Hair
Hair is a protective cover, mainly in mammals. In animals, hair is called fur or wool.
Each hair consists of three layers. The outer layer, cuticle, performs a protective function and is formed by thin cells like scales that overlap each other like a roof tile. When the scales of the cuticle lie neatly overlapping, the hair is silky, soft and shiny. Otherwise, they lose their luster, become brittle and are easily confused.
The gloss of hair depends on their own fatty grease. In the skin are sebaceous glands, they secrete their secret in the hair. As a lubricant, the secret provides excellent protection to the trunk of the hair, helping it retain moisture and maintain its elasticity. In some cases, for example, with excessive hormonal activity, when the sebaceous glands secrete too much secret, the hair becomes fat. If the secret is too small, they become dry.
Color of hair depends on the ratio of the two types of pigment melanin: eumelanin and pheomelanin. The main difference between these species is the shape of their granules. The granular pigment (eumelanin) is brown, it consists of a combination of three colors: blue, red and yellow. Diffuse (pheomelanin) - yellow. All natural hair contains both kinds of pigments. In total there can be three colors: blondes, reds and brunettes, and shades total about 300 kinds. Black hair contains more eumelanin, natural blondes have more pheomelanin.
The number of hair on the head: |
blondes - 150000 td> |
brown - 110000 |
black - 100000 |
red - 90000 |
Number of eyelashes: |
the top - 150-200 |
lower - 50-100 |
The number of body hair is 25000 |
Length of eyelashes: |
the top - 8-12 mm, |
lower - 6-8 mm | tr>
Daytime hair growth: |
on the head - 0,5-0,7 mm, |
beards – 0,6-0,8 mm | tr>
Daytime hair loss: |
on the head - 50-120 |
Lifespan of eyelashes - 150 days |
The strength of the hair is 80 g. |