Which nerve supplies the triceps and wrist extensors, enabling elbow and wrist extension, with sensory distribution over the posterior arm and hand?

Which nerve supplies the triceps and wrist extensors, enabling elbow and wrist extension, with sensory distribution over the posterior arm and hand?

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

Answer: (C)

This question tests which nerve drives elbow and wrist extension and also provides sensation to the posterior arm and hand. The radial nerve is the one that provides motor supply to the triceps brachii, which extends the elbow, and to the extensor muscles of the forearm, which extend the wrist. It also carries sensory information from the posterior aspect of the arm and forearm and the dorsum of the hand through its cutaneous branches. This combination—elbow and wrist extension plus posterior arm/hand sensation—is characteristic of the radial nerve. The other nerves don’t line up with both the motor extension functions and that specific sensory distribution.

This question tests which nerve drives elbow and wrist extension and also provides sensation to the posterior arm and hand. The radial nerve is the one that provides motor supply to the triceps brachii, which extends the elbow, and to the extensor muscles of the forearm, which extend the wrist. It also carries sensory information from the posterior aspect of the arm and forearm and the dorsum of the hand through its cutaneous branches. This combination—elbow and wrist extension plus posterior arm/hand sensation—is characteristic of the radial nerve. The other nerves don’t line up with both the motor extension functions and that specific sensory distribution.