Which nerve is responsible for innervating the triceps muscle?

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

Answer: (C)

The triceps muscle, located at the back of the upper arm, is responsible for extending the forearm at the elbow joint. The nerve that innervates the triceps muscle is the radial nerve. This nerve originates from the brachial plexus and travels down the arm, providing motor innervation to the triceps as well as sensory innervation to parts of the forearm and hand.

Other nerves mentioned, like the ulnar and median nerves, primarily innervate other muscles in the forearm and hand and do not have a direct role in the functioning of the triceps muscle. The femoral nerve, on the other hand, is involved with innervating muscles in the anterior thigh and is unrelated to the upper arm musculature. Therefore, the radial nerve's specific role in controlling the triceps muscle makes it the correct choice in this context.