Slide 1: MEDIAN NERVE Slide 2: Mixed nerve (contain motor & sensory fibers). Type : Root value : C 5,6,7,8 & T1 . Origin : Arises in the axilla by 2 roots (lat &med):
1) lat .root : from the lat . Cord of the brachial plexus .
2) med .root : from the med . Cord of the brachial plexus . Slide 3: Course & Relations Slide 4: 1)Course in the arm a) in the upper ½
b) in the middle of the arm
c) in the lower ½ of the arm 2) At the elbow a) in the cubital fossa
b) after leaving the cubital fossa 3) in the forearm 4) at the wrist Slide 5: The Cubital fossa Slide 6: 5) In the hand Slide 7: 6) Its End Slide 8: Branches of the median nerve 1) in the axilla & arm : NO branches 2) in the forearm : a) muscular branches
B) articular branch
C) anterior interosseous nerve
D) palmer cutaneous branch
E) communicating br .With the ulnar n It gives Slide 9: In the forearm Slide 10: 3) Branches in the hand: 1) the lat .terminal branch :
A) 3 common palmer digital branches.
B) recurrent muscular branch.
2) the med . Terminal branch :
it gives 2common palmer brs :
-The lat. Branch.
-The med. Branch. Slide 11: In the hand Slide 12: - In the forearm - In the hand Summary of the branches of the median nerve Slide 13: Motor branches (to 11 1/2 muscles) In the forearm : -Main trunk :
- supplies 4 muscles :
All superficial muscles of the front of the forearm except flex. Capri ulnaris. - Ant. Interosseous br.:
- supplies 2 ½ muscles : Slide 14: All deep muscles of the front of forearm except the med. ½ of flex. Digit. Profound. In the hand : -Lat. Terminal br.:
Supplies 4 muscles:
i.e. the 1st lumbrical m + all thenar mm (except add .poll.)
-Med. Terminal br.:
the 2nd lumbrical m. Slide 15: Sensory brs. (to lat. 2/3 of the hand) In the forearm : -the palmer cutaneous br.:
Arises in the lower end of forearm & descends to the hand to supply the skin of the lat. 2/3 of the palm. -lat. Terminal br.
Gives 3 palmer digital branches
- In the hand : -Med. Terminal br.:Gives 2 palmer digital brs. : -Med. Terminal br.:Gives 2 palmer digital brs. Articular brs. -main trunk
Supplies elbow & sup. Radioulner joint .
Supplies wrist & inf . Radioulner joint In the forearm : Slide 17: Vasomotor brs. -To the radial & ulnar arteries. Slide 18: Injury of median nerve * Median injury produces (1) paralysis of the muscles supplied by it.
(2) deformity of the hand.
(3) loss of sensation. Median nerve injury : Median nerve injury Slide 20: Above the Elbow Motor Affection (1) Paralysis of all muscles supplied .
(2) loss of pronation of the forearm .
(3)weak flexion of the wrist .
(4) loss of the flexion & opposition pf the thumb. Slide 21: Deformity : Monkey (ape) hand deformity : (1) hyper-extended thumb .
(2) adduction .
(3) flat thenar eminence . Sensory loss : Loss of sensation from : - lat. 2/3 of the palm of the hand . -lat. 3 ½ fingers anteriorly & their distal halves posteriorly. Slide 22: Deformity : Sensory loss : Motor Affection : Below the Elbow Monkey (ape) hand deformity - lat. 2/3 of the palm of the hand . -lat. 3 ½ fingers anteriorly & their distal halves posteriorly. -Paralysis of the 5 hand muscles supplied by the nerve.
-The forearm muscles escape the injury as they are supplied at elbow. Slide 23: Monkey (ape) hand deformity : Slide 24: Carpal tunnel syndrome Definition : It is compression of median n. as it passes through the carpal tunnel. causes : (1) dislocation of one of the carpal bones.
(2) thickening of the tendons passing.
(3) myxoedema or tumour inside the carpal tunnel . Slide 25: Effects : .As in the injury below the elbow but there is no sensory loss in the palm because the palmer cutaneous br . Passes outside the carpal tunnel. N.B : The characteristic deformity of all median n. injuries is monkey hand. Atrophy : Atrophy