Just in case you forgot, we humans have a total of 206 sizable bones in our bodies. There are also 6 additional bones, 3 in each ear, known as the ossicles (little bones). So the grand total is 212. We generally think of bone as being part of our skeletal system, but let's not forget its other important functions. These are:
- To serve as a "structural frame" for the human skeleton.
- To work with ligaments, tendons, and joints to provide movement of the skeleton.
- To be an outer shell protecting our internal organs (as the skull protects the brain within it).
- To house the bone marrow, the main source of blood formation in humans.
- To serve a source of calcium for the entire body.
Without bones, we would have no "structural frame" for our skeleton, be unable to move our skeleton, leave our internal organs poorly protected, lack blood and be short on calcium.
The construction of our bones is a complex process. Bone formation starts in the fetus 6 months before birth and is not generally "complete" until adolescence.
In truth, bone formation is never really "complete". It is constantly being destroyed and formed anew throughout our lifetime in a process of unremitting remodeling. The cells that participate in the maintenance and remodeling of bone include:
- Osteocytes (bone cells) that maintain bone as a living tissue;
- Osteoclasts (bone breakers) that destroy bone; and
- Osteoblasts (bone builders) that form the supporting matrix of new bone.