THE RADIAL ARTERY. 597 



elbow-joint. It passes transversely inward upon the Brachialis anticus, and, piercing 

 the internal intermuscular septum, winds round the back part of the humerus 

 between the Triceps and the bone, forming an arch above the olecranon fossa by its 

 junction with the posterior articular branch of the superior profunda. As this vessel 

 lies on the Brachialis anticus, branches ascend to join the inferior profunda, and 

 others descend in front of the inner condyle to anastomose with the anterior ulnar 

 recurrent. Behind the internal condyle an offset is given off which anastomoses 

 with the inferior profunda and posterior ulnar recurrent arteries and supplies the 

 Triceps. 



The muscular are three or four large branches, which are distributed to the 

 muscles in the course of the artery. They supply the Coraco-brachialis, Biceps, 

 and Brachialis anticus muscles. 



The Anastomosis around the Elbow-joint (Fig. 366). The vessels engaged in 

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

 behind the internal and external condyles. The branches anastomosing in front 

 of the internal condyle are the anastomotica magna, the anterior ulnar recurrent, 

 and the anterior terminal branch of the inferior profunda. Those behind the internal 

 condyle are the anastomotica magna, the posterior ulnar recurrent, and the 

 posterior terminal branch of the inferior profunda. The branches anastomosing in 

 i'r<>nt of the external condyle are the radial recurrent and one of the terminal 

 branches of the superior profunda. Those behind the external condyle (perhaps 

 more properly described as being situated between the external condyle and the 

 olecranon) are the anastomotica magna, the interosseous recurrent, and one of 

 the terminal branches of the superior profunda. There is also a large arch of 

 anastomosis above the olecranon, formed by the interosseous recurrent, joining with 

 the anastomotica magna and posterior ulnar recurrent (Fig. 366). 



From this description it will be observed that the anastomotica magna is the 

 vessel most engaged, the only part of the anastomosis in which it is not employed 

 being that in front of the external condyle. 



Radial Artery. 



The Radial Artery appears, from its direction, to be the continuation of the 

 brachial, but in size it is smaller than the ulnar. It commences at the bifurca- 

 tion 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, round the outer side 

 of the carpus, beneath the extensor tendons of the thumb, and, finally, passes 

 forward, between the two heads of the First dorsal interosseous muscle, into the 

 palm. of the hand, where it crosses the metacarpal bones to the ulnar border of the 

 hand, to form the deep palmar arch. At its termination it ini>jculates_jwjth the 

 deep branch of the ulnar artery. The relations of this vessel may thus be con- 

 veniently divided into three parts viz. in the forearm, at the back of the wrist, 

 and in the hand. 



Relations. In the forearm this vessel extends from opposite the neck of the 

 radius to the fore part of the styloid process, being placed to the inner side of the 

 shaft of the bone above and in front of it below. It is superficial throughout its 

 entire extent, being covered by the integument, the superficial and deep fasciae, 

 and slightly overlapped above by the Supinator longus. In its course downward 

 it lies upon the tendon of the Biceps, the Supinator brevis, the radial origin of the 

 Flexor sublimis digitorum, the Pronator radii teres, the Flexor longus pollicis, the 

 Pronator quadratus, and the lower extremity of the radius. In the upper third 

 of its course it lies between the Supinator longus and the Pronator radii teres ; 

 in its lower two-thirds, between the tendons of the Supinator longus and the 

 Flexor carpi radialis. The radial nerve lies along the outer side of the artery 

 in the middle third of its course, and some filaments of the musculo-cutaneous 

 nerve, after piercing the deep fascia, run along the lower part of the artery as it 

 winds round the wrist. The vessel is accompanied by venae comites throughout its 

 whole course. 



