Your bones!

By Al Lowe
Contributor

Your skeleton consists of bones - 206 of them. We think of bones as being very hard, solid things, but many of them are not nearly as solid as they seem. Actually, bones do a lot of things for us, besides holding us up. Bones are the framework of your body - our basic structure. Muscles are attached to bones, so they have something to pull on. Bones serve as protection for some of our most vital parts. They manufacture red and white blood cells, and they serve as storehouses for quite a few minerals.
Your skeleton is considered to be in two parts. The axial skeleton consists of the bones in your head, your backbone and your ribs. The appendicular skeleton is composed of the pectoral girdle (collarbone area), the pelvic girdle (hip bones), and your arms and legs.
Your skull appears to be one solid, rounded bone. Actually, a baby's skull is composed of eight separate bones, joined by rubber-like tissue. A baby's head must grow a lot to accommodate the brain, so these eight bones have a lot of expanding to do. Gradually, they fuse together to form the rounded cranium, which provides excellent protection for the brain. If you look at a real human skull, you can see the lines where the original bones joined.
Your pelvic (hip) girdle will be different if you are a woman than if you are a man. Female hip bones are spread wider apart, forming a sort of dish or bowl, to help hold babies for all those months. The opening is also larger in the female, to allow for the passage of a baby's head during childbirth.
The smallest bones in your body are the three tiny bones of the ear. They are only a fraction of an inch long. These little bones receive sound vibrations from the eardrum. The bones, called the anvil, hammer, and stirrup, act as levers, amplify the sound, and pass it on to the inner ear. From there, nerves pass the information to the brain, and you hear whoever is talking to you.
As a tiny baby, you have over 300 separate bones. But as you grow, many of the smaller bones fuse together, mostly in the head or the backbone.
This process is not fully accomplished until you are about 25 years old. Only then do you have your complete adult skeleton.
Some bones are largely solid, compact and hard. Others are lighter and full of little spaces - the spongy bones. All bones, though, are living, functioning tissue, like all the rest of our bodies.
There are lots more things, fascinating things about bones, But these are for another article.