Which nerve is primarily associated with palmar interossei and lumbrical function?

The ulnar nerve is primarily associated with the function of the palmar interossei and lumbrical muscles. The palmar interossei are responsible for adducting the fingers toward the midline of the hand, while the lumbricals flex the metacarpophalangeal joints and extend the interphalangeal joints. Both of these muscle groups contribute significantly to the intricate movements of the hand necessary for grasp and intricate tasks.

The ulnar nerve innervates these muscles, specifically the deep branches of the ulnar nerve that serve the interossei and the third and fourth lumbricals. This innervation is crucial for fine motor control and the ability to perform precise movements with the fingers. In contrast, the median nerve primarily innervates the thenar muscles and the first two lumbricals, which are situated differently in relation to finger movement. The radial and musculocutaneous nerves have distinct functions and do not innervate the interossei or lumbricals at all, further emphasizing the role of the ulnar nerve in this specific context.