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The skin is an important part of the immune system of humans and most living organisms. It is a barrier against all kinds of external influences. This is not only about bacteria and viruses, but also about ultraviolet radiation and mechanical action.
The skin provides a constant temperature of the internal environment, which allows our body and immune system to function well.
In addition, many people know that the skin is constantly updated. A person loses 30000 to 40000 dead skin cells every minute. Under these keratinized skin cells, new ones appear. This fact leads so many of us to regularly exfoliate, which removes the top layer of dead cells and “releases” new, fresh skin. In addition to all those mentioned, the skin has many more features.
We present you 10 interesting facts about the skin of living organisms: amazing discoveries about the human body.
10 The largest organ in the human body
Do you know that skin is the largest organ in the human body? In an adult, the surface of the skin is approximately 1,5 to 2 square meters. The skin and underlying connective tissue weigh about 18 kilograms.
The skin is 1 to 3 millimeters thick and consists of several layers. Each layer has a specific function. The top layer is the epidermis. The underside of the epidermis is made up of living cells and the top of dead cells: the stratum corneum.
New cells are always produced in the epidermis, and this is where the alternation of nutrients and waste occurs, as well as the production of pigment.
The dermis is under the epidermis. It contains fibroblasts, collagen fibers and elastin fibers. This is necessary to bring elasticity to the skin. Below the dermis is the subcutaneous tissue. This layer mainly consists of adipose tissue, which protects the body and retains heat.
One square inch of skin contains 650 sweat glands, 20 blood vessels, 60000 melanocytes (melanin-producing cells), and over 1000 nerve endings. The number of melanocytes in the epidermis of people of different races is similar; they differ in the intensity of melanin synthesis.
9. Sweat is a great habitat for bacteria
Sweat produced from 1 square inch (about 6,5 square centimeters) of human skin would be enough to feed nearly 65 bacteria.. By the way, in humans, the thinnest skin is on the eyelids (0,5 millimeters), and the thickest is on the upper back (0,5 centimeters).
8. The advent of white people
According to scientists, people with white skin appeared about 20-50 thousand years agowhen dark-skinned people migrated to areas less exposed to the sun than in equatorial Africa.
7. Birthmarks
Skin birthmarks appear in childhood and begin to disappear in adulthood. Their number and location are very individual. The typical white person has about 30 birthmarks, but some may have up to 400. It is not known why they appear on the skin and what role they play in a person’s health.
Scientists have discovered a curious pattern: people with a large number of birthmarks are more likely to get skin cancer, while their skin ages more slowly.
6. Skin renewal
The epidermis is quite thin, approximately like paper. It is scratched, squeezed and stretched thousands of times a day, but it does not wear out. This happens because the skin is constantly supplied with new living structural elements – keratinocytes. These cells are composed of keratin protein, which is very powerful: it is also involved in the formation of hair and nails, and in the animal world – claws and horns. By the way, the word car- comes from the ancient Greek language meaning “horn”.
Keratinocytes are formed from stem cells in the lowest layer of the epidermis and slowly move in layers throughout their monthly cycle until they form a strong barrier that protects the human body from various negative external influences. When this layer of cells is subjected to excessive stress, the well-known calluses are formed.
Interesting fact: analysis of indoor dust in homes and offices showed that it consists mainly (70-90 percent) of dead skin cells. Dead skin cells make up almost a billion tons of dust in the Earth’s atmosphere. Each of us loses 50000 skin cells per minute.
5. Human skin sensitivity
The skin is an important sensory organ, with which we feel, among other things, cold or heat, pressure and pain. The skin also gives important signals, such as redness, pallor, cyanosis (cyanosis), as well as the appearance of goosebumps.
Meissner bodies are tactile receptors found in the dermis and papillae of the feet, on the lips and tongue, around the penis and clitoris. These formations respond to a pressure of 20 milligrams – about the weight of a fly.
4. Fingerprints
A specific pattern on the pillows of the fingers is formed during the intrauterine development of the fetus (from 100 to 120 days) and differs even in identical twins. However, there are people without fingerprints. Two genetic diseases, pigmentary dermatopathy and Naegel syndrome, result in the absence of characteristic furrows on the balls of the fingers.
3. How does facial skin aging
To form a permanent forehead wrinkle, we need to stress it 200 times. Around the age of 000, gravitational wrinkles appear on the face, such as the nasolabial furrow or the so-called line of sadness, going down from the corners of the mouth.
Sagging facial skin in old age is also a consequence of the constant slow growth of the skull bone.. As people get older, their forehead protrudes and their cheekbones recede. When the skeletal fragments change their position, the muscles and the skin located on them also move. Soft tissues lose support and begin to sag.
2. Importance of Vitamin D
The body needs vitamin D to absorb calcium from food.. Therefore, it plays an important role in the growth and maintenance of the health of our teeth and bones. Vitamin D is produced by skin cells in response to sunlight. Therefore, people who live in areas with little sunshine should take a vitamin D supplement, as the skin itself does not produce enough vitamin D.
Interestingly, exposure to sunlight causes the formation of beta-endorphin in the skin, which enters the bloodstream and stimulates the appearance of an opioid-like effect, similar to drug intoxication. Scientists estimate that approximately 20 percent of avid beachgoers show signs of sun addiction, which are similar to symptoms of addiction to the use of psychoactive drugs.
1. skin glands
There are many sebaceous glands on the entire surface of the skin – an average of almost 100 per square centimeter, with the exception of the heel, hand and soles of the feet. Sebum is made up of a mixture of fats that keep the skin supple and protect it from drying out.
Like the sebaceous glands, sweat glands are found throughout the body. Sweat glands pass through all layers of the skin and end with the epidermis. There are two types of sweat glands: Eccrine sweat glands play an important role in regulating body temperature. When the body is overheated, these glands release sweat, which allows the body to cool down.
Apracrine sweat glands are found mainly in the armpits, around the nipples, and around the vulva. They work under the influence of adrenaline and secrete a small amount of sweat throughout the day.