Skeletal+System

The Skeletal System The skeletal system includes the 206 bones of the body.

JOBS of the skeletal system: 1. __SHAPE__: the skeleton determines how we look, by giving shape and form to our bodies. 2. __STRUCTURE__: the skeleton allows us to stand upright, and keeps our organs in place. Also, our skeleton supports our muscles. Our muscles attach to our bones with **tendons**. 3. __MOVEMENT__: The skeleton has joints where bones come together. Bones are held together at joints by ligaments. a. ball and socket joint - circular movement in shoulder, hip b. pivot joint - turning movement in neck c. hinge joint - open and closed movement in elbow, knee, fingers d. gliding joint - side-to-side movement in wrists, ankles, spine e. immoveable joint - no movement in skull 4. __PROTECTION__ - Our skeleton protects vital organs. The cranium protects the brain, vertebrae protects the spinal cord, the pelvis protects the intestines, the ribs protect the lungs and heart 5. __MAKING BLOOD CELLS__ - the bone **marrow** found inside bone makes red blood cells. Other parts of bone: compact bone (the hard outer covering of bone; spongy bone (has holes and is very strong) 6. __STORING SUBSTANCES__ - Our skeleton stores extra **calcium** our body needs. If we don't get the calcium in our diet, our bones give up the calcium, leaving them weak.

PROBLEMS WITH THE SKELETAL SYSTEM 1. Scoliosis - The vertebrae becomes curved in a C or S shape 2. Juvenile Rheumatoid Arthritis (JRA) - a child form of athritis, when the joints become stiff 3. Osteoporosis - when bones weaken because they have lost calcium