The Skeletal System In Human Body

THE SKELETAL SYSTEM HAP Unit 4thTHE SKELETAL SYSTEM Parts of the skeletal system include: Bones (skeleton) Joints Cartilages Ligaments Divided into two divisions: 1.Axial skeleton (skull, ribs and vertebra) 2.Appendicular skeleton (pelvis, extremities)FUNCTIONS OF BONES Support of the body Protection of soft organs Movement due to attached skeletal muscles Storage of minerals and fats Blood cell formationBONES OF THE HUMAN BODY The adult skeleton has 206 bones Two basic types of bone tissue Compact bone Homogeneous Spongy bone Small needle-like pieces of bone Many open spacesCLASSIFICATION OF BONES ON THE BASIS OF SHAPECLASSIFICATION OF BONES Long bones Typically longer than wide Have a shaft with heads at both ends Contain mostly compact bone Examples: Femur, humerus Short bones Generally cube-shape Contain mostly spongy bone Examples: Carpals, tarsalsCLASSIFICATION OF BONES Flat bones Thin and flattened, usually curved Thin layers of compact bone around a layer of spongy bone Examples: Skull, ribs, sternum Irregular bones Irregular in shape Do not fit into other bone classification categories Example: Vertebrae and hipGROSS ANATOMY OF A LONG BONE Diaphysis Shaft Composed of compact bone Epiphysis Ends of the bone Composed mostly of spongy bone Figure 5.2aSTRUCTURES OF A LONG BONE Periosteum Outside covering of the