Question

Which nerve supplies the region marked as 'Area B' in the image?

• A. Ulnar nerve
• B. Median nerve
• C. Radial nerve
• D. Posterior interosseous nerve

Hint:

The lateral dorsum of the hand and dorsal thumb-index skin is radial nerve territory.

Answer 1

The Correct Option is C

Step 1: Area B corresponds to the cutaneous territory on the dorsum (back) of the hand supplied by the radial nerve.
Step 2: The superficial terminal branch of the radial nerve is purely cutaneous. It supplies the lateral half of the dorsum of the hand.
Step 3: It also supplies the proximal parts of the dorsal surfaces of the thumb, the index finger, and the lateral half of the middle finger.
Step 4: The ulnar nerve supplies the medial dorsum and medial one and a half digits, the median nerve supplies the palmar lateral digits, and the posterior interosseous nerve is mainly motor. Hence the radial nerve supplies Area B.