Nerve · Forearm

Medial antebrachial cutaneous nerve

Nervus cutaneus antebrachii medialis

A purely sensory branch of the medial cord of the brachial plexus that runs down the inner side of the arm beside the basilic vein, pierces the deep fascia about halfway down, and then covers the whole inner forearm — front and back — as far as the wrist. It is the only nerve to that strip of skin, so its territory does not overlap with the ulnar nerve's: the ulnar nerve supplies the little-finger side of the HAND, while this nerve supplies the little-finger side of the FOREARM. The two territories sit end to end on the same border of the limb, but they belong to different nerves that part company in the axilla.