Arms, or limbs, are the upper appendages of the human body, consisting of the shoulder, elbow, wrist, and hand. They play a crucial role in various functions, including lifting, reaching, and manipulating objects. Each arm has three main segments: the humerus in the upper arm, the radius and ulna in the forearm. The structure of the arms includes bones, muscles, tendons, and ligaments, which work together to provide strength and flexibility. The muscles allow for movement, while the nerves transmit signals from the brain to coordinate actions. Proper arm function is essential for daily activities and overall mobility.