Where do people have the thinnest and thickest skin? How many nerve endings fit in one square inch of human skin? What are touch receptors and where are they most sensitive? When do fingerprints form on the fingers and are there people who do not have them? The answers to these and other questions can be found in the following list of 10 interesting facts about human skin.
Fun facts about human skin
I wonder how much of the information provided here will surprise you. For example, did you know that the skin is the largest organ of our body?
10 interesting facts about human skin
The skin is - contrary to what many readers of "Hustler" think - the largest organ of our body. If we spread it flat, the skin surface of an average adult would be 2 square meters on average. Its weight is 4.1 kilograms.
Sweat secreted on the surface of 1 square inch (about 6.5 square centimeters) of human skin would be enough to feed nearly 65,000 bacteria.
In humans, the thinnest skin is on the eyelids (0.5 millimeters), while the thickest is on the upper back (0.5 centimeters).
Scientists estimate that white skin appeared approximately 20-50 thousand years ago, when people with dark skin migrated to areas less exposed to the sun than equatorial Africa.
Skin moles appear in childhood and begin to disappear in middle age. Their number and location are very individual features. A typical Caucasian person has around 30 moles, but some may have up to 400. It is not known why this is so or what role moles play. However, it was discovered that people whose skin has many of them are more likely to develop skin cancer, but their skin ages more slowly.
One square inch of skin contains 650 sweat glands, 20 blood vessels, 60,000 melanocytes (cells that produce the pigment - melanin), and over a thousand nerve endings. The number of melanocytes in the epidermis of people of different races is similar, they differ in the intensity of melanin synthesis.
Tests of indoor dust in homes and offices have shown that it is composed mainly (70-90 percent) of exfoliated skin cells. Dead skin cells make up nearly a billion tons of dust in the Earth's atmosphere. Each of us loses 50,000 skin cells per minute.
Meissner bodies - tactile receptors found in the papillae of the dermis and the skin of the fingers, on the lips and tongue, in the area of the penis and clitoris - react to the pressure of 20 milligrams - it is approximately the weight of a fly.
The arrangement of fingerprints is created during fetal life (between 100 and 120 days) and is different even in identical twins. However, there are people without fingerprints. Two genetic diseases - dermatopathy pigmentosa and Naegele syndrome - result in the lack of characteristic furrows and grooves on the pads.
To get a permanent wrinkle on the forehead, we must wrinkle it 200,000 times. Around the age of 40, gravitational wrinkles appear on our face, for example, the nasolabial fold or the so-called line of sadness running from the corners of the mouth down. Facial sagging in old age is also an effect of the continuous, slow growth of the skull bones. As people age, their foreheads move forward while their cheekbones recede. When bone fragments change their position, the muscles and skin located on them also move. Soft tissues lose their support and begin to sag.
Aging of human skin
As the years go by, the activity of the sweat and sebaceous glands in the skin decreases, the skin's ability to retain water decreases, so it becomes dehydrated more easily. Melanocytes also change, and as a result, the skin loses its even color and becomes more transparent. The production of new cells decreases. The skin ages more slowly when we take care of its proper lubrication and hydration.
The largest and fastest changes occur in our skin under the influence of the sun. It is professionally called light degeneration-elastosis. This sun turns elastin and collagen into a shapeless mass of twisted fibers from which wrinkles form.
With age, the skin becomes thinner, and the structural connection between its layers: dermis and epidermis weaken, which is the result of the deterioration of the elastin and collagen fibers responsible for the elasticity of our outer shell.
The author of the article is Polish journalist, Olga Wozniak, and it was published in "Przekroj" magazine
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