186 



THE NERVOUS SYSTEM. 



Fig. 124. 



^ humerug and the M 



,11 



i*uns along the bone to its 



t id ^ it 



passes under the tendon of the M. extensor carpi ulnaris into the 

 palm of the hand and ends as the N. volaris digiti V medialis. 



/3. The R. ulnaris lateralis 

 passes near the thumb-rudi- 

 ment, covered by the M. ab- 

 ductor pollicis, deeply into the 

 palm of the hand, and supplies 

 by bifurcating branches the 

 adjacent sides of the second, 

 third, fourth, and. fifth fin- 

 gers (R. volares] ; it also gives 

 twigs to the muscles of the 

 palm. 



[II.] The N. radialis (Figs. 

 123, 124, and 125 R) passes 

 immediately beyond its origin 



Nerves of the ventral surface of the arm. The hand * . . 



supinated, and the superficial layer (Flex, carpi rad. from the N, brackiallS, between 

 and uln.. Flex. dig. coinrnun.) has been removed. 



R N. radialis. 



M N. ulnaris. 



we R. cutan. inf. of the N. ulnaris. 



urn Bifurcation of the N. ulnaris. 



gives off : 



a. Rami musculares to the separate parts of the M. triceps. 

 (3. The Ramus cutaneus superior (Fig. 125 re) to the skin of 



the outer surface of 

 the upper arm and fore- 

 arm. 



The nerve then sinks 

 deeply under the origins 

 of the M. extensor carpi 

 ulnaris and the M. ex- 

 tensor diffitorum commu- 

 nis, where it bifurcates 

 after giving off some 

 small twigs : 



y. Small muscular 

 twigs to the extensor 

 muscles of the hand and 

 fingers. 



8. The R. radialis 

 medialis (Rz], the 



ed 



ed 

 R 

 Hi 



JR2 



re 

 r'c' 



The N. radialis. 



M. extensor carpi ulnaris. 



M. extensor digit, comm. 



N. radialis. 



R. lateralis. 



R. medialis. 



R. cutaneus superior. 



R. cutaneus inferior. 



