Your bones have one more very important function. In addition to providing strength and protecting your body, your bones also are where blood is created. Your blood is alive. It is made up of millions and millions of tiny blood cells. These cells only live for a few months. This means that your blood supply must constantly be regenerated.
If you could see into the very center of your bones you would find a soft spongy material called bone marrow. This marrow is where new baby blood cells are being created. Whenever you bleed or your blood cells die of old age, they are replaced by new blood cells that come from inside your bones.
Go to the next page to learn much more about how bones work and what they are made of.
