[1] It is the smallest and medial-most branch of the brachial plexus, and arising from the medial cord receives its fibers from the eighth cervical and first thoracic spinal nerves.

[1] It passes through the axilla, at first lying behind, and then medial to the axillary vein, and communicates with the intercostobrachial nerve.

It descends along the medial side of the brachial artery to the middle of the arm, where it pierces the deep fascia, and is distributed to the skin of the back of the lower third of the arm, extending as far as the elbow, where some filaments are lost in the skin in front of the medial epicondyle, and others over the olecranon.

It communicates with the ulnar branch of the medial antebrachial cutaneous nerve.

[4][5][6] This article incorporates text in the public domain from page 937 of the 20th edition of Gray's Anatomy (1918)