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Hair — an interesting gift from evolution
Humans are among the least hairy mammals, but hair is an important issue for them. Some want to preserve it at all costs others want to strengthen it, and some want to remove it permanently.
Hair is a product of the epidermis and, like hooves, hoofs, claws or horns, is made of a protein called keratin. In order for it to reach the proper length and thickness, it must be well nourished. Unfortunately, as the epidermis has a protective function, there are no blood vessels in it from which the hair can draw nutrients. Millions of years of evolution, however, have allowed the epidermal diverticulum to reach the dermis, the place where blood vessels pass. This is presumably how the papilla of the hair was formed, which is perfectly in tune with the blood vessels that supply the hair with nutrients. Right next to it, but already on the epidermal side, is the hair matrix. Its main task is the intensive cell divisions of melanin-producing (pigment) melanocytes and keratin-producing keratinocytes.
Like any other protein, keratin is composed of many amino acids, but with a significant predominance of cysteine and methionine. They contain sulfur, which forms disulfide bonds that guarantee keratin’s resistance to breakage and elasticity. Living keratinocytes produce keratin only until they are filled to the brim with it. Then they die off and thus one can…
