Skip to Content

ulnar nerve

 

Definition: arises from the medial cord of the brachial plexus conveying fibers mainly from the C8 and T1 nerves; it passes down the arm, behind the medial epicondyle of the humerus, and down the ulnar side of the anterior compartment of the forearm to the hand; it gives off muscular branches in the forearm to the flexor carpi ulnaris muscle and the ulnar portion of flexor digitorum profundus and supplies the hypothenar, interosseous, medial lumbricals, adductor pollicis, and deep head of flexor hallucis brevis, and the intrinsic muscles of the hand and the skin of the small finger and medial side of the ring finger and adjacent portions of the palm of the hand. The ulnar nerve is most vulnerable to injury where it passes subcutaneously behind the medial epicondyle of the humerus. Mild injury here produces the so-called crazy bone sensation. An ulnar nerve lesion here causes loss of flexion of metacarpophalangeal joints and of extension at the interphalangeal joints (“claw hand”).

Synonym(s): nervus ulnarisTA, cubital nerve

Disclaimer: This site is designed to offer information for general educational purposes only. The health information furnished on this site and the interactive responses are not intended to be professional advice and are not intended to replace personal consultation with a qualified physician, pharmacist, or other healthcare professional. You must always seek the advice of a professional for questions related to a disease, disease symptoms, and appropriate therapeutic treatments.
© Copyright 2017 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.
Hide