Ulnar Nerve
- The ulnar nerve is positioned volar and superficial to the ulnar artery in section 9.
- Proximally in section 9 the ulnar nerve is radial to the pisiform and FCU tendon muscle.
- The common terminal branches of the ulnar nerve are the deep motor branch to the adductor pollicis and deep head of the flexor pollicis brevis muscles, motor branch to the hypothenar muscles and the ulnar two lumbricals, the ulnar digital sensory nerve to the little finger, and the common digital sensory nerve in the ring/little web space.
- Additionally, there are 2-3 small ulnar nerve sensory branches at the wrist level that provide sensation the hypothenar eminence.
Diagrams & Photos
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The ulnar nerve and its main sensory and motor branches. -
Ulnar nerve in section 9
Key Points
- The ulnar nerve originates from the medial cord of the brachial plexus, specifically from the C8-T nerve roots.
- The proximal third of Guyon's Canal contains motor and sensory components of the ulnar nerve so compressing lesions can affect motor and sensory function, the middle third motor and sensory separate and lesions compressing the nerve typically affect the motor branch, and in the distal third only sensory parts are at risk for compression.
- The nerve of Henle is a branch of the ulnar nerve in the distal forearm that. Provides sympathetic nerve fibers to the ulnar artery and sensory fibers to distal ulnar forearm and proximal hypothenar eminence.