hair

introduction

An essential difference between humans and other mammals is the extent and density of their hairs (hair), even if this can vary greatly from person to person.
In the course of human development, hair had lost many of its original functions, such as temperature compensation and protection.

However, it has retained one function. Hair, especially the scalp hair, is an important part of the external appearance and thus the effect on the environment. But as much admiration the hair on the head gets, it seems so annoying in other regions, e.g. on the legs. A certain ideal of beauty and the increased need for hygiene induce many to do without the little remaining body hair (hair).

Figure hair

Hair - build-up

1. Hair shaft - Stipes pili
2. Epidermis - epidermis
3. Hair root
4. Sebum -
   Glandula sebacea
5. Root sheath -
   Vagina radicularis epithelialis
6. Scent gland -
   Glandula sudorifera apocrina
7. Hair papilla -
   Papilla dermalis pili
8. Vascular network of the hair papilla -
   Rete capillare papillae pili
9. Growth zone - matrix
10. Hair bulb
11. Sweat gland -
    Glandula sudorifera merocrina
12. Hair follicle muscle -
    Arrector pili muscle
13. Hair pulp - Medulla
14. Hair bark - Cortex
15. Cuticle of hair -
    Cuticle
16. Glass skin - Membrana vitrea
17. Hair follicle - Vagina dermalis radicularis

You can find an overview of all Dr-Gumpert images at: medical illustrations

history

Of the Desire for a hairless body can be extended into the Antiquity track back. So many people in all cultures have always served themselves differently Ways of depilationto find out their unwanted body hair to get rid of. Usually this is not subject to any medical necessity. However, a particularly pronounced hair (hair) can in certain cases cause psychological damage to those affected. Since we are not dependent on the thermal protection of a fur due to our culture, this is Depilation can also be regarded as unproblematic, even if it goes so far that it makes hair growth permanently impossible (hair).

Hair shapes

Although you can hardly see it in most places, humans are almost completely covered in hair (hair). The main exceptions are Palms and soles. These are of the so-called Inguinal skin covered. If you look closely and compare the back of the hand with the palm, the difference is noticeable. The hairy skin on the back of the hand and the rest of the body is called Field skin. A distinction is also made between different types of hair in humans, which become detached and redistributed in the course of life. baby, especially Premature babies, are of a fluffy Lanugo hair covered, which quickly disappears. Children before puberty wear the main hair exclusively on the head, the rest of the body is from soft wool hair covered. Head hair is three times as thick as wool hair and, unlike the latter, is pigmented, which means it contains that Pigment melanincoloring it dark. Dark hair contains a lot of melanin, light hair contains little. Woolly hair, on the other hand, does not contain melanin and is therefore so light that it appears almost invisible. In addition, its growth phases are significantly shorter, so that it never reaches the length of head hair, which can grow unhindered for several years. In the puberty The woolen hair must give way to the main hair in places such as armpits, genital areas, legs and in men on the face (hair).

Hair structure

At this point, many young women in particular begin to think about how to get rid of unwanted hair quickly (hair) In order to understand the mechanisms of this depilation, one should first briefly look at the structure of the hair. The hair itself can be in Hair shaft, the part that protrudes from the skin and the Hair root subdivide within the skin.

The hair root is of the so-called Hair root sheath which influences their growth. The hair root arises from the Hair bulb, sprout into the blood vessels, which supply the hair with all the important nutrients and building materials for healthy growth. Also are here Melanocytes.
These are cells that produce the color pigment melanin, which is responsible for the color of our hair and our skin. This gives the visible hair its individual color. At the exit point of the hair, the Hair follicle visible, which surrounds the hair shaft and further down the hair root. The secretions of glands flow into it. These are mainly sebum and, in some parts of the body, also individual fragrances. The real ones Sweat glands are not closely associated with hair, which explains why the hairless soles of the feet and palms of the hands are no less likely to sweat than the hairy armpits. Hair is made up of cells derived from skin cells. These have lost a lot of water, but long strands of certain proteins, the keratins, have been concentrated inside them. These give the hair stability. Certain chemical bonds, so-called disulfide bridges, give hair its characteristic smooth or wavy shape (hair).

Hair growth

The Hair growth runs in cycles. The first phase is the real one Growth phase. First, a new hair root emerges from the onion, which spreads further upwards and finally becomes visible as a hair shaft. This phase depends on the body region and lasts the longest with hair on the head, at several years. In the second phase, of the Transition phase hair growth is interrupted by the fact that the hair follicle narrows. The hair becomes detached from the onion that supplies it and continues to migrate to the surface. It closes the third phase in which both the onion and the follicle regenerate (hair).