Ulnar nerve Flashcards
Course of ulnar nerve
Continuation of medial cord and leaves axilla
Descends medially down arm
At elbow it enters the forearm posteriorly to medial epicondyle (here it is easily palpable and vulnerable to injury)
In forearm, pierces 2 heads of flexor carpi ulnaris and descends alongside the ulna
Enters hand via ulnar canal/Guyon’s canal, superficial to flexor retinaculum
Termination of ulnar nerve
In the hand it divides into:
Deep branch
Superficial branch
What branches arise in the forearm
Muscular branch
Palmar cutaneous branch
Dorsal cutaneous branch
Function of muscular branch
Motor Innervation of:
Flexor carpi ulnaris
Medial half of flexor digitorum profundus
Function of deep branch
Motor Innervation to:
Hypothenar muscles
Medial 2 lumbricals
Adductor pollicis
Interossei
Spinal roots
C8 and T1
Function of palmar cutaneous branch
Sensory innervation to medial half of palm
Function of dorsal cutaneous branch
Sensory Innervation to dorsal surface of medial 1 and 1/2 fingers and associated dorsal area
Function of superficial branch
Sensory Innervation to palmar surface of medial 1 and 1/2 fingers
How is the ulnar nerve damaged at the elbow
Fracture of medial epicondyle
Consequence of damage at elbow
Paralysis of flexor carpi ulnaris and medial half of flexor digitorum profundus
Wrist Flexion is accompanied by abduction
Paralysis of hypothenar muscles, medial 2 lumbricals, adductor pollicis, interossei
Loss of sensory function over medial half of hand
Ulnar paradox
How does damage to ulnar nerve at wrist occur
Lacerations to wrist
Consequence of damage at wrist
Paralysis of interossei, medial 2 lumbricals, adductor pollicis, hypothenar muscles
Sensory loss over palmar surface of medial 1 and 1/2 fingers only
Ulnar claw
