Why do bones remain for centuries after a person dies?

Bones are made of two main materials: calcium salts make bones hard, and collagen fibers make them strong but also a bit flexible. After death the collagen rots away, leaving just the durable hard parts behind. In life, the bones of a person's skeleton support the body and protect its internal organs.

[image credit: visiblebody.com]

Inside a bone

The bones in your skeleton are moist, living organs with their own blood supply. if you look inside a bone you can see that it is not solid. If bones were solid they would be so heavy you would not be able to move.

Some numbers

206

The number of bones in an adult skeleton.

300

number of bones in a newborn baby's skeleton (as a baby grows, The some bones fuse together)

106

The number of bones in the hands and feet - is more than half the number of bones in the body.

99%

The percentage of calcium in the body is found in bones and teeth.

6

The number of times a living bone is stronger than a piece of steel of the same weight.

Two Skeletons

1. Axial (central) skeleton (the skull, backbone, and ribs): consists of 80 bones that run down the center of the body and protect the heart and lungs.

2. Appendicular skeleton (the arms, legs, shoulder girdle, and hip girdle): Consist of 126 bones that hang on to the axial skeleton and move the body.

Some Facts:

1. The smallest bone in the body is the stapes or stirrup bone. Found inside the ear. it is smallest than a grain of rice.

2. The femur or thighbone is the body's longest bone at about a quarter of the body's total length.

3. The skull is the body's most complex bone.

4. Our most complex joint is in the knee.

Your "Funny bone" isn't a bone at all; it's a spot on the outer bit of your elbow that, if you hit or knock it, gives you a weird tingly pain. This is because the ulnar nerve crosses the bone at that point.