Which nerve supplies impulses to the small finger side of the arm and the palm of the hand?

The ulna nerve is responsible for supplying impulses to the small finger side of the arm and the palm of the hand. It plays a crucial role in the sensory innervation of the fourth and fifth fingers, which are the ring and small fingers, respectively.

Additionally, the ulna nerve affects the skin on the inner side of the hand, allowing for the sensation and feeling in that particular area. It also contributes to the motor function of several hand muscles that control finger movement, particularly those related to fine motor skills and grip.

In contrast, the radial nerve primarily supplies the back of the arm and forearm, facilitating the movement of the triceps and wrist extensors. The median nerve mainly innervates the thumb, index finger, middle finger, and part of the ring finger, giving it a different region of influence in terms of sensation and motor function. The musculocutaneous nerve innervates the muscles in the front of the arm and provides sensation to the lateral aspect of the forearm but does not supply the small finger or the palm.

Therefore, the ulna nerve's primary role in the small finger's sensory and motor functions makes it the correct answer for this question.