BC: SLELETAL SYSTEM
FC: Skeletal System
1: Your Skeletal system is all of the bones in the body and the tissues such as tendons, ligaments and cartilage that connect them. Your teeth are also considered part of your skeletal system but they are not counted as bones. Your teeth are made of enamel and dentin. Enamel is the strongest substance in your body
2: The main job of the skeleton is to provide support for our body. Without your skeleton your body would collapse into a heap. Your skeleton is strong but light. Without bones you'd be just a puddle of skin and guts on the floor.
3: Babies have more than adults! At birth, you have about 300 bones. As you grow older, small bones join together to make big ones. Adults end up with about 206 bones.
4: Old bones are dead, dry and brittle. But in the body, bones are very much alive. They have their own nerves and blood vessels, and they do various jobs, such as storing body minerals like calcium. Bones are made of a mix of hard stuff that gives them strength and tons of living cells which help them grow and repair themselves.
5: A typical bone has an outer layer of hard or compact bone, which is very strong, dense and tough. Inside this is a layer of spongy bone, which is like honeycomb, lighter and slightly flexible. In the middle of some bones is jelly-like bone marrow, where new cells are constantly being produced for the blood. Calcium is an important mineral that bone cells need to stay strong so keep drinking that low-fat milk!