Skin over hypothenar eminence is supplied by?
**Core Concept**
The skin over the hypothenar eminence is supplied by a branch of the ulnar nerve. This area is a common site for nerve damage due to its anatomical location and the proximity of the ulnar nerve to the wrist.
**Why the Correct Answer is Right**
The ulnar nerve, specifically its superficial branch, provides sensory innervation to the skin over the hypothenar eminence. This is due to the branching pattern of the ulnar nerve as it courses through the wrist and hand. The superficial branch of the ulnar nerve arises from the ulnar nerve near the elbow and then descends through the forearm, giving off branches to the skin on the medial aspect of the hand and fingers. The hypothenar eminence, being a prominence on the medial side of the hand, receives its sensory supply from this branch.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify the correct nerve or branch responsible for the sensory supply to the hypothenar eminence.
**Option B:** This option is incorrect as the median nerve primarily supplies the skin on the palmar aspect of the thumb, index, and middle fingers, rather than the hypothenar eminence.
**Option C:** This option is incorrect as the radial nerve supplies the skin on the dorsal aspect of the hand and fingers, rather than the hypothenar eminence.
**Clinical Pearl / High-Yield Fact**
The superficial branch of the ulnar nerve can be damaged at the wrist, resulting in numbness or tingling over the hypothenar eminence. This can occur due to compression of the nerve by a ganglion cyst or other mass lesion.
**Correct Answer: C. The ulnar nerve.**