What are hairs for?
The function of hair on human body has dramatically changed during the evolution, as has its amount. It is considered that in human species as early as three million years ago the evolutionary process of body hair loss had already begun. It is not yet clarified if it happened when people settled in tropical areas, with global warming or with appearance of somewhat larger number of sweat glands. Another theory relies on the change in hormonal status of the species, which would explain the difference in hair volume between males and females.
There are hair follicles (hair roots) all over the body, and they consist of stem cells, blood vessels, connected sebaceous gland and lifting muscles. This is the live part of our hair and it is placed deep in the third layer of the skin, the dermis. The outer hair, the one we see, is the dead part of the hair comprised of keratin of various thickness and amount of pigment.
With the exception of mucous tissues, palms of the hands and soles of the feet, the whole body of the human species is covered in vellus hair – which is thin and bright, or in terminal hair – which is thick and sharp.
What is the function of the hair?
Our ancestors have had terminal hair all over the body, which protected them from the cold. Although we no longer have thick hair that performs thermoregulation, the lifting muscle connected to the root of the hair still warns us every time when we are exposed to cold, by giving us a sense of shivers.
Hairs also increase the sense of touch, so very important in special moments. Also, in countries where malaria is common, the hair function on the uncovered extremities is to warn when a mosquito lands on the skin and that is one of the reasons children are more in danger then adults.
Other then giving us a distinctive look, hair also protects us from UV radiation. In black people, the hair is curly because with density the protection capacity is increased. The function of the eyebrows is to stop the drops of sweat before they slide off the forehead towards the eyes, and the eyelashes protect the eyes from tiny particles from the environment. The hair that grows in all our noses stops the particles of soot and dust from coming into our upper airways. Keeping of the terminal hair in the area of the sex organs has had its function until first forms of underwear appeared and it was there to protect the mucous tissues of the reproductive organs and in the same time it lessened the friction during walking.
Today, in modern age, body hair is considered unwanted, for various valid and invalid reasons and there is a whole set of more or less effective ways of hair removal. They are – shaving, mechanical pulling, hot or cold wax depilation, depil creams, laser epilation, IPL devices, electro epilation. Of all these methods, the only one that permanently removes the hair is epilation by a real medical laser whose beam penetrates 3 to 5 mm deep into the skin, which enables the degradation of hair follicles only, and therefore solves the problems of hair growth forever.
Unfortunately, almost anything we do or try to do with our hair from outside doesn’t influence its quality and features. Hair quality is determined by the follicle itself, the root of the hair and the potential of stem cells placed in it.