Bone Facts

chewan

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What would happen if humans didn't have bones?

You'dbe floppy like a beanbag. Could you stand up? Forget it. Could youwalk? No way. Without bones you'd be just a puddle of skin and guts onthe floor.  Bones have twopurposes. Some, like your backbone, provide the structure which enablesyou to stand erect instead of lying like a puddle on the floor. Otherbones protect the delicate, and sometimes soft, insides of your body.Your skull, a series of fused bones, acts like a hard protective helmetfor your brain. The bones, or vertebrae, of your spinal column surroundyour spinal cord, a complex bundle of nerves. Imagine what could happento your heart and lungs without the protective armor of your rib cage!

[size=130%]How many bones do humans have?
Whenyou were born you had over 300 bones. As you grew, some of these bonesbegan to fuse together. The result? An adult has only 206 bones!


[size=130%]How do my bones move?
Witha lot of help. You need muscles to pull on bones so that you can move.Along with muscles and joints, bones are responsible for you being ableto move. Your muscles are attached to bones. When muscles contract, thebones to which they are attached act as levers and cause various bodyparts to move.   You alsoneed joints which provide flexible connections between these bones.Your body has different kinds of joints. Some, such as those in yourknees, work like door hinges, enabling you to move back and forth.Those in your neck enable bones to pivot so you can turn your head.Still other joints like the shoulder enable you to move your arms 360degrees like a shower head.

[size=130%]Are your bones alive?
Absolutely.Bones are made of a mix of hard stuff that gives them strength and tonsof living cells which help them grow and repair themselves. Like othercells in your body, the bone cells rely on blood to keep them alive.Blood brings them food and oxygen and takes away waste.   Ifbones weren't made of living cells, things like broken toes or armswould never mend. But don't worry, they do. That's because your bonecells are busy growing and multiplying to repair the break! How? Whenyou break your toe, blood clots form to close up the space between thebroken segments. Then your body mobilizes bone cells to deposit more ofthe hard stuff to bridge the break.

[size=130%]What's bone marrow?
Manybones are hollow. Their hollowness makes bones strong and light. It' sin the center of many bones that bone marrow makes new red and whiteblood cells. Red blood cells ensure that oxygen is distributed to allparts of your body and white blood cells ensure you are able to fightgerms and disease. Who would have thought that bones make blood!?!


[size=130%]Do all critters have a backbone?
Nope.In fact, some 97% of critters on earth don' t have a backbone or spine.Remarkably enough, of those that do have a backbone, there are lots ofsimilarities: a skull surrounding a brain, a rib cage surrounding aheart, and a jawbone or mouth opening.

[size=130%]Factoids

• 
  The human hand has 27 bones; your face has 14!

• The longest bone in your body? Your thigh bone, the femur, it' s about 1/4 of your height.

• The smallest is the stirrup bone in the ear which can measure 1/10 of an inch.

• Didyou know that humans and giraffes have the same number of bones intheir necks? Giraffe neck vertebrae are just much, much longer!

• You have over 230 moveable and semi-moveable joints in your body.

source : http://deeply-bonding-artikelsains.blogspot.com/

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