Hair
Hair protects your head and eyes from the sun. On other parts of your body, it helps you feel things brushing against your skin. And it helps to keep you warm. Most of a hair is made of dead cells.

Can hair really stand on end?
If you are cold or frightened, your hair may feel as if it is standing on end. A tiny muscle pulls on the root of each hair, levering it int a more upright position. As each hair moves, it pushed against the skin, making a 'goosebump'. Long ago humans had lots of body hair, and warm air would have been trapped in the little pits formed by goosebumps.

Tag :hair

SKIN, HAIR AND NAILS

Skin grows in step with the rest of your body, and although it constantly wears away, it is also replacing itself all the time. Like hair and nails, skin helps to protect your body from the out side world. It can do this because its surface is made of dead cells. These are very tough, and they from a barrier that shields the living cells underneath. Like the surface of skin, most of each hair is also made of dead cells.

Under the surface
Each part of your body has a different type of skin. For example, the skin on the back of your arm is covered with lots of hairs, although they may be too small for you to see. The skin on the palms of your hands and the inside of your fingers has no hair at all, but it does have lots of tiny ridges and invisible openings called sweat glands.

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Tag :hair
Tag :nails