According to a definition, hair is a specialised filament which is exclusive to mammals. There are different types of hair, though. It’s found on the almost entire body so you should learn something more. What is hair made up of?
Contrary to appearances, hair structure is very complex. Every single hair grows out of the hair follicles. There are more or less five million follicles on the whole body; around 150 thousand of them occurring on the scalp. Hair follicles can be found on the almost entire body with an exception of e.g. palms.
Fun fact: Hair follicles appear between the ninth and twenty-second week of the prenatal development. That’s why some babies are born with a good head of hair!
Follicles include cells that are responsible for hair growth, sebaceous glands and arrector pili muscles. To put it simply, each hair consists of the root and the stem which is found on the skin surface. Obviously, you can get stuck on the topic but such a division is enough to get the whole idea.
While discussing hair structure, the hair porosity must be mentioned. What is it? The stem of each hair is made up of the medulla (absent in fine hair), cortex and coat (the external part). The coat is built of a few layers of overlapping, keratin cuticle scales. The gaps between the scales are known as pores hence the porosity.
Fun fact: hair can have three types of porosity – low, medium or high, depending on the size of the gaps in the cuticle layer.
You must know that hair structure influences the hair function. Why do we need hair for? It keeps you warm. Especially hair on the scalp fulfills a heat control and protective function yet it’s slightly limited in humans (in comparison to other mammals). Nevertheless, the condition of your hair reflects your well-being.
Fun fact: Eyebrows and eyelashes are hairs, too. The brows protect the eyes from the sweat whereas the lashes save them from the impurities.
