Ulnar Nerve | Notion

Ulnar nerve

Overview

arises from medial cord of brachial plexus (C8, T1)

Motor to

medial two lumbricals
aDductor pollicis
interossei
hypothenar muscles: abductor digiti minimi, flexor digiti minimi
flexor carpi ulnaris

Sensory to

medial 1 1/2 fingers (palmar and dorsal aspects)

Path

the ulnar nerve travels through the posteromedial aspect of the upper arm to the flexor compartment of the forearm
it then enters the palm of the hand via the Guyon's canal, superficial to the flexor retinaculum and lateral to the pisiform bone

Image sourced from Wikipedia

Branches

Branch	Supplies
Muscular branch	Flexor carpi ulnarisMedial half of the flexor digitorum profundus
Palmar cutaneous branch (Arises near the middle of the forearm)	Skin on the medial part of the palm
Dorsal cutaneous branch	Dorsal surface of the medial part of the hand
Superficial branch	Cutaneous fibres to the anterior surfaces of the medial one and one-half digits
Deep branch	Hypothenar musclesAll the interosseous musclesThird and fourth lumbricalsAdductor pollicisMedial head of the flexor pollicis brevis

Patterns of damage