Question

Anterior interosseous nerve is a branch of?

• A. Radial nerve
• B. Median nerve
• C. Ulnar nerve
• D. Axillary nerve

Hint:

Think of the deep forearm flexor motor branch and its parent trunk that passes through pronator teres.

Answer 1

The Correct Option is B

Step 1: The anterior interosseous nerve (AIN) is a motor branch that arises from the median nerve in the proximal forearm, just below the elbow.

Step 2: It runs on the anterior surface of the interosseous membrane with the anterior interosseous artery, supplying the deep flexor muscles of the forearm - flexor pollicis longus, the lateral half of flexor digitorum profundus, and pronator quadratus.

Step 3: Note the distinction often confused in exams: the anterior interosseous artery is a branch of the common interosseous artery (from the ulnar artery), but the anterior interosseous NERVE is purely a branch of the median nerve.

Step 4: The radial, ulnar, and axillary nerves do not give rise to the anterior interosseous nerve, so the correct answer is the median nerve.