Final answer:
The ulnar nerve and ulnar artery pass through the carpal tunnel as they enter the hand. The carpal tunnel is formed by the U-shaped carpal bones and the flexor retinaculum. This space also contains tendons from nine muscles and is crucial for hand function.
Step-by-step explanation:
The ulnar nerve and ulnar artery pass through a well-defined structure in the wrist as they enter the hand, known as the carpal tunnel. The carpal tunnel is a narrow passageway on the palmar side of the wrist, connecting the anterior forearm to the hand. It is bounded by the carpal bones, which form the walls and floor, and the flexor retinaculum, a strong ligament that forms the roof of this space. The flexor retinaculum is attached on the lateral side to the scaphoid and trapezium bones and on the medial side to the pisiform and hamate bones.
The carpal tunnel serves as the passageway for not only the ulnar nerve and artery but also the tendons of nine muscles. The ulnar artery, after running parallel to the ulna bone, contributes to the formation of the superficial and deep palmar arches within the carpal region, providing blood to the hand and digital arteries. Swelling or inflammation in this area can result in a condition known as carpal tunnel syndrome, characterized by pain, numbness, and muscle weakness in the hand.