THE RADIAL ARTERY 



583 



skin, superficial and deep fascia, to expose the vessel, and in addition in the upper 

 third to separate the brachio-radialis from the pronator teres. 



Relations. — In front, the artery is at first overlapped by the brachio-radialis, but for the 

 rest of its course it is merely covered by the skin, superficial and deep fasciae, by some cutaneous 

 veins, and by cutaneous branches of the musculo-cutaneous nerve. 



Behind, it Ues successively from above downward on the tendon of the biceps, the supinator, 

 from which it is separated by a layer of fat, the insertion of the pronator teres, the radial origin 

 of the flexor digitorum subhmis, the flexor pollicis longus, the pronator quadrat us, and the 

 volar surface of the lower end of the radius. It is in this last situation, where the artery lies 

 upon the bone and can therefore be easily pi-essed against it, that the pulse is usually felt. 



Fig. 474. — Diagram of the Relation of the Arteries of the Left Forearm to 



THE Bones. (Walsham.) 



Superior ulnar collateral artery 

 Brachial artery 



Inferior ulnar collateral artery 



Volar ulnar recurrent L_Vi.i/r^^ 



Dorsal ulnar recvirrent — -' 



Ulnar artery 

 Common interosseous artery 



Volar interosseous artery 



Volar ulnar carpal - 



Superficial branch of ulnar artery 

 (superficial volar arch) 



P'rofunda artery 



■^: Lateral epicondyle 



— Articular branch of profunda artery 

 Radial recurrent artery 

 Interosseous recurrent artery 



Radial artery 

 Oblique ligament 



Interosseous membrane 

 Dorsal interosseous artery 



Volar radial carpal 

 Radial artery of wrist 

 Superficial volar branch of radial 

 artery 



Common volar digital artery LL' 



II', 



Deep volar arch 



On its lateral side it has, throughout the whole of its course, the brachio-radialis muscle, 

 the guide to the artery in ligature, and the lateral vena comitans; in its middle third, the 

 superficial radial nerve as well. In its lower third the superficial radial nerve is to its lateral 

 side, but separated from it by the brachio-radialis and fascia. 



On its medial side, in the upper third is the pronator teres, in the lower third the tendon 

 of the flexor carpi radialis, and throughout the whole of its course the medial vena comitans. 



The branches of the radial artery in the forearm are: — (1) The radial re- 

 current; (2) the muscular; (3) the volar radial carpal; (4) the superficial volar. 



(1) The radial recurrent [a. recurrens radialis] usually arises from the lateral side of the 

 radial just below its origin from the brachial. It at first runs laterally on the supinator and then 

 divides into three chief branches (fig. 475). One of these continues laterally through the fibres 

 of the radial (musculo-spiral) nerve, or between the superficial (radial) and deep radial (posterior 

 interosseous) nerves when the radial (musculo-spiral) divides higher than usual, into the brachio- 

 radiaUs and extensor carpi radiahs longus and brevis, and anastomoses with the interosseous 

 recurrent. A second ascends between the brachiahs and brachio-radiahs, with the radial 



