Which of the following muscles is innervated by the ulnar nerve?

• A. Flexor carpi radialis
• B. Flexor carpi ulnaris
• C. Deep digital flexor
• D. Triceps

Answer: (B)

The Flexor carpi ulnaris muscle is indeed innervated by the ulnar nerve. This muscle is located on the medial side of the forearm and plays a crucial role in wrist flexion and adduction. The ulnar nerve innervates muscles that are primarily involved in fine motor movements and activities that require a high degree of coordination, particularly in the hand and fingers.

In contrast, the Flexor carpi radialis is innervated by the median nerve and is primarily responsible for flexing and abducting the wrist. The Deep digital flexor is a muscle with two heads; while parts of it are innervated by both the median and ulnar nerves, it is not exclusively innervated by the ulnar nerve, which makes it not the best choice for this question. Lastly, the Triceps muscle is innervated by the radial nerve and is primarily responsible for extending the elbow. Thus, the correct identification of the Flexor carpi ulnaris illustrates the specific role of the ulnar nerve in the innervation of certain forearm muscles.