26 - ulnar nerve anatomy part 2

MUSCULAR BRANCHES AND INNERVATION :  the ulnar nerve and its branches innervate the following muscles in the forearm and hand:

An articular branch that passes to the elbow joint while the ulnar nerve is passing between the olecranon and medial epicondyle of the humerus.

 In the forearm, via the muscular branches of ulnar nerve:

 1. Flexor carpi ulnaris

2. Flexor digitorum profundus (medial half)

 In the hand, via the deep branch of ulnar nerve:

 1. Hypothenar muscles

2. Opponens digiti minimi

3. Abductor digiti minimi

4. Flexor digiti minimi brevis

5. Adductor pollicis

6. The third and fourth lumbrical muscles

7. Dorsal interossei

8. Palmar interossei

 

In the hand, via the superficial branch of ulnar nerve:

 1. Palmaris brevis

 CUTANEOUS INNERVATION : the ulnar nerve also provides sensory innervation to the part of the hand corresponding to the fourth and fifth digits:

 1. Palmar branch of ulnar nerve - anterior

2. Dorsal branch of ulnar nerve – posterior

 ULNAR NERVE ENTRAPMENT : the ulnar nerve can be trapped or pinched in various ways as it proceeds down the arm from the brachial plexus to the ring and middle fingers. One common cause is cubital tunnelsyndrome, where the tunnel runs the inner outside side of the elbow. Pinching of the nerve often causes tingling symptoms in the little and ring fingers. In some cases moderate to severe pain is experienced from pinching this nerve. Often such pins and needles sensations can be caused by sleeping wrongly on your arm, or by cycling for extended periods of time, but sometimes the problems last for days. In severe cases, surgery is performed to move the nerve.