Anatomical terms of muscle Anatomical terms of muscle Muscles are described using unique anatomical terminology according to their actions and structure. There are three types of muscle tissue in the human body: skeletal, smooth, and cardiac. Skeletal striated muscle, or "voluntary muscle", primarily joins to bone with tendons. Skeletal muscle enables movement of the bones of the human skeleton and maintains posture. Smooth muscle tissue is found in parts of the body where it conveys action without conscious intent. The majority of this type of muscle tissue is found in the digestive and urinary systems where it acts by propelling forward food, chyme, and
Second metacarpal bone Second metacarpal bone The second metacarpal bone (metacarpal bone of the index finger) is the longest, and its base the largest, of all the metacarpal bones. Its base is prolonged upward and medialward, forming a prominent ridge. It presents four articular facets, three on the upper surface and one on the ulnar side: The extensor carpi radialis longus muscle is inserted on the dorsal surface and the flexor carpi radialis muscle on the volar surface of the base. The shaft gives origin to the first palmar interosseus and the first and second dorsal interossei. This bone is often the most