Which nerve is primarily responsible for finger extension?

The primary nerve responsible for finger extension is the radial nerve. This nerve innervates the extensor muscles located on the posterior side of the forearm, which are crucial for extending the fingers. The radial nerve operates the muscles, such as the extensor digitorum, allowing for the extension of the fingers at the metacarpophalangeal joints and beyond. This action is essential for various day-to-day functions, including grasping and releasing objects.

The other options provided relate to different functions. The ulnar nerve primarily affects the intrinsic muscles of the hand that help with finger adduction and abduction, the median nerve mainly facilitates thumb opposition and flexion of the fingers, while the axillary nerve is responsible for innervating the deltoid and teres minor muscles and does not play a significant role in finger movements. Understanding the role of the radial nerve in finger extension is essential for anyone studying neurology or physical therapy, as it highlights the complexities of nerve functions in motor control.