Ulnar Nerve
ULNAR NERVE
- Ulnar nerve is also called “musician nerve” as it controls the movement of fingers.
- The ulnar nerve arises from the medial cord of the brachial plexus (C7–8, T1) (ulnar nerve recieves its C7, fibres as a branch of lateral cord of these have not already passed to medial cord from ventral ramus of C7).
BRANCHES:
A. IN ARM: No branch
B. IN FOREARM: There are following branches:-
1. Muscular: In proximal part of forearm it supplies flexor carpi ulnaris & medial half of flexor digitorum profundus.
2. Cutaneous: There are two cutaneous branches in forearm:-
- Palmar cutaneous branch: Supplies skin over the hypothenar eminence.
- Dorsal (posterior) cutaneous branch: Supplies skin over medial 1/3 of dorsum of hand & dorsal surface of medial 1,1/2 fingers.
C. IN HAND: Ulnar nerve enters the palm by passing superficial to flexor retinaculum & divides into two terminal branches:-
- Superficial terminal branch: It supplies palmaris brevis & skin of palmar surface of medial 1,1/2 fingers.
- Deep terminal branch: It supplies adductor pollicis, all interossei, medial two (3rd & 4th) lumbricals & all hypothenar muscles except palmaris brevis (i.e. abductor digiti minimi, flexor digiti minimi, opponens digiti minimi).
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MUSCULAR |
CUTANEOUS |
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Flexor carpi ulnaris |
Medial 1/3 of the palmar & dorsal aspect of hand. |
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Medial half of flexor digitorum profundus |
Medial 1,1/2 fingers including the dorsal distal phalanges & nail beds. |
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Palmar brevis |
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Hypothenar eminence muscles |
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Medial two lumbricals |
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All 4 dorsal interossei |
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All 4 palmar interossei |
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Adductor pollicis |
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SENSORY SUPPLY OF ULNAR NERVE:
- Medial 1/3rd of the palm (hypothenar area)
- Medial one & half fingers (whole little fingers & medial half of ring finger).
- Autonomous zone of sensory supply for ulnar nerve is tip of little finger.
Exam Question
- Ulnar nerve is Also known as musician nerve
- Ulnar nerve Arises from C7,8 & T1 roots
- No branch of ulnar nerve in Arm.
- Ulnar nerve injury results in Clawing of fingers.
- Most common nerve used for monitoring during anaesthesia is ulnar nerve.
- Forms Martin-Gruber connections with Median nerve.
- Cervical rib if present it causes pressure on ulnar nerve.
- Deep branch: accompanies deep ulnar artery & supplies 3 muscles of hypothenar eminence(abductor digitii minimi, flexor digitii minimi and opponens digitii minimi), medial two lumbricals(3rd & 4th), eight interossei, adductor pollicis & wrist joint and occasionally deep head of the flexor pollicis brevis.
- Also supplies skin over Hypothenar eminence
- Hypothenar muscles is supplied by deep branch of ulnar nerve
- The four dorsal interossei is supplied by deep branch of ulnar nerve