Anatomy Ulna Nerve

Nerve supply

- C7, C8, T1 

- nerve picks up some branches of C7 from the lateral cord

 

Origin

- direct continuation medial cord

- runs between the brachial artery and the vein in the arm

- behind MCNFA

 

Arm

- pierces the medial intermuscular septum to run in posterior compartment

- runs anterior to the triceps

 

Elbow

- enters the cubital tunnel between the medial epicondyle and the olecranon

- running on MCL 

- covered by osbourne's ligament

- gives articular branches to the elbow

 

Ulna Nerve MRI Cubital Tunnel

 

Forearm

- runs between the two heads of FCU (anterior aspect medial epicondyle and proximal ulna)

- branches to (usually) medial 2 FDP and to FCU

- nerve descends on FDP, under the cover of FCU

 

Wrist

- nerve runs with the ulna artery to the wrist

- it emerges on the lateral aspect of FCU

- nerve is ulna to artery

- dorsal sensory branch which runs under FCU and supplies dorsum of hand in region of 1 and 1/2 fingers

- palmar cutaneous branch which supplies sensation over the hypothenar muscles

 

Guyon's canal 

- superficial to TCL

- under volar carpal / pisohamate ligament

- between hook of hamate and pisiform

- nerve is ulna to the artery

- at the distal edge volar carpal ligament divides into a sensory and motor branch

 

Motor branch 

- runs between abductor and flexor digiti minimi 

- through opponens 

- crosses the palm within the concavity of the deep palmar arch

- gives branches to the lateral 2 lumbricals, all the interossei and ends by supplying adductor pollicis