What is the skeleton system ?
In biology, the skeleton or skeletal system is the biological system providing physical support in living organisms. (By extension, non-biological outline structures such as gantries or buildings may also acquire skeletons.) Skeletal systems are commonly divided into three types – external (an exoskeleton), internal (an endoskeleton), and fluid based (a hydrostatic skeleton), although hydrostatic skeletal systems may be classified separately from the other two, since they lack hardened support structures. An internal skeletal system consists of rigid (or semi-rigid) structures, within the body, moved by the muscular system. If the structures are mineralized or ossified, as they are in humans and other mammals, they are referred to as bones. Cartilage is another common component of skeletal systems, supporting and supplementing the skeleton. The human ear and nose are shaped by cartilage. Some organisms have a skeleton consisting entirely of cartilage and without any calcified bones at
