Which nerve innervates the wrist extensors?

The correct choice is the radial nerve, as it is primarily responsible for innervating the wrist extensors. The wrist extensors, which include muscles such as the extensor carpi radialis longus and brevis, as well as the extensor carpi ulnaris, are involved in the extension of the wrist joint. These muscles receive their motor supply from branches of the radial nerve that travel into the posterior compartment of the forearm.

The role of the radial nerve in this context is crucial, as it not only supplies the muscles responsible for wrist extension but also has a significant function in finger extension. Damage to this nerve can lead to wrist drop, a condition where the individual is unable to extend the wrist due to loss of function in the extensors, further highlighting the importance of the radial nerve in upper limb function.

Other nerves mentioned, such as the median and ulnar nerves, primarily innervate different muscle groups, including the wrist flexors and intrinsic hand muscles, which do not contribute to the extension of the wrist. The musculocutaneous nerve is primarily associated with the innervation of the biceps brachii and other flexors of the elbow, which is distinct from the role of wrist extensors.