Skin is an outer sheath. Thanks to skin of people has acceptable appearance and can look beautifully. But skin is given not only for appearance. The vital function of skin – protective. For full realization of this function skin provides to an organism protection at several levels.
Instruction
1. Mitigation and elimination of the harm done from the outside. Skin constantly interacts with the world around, and undertakes the first blow from the outside. Internals, muscles and fabrics are under protection of skin. The integument protects an organism from infections.
2. Protection against pernicious ultra-violet radiation. In cages of the top thin layer of skin – epidermis – there is a pigment melanin. Melanin does not pass harmful sunshine deep into of skin – in a term.
3. Support of constant body temperature. In a term – an inside thick layer of skin – there are sebaceous glands which excrete a fat secret. A fat secret softens skin and hair and does them waterproof. The water tightness allows skin to maintain constant internal body temperature at the level of about 37 wasps.
4. Ensuring sweating. Sweat glands also promote regulation of body temperature. The drops of sweat allocated by them evaporate and cool a body during a heat.
5. Body indumentum. Hair follicles are in a skin term too. The core of a hair consists of the died-off cages filled with dense protein a keratin. Cages on the basis of a follicle share and push out a hair outside. Hair promote protection of an organism against temperature fluctuations and recognition of touches. The hair color depends on the level of content of melanin in them.
6. Recognition of external irritants – touches, pressure, pains, heat and cold. The sensitive nervous terminations are located in a term. They instantly transfer information on the environment to a brain, and provide vital feeling – touch.
7. Function of accustoming to irritants. For example, after a while after putting on of clothes, skin gets used to it and ceases to distinguish it as an irritant. Function of accustoming allows the person to feel comfort.