The upper arm and cubital fossa pdf - Upper limb

Basic Anatomy

through the joint and emerges beneath the transverse

The tendon of the long head of the biceps muscle passes

lary nerve, and the posterior circumflex humeral vessels

The long head of the triceps muscle, the axil

Inferiorly:

bursa, coracoacromial ligament, and deltoid muscle

The supraspinatus muscle, subacromial

Superiorly:

The infraspinatus and teres minor muscles

Posteriorly:

367

■

ligament.

intercostobrachial nerves

(T1) and the

the arm

medial cutaneous nerve of

of the arm is supplied by the

(C5 and 6). The skin of the armpit and the medial side

a branch of the radial nerve

cutaneous nerve of the arm,

lower lateral

the arm below the deltoid is supplied by the

lary nerve (C5 and 6). The skin over the lateral surface of

a branch of the axil

lateral cutaneous nerve of the arm,

upper

over the lower half of the deltoid is supplied by the

(C3 and 4). The skin

supraclavicular nerves

is from the

point of the shoulder to halfway down the deltoid muscle

The sensory nerve supply (Fig. 9.38) to the skin over the

Superficial Sensory Nerves

these movements.

shows the direction of pull of the muscles responsible for

summarizes the movements of abduction of the arm and

head is accomplished by rotating the scapula. Figure 9.37

of the acromion. Further elevation of the arm above the

ity of the humerus comes into contact with the lateral edge

At about 120° of abduction of the arm, the greater tuberos

joint and a 1° abduction occurs by rotation of the scapula.

abduction of the arm, a 2° abduction occurs in the shoulder

as well as movement at the shoulder joint. For every 3° of

Abduction of the arm involves rotation of the scapula

clavicular ligament.

of rotation may be considered to pass through the coraco

so that the position of the glenoid fossa is altered, the axis

tone of muscles. When the scapula rotates on the chest wall

cle by the strong coracoclavicular ligament assisted by the

The scapula and upper limb are suspended from the clavi

The Scapular–Humeral Mechanism

The Upper Arm

Skin

(T2). The

skin of the back of the arm (Fig. 9.38) is supplied by
the
the radial nerve (C8).

a branch of

posterior cutaneous nerve of the arm,

Stability of the Shoulder Joint

example, diseases of the spinal cord and vertebral column and

Injury to the shoulder joint is followed by pain, limitation of

nerve. The joint is sensitive to pain, pressure, excessive traction,

displacement of the humerus can also stretch and damage the

of skin sensation over the lower half of the deltoid. Downward

nerve, as indicated by paralysis of the deltoid muscle and loss

into the quadrangular space can cause damage to the axillary

muscle. A subglenoid displacement of the head of the humerus

the humerus is no longer bulging laterally beneath the deltoid

shoulder is seen to be lost because the greater tuberosity of

with shoulder dislocation, the rounded appearance of the

violence to the front of the joint. On inspection of the patient

Posterior dislocations are rare and are usually caused by direct

tendons of these muscles are fused to the underlying capsule of

of the short muscles that bind the upper end of the humerus to

ble structure. Its strength almost entirely depends on the tone

The shallowness of the glenoid fossa of the scapula and the lack

of support provided by weak ligaments make this joint an unsta-

the scapula—namely, the subscapularis in front, the supraspi-

natus above, and the infraspinatus and teres minor behind. The

the shoulder joint. Together, these tendons form the rotator cuff.

The least supported part of the joint lies in the inferior loca-

tion, where it is unprotected by muscles.

Dislocations of the Shoulder Joint

The shoulder joint is the most commonly dislocated large joint.

Anterior Inferior Dislocation
Sudden violence applied to the humerus with the joint fully

abducted tilts the humeral head downward onto the inferior

weak part of the capsule, which tears, and the humeral head

comes to lie inferior to the glenoid fossa. During this move-

ment, the acromion has acted as a fulcrum. The strong flexors

and adductors of the shoulder joint now usually pull the humeral

head forward and upward into the subcoracoid position.

Posterior Dislocations

radial nerve.

Shoulder Pain

The synovial membrane, capsule, and ligaments of the shoulder

joint are innervated by the axillary nerve and the suprascapular

and distention. The muscles surrounding the joint undergo reflex

spasm in response to pain originating in the joint, which in turn

serves to immobilize the joint and thus reduce the pain.

movement, and muscle atrophy owing to disuse. It is important

to appreciate that pain in the shoulder region can be caused by

disease elsewhere and that the shoulder joint may be normal; for

the pressure of a cervical rib (see page XXX) can cause shoul-

der pain. Irritation of the diaphragmatic pleura or peritoneum

can produce referred pain via the phrenic and supraclavicular

nerves.

C L I N I C A L N O T E S

Basic Anatomy

369

supraclavicular

nerves

intercostobrachial

nerve

medial cutaneous

nerve of arm

medial cutaneous

nerve of forearm

posterior cutaneous branch

of ulnar nerve

palmar cutaneous branch

of ulnar nerve

ulnar nerve

anterior surface

median nerve

palmar cutaneous

branch of

median nerve

superficial branch

of radial nerve

lateral

cutaneous nerve

of forearm

lower lateral

cutaneous nerve

of arm

upper lateral

cutaneous nerve

of arm

posterior surface

upper lateral cutaneous

nerve of arm

posterior cutaneous

nerve of arm

posterior cutaneous

nerve of forearm

superficial branch of

radial nerve

lateral cutaneous

nerve of forearm

FIGURE 9.38

Cutaneous innervation of the upper limb.

Superficial Lymph Vessels

similar to those of the arteries.

that provide vasomotor tone. The origin of these fibers is

is innervated by sympathetic postganglionic nerve fibers

Like the arteries, the smooth muscle in the wall of the veins

Nerve Supply of the Veins

form the axillary vein.

major joins the venae comitantes of the brachial artery to

pierces the deep fascia and at the lower border of the teres

medial side of the biceps (Fig. 9.39). Halfway up the arm, it

ascends in the superficial fascia on the

basilic vein

The

lar fossa, drains into the axillary vein.

lateral side of the biceps and, on reaching the infraclavicu

ascends in the superficial fascia on the

cephalic vein

The

superficial fascia.

The superficial veins of the arm (Fig. 9.39) lie in the

in pairs, and the axillary vein.

comitantes, which accompany all the large arteries, usually

superficial and deep. The deep veins comprise the venae

The veins of the upper limb can be divided into two groups:

Superficial Veins

The superficial lymph vessels draining the superficial tissues
of the upper arm pass upward to the axilla (Fig. 9.40).

cephalic vein

venae
comitantes
of brachial
artery

median
cubital
vein

anterior
median vein
of forearm

axillary
vein

basilic vein

cephalic vein

median
cephalic
vein

basilic vein

median
cubital
vein

median basilic
vein

anterior median
vein of forearm

FIGURE 9.39

Superficial veins of the upper limb. Note the

common variations seen in the region of the elbow.

370

CHAPTER 9

weak flexor of the shoulder joint.

The biceps also is a powerful flexor of the elbow joint and a

the cork or driving the screw into wood with a screwdriver.

this action is made use of in twisting the corkscrew into

Note that the biceps brachii is a powerful supinator, and

in Figures 9.43 and 9.44 and are described in Table 9.5.

The muscles of the anterior fascial compartment are shown

Muscles of the Anterior Fascial Compartment

part of the compartment.

and basilic vein. The radial nerve is present in the lower

locutaneous, median, and ulnar nerves; brachial artery

Muscu

Structures passing through the compartment:

Musculocutaneous nerve

Nerve supply to the muscles:

Brachial artery (Fig. 9.42)

Blood supply:

Biceps brachii, coracobrachialis, and brachialis

Muscles:

of the Upper Arm

Contents of the Anterior Fascial Compartment

ment, each having its muscles, nerves, and arteries.

divided into an anterior and a posterior fascial compart

the humerus, respectively. By this means, the upper arm is

attached to the medial and lateral supracondylar ridges of

one on the lateral side, extend from this sheath and are

(Fig. 9.41). Two fascial septa, one on the medial side and

The upper arm is enclosed in a sheath of deep fascia

axillary nodes.

deep structures of the arm drain into the lateral group of

draining the muscles and

deep lymphatic vessels

The

axillary nodes.

medial side follow the basilic vein to the lateral group of

vein to the infraclavicular group of nodes; those from the

Those from the lateral side of the arm follow the cephalic

The Upper Limb

Fascial Compartments of the Upper Arm

■

Venipuncture and Blood Transfusion

termination, the cephalic vein joins the axillary vein at a right angle.

the clavicle and join the external jugular vein. In its usual method of

topectoral triangle. One or more of these branches may ascend over

The cephalic vein does not increase in size as it ascends the arm,

valves in the axillary vein may be troublesome, but abduction of the

diameter and is in direct line with the axillary vein (Fig. 9.39). The

basilic vein reaches the axillary vein, the basilic vein increases in

tral venous catheterization, because from the cubital fossa until the

crosses in front of the clavicle. Fracture of the clavicle can result

municates with the external jugular vein by a small vein that

obtain blood from the arm. When a patient is in a state of shock,

The superficial veins are clinically important and are used for

venipuncture, transfusion, and cardiac catheterization. Every

clinical professional, in an emergency, should know where to

the superficial veins are not always visible. The cephalic vein

lies fairly constantly in the superficial fascia, immediately pos-

terior to the styloid process of the radius. In the cubital fossa,

the median cubital vein is separated from the underlying brachial

artery by the bicipital aponeurosis. This is important because it

protects the artery from the mistaken introduction into its lumen

of irritating drugs that should have been injected into the vein.

The cephalic vein, in the deltopectoral triangle, frequently com-

in rupture of this communicating vein, with the formation of a

large hematoma.

Intravenous Transfusion and Hypovolemic Shock

In extreme hypovolemic shock, excessive venous tone may

inhibit venous blood flow and thus delay the introduction of intra-

venous blood into the vascular system.

Anatomy of Basilic and Cephalic Vein Catheterization

The median basilic or basilic veins are the veins of choice for cen-

shoulder joint may permit the catheter to move past the obstruction.

and it frequently divides into small branches as it lies within the del-

It may be difficult to maneuver the catheter around this angle.

C L I N I C A L N O T E S

lateral group

of axillary

nodes

infraclavicular group

of nodes

supratrochlear lymph node

FIGURE 9.40

Superficial lymphatics of the upper limb. Note

the positions of the lymph nodes.

Basic Anatomy

371

venae comitantes

brachial artery

median nerve

medial cutaneous nerve

of forearm

basilic vein

medial

intermuscular septum

ulnar nerve

superior ulnar

collateral artery

skin

deep fascia

long head of triceps

medial head of triceps

lateral head of triceps

radial nerve

profunda artery

lateral intermuscular septum

humerus

brachialis

cephalic vein

biceps brachii

musculocutaneous nerve

FIGURE 9.41

Cross section of the upper arm just below the level of insertion of the deltoid muscle. Note the division of the

arm by the humerus and the medial and lateral intermuscular septa into anterior and posterior compartments.

anterior and posterior
cicumflex humeral arteries

profunda artery

radial artery

axillary
artery

brachial

artery

superior ulnar

collateral artery

inferior ulnar

collateral artery

common

interosseous artery

ulnar artery

anterior interosseous

artery

deep palmar arch

superficial palmar arch

digital

arteries

FIGURE 9.42

The main arteries of the upper limb.

Lymphangitis

glenoid tubercle within the shoulder joint. Advanced osteo

lary nodes; those from the middle, ring, and little fingers and

are characteristic of the condition. The lymph vessels from

Infection of the lymph vessels (lymphangitis) of the arm is

common. Red streaks along the course of the lymph vessels

the thumb and index finger and the lateral part of the hand

follow the cephalic vein to the infraclavicular group of axil-

from the medial part of the hand follow the basilic vein to the

supratrochlear node, which lies in the superficial fascia just

above the medial epicondyle of the humerus, and thence to

the lateral group of axillary nodes.

Lymphadenitis

Once the infection reaches the lymph nodes, they become

enlarged and tender, a condition known as lymphadenitis.

Most of the lymph vessels from the fingers and palm pass to

the dorsum of the hand before passing up into the forearm.

This explains the frequency of inflammatory edema, or even

abscess formation, which may occur on the dorsum of the

hand after infection of the fingers or palm.

Biceps Brachii and Osteoarthritis of the Shoulder Joint

The tendon of the long head of biceps is attached to the supra-

arthritic changes in the joint can lead to erosion and fraying

of the tendon by osteophytic outgrowths, and rupture of the

tendon can occur.

C L I N I C A L N O T E S

372

CHAPTER 9

The Upper Limb

trapezius

clavicle

deltoid

short head of biceps

long head of biceps

coracobrachialis

median nerve

brachial artery

brachialis

musculocutaneous nerve

brachioradialis

extensor carpi radialis longus

biceps tendon

radial artery

ulnar artery

flexor carpi ulnaris

bicipital aponeurosis

palmaris longus

flexor carpi radialis

pronator teres

brachialis

medial intermuscular septum

triceps

ulnar nerve

pectoralis major

sternocleidomastoid

radial
nerve

FIGURE 9.43

hii has been removed to show the muscu

Anterior view of the upper arm. The middle portion of the biceps brac

locutaneous nerve lying in front of the brachialis.

Basic Anatomy

373

trapezius

clavicle

sternocleidomastoid

pectoralis major

deltoid

biceps

coracobrachialis

medial intermuscular septum

brachialis

lateral intermuscular

septum

lateral epicondyle

head of radius

bicipital tuberosity

coronoid process of ulna

medial epicondyle

FIGURE 9.44

Anterior view of the upper arm showing the insertion of the deltoid and the origin and insertion of the brachialis.

374

CHAPTER 9

(Fig. 9.38).

of the forearm as the lateral cutaneous nerve of the forearm

fascia just above the elbow. It runs down the lateral aspect

lateral margin of the biceps tendon and pierces the deep

biceps and brachialis muscles (Fig. 9.43). It appears at the

cle (Fig. 9.15), and then passes downward between the

downward and laterally, pierces the coracobrachialis mus

(C5, 6, and 7) in the axilla is described on page 352. It runs

taneous nerve from the lateral cord of the brachial plexus

The origin of the musculocu

Musculocutaneous Nerve

around the elbow joint (Fig. 9.45).

mination of the artery and takes part in the anastomosis

arises near the ter

inferior ulnar collateral artery

The

(Fig. 9.45).

middle of the upper arm and follows the ulnar nerve

arises near the

superior ulnar collateral artery

The

ral groove of the humerus (Fig. 9.45).

brachial artery and follows the radial nerve into the spi

arises near the beginning of the

profunda artery

The

to the humerus

nutrient artery

The

upper arm

to the anterior compartment of the

Muscular branches

Branches

(Fig. 9.43).

lies lateral to the artery in the lower part of its course

lis and biceps muscles above; the tendon of the biceps

The median nerve and the coracobrachia

Laterally:

median nerve lies on its medial side (Fig. 9.43).

upper part of the arm; in the lower part of the arm, the

The ulnar nerve and the basilic vein in the

Medially:

brachialis insertion, and the brachialis (Fig. 9.43).

The artery lies on the triceps, the coraco

Posteriorly:

(Fig. 9.43).

part; and the bicipital aponeurosis crosses its lower part

of the upper part; the median nerve crosses its middle

The medial cutaneous nerve of the forearm lies in front

from the lateral side by the coracobrachialis and biceps.

The vessel is superficial and is overlapped

Anteriorly:

Relations

of the radius by dividing into the radial and ulnar arteries.

supply to the arm (Fig. 9.42). It terminates opposite the neck

tinuation of the axillary artery. It provides the main arterial

begins at the lower border of the teres major muscle as a con

The brachial artery (Figs. 9.42 and 9.43)

Brachial Artery

Compartment

Structures Passing through the Anterior Fascial

The Upper Limb

■

Muscles of the Arm

T A B L E 9 . 5

Triceps

Tuberosity of radius

Muscle

Origin

Insertion

Nerve Supply

Nerve Roots

Action

Anterior Compartment
Biceps brachii
Long head

Supraglenoid

tubercle of scapula

and bicipital

aponeurosis into

deep fascia of

forearm

Musculocutaneous

nerve

C5, 6

Supinator of forearm

and flexor of elbow

joint; weak flexor

of shoulder joint

Short head

Coracoid process of

scapula

Coracobrachialis

Coracoid process of

scapula

Medial aspect of shaft

of humerus

Musculocutaneous

nerve

C5, 6, 7

Flexes arm and also

weak adductor

Brachialis

Front of lower half of

humerus

Coronoid process of

ulna

Musculocutaneous

nerve

C5, 6

Flexor of elbow joint

Posterior Compartment

Long head

Infraglenoid tubercle

of scapula

Lateral head

Upper half of

posterior surface

of shaft of humerus

Olecranon process of

ulna

Radial nerve

C6, 7, 8

Extensor of elbow

joint

Medial head

Lower half of

posterior surface

of shaft of humerus

The predominant nerve root supply is indicated by boldface type.

Basic Anatomy

Ulnar Nerve

chial artery.

(Fig. 9.22), except for a small vasomotor nerve to the bra

The median nerve has no branches in the upper arm

further course of this nerve is described on page XXX.

at the elbow, it is crossed by the bicipital aponeurosis. The

The nerve, like the artery, is therefore superficial, but

downward on its medial side.

upper arm, it crosses the brachial artery and continues

side of the brachial artery (Fig. 9.43). Halfway down the

is described on page 352. It runs downward on the lateral

medial and lateral cords of the brachial plexus in the axilla

The origin of the median nerve from the

Median Nerve

to the elbow joint

Articular branches

of the forearm down as far as the root of the thumb.

supplies the skin of the front and lateral aspects

forearm

lateral cutaneous nerve of the

Cutaneous branches;

brachialis (Fig. 9.22)

to the biceps, coracobrachialis, and

Muscular branches

Branches

375

■

the

■

The origin of the ulnar nerve from the

pierces the medial fascial septum, accompanied by the

Here, at the insertion of the coracobrachialis, the nerve

brachial artery as far as the middle of the arm (Fig. 9.43).

on page 353. It runs downward on the medial side of the

medial cord of the brachial plexus in the axilla is described

superior ulnar collateral artery, and enters the

ior

poster

axillary artery

anterior circumflex

posterior circumflex

humeral artery

profunda artery

interosseous recurrent artery

radial recurrent artery

neck of radius

radial artery

anterior interosseous artery

common interosseous artery

ulnar artery

posterior ulnar recurrent artery

anterior ulnar recurrent artery

inferior ulnar collateral artery

superior ulnar collateral artery

brachial artery

teres major

posterior interosseous

artery

FIGURE 9.45

Main arteries of the upper arm. Note the arterial anastomosis around the elbow joint.

376

CHAPTER 9

Radial Nerve

partment of the upper arm (Fig. 9.23).

The ulnar nerve has no branches in the anterior com

medial epicondyle of the humerus.

compartment of the arm; the nerve passes behind the

The Upper Limb

On leaving the axilla, the radial nerve immedi

rior cord of the brachial plexus in the axilla is described on

The origin of the radial nerve from the poste

Radial Nerve

Compartment

Structures Passing through the Posterior Fascial

in Table 9.5.

The triceps muscle is seen in Figure 9.46 and is described

Muscle of the Posterior Fascial Compartment

nerve and ulnar nerve

Radial

Structures passing through the compartment:

arteries

Profunda brachii and ulnar collateral

Blood supply:

Radial nerve

Nerve supply to the muscle:

The three heads of the triceps muscle

Muscle:

of the Upper Arm

Contents of the Posterior Fascial Compartment

the anterior compartment just above the lateral epicondyle.

ately enters the posterior compartment of the arm and enters

■

supraspinatus

infraspinatus

teres major

long head of triceps

medial head of triceps

ulnar nerve

medial epicondyle

olecranon process of ulna

flexor carpi ulnaris

extensor carpi radialis longus

extensor carpi radialis brevis

anconeus

brachioradialis

lateral intermuscular septum

brachialis

posterior cutaneous nerve of forearm

lower lateral cutaneous nerve of arm

profunda artery

radial nerve

lateral head of triceps

upper lateral cutaneous nerve of arm

posterior division of

axillary nerve

anterior division of

axillary nerve

surgical neck of humerus

teres minor

deltoid

extensor carpi ulnaris

FIGURE 9.46

Posterior view of the upper arm. The lateral head of the triceps has been divided to display the radial nerve and

the profunda artery in the spiral groove of the humerus.

Basic Anatomy

medial epicondyle of the humerus (Fig. 9.46) on the medial

ulnar collateral vessels. At the elbow, it lies behind the

of the triceps. The nerve is accompanied by the superior

behind the septum, covered posteriorly by the medial head

halfway down the upper arm, the ulnar nerve descends

Having pierced the medial fascial septum

Ulnar Nerve

to the elbow joint.

branches

articular

radialis longus muscles (Fig. 9.47). It also gives

the brachialis, the brachioradialis, and the extensor carpi

has pierced the lateral fascial septum, it gives branches to

after the nerve

anterior compartment of the arm,

In the

of the forearm as far as the wrist.

runs down the middle of the back

nerve of the forearm

posterior cutaneous

of the lower part of the arm. The

supplies the skin over the lateral and anterior aspects

lower lateral cutaneous nerve of the arm

anconeus. The

the lateral and medial heads of the triceps and to the

(Fig. 9.46), branches are given to

spiral groove

In the

is given off.

neous nerve of the arm

posterior cuta

and medial heads of the triceps, and the

branches (Fig. 9.25) are given to the long

axilla,

In the

Branches

directly in contact with the shaft of the humerus (Fig. 9.46).

the nerve is accompanied by the profunda vessels, and it lies

and brachioradialis muscles (Fig. 9.47). In the spiral groove,

cubital fossa in front of the elbow, between the brachialis

septum above the elbow and continues downward into the

heads of the triceps (Fig. 9.46). It pierces the lateral fascial

the spiral groove on the back of the humerus between the

page 353. The nerve winds around the back of the arm in

377

■

musculocutaneous nerve

brachioradialis

radial nerve

extensor carpi

radialis longus

supinator

deep branch

of radial nerve

extensor carpi

radialis brevis

superficial branch of

radial nerve

radial artery

ulnar artery

flexor carpi ulnaris

palmaris longus

ulnar head of pronator teres

bicipital aponeurosis

humeral head of pronator teres

medial epicondyle

biceps tendon

median nerve

brachial artery

brachialis

biceps brachii

flexor carpi radialis

FIGURE 9.47

Right cubital fossa.

378

CHAPTER 9

The Upper Limb

ligament of the elbow joint. It continues downward to enter

of the fossa is formed by the supinator muscle

floor

The

drawn between the two epicondyles of the humerus.

of the triangle is formed by an imaginary line

The

The pronator teres muscle

Medially:

The brachioradialis muscle

Laterally:

of the elbow (Figs. 9.47 and 9.48).

The cubital fossa is a triangular depression that lies in front

elbow joint.

brachial artery and take part in the anastomosis around the

superior and inferior ulnar collateral arteries arise from the

The

Superior and Inferior Ulnar Collateral Arteries

sis around the elbow joint.

supplies the triceps muscle, and takes part in the anastomo

It accompanies the radial nerve through the spiral groove,

arises from the brachial artery near its origin (Fig. 9.45).

The profunda brachii artery

Profunda Brachii Artery

(Fig. 9.23).

The ulnar nerve has an articular branch to the elbow joint

Branches

carpi ulnaris (see page 390).

the forearm between the two heads of origin of the flexor

The Cubital Fossa

Boundaries

■

base

bicipital

aponeurosis

basilic vein

palmaris

longus

flexor

digitorum

superficialis

flexor carpi

ulnaris

pisiform

bone

biceps

brachii

biceps brachii tendon

cubital fossa

brachioradialis

cephalic vein

flexor carpi

radialis

site fo

palpati

of radi

artery

FIGURE 9.48

The cubital fossa and anterior surface of the

forearm in a 27-year-old man.

laterally and the brachialis muscle medially. The

joint and with the head of the radius at the proximal

proximal end articulates with the humerus at the elbow

The ulna is the medial bone of the forearm (Fig. 9.49). Its

radius are shown in Figure 9.49.

The important muscles and ligaments attached to the

of the extensor pollicis longus (Fig. 9.49).

which is grooved on its medial side by the tendon

tubercle,

dorsal

terior aspect of the distal end is a small tubercle, the

articulates with the scaphoid and lunate bones. On the pos

the round head of the ulna. The inferior articular surface

which articulates with

ulnar notch,

medial surface is the

projects distally from its lateral margin (Fig. 9.49). On the

styloid process;

At the distal end of the radius is the

its lateral side.

tion of the pronator teres muscle, lies halfway down on

for the inser

pronator tubercle,

and ulna together. The

ment of the interosseous membrane that binds the radius

medially for the attach

interosseous border

has a sharp

of the ulna, is wider below than above (Fig. 9.49). It

The shaft of the radius, in contradistinction to that

for the insertion of the biceps muscle.

bicipital tuberosity

Below the neck is the

neck.

to form the

notch of the ulna. Below the head, the bone is constricted

The circumference of the head articulates with the radial

and articulates with the convex capitulum of the humerus.

(Fig. 9.49). The upper surface of the head is concave

head

At the proximal end of the radius is the small circular

radioulnar joint.

of the hand at the wrist joint and with the ulna at the distal

distal end articulates with the scaphoid and lunate bones

joint and with the ulna at the proximal radioulnar joint. Its

Its proximal end articulates with the humerus at the elbow

The radius is the lateral bone of the forearm (Fig. 9.49).

The forearm contains two bones: the radius and the ulna.

nodes (Fig. 9.40).

pass up to the axilla and enter the lateral axillary group of

the medial side of the forearm. The efferent lymph vessels

fourth, and fifth fingers; the medial part of the hand; and

(Fig. 9.40). It receives afferent lymph vessels from the third,

fascia over the upper part of the fossa, above the trochlea

lies in the superficial

supratrochlear lymph node

The

and the radial nerve and its deep branch.

ulnar and radial arteries, the tendon of the biceps muscle,

median nerve, the bifurcation of the brachial artery into the

tures, enumerated from the medial to the lateral side: the

The cubital fossa (Fig. 9.47) contains the following struc

aponeurosis.

formed by skin and fascia and is reinforced by the bicipital

roof

Contents

Bones of the Forearm

Radius

this

Ulna