Wasting of the intrinsic muscles of the hand can be expected to be due to injury which nerve ?
**Core Concept**
The intrinsic muscles of the hand are a group of small muscles that are responsible for fine motor movements and finger dexterity. These muscles are supplied by the median and ulnar nerves, which provide motor innervation to the hand. Injury to these nerves can lead to wasting and weakness of the intrinsic muscles.
**Why the Correct Answer is Right**
The median nerve supplies the thenar muscles (thumb muscles) and the lateral two lumbricals, while the ulnar nerve supplies the medial two lumbricals, the interosseous muscles, and the adductor pollicis. Damage to the median nerve can result in weakness and wasting of the thenar muscles, leading to a characteristic "ape hand" deformity. Similarly, damage to the ulnar nerve can result in weakness and wasting of the intrinsic muscles of the hand, leading to a characteristic "claw hand" deformity.
**Why Each Wrong Option is Incorrect**
* **Option A:** The radial nerve primarily supplies the extensor muscles of the wrist and fingers, and is not directly involved in the innervation of the intrinsic muscles of the hand.
* **Option B:** The musculocutaneous nerve supplies the biceps and brachialis muscles, and is not directly involved in the innervation of the intrinsic muscles of the hand.
* **Option D:** The axillary nerve primarily supplies the deltoid and teres minor muscles, and is not directly involved in the innervation of the intrinsic muscles of the hand.
**Clinical Pearl / High-Yield Fact**
The "claw hand" deformity resulting from ulnar nerve injury can be remembered by the acronym "MUSCLE" - Median and Ulnar nerves Supplying the Lateral and Medial Lumbricals, and the Interosseous and Adductor Pollicis muscles.
**Correct Answer: C. Ulnar nerve.**