Definition of Ulnar nerve

Ulnar nerve: A major nerve in the upper extremity. The ulnar nerve begins in the lower cervical and upper thoracic portions of the spinal cord (from C7 to T1), travels via the brachial plexus down into the arm, through the cubital tunnel at the elbow, and supplies both sensory and motor innervation to parts of the forearm, and hand. Known in anatomy also as the nervus ulnaris. See also: Cubital tunnel syndrome.