Main functions and structure of the skeleton system?

Answer 1

The skeleton has several main functions, some pretty obvious and some less

so. First and most obvious is support. Bones are pretty strong, and they

hold you up. If you didn't have bones, you'd fall down like a bag full of

Jello! Second, bones create protected spaces in your body. Your heart and

lungs, for example, and other sensitive organs, are protected by you rib

cage. The soft bone marrow where your blood cells are constantly being made

is kept safely inside your bones. Even more importantly, your brain and

spinal cord, which are very soft and easily damaged, are protected by the

very strong skull and vertebrae (backbones). Third, movement. Without bones

to pull against, your muscles would have a tough time getting your arms,

legs or fingers to move - or your jaw to move and chew food when you eat!

Fourth, a few bones have very specialized functions. In your ear, sound

vibrations that make your eardrum vibrate are picked up and transmitted

through the tiny bones known as the hammer, anvil, and stirrup, which in

turn send them into the cochlea, where they get changed into nerve impulses

that your brain can sense.

Finally, and here's the least obvious one, bones act like a "bank" where

your body stores minerals that it needs to carry out its special chemistry.

Unseen except in the microscope, your bones have cells in them that make

bone (called "osteoblasts") and cells that eat bone (called "osteoclasts").

All through your life, there are "deposits" and "withdrawals" made by these

cells. The hard, white mineral stuff in bones is made mainly of the

elements calcium and phosphorus. Both of these are absolutely necessary to

your normal body chemistry for everything from transmitting nerve signals

to your muscles, to building new DNA, to generating the energy you use. So

your body builds bone when you have enough of these things in your diet,

and at the same time, it digests bone to keep the calcium and phosphorus

levels in your bloodstream at level they need to be at for all these

biochemical processes to work. When you're grown up, about 10% of your

skeleton will get torn down and rebuilt every year in this constant

remodeling process.