Of course, it makes no sense to argue about which organ is the most important in the human body. The human body is a very complex mechanism, the parts of which are so precisely fitted to each other that the failure of one of them leads to troubles for the whole organism.
Nevertheless, even with this caveat, the skin appears to be one of the most important organs of the human body. First of all, this is not due to the danger of skin diseases, but to the fact that these diseases are almost always visible to everyone around them. American science fiction writer and, concurrently, popularizer of science Isaac Asimov described acne in one of his books. Azimov called pimples on the face of adolescents one of the most terrible diseases not in terms of mortality or disability, but in terms of the effect on the human psyche. As soon as a guy or a girl, wrote Asimov, think about the existence of the opposite sex, the visible parts of his or her body, first of all, the face, are affected by terrible pimples. Their health risks are small, but the psychological damage caused by acne is enormous.
With no less reverence than adolescents, they treat the condition of a woman's skin. Each new wrinkle becomes a problem, for the solution of which billions of dollars are spent on cosmetics worldwide. And, often, these expenses are pointless - not only cosmetologists cannot turn back the clock. Plastic surgery can help for a while, but in general, skin aging is an irreversible process.
Skin, even not in the best aesthetic condition, is the most important defense of the human body against many threats. It is covered with a mixture of sweat and sebum, and protects the body from overheating, hypothermia and infection. The loss of even a relatively small part of the skin is a serious threat to the entire body. Fortunately, in modern medicine such technologies are used for the emergency restoration of damaged or removed skin areas, which even allow them to preserve their appearance. But, of course, it is better not to go to extremes, but to know what the skin consists of, how it works and how to care for it.
1. It is clear that the bodies of different people have different sizes, but on average, we can assume that the area of human skin is about 1.5 - 2 m2, and its weight excluding subcutaneous fat is 2.7 kg. Depending on the place on the body, the thickness of the skin can vary 10 times - from 0.5 mm on the eyelids to 0.5 cm on the soles of the feet.
2. In a layer of human skin with an area of 7 cm2 there are 6 meters of blood vessels, 90 fatty glands, 65 hairs, 19,000 nerve endings, 625 sweat glands and 19 million cells.
3. Simplifying, they say that the skin consists of two layers: the epidermis and the dermis. Sometimes also subcutaneous fat is mentioned. From the point of view of science, only the epidermis has 5 layers (from bottom to top): basal, prickly, granular, shiny and horny. Cells gradually rise from one layer to another and die off. In general, the process of complete renewal of the epidermis takes about 27 days. In the dermis, the lower layer is called reticular, and the upper is called the papillary.
4. The average number of cells in human skin exceeds 300 million. Considering the rate of renewal of the epidermis, the body produces approximately 2 billion cells per year. If you weigh the skin cells that a person loses throughout his life, you get about 100 kg.
5. Every person has moles and / or birthmarks on their skin. Their different color indicates a different nature. Most often, moles are brown. These are clumps of cells overflowing with pigment. Newborns almost never have moles. On the body of any adult, there are always several dozen moles. Large moles (more than 1 cm in diameter) are dangerous - they can degenerate into tumors. Even mechanical damage can become the cause of rebirth, so it is better to remove large moles on the body in places that are risky from the point of view of damage.
6. Nails and hair are derivatives of the epidermis, its modifications. They consist of living cells at the base and dead cells at the top.
7. Redness of the skin caused by physical exertion or emotional factors is called vasodilation. The opposite phenomenon - the drainage of blood from the skin, causing pallor - is called vasoconstriction.
8. Calluses on the hands and feet of a person and the horns and hooves of animals are phenomena of the same order. All of them are a product of the so-called keratinization of the epidermis. Keratin is a horny substance, and when it is oversaturated, the skin loses its softness and plasticity. It becomes rough and rough, forming growths.
9. In the 19th century, rickets was called an English disease. Avitaminosis in the diet of even wealthy Britons was terrifying (there is even a theory that interdental and hissing sounds so unusual for foreigners in English appeared precisely because of vitamin deficiency and the accompanying scurvy, in which teeth fall out). And because of the smog, the British townspeople lacked sunlight. At the same time, they were looking for ways to combat rickets anywhere, but not in England. Pole Andrzej Snyadecki found that exposure to sunlight helps not only in the prevention, but also in the treatment of rickets. At the beginning of the twentieth century, it was found that sunlight in this respect can be replaced by a quartz lamp. Physiologists intuitively understood that human skin, under the influence of humans, produces a certain substance that prevents the appearance of rickets. American physician and physiologist Alfred Fabian Hess, examining rats with white and black skin, found that black rats developed rickets, even irradiating them with the light of a quartz lamp. Hess went further - he started feeding control groups of white and black rats with either an irradiated quartz lamp or “clean” skin. After receiving "irradiated" skin, black rats ceased to get sick with rickets. So it was revealed that under the influence of ultraviolet radiation, the skin is able to produce vitamin D. It is produced from a substance called "styrene", which means "solid alcohol" in Greek.
10. Independent researchers have found that 82% of labels on skin cosmetics contain outright lies, disguised as inaccurate wording and false references. It would be good to deal only with seemingly harmless statements, like 95% of women choose the night cream "NN". But after all, the stories about the 100% natural origin of the components of the same cream, which makes it absolutely safe, are also frankly false. Lavender and citrus oils, rhubarb leaves, witch hazel, and snake venom are all natural substances, but have been scientifically proven to be harmful. The statement that the cosmetic cream completely protects the owner from external harmful influences is also incorrect. It can become true only if the owner of the cream stops eating, drinking and breathing, and begins to wear tight clothing that completely covers the body.
11. There is a somewhat extravagant hypothesis about human settlement around the planet. It is based on the ability of human skin to produce vitamin D and thus counteract rickets. According to this theory, when migrating from Africa to the north, people with lighter skin had an advantage over dark-skinned brethren. prone to rickets due to a lack of vitamin D. Gradually, dark-skinned people in Northern and Western Europe died out, and light-skinned people became the progenitors of the population of Europe. At first glance, the hypothesis seems rather ridiculous, but two serious arguments speak in its favor. First, people with fair skin and blond hair were the predominant population exclusively in Europe. Second, dark-skinned populations in Europe and North America are at greater risk for rickets than fair-skinned people.
12. The color of human skin is determined by the amount of pigment it contains - melanin. Strictly speaking, melanins are a large group of pigments, and the color of the skin is influenced by the honor of these pigments, united in the group of eumelanins, but usually they operate with the name “melanin”. It absorbs well ultraviolet light, which is generally damaging to the skin and the body as a whole. Sunburn caused by the same ultraviolet light is not at all a symptom of melanin production in the skin. Sunburn is a mild skin inflammation. But initially dark skin of people is evidence of a high concentration of melanin. Melanin also determines the color of a person's hair.
13. The human skin contains carotene pigment. It is widespread and has a yellow color (perhaps its name comes from the English word "carrot" - "carrot"). The predominance of carotene over melanin gives the skin a yellowish tint. This is clearly visible in the skin color of some East Asian peoples. And also, concurrently, the skin of about the same East Asian peoples emits much less sweat and sebum than that of Europeans and Americans. Therefore, for example, even from heavily sweated Koreans, an unpleasant odor is not heard.
14. The skin contains about 2 million sweat glands. With their help, body temperature is regulated. The skin gives off heat to the atmosphere without them, but this process is quite stable. Evaporation of a liquid is a very costly process in terms of energy consumption, so the sweat evaporating from the skin allows you to relatively quickly lower the temperature of the human body. The darker the skin, the more sweat glands it contains, which makes it easier for black people to tolerate heat.
15. The unpleasant smell of sweat is actually the smell of decomposing sebum. It is secreted by the sebaceous glands, which are located in the skin just above the sweat glands. Sweat generally consists of virtually one water with minimal salt added. And the sebum, when excreted from the glands, has no smell - it contains no volatile substances. The smell occurs when the mixture of sweat and sebum begins to break down bacteria.
16. About 1 in 20,000 people are albino. Such people have little or no melanin in their skin and hair. Albino skin and hair are dazzling white, and their eyes are red - instead of pigment, the color is given by translucent blood vessels. Interestingly, albinos are most often found among peoples with very dark skin. The largest number of albinos per capita is in Tanzania - there the concentration of albinos is 1: 1,400. At the same time, Tanzania and neighboring Zimbabwe are considered the most dangerous countries for albinos. In these countries, it is believed that eating albino meat heals disease and brings good luck. Tens of thousands of dollars are paid for body parts of albinos. Therefore, albino babies are immediately taken to special boarding schools - they can be sold or eaten even by their own relatives.
17. Medieval statements that now cause laughter that washing the body is harmful (some kings and queens washed only twice in their lives, etc.), oddly enough, have some basis. Of course, their partial confirmation came much later. It turned out that microorganisms live on the skin that destroy pathogenic bacteria. Assuming the skin is completely sterile, these bacteria can enter the body. But it is impossible to achieve complete sterility of the skin by taking a shower or bath, so you can wash yourself fearlessly.
18. In theory, the bodies of dark-skinned people should absorb much more heat than the bodies of people with white skin. At least, purely physical calculations show that the bodies of representatives of the Negroid race should absorb 37% more heat. This, in theory, in those climatic zones where it should lead to overheating with the corresponding consequences. However, the research, as the scientists write, "did not give unequivocal results." If black bodies were to absorb this amount of heat, they would have to give off huge amounts of sweat. Blacks sweat more than fair-skinned people, but the difference is not critical. Apparently, they have a different sweat secretion system.
19. People with blue skin live on Earth. This is not any special race. The skin can turn blue for several reasons. In the Chilean Andes, back in the 1960s, people were discovered living at an altitude of more than 6,000 meters. Their skin has a blue tint due to the increased content of hemoglobin - hemoglobin not enriched with oxygen has a blue color, and in the highlands, due to the low pressure, there is little oxygen for human breathing. The skin may be blue due to a rare genetic mutation. For a century and a half, the Fugate family lived in the United States, all of whose members had blue skin. The descendants of the French immigrant entered into closely related marriages, but all their children inherited the rare trait of their parents. The most surprising thing is that Fugate's descendants were subjected to deep medical examinations, but no pathology was found. Subsequently, they gradually mixed with people with normal skin, and the genetic anomaly disappeared. Finally, the skin may turn blue from ingestion of colloidal silver. It used to be part of many popular medicines. American Fred Walters, turned blue after consuming colloidal silver, even showed his skin for money in public appearances. True, he died from the consequences of taking colloidal silver.
20. Skin tightness does not depend on the presence of collagen or its amount. Collagen is present in any skin, and its tightness depends on the state of the collagen molecules. In young skin, they are in a twisted state, and then the skin is in an elastic taut state. Collagen molecules unwind with age. as if "stretching" the skin, making it less taut. Therefore, the cosmetic effect of collagen, which is often praised in cosmetics advertising, applies only to the time when the cream applied to the face slightly tightens the skin. Collagen does not penetrate into the skin, and after removing the cream, it returns to its previous state. Elemental petroleum jelly has a similar effect to collagen. The same applies to fashionable resveratrol, but when applied externally, it does not even give a constricting effect.
