5 facts about the human body that will surprise you

1. Bleach turns our skin into soap

If you get a little bleach on your hands, you may feel that after a while they become slippery and as if soapy. And even if you rinse them with water without detergent, this feeling will still not disappear.

The fact is that hypochlorite and sodium hydroxide, which are included in compound household bleach, upon contact with the skin, dissolve its top layer and begin to turn sebum, fats and oils... into soap!

Dissolved exfoliated skin and saponified sodium hydroxide fat and cause a feeling of slippery fingers. So do not neglect gloves while cleaning.

2. The human body grows extra bones

There are 206 bones in the adult human body. But sometimes some lucky ones can grow a couple more - under the kneecaps. These bones are called fabella. They are embedded in the tendon of the calf muscle.

Fabella is not formed at birth, but already at a fairly adult age. About 100 years ago, these small bones formed only 7.64% of the population, but

research 2019 showed that now half of the people already have fabella.

And they say that man has ceased to evolve.

Scientists are not sure why fabella is needed. Maybe they do nothing and even bring additional pain to people with arthritis. But it is also possible that fabellas reduce friction in the tendons under the kneecap, increasing mechanical strength of the muscle.

Perhaps this is a consequence of the fact that people have recently begun to eat better and become larger and heavier, and the knees adapt to this.

3. Actually we have four nostrils

How many nostrils do you think you have? Naturally, two, you will say, and you will be right... but only half. Because people have another pair of nostrils, but we can't see them. These two openings are called choanae and are located in the throat. Through them, the inhaled air enters first into the nasopharynx, and then into the trachea, that is, the windpipe.

Such a device of the body allows you to breathe both through the nose and mouth if necessary.

joans got we inherited from distant ancestors, fish. Initially, those had two pairs of nostrils - one sucked water in, the second threw it out. This was necessary to capture odors in the water using the olfactory epithelium inside the nose.

Then the fish, who decided to move to land, had a need to breathe atmospheric air. And one pair of their external nostrils gradually, over long millions of years of evolution, passed into the throat - in order to send air, not water, to the newly acquired lungs. And she remained with all four-legged animals, including us.

One of the "transitional links" from waterfowl to land animals is discovered in China in 1993, a Devonian kenichthys fish that lived 395 million years ago. Her back nostrils had not yet moved completely into her throat, but stuck out on the palate between her front teeth. This is what happens when you start evolve, but has not yet brought the case to a sane result.

In human embryos at an early stage, the choanae are in the same place as in kenichthys. And if they do not connect, as expected, then the child will cleft palate. This pathology occurs in one in 1700 children.

4. Our heart has a little built-in brain

We already somehow toldthat the human gut has its own nervous system, which has more neurons than the average cat's head. Similar "extra brain" There is and in another vital organ, the heart.

Scientists at Jefferson University in Philadelphia amounted to map these neurons using rats as test subjects. And they found out that in their structure, the nerve cells of the heart are almost identical to those that make up the brain - both in rodents and in humans. This "additional processor" allows you to fine-tune your heart rate.

Researchers considerthat, by feeding signals to this neural network, it will be possible to cure many diseases without the additional intervention of a cardiologist. By the way, it is connected to the main brain by the vagus nerve. And that is why stress, anxiety and neurosis negatively affect, among other things, the heart.

Therefore, if possible, avoid worries and think more about the good.

5. Our nose is capable of erection

There are people whose sneezing is triggered by orgasm, or sexual intercourse, or masturbation, or just exciting thoughts. Both men and women are subject to this phenomenon.

Explained this is because the nasal cavity contains erectile tissue. In the past, it was necessary for our distant ancestors - animals to capture pheromones. Now chemosexual communication is not as developed in humans, but the tissue is still there and it swells during arousal. This leads to sneezing in some sensual natures, which called honeymoon rhinitis.

For the same reason, by the way, Viagra Maybe call nasal congestion, so do not overuse.