266 THE VASCULAR SYSTEMS 



The branches of the radial artery are divided into three groups : 



I. In the forearm: (a) The radial recurrent, between the supi- 

 nator longus and the brachialis anticus, joins the superior 

 profunda. 



(6) The muscular, to the radial side of the forearm. 



(c) The superficialis voice, through the muscles of the thumb; 

 sometimes it ends in them, or it may be very large, or may 

 complete the superficial arch. 



(d) The anterior carpal runs inward to join in the anterior 

 carpal arch with the ulnar branch. 



II. In the wrist: (e) The posterior carpal joins the ulnar 

 branch, forming the posterior carpal arch. This arch gives off 

 the third and fourth dorsal interosseous branches. 



(/) The metacarapl runs on the second dorsal interosseous 

 muscle, and joins, by branches, the first superior perforating 

 and palmar digital arteries. It divides into two dorsal digital 

 branches for the index and middle fingers, their adjacent sides, 

 and it also gives off an inferior perforating artery to the corre- 

 sponding palmar digital. 



(g) Two dorsales pollicis, along the sides of the thumb. 



(h) The dorsalis indicis, along the radial side of the index 

 finger. 



III. In the hand: (i) The princeps pollicis, along the ulnar 

 side of the first metacarpal to the proximal phalanx, where it 

 divides into two branches for the palmar sides of the phalanges. 



(j) The radialis indicis, along the radial border of the palmar 

 surface of the index finger. 



(/c) The superior perforating arteries pass back between the 

 heads of the last three dorsal interossei muscles to join the 

 dorsal interosseous arteries. 



(I) Three or four palmar interosseous branches join the palmar 

 digital arteries at the finger clefts. 



The Ulnar Artery 



The ulnar artery runs along the inner side of the forearm to 

 the wrist, crosses the annular ligament and the palm of the hand, 

 and joins the superficialis volse to form the superficial arch. 



In the Forearm. Relations. In front, integument, fascia, and 

 superficial flexor muscles, median nerve, and palmar cutaneous 

 branch of the ulnar nerve; behind, brachialis anticus, flexor 



