Final answer:
The ulnar nerve runs along the posterior surface of the distal ulna and interosseous membrane, innervating several muscles including the flexor carpi ulnaris, flexor digiti minimi brevis, and extensor carpi ulnaris, which are responsible for various hand and wrist movements.
Step-by-step explanation:
The Ulnar Nerve and Its Innervation
The ulnar nerve is a key component of the arm's anatomy, running from the neck all the way to the hand. Its path includes following the posterior surface of the distal ulna and the interosseous membrane. The nerve provides innervation to a number of muscles that manage movements of the wrist, hand, and forearm. Specifically, some of the muscles innervated by the ulnar nerve include the flexor carpi ulnaris, which flexes and adducts the hand at the wrist; the flexor digiti minimi brevis, which flexes the little finger; and the extensor carpi ulnaris, which extends and adducts the hand at the wrist.
Moreover, the ulnar nerve is vital in controlling muscles that contribute to fine motor actions and the complex movements of the fingers. These muscles include the interosseous muscles of the hand as well as the flexor digitorum longus, which flexes the four small toes. While not part of the muscles that the ulnar nerve innervates, it is important to mention that other muscles such as the biceps brachii, brachialis, and brachioradialis, involved in flexing the forearm, are innervated by different nerves.