Nerves

Question 1

Radial Nerve

Answer 1

Levels: C5-T1
Innervates: triceps, wrist extensors, finger extensors
Sensation: dorsum of thumb, index, middle, 1/2 ring finger
Key deficits: wrist drop, numbness

Question 2

Median Nerve

Answer 2

Levels: C5-T1
Innervates: most forearm flexors, FPL, lateral half FDP, lateral 2 lumbricals, thenar eminence
Sensation: palm of thumb, index, middle, 1/2 ring finger
Key deficits: atrophy of thenar eminence, “Ape hand”, numbness

Question 3

Ulnar Nerve

Answer 3

Levels: C8-T1
Innervates: FCU, medial half of FDP, medial 2 lumbricals, hypothenar eminence, interossei, deep head FPB, adductor pollicis
Sensation: lateral hand, pinky, 1/2 ring finger
Key deficits: “Claw hand”, numbness

Question 4

Axillary Nerve

Answer 4

Levels: C5-6
Innervates: deltoid, teres minor
Sensation: tip of shoulder

Question 5

Common Peroneal Nerve

Answer 5

Levels: L4-S2
Innervates: fibularis longus/brevis, tibialis anterior, extensor hallucis longus, EDL
Sensation: lateral lower leg, dorsum of foot
Key deficits: foot drop

Question 6

Sciatic Nerve

Answer 6

Levels: L4-S3
Splits into tibial and common fibular at the knee

Question 7

Tibial Nerve

Answer 7

Levels: L4-S3
Innervates: posterior compartment of lower leg, intrinsic muscles in sole of foot
Sensation: sole of foot
Key deficits: weak PF and toe flexion, numbness sole of foot

Question 8

Femoral Nerve

Answer 8

Levels: L2-L4
Innervates: hip flexors, quadriceps
Sensation: anterior/medial thigh, medial leg/foot (via saphenous nerve)
Key deficits: weak knee extension, numbness

Question 9

Lateral Femoral Cutaneous Nerve

Answer 9

Meralgia paresthetica
Key deficit: sensory loss anterolateral leg