Which nerve provides the thenar muscles and finger flexors, enabling thumb opposition and finger flexion, with sensation to the palmar surfaces of the thumb, index, middle, and half of the ring finger?

Which nerve provides the thenar muscles and finger flexors, enabling thumb opposition and finger flexion, with sensation to the palmar surfaces of the thumb, index, middle, and half of the ring finger?

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

Answer: (D)

The nerve in question is the median nerve. It supplies the thenar muscles through its recurrent branch, including the muscles that enable thumb opposition, and it innervates the forearm flexors that bend the fingers (notably the flexor digitorum superficialis and the lateral part of the flexor digitorum profundus, as well as the flexor pollicis longus). The sensory fibers of the median nerve cover the palmar surfaces of the thumb, index, middle, and the radial half of the ring finger. That combination of motor ability (thumb opposition and finger flexion) and the specified cutaneous distribution aligns with the median nerve. The other nerves don’t match both features: the ulnar nerve mainly handles the intrinsic hand muscles on the ulnar side and sensation to the little finger and medial ring finger; the radial nerve covers the dorsum of the hand and extensor muscles; the musculocutaneous nerve supplies the anterior arm and lateral forearm sensation but not the palmar surface of these digits.

The nerve in question is the median nerve. It supplies the thenar muscles through its recurrent branch, including the muscles that enable thumb opposition, and it innervates the forearm flexors that bend the fingers (notably the flexor digitorum superficialis and the lateral part of the flexor digitorum profundus, as well as the flexor pollicis longus). The sensory fibers of the median nerve cover the palmar surfaces of the thumb, index, middle, and the radial half of the ring finger. That combination of motor ability (thumb opposition and finger flexion) and the specified cutaneous distribution aligns with the median nerve. The other nerves don’t match both features: the ulnar nerve mainly handles the intrinsic hand muscles on the ulnar side and sensation to the little finger and medial ring finger; the radial nerve covers the dorsum of the hand and extensor muscles; the musculocutaneous nerve supplies the anterior arm and lateral forearm sensation but not the palmar surface of these digits.