Ulnar nerve
Latin: Nervus ulnaris sinistra
Paired structure: one on the left and one on the right side of the body.
View the ulnar nerve in 3DRoots
Medial cord (C8–T1).
Course
Descends medial to the brachial artery in the arm, pierces the medial intermuscular septum mid-arm, passes behind the medial epicondyle in the cubital tunnel, runs between the two heads of flexor carpi ulnaris, and continues with the ulnar artery into Guyon's canal at the wrist.
Motor supply
Flexor carpi ulnaris, ulnar half of flexor digitorum profundus, the hypothenar muscles, interossei, medial two lumbricals and adductor pollicis.
Sensory supply
Medial palm, little finger and ulnar half of the ring finger.
Clinical relevance
The funny bone — struck at the medial epicondyle, its electric jolt is legendary. Cubital tunnel syndrome numbs the little finger; low lesions claw the hand (interossei palsy) while high lesions spare the claw because profundus is weak too — the ulnar paradox.
Educational anatomy reference, not medical advice. About this content.