THE BRACHIAL PLEXUS 



153 



flexed at the interphalangeal joints, when the hand is at rest, 

 but these fingers retain all their normal movements. 



The sensory symptoms are due to the paralysis of the volar 



FIG. 67.- 



-The Nerve- supply of the Skin on the Dorsal Aspect 

 of the Upper Limb. 



A. The segmental supply. 



B. The individual nerves of supply. 



1. Posterior supra-clavicular nerves. 



2. Lateral cutaneous nerve of arm. 



3, 4. Dorsal cutaneous nerve of forearm 

 (upper and lower external cutane- 

 ous branches of musculo-spiral 

 nerve). 



5. Lateral cutaneous nerve of forearm. 



6. Superficial division of radial nerve. 



7. Dorsal cutaneous branch of ulnar 



nerve. 



8. Medial cutaneous nerve of forearm 



(internal cutaneous nerve). 



9. Intercosto-brachial nerve. 



10. Posterior cutaneous nerve of arm (in- 

 ternal cutaneous branch of musculo- 

 spiral nerve). 



cutaneous branch and the digital nerves, and, unless tendons 

 have been divided in addition, deep sensibility is not inter- 

 fered with. As usual in these cases, the area of epicritic loss 



