Which nerve is involved in providing sensation to the thumb?

The median nerve is primarily responsible for providing sensation to the thumb. This nerve innervates the areas of the hand that include the radial side of the palm and the palmar aspect of the thumb, index finger, middle finger, and part of the ring finger. It plays a crucial role in the grip and sensory functions of the hand.

In contrast, while the radial nerve does contribute to sensation in the hand, particularly in the back of the hand and the thumb area, it does not provide sensation to the palmar side of the thumb where the median nerve does. The ulnar nerve also innervates parts of the hand but primarily affects the little finger and the ulnar side of the ring finger, not the thumb. The axillary nerve is mainly involved with sensory functions in the shoulder region and does not play a role in thumb sensation. Therefore, the median nerve's specific pathway and areas of innervation make it the correct choice for sensation to the thumb.