THE ROLE OF SKELETON1) Support for animals that live on land, the air does not support softer tissues like muscle and so the hard, incompressible bone holds the rest of the body in position

THE ROLE OF SKELETON2) Protection vital tissues and organs can be protected from physical damage by a covering of bone For example, the brain is protected from shock inside the skull and the heart and lungs are protected inside the rib cage

THE ROLE OF SKELETON3) Movement (locomotion) bones meet at joints which form levers Muscle pull on these levers to move the body4) Storage both calcium and phosphate are stored in the bone5) Manufacture of blood cells the marrow inside some of the bones make blood cells

THE VERTEBRATE SKELETONIs made up of :An axis the skull, backbone and rib cageAppendages the arms and legs constructed to the same patternGirdles which connect the appendages to the axis

THE VERTEBRATE SKELETONENDOSKELETONSkull protects the brainBackbone supports the human body in upright positionForelimb movement of this helps in feeding and the use of toolsPelvic girdle like all bones is a store of calcium and phosphateLong bone of leg (femur) has marrow where bone cells are manufactured

EXOSKELETON The exoskeleton is made of chitin which :Prevents water lossProtects the soft tissues, like muscles from predatorsMust be shed and replaced as the insect grows (the insect is vulnerable during shedding) * Crustaceans such as crabs have a similar exoskeleton

HYDROSKELETONSoft-bodied animals have a hydroskeletonThe watery fluid is incompressible and forms an almost solid structure when it is squeezed by the muscle layers