The clavicle, or collarbone, runs from the sternum to the scapula, also known as the shoulder blade. The upper arm bone is called the humerus, and the forearm consists of two bones: the radius, located on the thumb side, and the ulna on the opposite side. These bones lead to the wrist, or carpus, which is made up of eight bones organized into two rows of four. The first row, starting from the thumb side, includes the scaphoid, lunate, triquetal, and pisiform bones. The second row comprises the trapezium, trapezoid, capitate, and hamate. Extending from the carpus are five elongated metacarpal bones, each leading to a finger. Attached to these metacarpals are the phalanges; each finger has three, while the thumb has two.