Some people have grey hair at the age 20, but to others it grow at age 40. Genetic factor decide wether someone is slow or fast to have a grey hair. Beside that stress and illness also can cause hair faster to grey.
There are two kinds of pigmen (melanin). That is eumelanin that makes our hair black or brown, depend on the amount of pigmen that live on the hair cell and pheomelanin that makes our hair yellow or red. Black hair is the result of large production of uemelanin. Black people usually have black hair. Pheomelanin makes hair goldy. The different of hair colour to every people is decide by the level of eumelanin and pheomelanin inside the hair roots. So everyone have different hair colour. Every head has lots of hair look because every hair roots doesn’t produce the same amount of melanin.
Melanin is produce by melonocyles, if this substance no longer can produce melanin the hair will become grey or white. Black hair is form by 99% eumelanin and 1% pheomelanin. Brown hair is form by 95% eumelanin and 5% pheomelanin. Red Hair is form by 67% eumelanin and 33% pheomelanin.
Eventhough black hair have only 1% pheomelanin the hair is cover by large amount of eumelanin so it can’t be seen. Hair colour effect the amount of hair. Blond hair can grow 120.000 pieces, and dark hair generally grow 110.000 pieces. The colour of hair can change naturally because of the change of melanin level, medicine, or kemotherapy. Healthy hair has a smooth surface so they reflect light better and look more shiny.In the opposite unhealthy hair have rough surface and look dull.
This condition cause by the water quality that is bad, to much shampoo that contain detergen , brushing the hair roughly, or didn’t wash the hair with a good hair styling product.
Human hair can be divide into 2 types : vellus is a very smooth hair , almost unseen, and can only be seen by using microscope. Terminal is the rougher type of hair, long, and easily seen.
Hair types is wavy, straight, curly and afro (small curl and look like a mess ) curly hair is blossoming and look thick. Straight hair usually stick to the skin head. There is hair that look thick and thin. Curly hair look thicker than straight hair.
