nerve injury of upper limb continuation Flashcards
what branch does the ulnar nerve come from
the medial chord of the brachial plexus
where is the ulnar nerve located in the arm
lies medial to the axillary artery
passes posteriorly to the medial epicondyle of humerus
where is the ulnar nerve located in the forearm
enters between 2 heads of flexor carpi ulnaris
passes down medially between flexor carpi ulnaris and flexor digitorum profundus
where is the ulnar nerve located at the wrist
it lies lateral to the tendon of flexor carpi ulnaris & superficial to the flexor retinaculum (this is a dangerous position)
does the ulnar nerve branch in the arm?
no
what branches does the ulnar nerve spilt into in the forearm
- Muscular branches to the flexor carpi ulnaris and to the medial 1/2 of the flexor digitorum profundus.
- Palmar branch: supply skin on the medial 1/3 of the palm.
- Dorsal branch: supplies the skin of the medial 1/3 of the dorsal surfaces of the hand & the medial 1 ½ fingers.
what branches does the ulnar nerve supply in the hand
- Deep branch supplies the interossei, adductor pollicis, and the 2 medial lumbricals.
- Superficial branch supplies palmaris brevis muscle skin on the palmar surface of the medial 1 ½ fingers.
what could be the cause of Loss of wrist adduction with weak wrist flexion, due to loss of function of flexor carpi ulnaris.
injury to the ulnar nerve behind the medial epicondyle
what could be the effect of elbow joint dislocation or fracture of the medial epicondyle of the humerus
Injury of the ulnar nerve behind the medial epicondyle:
clawed hand is a sign of injury to what nerve
to the ulnar nerve
what are the position of the hand when claw hand is suspected
Clawing is less pronounced in the lateral fingers because the lateral 2 lumbricals are innervated by the median nerve ;while the function of all intrinsic muscles of medial digits is lost.
what causes injury to the ulnar at the wrist
Open trauma at the wrist.
Nerve compression by tumors (ulnar tunnel)
what would be suspected if there is Loss of sensation in skin on the palmar surface of the medial 1 ½ fingers (Superficial branch).
injury of the ulnar nerve at the wrist
which branch of the brachial plexus does the radial nerve come from
branch of the posterior cord
what is the position of the radial nerve in the arm
Crosses the radial groove from medial to lateral.
On the lateral side of the arm, it passes anteriorly through piercing the lateral intermuscular septum.
what is the position of the radial nerve in the arm
Enters the forearm between the brachialis and the brachioradialis muscles.
Divides into deep (motor) and superficial (cutaneous) branches.
The deep branch pierces supinator to enter the back of forearm.
The radial nerve supplies the lateral part of brachialis, triceps , anconeus, brachioradialis and extensor carpi radialis longus.
what branches does the radial nerve have in the axilla
Muscular branches to the triceps.
Posterior cutaneous nerve of the arm which supplies the skin of back of arm.
what branches does the radial nerve have in the arm
Muscular branches to the triceps, anconeus, brachialis, brachioradialis and to extensor carpi radialis longus.
Lower lateral cutaneous nerve of the arm supplies the skin over the lateral and anterior aspects of the lower part of the arm.
Posterior cutaneous nerve of forearm supplies the skin of back of forearm
how does the radial nerve branch in the forearm
The deep branch of the radial nerve: Innervates the extensor carpi radialis brevis and supinator muscle then emerges between its 2 heads as posterior interosseous nerve.
what is the posterior interosseous nerve
Is the continuation of the deep branch of radial nerve.
It supplies the remaining extensor muscles of the forearm.
what does the superficial branch of the radial nerve supply
Supplies the skin of the lateral 2/3 of the dorsal surface of the hand and the skin of the dorsal surface of the lateral 3½ fingers except the distal phalanges which are supplied by median nerve.
which nerve would a fracture of the mid shaft of the humerus
radial nerve
what would be the effect of a injury to the radial nerve in the radial(spiral) groove
Wrist drop (loss of function of forearm extensors ). Loss of sensation on the skin of the lower lateral arm, back of forearm & dorsal surface of the lateral 2/3 of hand with lateral 3½ fingers .
