296 



THE SPINAL NERVES. 



or replaced to a greater or less extent, by a branch of the ulnar nerve. In one instance the 

 posterior branch was large and extended to the hand, taking the place of the absent dorsal 

 branch of the iilnar nerve (Gr. D. T.). 



Fig. 196. ANTERIOR CUTANEOUS NERVES OF THE SHOULDER AND ARM. (From Sappey, after 

 Hirschf eld and Leveille. ) 1 



1, 1, supraclavicular nerves from the cervical plexus ; 2, 2, 2, cutaneous branches of the circumflex 

 nerve ; 3, 4, upper branches of the internal cutaneous nerve ; 5, upper external cutaneous branch of 

 the musculo-spiral ; 6, internal cutaneous nerve piercing the deep fascia ; 7, its posterior branch ; 8, 

 communicating twig with one of the anterior branches ; 9, 10, anterior branches of this nerve, some 

 turning round the median basilic and ulnar veins ; 11, musculo- cutaneous nerve descending 

 (exceptionally) over the median- cephalic vein ; 12, lower external cutaneous branch of the musculo- 

 spiral nerve. 



Fig. 197. ANTERIOR CUTANEOUS NERVES OF THE FOREARM AND HAND. (From Sappey, after Hirschf eld 



and Leveille.) i 



9, 10, 13, distribution of the anterior division of the internal cutaneous nerve ; 14, union of one of 

 these with a twig of the ulnar nerve ; 12, lower external cutaneous branch of the musculo-spiral nerve ; 

 11, 15, distribution of the external cutaneous nerve ; 16, union of one of its branches with 17, the 

 radial nerve ; 18, palmar cutaneous branch of the median nerve ; 19, 20, internal and external 

 digital branches to the thumb from the median nerve; 21, external digital to the index finger; 

 22, 23, digital branches to the index, middle, and ring fingers ; 24, 25, digital branches from the ulnar 

 nerve to the ring and little fingers. 



Small internal cutaneous nerve. The small internal cutaneous nerve or 

 nerve of Wrisberg (n. cutaneus brachn medialis), derived from the first dorsal nerve, 

 commonly arises from the inner cord of the brachial plexus in union with the large 

 internal cutaneous nerve. In the axilla it lies at first behind the axillary vein, but 

 it soon appears on the inner side of that vessel, and communicates with the 

 intercosto-humeral nerve. It then descends along the inner side of the basilic vein 



