854 



THE NERVOUS SYSTEM OF THE DOG 



the forearm it gives off the dorsal branch (R. dorsahs), which suppUes cutaneous 

 twdgs to the dorso-lateral surface of the distal part of the forearm and carpus and 

 terminates as the lateral dorsal digital nerve of the fifth digit. Descending under 

 cover of the flexor carpi ulnaris, the ulnar inclines medially under the tendon of 

 insertion of that muscle and divides into superficial and deep branches. The 

 superficial branch (R. superficiahs) descends along the lateral border of the flexor 

 tendons, gives off the lateral volar digital nerve of the fifth digit (N. dig. vol. lat. dig. 

 V), and a branch (N. met. vol. IV) which descends in the space between the fourth 

 and fifth metacarpal bones and unites with the deep branch. The deep branch 

 (R. profundus) descends in the carpal canal and divides under the deep flexor 



Branch 

 radial 



Dorsal 



branch of 



ulnar nerve 



Dorsal com- 

 mon digital 

 nerves 



Median nerve 



Ulnar 



Deep 

 branch 

 Super- 

 ficial 

 branch 



Fig. 684. — Nerves of Distal Part of Right Fore- 

 limb OF Dog; Dorsal View (Schematic). 

 p, Doraal proper digital nerves. 



Fig. 685. — Nerves of Distal Part of Right Fore- 

 limb OF Dog; Volar View (Schematic). 

 p, Volar proper digital nerves. 



tendon into its terminal branches. The smaller of these supply the volar meta- 

 carpal muscles. The larger terminals are the three volar common digital nerves 

 (Nn. dig. col. comm. II, III, IV), which descend along the second, third, and fourth 

 intermetacarpal spaces, subdivide, and concur with the volar metacarpal branches 

 of the median nerve in forming the volar proper digital nerves (Nn. dig. vol. proprii). 

 The median nerve descends behind the brachial artery, passes over the medial 

 epicondyle of the humerus, then under the pronator teres, and continues in the 

 forearm under cover of the flexor carpi radialis. It gives branches below the elbow 

 to the flexor and pronator muscles, and lower down a volar branch to the skin on 

 the medial and volar aspect of the carpus, and terminates between the superficial 

 and deep flexor tendons by dividing into three volar metacarpal nerves (N. met. vol. 



