VEINS, LYMPHATICS, ARTERIES, AND NERVES 79 



coracoid muscle craniad of the posterior humeral circumflex 

 artery (7) to pass to the lateral side of the arm. 



6. Medial brachial cutaneous (lesser internal cutaneous, 

 Wrisberg's) n.: T.I mainly; to integument and fascia on caudal 

 side of brachium and proximal third of antibrachium. A long, 

 slender nerve. 



7. Median n.: TI, C.VIII, and C.VII; to middle and radial 

 flexors of forearm and branches to digits II, III, and IV. This 

 nerve is easily recognized as the largest craniad of the three 

 trunks in the brachial region and it accompanies the brachial 

 and radial arteries to the carpus. 



8. Musculospiral n.: T.I, C.VIII, and C.VII mainly; to 

 triceps m., antibrachium and integument; by two important 

 medial branches to triceps brachii and perforating the medi- 

 triceps it gives off a branch, the superficial radial (lateral anti- 

 brachial cutaneous) n. which accompanies the cephaUc vein 

 to the dorsum of the hand. The radial nerve passes between 

 the extensor carpiradialis m. and distal end of humerus, sends 

 branches to the extensors of the forearm, to other muscles and 

 passes into the volar surface of the hand. 



9. Ulnar n.: T.I and C.VIII; to skin and muscles of fore- 

 arm and hand; branches go to the elbow region and to several of 

 the flexors of the forearm. It passes along the medial side of the 

 arm, between the long and medial heads of the triceps muscle, 

 distad to the medial epicondyle of the humerus and mediad to 

 the olecronal process along the ulnar side between the flexor 

 carpi ulnaris m. (29) and the flexor profundus m. (31) : crossing 

 under the tendon of the former it passes craniad to the pisiform 

 bone and into the palm. Usually it is not practical to follow 

 the distribution of the ulnar, median, and radial nerves to the 

 digits. 



D. ARTERIES OF THE FOREARM AND HAND 



(Nos. 12-17; Fig. 23) 

 About the middle of the proximal third of the radius the bra- 

 chial artery divides to form the radial and ulnar arteries. The 



