v The Skeletal System is composed ofbones and tissuesØ Bone:The substance that forms the skeleton of the body. It is composed chiefly ofcalcium phosphate and calcium carbonate. It also serves as a storage area forcalcium, playing a large role in calcium balance in the blood.
Ø Tissue:A group or layer of similarly specialized cells that together perform certainspecial functions.Ø Ligament:Connects bones to other bonesØ Tendon:Attatches muscles to bones.Ø Joint:Joints support movement.Ø Cartilage:Protects the bones, and acts as a cushion between the bones and joints.v The Skeleton can be divided intotwo sections:Ø The Axial Skeleton§ Composedof the bones in the head, trunk, and vertebrae. 80 bonesØ The Appendicular Skeleton· Composed of the shoulder girdle, thepelvic girdle, and the bones in the arms and legs. 126 bones.
v The Skeleton has six majorfunctions:Ø Support:It is the framework that supports and maintains the shape of the body. Ø Movement:Joints, which are in between bones, allow for movement e.g. ball and socketjoint.Ø Protection:The skeleton protects our organs from damage e.g. the skull protects the brainand eyes, ribs protect the lungs and heart, the vertebrae protect the spinalcord.Ø Blood Cell Production:The development of bleed cells, Haematopoiesis, happens in the skeleton.
Ø Storage:Calcium is stored in the bone matrix, and also bone marrow can store iron andferritin. v Bone CompositionØ Compact Bone: Densebone e.g.
the long bones in the arms and legs.Ø Spongy Bone:Honeycomb-like, flexible e.g. ribs, skull, vertebraeØ Bone Marrow:Soft blood-forming tissue that fills cavities of bones, and contains fat andimmature, as well as mature blood cells.v Bone Shapes:Ø Long Bones: Hard,dense bones that provide strength, structure, and mobility e.g.
arms, legs, andfingers.Ø Short:As wide as they are long. Provides support and stability e.
g.wrist and anklesØ Flat:Expanded into broad flat plates. Provides extensive protection e.g.
skull andSternumØ Irregular:Various functions in the body such as, protection of nervous tissue tongueattachment. e.g. Spine