158. Ulnar nerve · Anatomy Bones and Muscles · MU Pleven

158. Ulnar nerve.

Covers the ulnar nerve from its origin as a continuation of the medial cord of the brachial plexus in the axilla, through its course in the arm, forearm and hand. It then lists the branches in each region, separating motor from cutaneous branches in the forearm and naming the deep and superficial terminal branches in the hand. Four pictures accompany the course and branching.

Inside: 3 sections · 4 labelled pictures · 10 flashcards · 2 min

Topic 157 of 236 in the MU Pleven syllabus for Anatomy Bones and Muscles (Medicine, Year 2). The free AceMed note covers it in 3 sections, about 214 words (2 min of reading), with 10 flashcards.

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

1. To flex. carpi. ulnaris.
2. To medial half of flex. digit. profundus.

Cutaneous :

3. Palmar cutaneous branch. supplying medial 1/3 of palm of hand.
4. Dorsal " " supplying medial 1/3 of dorsum of hand & dorsum of med 1½ finger

In hand :

5. Deep terminal br. sinks with deep palmar arch & supplies all muscles of hand except palmaris brevis, thenar muscles, & lateral 2 lumbricals.
6 Superficial terminal br. supplies palmaris brevis and palmar aspect of medial 1 ½ fingers.