Which nerve provides sensation to the thumb, index finger, middle finger, and part of the ring finger and mediates some hand muscle function?

Which nerve provides sensation to the thumb, index finger, middle finger, and part of the ring finger and mediates some hand muscle function?

• A. Ulnar nerve
• B. Median nerve
• C. Radial nerve
• D. Axillary nerve

Answer: (B)

This item tests the distribution of nerve sensation and some hand muscle function. The median nerve supplies sensation to the palmar side of the thumb, index finger, middle finger, and the lateral half of the ring finger, and it also innervates important hand muscles—the thenar muscles that move the thumb and the lateral two lumbricals that help flex the fingers at the metacarpophalangeal joints. That combination of sensory territory and motor function fits precisely with the description. The other nerves have different patterns: the ulnar nerve mainly covers the little finger and the medial ring finger and most intrinsic hand muscles; the radial nerve provides dorsum and extensor function rather than palmar sensation to these digits; the axillary nerve serves the shoulder region.

This item tests the distribution of nerve sensation and some hand muscle function. The median nerve supplies sensation to the palmar side of the thumb, index finger, middle finger, and the lateral half of the ring finger, and it also innervates important hand muscles—the thenar muscles that move the thumb and the lateral two lumbricals that help flex the fingers at the metacarpophalangeal joints. That combination of sensory territory and motor function fits precisely with the description. The other nerves have different patterns: the ulnar nerve mainly covers the little finger and the medial ring finger and most intrinsic hand muscles; the radial nerve provides dorsum and extensor function rather than palmar sensation to these digits; the axillary nerve serves the shoulder region.