ANATOMY & PHYSIOLOGY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site smooth muscle Smooth muscle from a section of small intestine One of three main types of muscle, the others being skeletal muscle and cardiac muscle. Smooth muscle, which is also called unstriated or unstriped muscle, is muscle over which we have no conscious (voluntary) control. Instead, it is under control of the autonomic nervous system. Smooth muscle is found mainly in the walls of hollow internal organs such as blood vessels, the gastrointestinal tract, the urinary bladder, and the uterus. It is capable of slow, sustained, and rhythmic contractions such as those needed to push food steadily through the gut. Smooth muscle cells lie parallel to one another and contract as a single unit, with the impulse to contract being passed to small groups of cells by a single innervating nerve, coordinating with other nerves. A smooth muscle cell is spindle-shaped, tapering to a point at each end, and has a central nucleus. Each cell is about 0.2 mm long and about 0.007 mm wide. Related category    • ANATOMY AND PHYSIOLOGY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP