July 25, 2009
A Small Introduction to Hair
Hair is non-living thing made of protein filament. Hair grows within the dermis and goes throw epidermis. Hairs are found on body on human. Hairs also grow on other mammals. We call them fur if they are soft or wool if they are curly. It is also used as specification for different mammals. Even non mammals have outgrowths but these are not called hairs. This is one of the major differences between mammal and non mammals. Trees also have so called “hairs” but those are actually roots of that tree. Mammals have hairs, sometimes they are visible and sometimes not, like hairs on body of mouse, they are hardly visible. At some stage of life mammals start losing their hairs like at higher age human may loss their hair due to hail fall. Keratin is the main element in human hairs.
Hairs have some characteristics. We can divide them on basis of these characteristics. Many hair treatments are done according to these characteristic. Some characteristics are –
Balding and grey –
As human grow old their hair color start becoming gray. This happens because of production of hydrogen peroxide and reduction in production of melanin which is responsible for black color of hairs. This is the main characteristic of aging of human hair. Grey hairs start developing at age nearly 75, but in some cases it can start early stages because of pollution or less notorious diet. In actual, hair color is not of grey color. They are mixture of white and black. So they look grey. People who have red color hair, their hair color never changes to grey color.
Distribution rate –
Normal human hairs grow 0.4 mm daily. But in some case their growth is slow because of emotional stress or heredity problems. Human hairs don’t grow after death.
1. Hair texture can be of different types such as wiry, medium, fine, and coarse. Hairs can also be straight, curly, wavy or kinky. 2. Hair texture can be affected by hair conditioners, crimpers, curlers and hairdresser. Our hair texture is determined by follicle. Hair texture also determines their dryness. Curly hairs remain dry than straight hairs.
Human hair size diameter varies from 17 to 181 µm. Their density also varies person to person depending on climate, diseases, heredity and other conditions.
Several diseases may result in hair fall. This hair fall can be temporary or permanent depending on diseases. Like in traumas hair fall is temporary and in diseases like cancer, hyperthyroidism or hypothyroidism etc. hair fall can be permanent.