Human Anatomy Vol 1

Radial bursa Ulnar bursa

Digital synovial

Fig. 9.7: The synovial sheaths of the flexor tendons, i.e. ulnar
bursa, radial bursa and digital synovial sheaths

sheaths. The digital sheath of the little finger is

continuous with the ulnar bursa, and that of the

thumb with the radial bursa. However, the digital

sheaths of the index, middle and ring fingers are

separate and independent (Fig. 9.7).

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The vincula longa and brevia are slmovial folds, similar
to the mesentery, which connect the tendons to the
phalanges. They transmit vessels to the tendons
(Fig. 9.8). These are the remnants of mesotendon.

DISSECIION

Having dissected the superficial and deep group of

muscles of the forearm, identify the terminal branches

of the brachial artery, e.g. ulnar and radial afteries and

their branches.

Radial aftery follows the direction of the brachial

artery.

Ulnar artery passes obliquely deep to heads of

pronator teres and then runs vertically till the wrist.

Carefully look for common interosseous branch of ulnar

aftery and its anterior and posterior branches.

Feolules

The most conspicuous arteries of the forearm are the
radial and ulnar arteries. However, they mainly supply
the hand through the deep and superficial palmar
arches. The arterial supply of the forearm is chiefly
derived from the common interosseous branch of the
ulnar artery, which divides into anterior and posterior

FOREARM AND HAND

Tendon of flexor digitorum profundus

Proximal phalanx

Vincula longa

Tendon of

flexor digitorum

superficialis

Vincula longa

Vincula brevia

Terminal phalanx

Fig. 9.8: The flexor tendons of a finger showing the vincula longa

and brevia

interosseous arteries. The posterior interosseous artery

is reinforced in the upper part and replaced in the lower

part by the anterior interosseous artery.

RADIAL ARTERY

Beginning, Coulse ond Telminolion

Radial artery (Fig.9.9) is the smaller terminal branch

of the brachial artery in the cubital fossa. It runs

downwards to the wrist with a lateral convexity. It

leaves the forearm by turning posteriorly and

entering the anatomical snuff box. As compared to

the ulnar afiety, it is quite superficial throughout its

whole course. Its distribution in the hand is described

later.

Relotions

I Anteriorly: It is overlapped by the brachioradialis in

its upper part, but in the lower half it is covered only

by skin, superficial and deep fasciae.

2 Posteriorly: ll is related to the muscles attached to

anterior surface of radius, i.e. biceps brachii, flexor

pollicis longus, flexor digitorum superficialis and

pronator quadratus.

3 Medially: It is related to the pronator teres in the

upper one-third and the tendon of the flexor carpi

radialis in the lower two-thirds of its course

(Figs 9.9 and 9.10).

4 Laterally: Brachioradialis in the whole extent and the

radial nerve in the middle one-third.

5 The artery is accompanied by venae comitantes.

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