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
Stapedius muscle of the facial nerve, the stapedius is paralyzed and hyperacusis may result. Like the stapes bone to which it attaches, the stapedius muscle shares evolutionary history with other vertebrate structures. The mammalian stapedius evolved from a muscle called the depressor mandibulae in other tetrapods, the function of which was to open the jaws (this function was taken over by the digastric muscle in mammals). The depressor mandibulae arose from the levator operculi in bony fish, and is equivalent to the epihyoidean in sharks. Like the stapedius, all of these muscles derive from the hyoid arch and are innervated by cranial