ULNAR NERVE (C8 - T1)
- The ulnar nerve arises from the brachial plexus within the axilla region. It is a continuation of the medial cord.
Course §
In axilla and arm: medial to the 3rd part of axillary a. & upper half of brachial a.
At the middle of arm pierces med. intermuscular septum to enter post. compartment of arm & runs behind med. epicondyle of humerus.
In forearm: Enters forearm by passing between 2 heads of flexor carpi ulnaris.
Runs between flex. carpi ulnaris & flex. digit. profundus medial to ulnar a.
In hand: Enters hand by passing superficial to flex. retinaculum lateral to pisiform bone.
Ends by dividing into superficial and deep terminal branches.
Branches :
In axilla & arm : No branches.
In forearm :
2 cutaneous + 2 motor branches.
* motor
- To flex. carpi ulnaris,
- To medial half of flex. digit. profundus.
* cutaneous :
- Palmar cutaneous branch. supplying medial 1/3 of palm of hand.
- Dorsal "" supplying medial 1/3 of dorsum of hand & dorsum of med 1 ½ fingers.
In hand :
- Deep terminal br. sinks with deep palmar arch & supplies all muscles of hand except palmaris brevis, thenar muscles, & lateral 2. lumbricals.
- Superficial terminal br. supplies palmaris brevis and palmar aspect of medial 1 ½ fingers.