150 



Spinal Nerves. 



NN. SUPRA- 



DLAVICUL. 



N. CUTAN. 

 BRACHII EXT. 



R. CUTAN. ANTIBR 

 N. RADIAL 



R. CUTAN. PALMAR. 

 N. MEDIAN. 



R. CUTAN. EXTERN. 

 N. RADIAL. 



494. The Cutaneous 



Nerves of the Upper 



Extremity, 



at the flexor surface. 



The infraclavicular por- 

 tion of the brachial plexus sur- 

 rounds the subclavian (axillary) 

 artery with three cords, at the 

 outer, inner and posterior sides. It 

 forms the following branches : 



1. Lesser internal cu- 

 taneous, N. cutaneus brachii in- 

 terims, arises from the inner cord, 

 passes down behind the axillary 

 vein, communicates with a branch 

 of the second dorsal nerve, the 

 intercosto - humeral, pierces 

 the fascia of the upper arm at the 

 inner surface, and is distributed 

 to the integument of the arm 

 down to the elbow-joint. 



2. Internal cutaneous, 

 N. cutaneus brachii medius arises 

 from the inner cord, runs on the in- 

 ner side of the axillary, then the ba- 

 silic vein, pierces with the latter 

 the fascia of the upper arm, and 

 divides into two branches, an an- 

 terior, It. cutaneus palmar is, and 

 a posterior, E. cutaneus ulnaris. 

 The anterior descends on the an- 

 terior surface of the ulnar side of 

 the forearm, distributing filaments 

 to the integument as far as the 

 wrist, the posterior passes down- 

 wards on the inner side of the 

 basilic vein at the ulnar side of 

 the forearm and communicates 

 with the dorsal branch of the 

 ulnar nerve; it distributes fila- 

 ments to the integument on the 

 inner and posterior surfaces of 

 the forearm. 



