The biceps reflex is mediated by which nerve?

The biceps reflex is mediated by which nerve?

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

Answer: (D)

Reflexes rely on the nerve that supplies the muscle being tested. The biceps brachii is innervated by the musculocutaneous nerve, which carries motor signals from the C5–C6 spinal segments to the muscle. When you strike the biceps tendon, the reflex arc triggers a contraction of the biceps through that same nerve. The other nerves listed do not innervate the biceps—the radial nerve controls the extensors (and the brachioradialis reflex), while the median and ulnar nerves serve other forearm/hand muscles. So the biceps reflex is mediated by the musculocutaneous nerve.

Reflexes rely on the nerve that supplies the muscle being tested. The biceps brachii is innervated by the musculocutaneous nerve, which carries motor signals from the C5–C6 spinal segments to the muscle. When you strike the biceps tendon, the reflex arc triggers a contraction of the biceps through that same nerve. The other nerves listed do not innervate the biceps—the radial nerve controls the extensors (and the brachioradialis reflex), while the median and ulnar nerves serve other forearm/hand muscles. So the biceps reflex is mediated by the musculocutaneous nerve.