

Upper two thirds

Greater tuberosity

Axillary nerve

C5, 6

lateral border of

of humerus

scapula

Lateral

Infraspinatus

Infraspinous fossa

Greater tuberosity

Suprascapular

C5, 6

rotation

of scapula

of humerus

nerve

Teres minor

Upper two thirds

Greater tuberosity

Axillary nerve

C5, 6

lateral border of

of humerus

scapula

Deltoid

Spine of scapula

Middle of lateral

Axillary nerve

C5, 6

(posterior

surface of shaft

fibers)

of humerus

Medial

Subscapularis

Subscapular fossa

Lesser tuberosity

Upper and lower

C5, 6

rotation

of humerus

subscapular

nerves

Latissimus

Iliac crest, lumbar

Floor of bicipital

Thoracodorsal

C6, 7, 8

dorsi

fascia, spines of

groove of

nerve

lower three or

humerus

four ribs, inferior

angle of scapula

Teres major

Lower third lateral

Medial lip bicipital

Lower subscapular

C6, 7

border of

groove of

nerve

scapula

humerus

Deltoid (anterior

Clavicle

Middle of lateral

Axillary nerve

C5, 6

fibers)

surface of shaft

of humerus

^a Circumduction is a combination of all the movements described.

^b The predominant segmental nerve supply is indicated by boldface type.

Appendix

429

Musculoskeletal System

Summary of the Movements of the Elbow Joint and the Muscles Producing

Table IV

Those Movements

Segmental

Movements

Muscles

Origin

Insertion

Nerve Supply

Nerve^a

Flexion

Brachialis

Front of lower

Coronoid process

Musculocutaneous

C5, 6

half of humerus

of ulna

nerve

Biceps brachii

Long head

Supraglenoid

Tuberosity of

Musculocutaneous

C5, 6

tubercle of

radius, deep

nerve

scapula

fascia of forearm

Short head

Coracoid process

of scapula

Brachioradialis

Lateral

Styloid process

Radial nerve

C5, 6, 7

supracondylar

of radius

ridge of humerus

Pronator teres

Humeral head

Medial epicondyle

Lateral aspect of

Median nerve

C6, 7

of humerus

shaft of radius

Ulnar head

Coronoid process

of ulna

Extension

Triceps

Long head

Infraglenoid tubercle

Olecranon

Radial nerve

C6, 7, 8

of scapula

process of ulna

Lateral head

Posterior surface of

shaft of humerus

Medial head

Lower half of

posterior surface

of shaft of humerus

Anconeus

Lateral epicondyle

Olecranon

Radial nerve

C7, 8; T1

of humerus

process of ulna

^aThe predominant segmental nerve supply is indicated by boldface type.

430

Appendix

Musculoskeletal System

Summary of the Movements of the Wrist Joint and the Muscles Producing Those

Table V

Movements

Segmental

Movements

Muscles

Origin

Insertion

Nerve Supply

Nerve^a

Flexion

Flexor carpi

Medial epicondyle

Bases of second

Median nerve

C6, 7

radialis

of humerus

and third

metacarpal bones

Flexor carpi

ulnaris

Humeral head

Medial epicondyle

Pisiform bone,

Ulnar nerve

C7, 8

of humerus

hook of hamate,

base of fifth

metacarpal bone

Ulnar head

Olecranon process,

posterior border

of ulna

Palmaris longus

Medial epicondyle

Flexor

Median nerve

C7, 8

of humerus

retinaculum,

palmar

aponeurosis

Flexor digitorum

superficialis

Humeroulnar

Medial epicondyle

Middle phalanx

Median nerve

C7, 8; T1

head

of humerus,

of medial four

coronoid process

fingers

of ulna

Radial head

Oblique line anterior

surface shaft of

radius

Flexor digitorum

Anterior surface

Distal phalanx

Ulnar half—

C8; T1

profundus

shaft of ulna,

of medial four

ulnar nerve,

interosseous

fingers

radial half—

membrane

median nerve

Flexor pollicis

Anterior surface

Distal phalanx

C8; T1

longus

shaft of radius

of thumb

interosseous

branch of

median nerve

Extension

Extensor carpi

Lateral supracondylar

Base of second

Radial nerve

C6, 7

radialis longus

ridge of humerus

metacarpal bone

Extensor carpi

Lateral epicondyle of

Base of third

Deep branch

C7, 8

radialis brevis

humerus

metacarpal bone

of radial nerve

Extensor carpi

Lateral epicondyle

Base of fifth

Deep branch

C7, 8

ulnaris

of humerus

metacarpal bone

of radial nerve

Extensor

Lateral epicondyle

Middle and distal

Deep branch of

C7, 8

digitorum

of humerus

phalanges of

radial nerve

medial four

fingers

Appendix

431

Table V

(continued)

Segmental

Movements

Muscles

Origin

Insertion

Nerve Supply

Nerve^a

Extensor indicis

Shaft of ulna and

Extensor

Deep branch of

C7, 8

interosseous

expansion of

radial nerve

membrane

index finger

Extensor digiti

Lateral epicondyle

Extensor

Deep branch of

C7, 8

minimi

of humerus

expansion of

radial nerve

little finger

Extensor pollicis

Shaft of ulna and

Base of distal

Deep branch of

C7, 8

longus

interosseous

phalanx of thumb

radial nerve

membrane

Abduction

Flexor carpi

Medial epicondyle

Bases of second

Median nerve

C6, 7

radialis

of humerus

and third

metacarpal bones

Extensor carpi

Lateral

Base of second

Radial nerve

C6, 7

radialis longus

supracondylar

metacarpal bone

ridge of humerus

Extensor carpi

Lateral epicondyle

Bases of third

Deep branch of

C7, 8

radialis brevis

of humerus

metacarpal bone

radial nerve

Abductor pollicis

Shafts of radius

Base of first

Deep branch of

C7, 8

longus

and ulna

metacarpal bone

radial nerve

Extensor pollicis

Shaft of ulna and

Base of distal

Deep branch of

C7, 8

longus

interosseous

phalanx of thumb

radial nerve

membrane

Extensor pollicis

Shaft of radius and

Base of proximal

Deep branch of

C7, 8

brevis

interosseous

phalanx of thumb

radial nerve

membrane

Adduction

Flexor carpi

ulnaris

Humeral head

Medial

Pisiform bone,

Ulnar nerve

C7, 8

epicondyle of

hook of

humerus

hamate, base

of fifth

metacarpal bone

Ulnar head

Olecranon process

of ulna

Extensor carpi

Lateral epicondyle

Base of fifth

Deep branch of

C7, 8

ulnaris

of humerus

metacarpal

radial nerve

bone

^a The predominant segmental nerve supply is indicated by boldface type.

432

Appendix

Musculoskeletal System

Summary of the Movements of the Hip Joint and the Muscles Producing

Table VI

Those Movements^a

Segmental

Movements

Muscles

Origin

Insertion

Nerve Supply

Nerve^b

Flexion

Iliacus

Iliac fossa

Lesser trochanter

Femoral nerve

L2, 3

of femur

Psoas

Body of twelfth

Lesser trochanter

Lumbar plexus

L1, 2, 3

thoracic vertebra,

of femur

transverse

processes, bodies

and intervertebral

discs of the five

lumbar vertebrae

Rectus femoris

Straight head

Anterior inferior

Patella

Femoral nerve

L2, 3, 4

iliac spine

Reflected head

Ilium above

acetabulum

Sartorius

Anterior superior

Upper medial

Femoral nerve

L2, 3

iliac spine

surface of shaft

of tibia

Extension

Gluteus

Outer surface of

Iliotibial tract,

Inferior gluteal

L5; S1, 2

(a posterior

maximus

ilium, sacrum,

gluteal

nerve

movement

coccyx, sacrotuber-

tuberosity of

of the flexed

ous ligament

femur

thigh)

Biceps femoris

Long head: ischial

Head of fibula

Tibial nerve

L5; S1, 2

tuberosity

(sciatic nerve)

Semitendinosus

Ischial tuberosity

Upper part of

Tibial nerve

L5; S1, 2

medial surface of

(sciatic nerve)

shaft of tibia

Semimembra-

Ischial tuberosity

Medial condyle of

Tibial nerve

L5; S1, 2

nosus

tibia

(sciatic nerve)

Adductor magnus

Ischial tuberosity

Adductor tubercle

Tibial nerve

L2, 3, 4

of femur

(sciatic nerve)

Abduction

Gluteus medius

Outer surface of

Greater

Superior gluteal

L5; S1

ilium

trochanter of

nerve

femur

Gluteus minimus

Outer surface of

Greater

Superior

L5; S1

ilium

trochanter of

gluteal nerve

femur

Sartorius

Anterior superior

Upper medial

Femoral nerve

L2, 3

iliac spine

surface of shaft

of tibia

Tensor fasciae

Iliac crest

Iliotibial tract

Superior gluteal

L4, 5

latae

nerve

Piriformis

Anterior surface of

Greater

Sacral plexus

L5; S1, 2

sacrum

trochanter of

femur

Appendix

433

Table VI

(continued)

Segmental

Movements

Muscles

Origin

Insertion

Nerve Supply

Nerve^a

Adduction

Adductor longus

Body of pubis

Posterior surface

Obturator nerve

L2, 3, 4

of shaft of femur

Adductor brevis

Inferior ramus of

Posterior surface

Obturator nerve

L2, 3, 4

pubis

of shaft of femur

Adductor magnus

Inferior ramus of

Posterior surface

Obturator nerve

L2, 3, 4

(adductor fibers)

pubis, ramus of

of shaft of femur,

ischium, ischial

adductor tubercle

tuberosity

of femur

Pectineus

Superior ramus of

Upper end of

Femoral nerve

L2, 3

pubis

shaft of femur

Gracilis

Inferior ramus of

Upper part of

Obturator nerve

L2, 3

pubis, ramus of

shaft of tibia on

ischium

medial surface

Lateral

Piriformis

Anterior surface of

Greater trochanter

Sacral plexus

L5; S1, 2

rotation

sacrum

of femur

Obturator

Inner surface of

Greater trochanter

Sacral plexus

L5; S1

internus

obturator membrane

of femur

Obturator

Outer surface of

Greater trochanter

Obturator nerve

L3, 4

externus

obturator membrane

of femur

Superior

Spine of ischium

Greater trochanter

Sacral plexus

L5; S1

gemellus

of femur

Inferior gemellus

Ischial tuberosity

Greater trochanter

Sacral plexus

L5; S1

of femur

Quadratus

Ischial tuberosity

Quadrate tubercle

Sacral plexus

L5; S1

femoris

on upper end of

posterior

surface of femur

Gluteus maximus

Outer surface of

Iliotibial tract,

Inferior gluteal

L5; S1, 2

ilium, sacrum,

gluteal tuberosity

nerve

coccyx,

of femur

sacrotuberous

ligament

Medial

Gluteus medius

Outer surface of

Greater trochanter

Superior gluteal

L5; S1

rotation

ilium

of femur

nerve

Gluteus

Outer surface of ilium

Greater trochanter

Superior gluteal

L5; S1

minimus

of femur

nerve

Tensor fasciae

Iliac crest

Iliotibial tract

Superior

L4, 5

latae

gluteal nerve

^a Circumduction is a combination of all the movements described.

^b The predominant segmental nerve supply is indicated by boldface type.

434

Appendix

Musculoskeletal System

Summary of the Movements of the Knee Joint and the Muscles

Table VII

Producing Those Movements

Segmental

Movements

Muscles

Origin

Insertion

Nerve Supply

Nerve^a

Flexion

Biceps femoris

Long head

Ischial tuberosity

Head of fibula

Tibial nerve

L5; S1, 2

Short head

Shaft of femur

Common

peroneal

nerve

Semitendinosus

Ischial tuberosity

Upper part of

Tibial nerve

L5; S1, 2

medial surface

of shaft of tibia

Semimem-

Ischial tuberosity

Medial condyle of

Tibial nerve

L5; S1, 2

branosus

tibia

Gastrocnemius

Medial, lateral

Via Achilles tendon

Tibial nerve

S1, 2

condyles of

into calcaneum

femur

Extension

Quadriceps

femoris: rectus

femoris

Straight head

Anterior inferior

Patella

Femoral nerve

L2, 3, 4

iliac spine

Reflected head

Ilium above

acetabulum

Vastus lateralis

Upper end and

Patella

Femoral nerve

L2, 3, 4

shaft of femur

Vastus medialis

Upper end and

Patella

Femoral nerve

L2, 3, 4

shaft of femur

Vastus inter-

Shaft of femur

Patella

Femoral nerve

L2, 3, 4

medius

Medial

Sartorius

Anterior superior

Upper medial

Femoral nerve

L2, 3

rotation

iliac spine

surface of shaft

of tibia

Gracilis

Interior ramus of

Upper part of shaft

Obturator nerve

L2, 3

pubis, ramus

of tibia on medial

of ischium

surface

Lateral

Biceps femoris

rotation

Long head

Ischial tuberosity

Head of fibula

Tibial nerve

L5; S1, 2

Short head

Shaft of femur

—

Common

L5; S1, 2

peroneal

nerve

^a The predominant segmental nerve supply is indicated by boldface type.

Appendix

435

Musculoskeletal System

Summary of the Movements of the Ankle Joint and the Muscles Producing

Table VIII

Those Movements

Nerve

Segmental

Movements

Muscles

Origin

Insertion

Supply

Nerve^a

Dorsiflexion

Tibialis anterior

Shaft of tibia,

Medial cuneiform,

Deep peroneal

L4,5

interosseous

base of first

nerve

membrane

metatarsal bone

Extensor hallucis

Shaft of fibula,

Base of distal

Deep peroneal

L5, S1

longus

interosseous

phalanx of great

nerve

membrane

toe

Extensor digitorum

Shaft of fibula,

Dorsal extensor

Deep peroneal

L5, S1

longus

interosseous

expansion of

nerve

membrane

lateral four toes

Peroneus tertius

Shaft of fibula,

Base of fifth

Deep peroneal

L5, S1

interosseous

metatarsal bone

nerve

membrane

Plantar-

Gastrocnemius

Medial, lateral

Via Achilles tendon

Tibial nerve

S1,2

flexion

condyles of

into calcaneum

femur

Soleus

Shaft of tibia

Via Achilles tendon

Tibial nerve

S1,2

and fibula

into calcaneum

Plantaria

Lateral supra-

Calcaneum

Tibial nerve

S1,2

condylar ridge

of femur

Peroneus longus

Shaft of fibula

Base of first

Superficial

L5; S1,2

metatarsal and

peroneal nerve

medial cuneiform

Peroneus brevis

Shaft of fibula

Base of fifth

Superficial

L5; S1,2

metatarsal bone

peroneal nerve

Tibialis posterior

Shaft of tibia,

Tuberosity of

Tibial nerve

L4,5

fibula, in-

navicular

terosseous

membrane

Flexor digitorum

Shaft of tibia

Distal phalanges

Tibial nerve

S2,3

longus

of lateral four toes

Flexor hallucis

Shaft of fibula

Base of distal

Tibial nerve

S2,3

longus

phalanx of big toe

^a The predominant segmental nerve supply is indicated by boldface type.

436

Appendix

Digestive System

Table IX

Lengths and Capacities

Region (approx.)

Lengths (approx.)

Capacities (Approx.)

Esophagus

10 in. (25 cm)

—

Stomach^a

Lesser curvature 4.8-5.6 in. (12-14 cm)

1,500 mL

Duodenum

10 in. (25 cm)

—

Jejunum

8 ft (2.4 M)

—

Ileum

12 ft (3.7 M)

—

Appendix

3-5 in. (8-13 cm)

—

Ascending colon

5 in. (13 cm)

—

Transverse colon

15 in. (38 cm)

—

Descending colon

10 in. (25 cm)

—

Sigmoid colon

10-15 in. (25-38 cm)

—

Rectum

5 in. (13 cm)

—

Anal canal

1.5 in. (4 cm)

—

Gallbladder

2.8-3.9 in. (7-10 cm)

30-50 mL

Cystic duct

1.5 in. (3.8 cm)

—

Bile duct

3 in. (8 cm)

—

^a The curved course taken by a nasogastric tube from the cardiac orifice to the pylorus is usually

longer, 6-10 in. (15-25 cm).

Urinary System

Reproductive System

Table X

Lengths and Capacities

Table XI

Dimensions

Capacity

Organ

Dimensions (approx.)

Organ

Lengths (approx.)

(approx.)

Male

Ureter

10 in. (25 cm)

—

Testis

1 in. (5

2.5 cm)

Bladder

—

500 mL

Vas deferens

18 in. (45 cm)

Male urethra

8 in. (20 cm)

—

Penis (erect)

6 in. (15 cm)

Penile

6 in. (15.7 cm)

—

Female

Membranous

0.5 in. (1.25 cm)

—

Ovary

1.5

0.75 in. (4

2 cm)

Prostatic

1.25 in. (3 cm)

—

Uterine tube

4 in. (10 cm)

Female urethra

1.5 in. (3.8 cm)

—

Uterus

1 in. (8

2.5 cm)

Vagina

3 in. (8 cm)