1. Median nerve

2. MEDIAN NERVE

3. Root value: C5,6,7,8,T1.
Beginning:
by 2 roots, Lat root from lat cord & med root from med cord of brachial plexus.
Course and relations:
- Descends lat to axillary & brachial A.
- At the middle of the arm it crosses the brachial A & passes med to it to enter the cubital fossa.
- Leaves cubital fossa by passing between 2 heads of pronator teres.
- Descends between flexor digitorum superficialis (superficial) & flexor digitorum profundus (deep).
- Passes deep to flexor retinaculum to the hand then divides into terminal branches

5. Injury of median nerve: (Ape like hand)
A] Injury above cubital fossa:
Motor:
• Paralysis of pronator teres & quadrates loss of pronation.
• Paralysis of wrist flexors except flexor carpi ulnar is weak flexion accompanied by adduction.
• Paralysis of flexor pollicis longus & brevis → loss of thumb flexion.
• Paralysis of opponens pollicis → loss of opposition (Ape like).

6. Sensory: loss of sensation of ant side of lat 2/3 of hand & lat 3½ fingers.
B] Injury at wrist:
Cause: carpal tunnel syndrome due to compression by inflammation, bone dislocation or overstretch by extended hands (e.g.: typewriters).
Motor: loss of opposition (Ape like hand).
Sensory: loss of sensation of ant side of lat 3½ fingers.

7. ULNAR NERVE

8. Root value: C7,8,T1.
Beginning: from med cord of brachial plexus.
N.B.: med cord of brachial plexus does not contain C7, it reaches the ulnar nerve through lat root of median nerve.
Course and relations:
- Descends med to axillary & brachial A.
- At mid arm it passes to post compartment.
- Passes post to med epicondyle.
- Passes between 2 heads of flexor carpi ulnaris to forearm.
- Descends between flexor carpi ulnaris (superficial) & flexor digitorum profundus (deep).
- Passes superficial to flexor retinaculum to the hand.

10. Injury of ulnar nerve: (partial claw hand)
A] Injury above the elbow:
Motor:
• Paralysis of flexor carpi ulnaris  weak flexion of wrist accompanied by abduction.
• Paralysis of med 2 lumbricals  clawing of ring & little fingers (partial claw hand).
• Paralysis of interossei  loss of adduction and abduction of med 4 fingers.
• Paralysis of adductor pollicis  loss of adduction of thumb.

11. Sensory: loss of sensation of med 1/3 of hand & med 1½ fingers (ant & post).
B] Injury at wrist: differs in:
Motor:
• Claw hand is more severe due to further flexion by flexor digitorum profundus (ulnar paradox).
• No affection of wrist flexion
Sensory: loss of sensation of med 1½ fingers.