Page 68 - untitled

AAAC28 21/5/05 10:44 AM Page 67
The axillary artery
radialis. This is where the radial pulse is best felt.
• Course: the axillary artery commences at the lateral border of the 1st
• Branches:
rib as a continuation of the subclavian artery (see Fig. 60.1) and ends at
the inferior border of teres major where it continues as the brachial the artery lies on the distal radius lateral to the tendon of flexor carpi
• Palmar and dorsal carpal branches are given off at the wrist.
artery. The axillary vein is a medial relation throughout its course. It is •A superficial palmar branch arises at the wrist which supplies the
crossed anteriorly by pectoralis minor which subdivides it into three thenar muscles and consequently anastomoses with the superficial
parts: palmar branch of the ulnar artery to form the superficial palmar
• First part (medial to pectoralis minor). arch.
• Second part (behind pectoralis minor)agives off the lateral • The radial artery passes backwards under the tendons of abductor
thoracic artery (which helps to supply the breast) and the thora- pollicis longus and extensor pollicis brevis to enter the anatomical
coacromial artery (p. 75). snuffbox. It consequently passes over the scaphoid and trapezium
• Third part (lateral to pectoralis minor)agives off the subscapular in the snuffbox and exits by passing between the two heads of
artery which follows the lateral border of the scapula and gives off adductor pollicis to enter the palm and forms the deep palmar arch
the circumflex scapular artery. with a contribution from the ulnar artery (deep palmar branch). It
gives off the princeps pollicis to the thumb and the radialis indicis
The brachial artery to the index finger.
• Course: the brachial artery commences at the inferior border of teres • The deep palmar arch gives off three palmar metacarpal arteries
major as a continuation of the axillary artery and ends by bifurcating which subsequently join the common palmar digital arteries (from
into the radial and ulnar arteries at the level of the neck of the radius. It the superficial arch) to supply the digits.
lies immediately below the deep fascia throughout its course. The
brachial artery is crossed superficially by the median nerve in the mid- The ulnar artery
arm from lateral to medial and hence lies between the median nerve • Course: the ulnar artery commences as the terminal bifurcation of
(medial relation) and biceps tendon (lateral relation) in the cubital fossa the brachial artery at the level of the neck of the radius. It passes deep to
(see Fig. 36.3). the deep head of pronator teres and deep to the fibrous arch of flexor
• Branches: digitorum superficialis and descends on flexor digitorum profundus
• Profunda brachiiaarises near the origin of the brachial artery and with the ulnar nerve lying medial to it and flexor carpi ulnaris overlap-
winds behind the humerus with the radial nerve in the spiral groove ping it in the proximal half of the forearm.
before taking part in the anastomosis around the elbow joint. At the wrist both the ulnar artery and nerve lie lateral (radial) to
• Other branchesainclude a nutrient artery to the humerus and flexor carpi ulnaris and pass over the flexor retinaculum giving carpal
superior and inferior ulnar collateral branches which ultimately branches which contribute to the dorsal and palmar carpal arches.
take part in the anastomosis around the elbow. • Branches:
‘Volkman’s ischaemic contracture’ is a deformity arising as a result •A deep palmar branch completes the deep palmar arch (see above)
of brachial artery spasm following injury (usually from fractures of the and the ulnar artery continues as the superficial palmar arch which
distal humerus). The reduced arterial flow results in ischaemic necro- is completed by the superficial palmar branch of the radial artery.
sis of the forearm musculature which is eventually replaced by short- • The common interosseous artery (see below).
ened fibrous tissue. In the classical deformity the forearm is wasted and
the wrist joint flexed with the fingers extended. When the wrist is The common interosseous artery
extended the fingers flex. The common interosseous artery is the first ulnar branch to arise and it
subdivides into the:
The radial artery • Anterior interosseous artery: descends with the interosseous branch
• Course: the radial artery arises at the level of the neck of the radius of the median nerve on the anterior surface of the interosseous
from the bifurcation of the brachial artery. It passes over the biceps ten- membrane. It predominantly supplies the flexor compartment of the
don to lie firstly on supinator then descends on the radial side of the forearm.
forearm, lying under the edge of brachioradialis in the upper half of • Posterior interosseous artery: passes above the upper border of the
its course and then between the tendons of brachioradialis and flexor interosseous membrane to enter the extensor compartment where it
carpi radialis in the lower forearm. The radial artery passes sequentially runs with the deep branch of the radial nerve supplying the extensor
over supinator, pronator teres, the radial head of flexor digitorum muscles of the forearm, eventually anastomosing with the anterior
superficialis, flexor pollicis longus and pronator quadratus. At the wrist interosseous artery.

Arteries of the upper limb 67