The lateral part of the flexor digitorum profundus is innervated by which nerve?

The lateral part of the flexor digitorum profundus muscle is innervated by the anterior interosseous nerve, which is a branch of the median nerve. This muscle is responsible for flexing the distal interphalangeal joints of the fingers. The flexor digitorum profundus is unique in its innervation; while the medial part of the muscle (which flexes the fourth and fifth fingers) is innervated by the ulnar nerve, the lateral part (which flexes the second and third fingers) receives its motor supply from the anterior interosseous nerve.

The anterior interosseous nerve innervates muscles in the forearm that are involved in deep flexion, particularly the lateral part of the flexor digitorum profundus as well as the flexor pollicis longus and part of the pronator quadratus. This specialized innervation allows for more precise finger movements, especially for the index and middle fingers, which are critical for fine motor tasks.

Understanding the distribution of these nerves is essential for diagnosing and managing various conditions that may affect hand function, making this knowledge vital for surgical practice.