The dorsal branch of ulnar nerve
arises about 5 cm. proximal to the wrist
; it passes backward beneath the Flexor carpi ulnaris
, perforates the deep fascia
, and, running along the ulnar side of the back of the wrist and hand, divides into two dorsal digital branches; one supplies the ulnar side of the little finger
; the other, the adjacent sides of the little and ring fingers
It also sends a twig to join that given by the superficial branch of the radial nerve
for the adjoining sides of the middle and ring fingers, and assists in supplying them.
A branch is distributed to the metacarpal
region of the hand, communicating with a twig of the superficial branch of the radial nerve.
Image:Gray811and813.PNG|Cutaneous nerves of right upper extremity.
Image:Gray812and814.PNG|Diagram of segmental distribution of the cutaneous nerves of the right upper extremity.