Which of the following muscle is supplied by deep branch of the ulnar nerve?
**Core Concept**
The deep branch of the ulnar nerve is a motor branch that supplies muscles in the forearm and hand, playing a crucial role in fine motor control and hand function. This branch is responsible for innervating muscles that are essential for wrist and finger movements.
**Why the Correct Answer is Right**
The deep branch of the ulnar nerve innervates the hypothenar muscles (opponens digiti minimi, flexor digiti minimi brevis, and abductor digiti minimi), as well as the medial half of the flexor digitorum profundus and the medial half of the flexor pollicis longus. These muscles are responsible for wrist and finger movements, particularly those involving opposition and flexion. The deep branch of the ulnar nerve originates from the ulnar nerve, which arises from the C8 and T1 nerve roots.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the lateral half of the flexor digitorum profundus is actually supplied by the median nerve, not the deep branch of the ulnar nerve.
**Option B:** This option is incorrect because the palmar interosseous muscles are supplied by the ulnar nerve, but they are innervated by the superficial branch of the ulnar nerve, not the deep branch.
**Option C:** This option is incorrect because the adductor pollicis muscle is supplied by the ulnar nerve, but it is innervated by the superficial branch of the ulnar nerve, not the deep branch.
**Clinical Pearl / High-Yield Fact**
When evaluating a patient with ulnar nerve injury, it's essential to assess for weakness or paralysis of the intrinsic muscles of the hand, particularly those supplied by the deep branch of the ulnar nerve. This can lead to characteristic clawing of the little and ring fingers.
**Correct Answer:** C. Adductor pollicis