Some facts about hair:

- Hair is important to the appearance of men and woman

- It is only part of the body that is renewable without scarring

- Hair has two seperate structures-follicles and the shaft

- Fetus has all follicles formed in 5 months (5.000.000 follicles)

Follicle is a stocking-like structure, it contains several layers. At the base of the follicle is a projection formed like sticking a finger in the bottom of a stocking and pushing it in a small amount. This is called a papilla and it contains capillaries, that feed the cells. The living part of the hair is bottom part of the stocking surrounding the papilla called the bulb. This bottom part is the only part fed by the capillaries. The cells in the bulb divide every 23 to 72 hours.

Follicle is surraunded by two sheats, inner and uoter

The inner sheath follows the hair shaft and ends below the opening of a sebaceous gland, and sometimes an apocrine gland. The outer sheath continues all the way up to the gland. A muscle called an erector pili muscle attaches below the gland to a fibrous layer around the outer sheath. When the muscle contracts, the hair stands up.

- the sebaceous gland is important because it produces sebum which is a natural conditioner

- The hair shaft is made up of dead, hard protein called keratin in three layers. The inner layer is called the medulla and may not be present. The next layer is the cortex and the outer layer is the cuticle. The cortex makes up the majority of the hair shaft. The cuticle is formed by tightly packed scales in an overlapping structure similar to roof shingles.

- Hair grows 4 mm per year

- If hair is similar to a circle, it is straight, if is flattened or elliptical than is curly

- The cross-sectional shape determines the amount od shine the hair will have

- If the hair is kinkier, than is also more dryer