Which nerve is responsible for supplying the arm and hand?

The median nerve plays a crucial role in supplying sensory and motor functions to the arm and hand, particularly affecting the anterior (flexor) aspect. It's responsible for the innervation of several muscles in the forearm, specifically those responsible for flexing the hand and fingers. The median nerve also provides sensation to parts of the hand, including the thumb, index finger, middle finger, and half of the ring finger, allowing for the fine motor skills necessary for tasks such as grasping or manipulating objects.

In contrast, while the radial nerve, ulnar nerve, and axillary nerve also contribute to the functioning of the arm and hand, their areas of innervation are more specific. The radial nerve primarily controls the back of the arm, forearm, and hand, focusing on the extensor muscles; the ulnar nerve provides sensation and muscle control primarily to the small finger and part of the ring finger; and the axillary nerve is mainly responsible for sensation around the shoulder area and innervation to the deltoid and teres minor muscles. Thus, the median nerve stands out for its comprehensive role in the overall functioning of the arm and hand.