When you’re born, if you are a typical infant, you have 270 bones and by the time you’re about 30 you have 206 bones. Don’t panic, though, it doesn’t mean you lost any along the way, it simply means that some of the smaller ones fused into larger ones.

Take for example, the humerus, it begins as three bones and by puberty fuses into one long bone. This happens all over your body.

bones humanBelieve it or not, your bones are made up of mostly collagen, which is a type of semi-soft protein. It’s the combination of collagen and calcium that makes the bones strong and solid feeling. To me this is so absolutely cool; the collagen weaves itself into a flexible framework and then the minerals calcium carbonate and calcium phosphate fuse with the collagen creating a really interesting structure that is both strong and flexible (hopefully).

Your bones are alive and in a way ever changing, even though they feel like they’re formed and solid. They actually are in a constant cycle of breaking down (resorption) and rebuilding (formation). When they are in the process of breaking down they generate cells called osteoclasts, which help break down the old bone structure and make it available to be resorbed into the body. Once that phase is completed the body starts forming cells called osteoblasts. Osteoblasts are responsible for helping the body form new bones in place of what was broken down. When they are broken down they but don’t have the adequate or appropriate mineral balance to rebuild this contributes to bone density loss, like osteoporosis. Of course, there are actually quite a few other minerals and hormones involved in the whole process so osteoporosis isn’t only caused by calcium deficiency.

bone layersYour bone is made up of two types of bone. The outside is called cortical bone and it is the outer layer of the bone that feels almost solid. The trabecular bone is the layer inside the cortical layer, it’s a little spongier and more flexible. Together these two layers surround your bone marrow, which is a different ingredient entirely, and form the structure for your body.

Your bones form your very cool skeleton. They use calcium to fuse the collagen into a strong container and they also store calcium for you. 99% of the calcium in your body is in your bones, functionally creating bony structure and also being stored for future use. 1% is found in your blood, traveling around your body waiting to be put to good use.

Have you ever broken a bone? The way bones heal is pretty miraculous; hundreds of tiny cells and blood vessels form on each end of the bone, rebuilding the material and binding across the gap of the break until all is knitted together again.