The Body’s Covering System The Skeletal, Muscular, and Integumentary Systems: The Body’s Covering System

The Skeleton In order to retain their shape, all organisms need a form of structural support - unicellular: cytoskeleton composed of protein spikes called microtubules - multicellular: either an internal framework called endoskeleton or an external framework called exoskeleton For human beings, the skeleton (endow) is composed of calcium-rich tissue called bone

The Skeleton Supports the body, internal organs, provides for movement, stores minerals (Ca); and provides for red blood cell formation (hematopoiesis) Bones provide a system of levers on which muscles act to produce movement - fixed rigid rods that move about a fixed point There are 206 bones in the adult human skeleton

The Skeleton Skeletal framework - 206 bones total - divided into: * axial skeleton supports the central axis of the body; includes the skull, vertebral column and rib cage * appendicular skeleton provides for movement; includes the arms and legs along with the pelvis (hip) and shoulder area