Human hair exists everywhere on the body, apart from on the soles of the feet and palms of the hands. It is mostly so fine that it cannot be seen. The reason we have hair on our bodies is that when it is cold, the muscles around the hair follicles contract and the hair stands up on end, to trap more warmth on to the skin, hence the appearance of ‘goose bumps’.
Your hair begins its journey of growth from a root in the bottom of the hair follicle. This root consists of cells and keratin, a protein which is essential for healthy hair growth. Blood from the blood vessels in the scalp nourish the root, which creates more cells and encourages the hair to grow. As the hair is pushed up through the skin as it grows, it passes an oil gland, along the way.
As new, healthy hair cells are produced by the follicles, the old cells are forced out through the surface of the skin. Therefore, the hair that you can see growing on your head, for example, is made of a string of dead keratin cells.
