592 ANGIOLOGY 



olecranon, accompanied by the ulnar nerve, and ends under the Flexor carpi ulnaris 

 by anastomosing with the posterior ulnar recurrent, and inferior ulnar collateral. 

 It sometimes sends a branch in front of the medial epicondyle, to anastomose 

 with the anterior ulnar recurrent. 



4. The inferior ulnar collateral artery (a. collateralis ulnaris inferior; anastomotica 

 magna artery) arises about 5 cm. above the elbow. It passes medialward upon the 

 Brachialis, and piercing the medial intermuscular septum, winds around the back of 

 the humerus between the Triceps brachii and the bone, forming, by its junction with 

 the profunda brachii, an arch above the olecranon fossa. As the vessel lies on the 

 Brachialis, it gives off branches which ascend to join the superior ulnar collateral: 

 others descend in front of the medial epicondyle, to anastomose with the anterior 

 ulnar recurrent. Behind the medial epicondyle a branch anastomoses with the 

 superior ulnar collateral and posterior ulnar recurrent arteries. 



5. The muscular branches (rami musculares) three or four in number, are dis- 

 tributed to the Coracobrachialis, Biceps brachii, and Brachialis. 



The Anastomosis Around the Elbow-joint (Fig. 526). The vessels engaged in 

 this anastomosis may be conveniently divided into those situated in front of and 

 those behind the medial and lateral epicondyles of the humerus. The branches 

 anastomosing in front of the medial epicondyle are : the anterior branch of the 

 inferior ulnar collateral, the anterior ulnar recurrent, and the anterior branch of 

 the superior ulnar collateral. Those behind the medial epicondyle are: the inferior 

 ulnar collateral, the posterior ulnar recurrent, and the posterior branch of the supe- 

 rior ulnar collateral. The branches anastomosing in front of the lateral epicondyle 

 are: the radial recurrent and the terminal part of the profunda brachii. Those 

 behind the lateral epicondyle (perhaps more properly described as being situated 

 between the lateral epicondyle and the olecranon) are: the inferior ulnar collateral, 

 the interosseous recurrent, and the radial collateral branch of the profunda brachii. 

 There is also an arch of anastomosis above the olecranon, formed by the interosseous 

 recurrent joining with the inferior ulnar collateral and posterior ulnar recurrent 

 (Fig. 529). 



The Radial Artery (A. Radialis) (Fig. 527). 



The radial artery appears, from its direction, to be the continuation of the brachial, 

 but it is smaller in caliber than the ulnar. It commences at the bifurcation of the 

 brachial, just below the bend of the elbow, and passes along the radial side of the 

 forearm to the wrist. It then winds backward, around the lateral side of the carpus, 

 beneath the tendons of the Abductor pollicis longus and Extensores pollicis longus 

 and brevis to the upper end of the space between the metacarpal bones of the thumb 

 and index finger. Finally it passes forward between the two heads of the first 

 Interosseous dorsalis, into the palm of the hand, where it crosses the metacarpal 

 bones and at the ulnar side of the hand unites with the deep volar branch of the 

 ulnar artery to form the deep volar arch. The radial artery therefore consists 

 of three portions, one in the forearm, a second at the back of the wrist, and a third 

 in the hand. 



Relations. (a) In the forearm the artery extends from the neck of the radius to the forepart 

 of the styloid process, being placed to the medial side of the body of the bone above, and in front 

 of it below. Its upper part is overlapped by the fleshy belly of the Brachioradialis; the rest of 

 the artery is superficial, being covered by the integument and the superficial and deep fasciae. 

 In its course downward, it lies upon the tendon of the Biceps brachii, the Supinator, the Pronator 

 teres, the radial origin of the Flexor digitorum sublimis, the Flexor pollicis longus, the Pronator 

 quadratus, and the lower end of the radius. In the upper third of its course it lies between the 

 Brachioradialis and the Pronator teres; in the lower two-thirds, between the tendons of the 

 Brachioradialis and Flexor carpi radialis. The superficial branch of the radial nerve is r close to 

 the lateral side of the artery in the middle third of its course; and some filaments of the lateral 

 antibrachial cutaneous nerve run along the lower part of the artery as it winds around the wrist. 

 The vessel is accompanied by a pair of vena? comitantes throughout its whole course. 





