Nerve · Hand

Deep branch of ulnar nerve

Ramus profundus nervi ulnaris

A purely motor nerve that supplies more muscles than any other nerve in the hand. It leaves the ulnar nerve inside Guyon's canal at the wrist, dives between the muscles of the little-finger mound, and then sweeps right across the palm alongside the deep palmar arch, lying on the interossei and passing behind the long flexor tendons, to end in adductor pollicis on the thumb side. On the way it supplies the hypothenar muscles, all the interossei, the medial two lumbricals and the deep head of flexor pollicis brevis — in other words nearly all the fine machinery of the hand. It touches no skin at all.