- Is it true that we see objects differently than animals?
Animals of different species in the process of evolution
For the same reason, in birds, many of whichhunt on the fly, vision is much sharper than ours. They simply need “optical sights”, because this is the only way to notice a small animal in the grass from a great height, moving very quickly. Some insects even see in the ultraviolet range - this is necessary in order to better notice flowers with nutritious nectar. And the mantis shrimp has the most “superheroic” vision: it perceives not only ultraviolet, but also infrared (thermal) radiation. This predator has as many as 12 types of receptors, which is 3-4 times more than in birds and mammals. He quickly rotates his eyes in different directions independently of each other, getting, in fact, two 360-degree pictures at once. All this data is processed by a special structure, which evolution has awarded the mantis shrimp for lightning attacks on prey.
According to one theory, people lost visual acuity inprocess of evolution. Veronica Seider from Germany can distinguish faces at a distance of 1.5 km and a huge number of shades, which may be the accidentally preserved legacy of distant ancestors whose survival depended on successful hunting. By the way, recent studies have shown that caffeine affects the skill of tracking moving objects, and cocoa affects the acuity of human vision in the dark (but the discovered phenomenon requires further study). Interesting data has been obtained about the effect of dark red light in the morning: three minutes of exposure can improve cone function in older people to the level of young people for a week. If further research confirms this, there may be a new method that will allow you to maintain good vision for many years.
- Why do some people get water in their nose and out through their ears? And why is it customary to say "ear-throat-nose"?
Our nasal passages open into the nasopharynx(in a simple way - in the throat). On the back wall of the nasopharynx there are two small openings - they end with the Eustachian tube. The other end of this tube opens into the middle ear - the place where special auditory ossicles are located. From this section, water cannot enter the ear canal and "leak out" because the eardrum interferes with it. Another thing is if there are holes in it, this is an anomaly, but it happens, and a person may not even be aware of it.
By the way, in medicine the internal cavities of the nasopharynx,The larynx, middle ear, and sinuses of the facial bones constitute a single system. Often, inflammation that occurs in one place spreads to the entire “space.” Therefore, treatment is carried out by one specialist - an otorhinolaryngologist, or ENT doctor for short.
ear structure
- Why do we need two circulatory systems: venous and arterial?
In fact, there is only one circulatory system.It consists of vessels: veins, which bring blood to the heart, and arteries, which carry blood away from the heart. Arteries and veins are connected by capillaries. Together they are combined into two circles of blood circulation: small and large. Our lungs are penetrated by small capillaries; they absorb oxygen. And in the capillaries of the systemic circle, O2 passes from the blood into the cells.
Oxygen is needed by the cells of the body toproduce energy for life. By the way, despite the fact that people have been studying anatomy since the birth of civilization and the technological age has brought many discoveries, the human body is still an inexhaustible field for research - just like elementary particles or the structure of the Universe. For example, a group of scientists recently discovered that the hearts of goats, whose structure is very similar to humans, have a natural backup pacemaker. This work can greatly change our understanding of the anatomy of the organ.
- Is it true that humans exist in symbiosis with a million bacteria?
It really is.It is estimated that there are three times more bacteria in our body than our own cells - that is, about 100 trillion. Symbiosis is when organisms benefit each other. People give food to bacteria in the form of undigested food leftovers in the intestines or in the form of dead cells on the skin. And the microscopic "partners" of a person - or microflora - help digest coarse fiber and provide the body with some vitamins.
Scientists are actively studying microflora and tryingfind out its effect on immunity and the development of certain diseases. Thus, a real sensation was the discovery that the transplantation of microbes from young mice to old ones led to an improvement in the general condition and specifically in memory, the ability to navigate in space and cognitive functions. In addition, the symbionts may hold the key to unlocking the secret of long-livers. Scientists have discovered that the microflora of centenarian people has its own regular characteristics.
- Can a human brain be transplanted into an android?
The brain is closely connected with all other organs inour body, which means that it will die during extraction. However, technology is evolving rapidly and sometimes unpredictably. There are a lot of brain experiments being done today to develop human mental abilities and raise medicine to a new level. For example, Japanese scientists were able to "breathe life" into the brain cells of a dead pig, which is of great importance in the treatment of stroke and traumatic brain injury, and also maintained the autonomous existence of living mouse brain tissue for several weeks.
Russian scientists are also not lagging behind:They are developing a brain implant that, according to the hypothesis, can restore partial vision to blind people even if they have no eyes at all. Theoretically, with its help they will be able to distinguish the contours of objects. The idea is that the device will receive information not from the visual organs, but from external video cameras and a microcomputer. So far, tests have only been carried out on mice.
So a brain transplant is far from the mostan important and interesting task facing cyber and biotechnologists. A person does not need an android body to get a second life. It is much more urgent to create a neural interface to control all electronic devices wirelessly. This will greatly help those who suffer from serious illnesses such as complete or partial paralysis. By the way, a group of scientists has already managed to connect the human brain to a computer with Windows 10.
- Why do some smells seem pleasant to us, while others do not?
The sensation of "nuisance" smell helps to avoidus different dangers. Probably, in the process of evolution, it so happened that only those organisms survived that distinguished unpleasant "aromas", avoided them and, thus, did not die. For example, we are disgusted by the smell of spoiled foods (first of all, protein - meat or eggs). Those human ancestors who in the distant past did not feel this and ate rotten food, for obvious reasons, did not leave offspring.
But the feeling of "pleasant" smell, probablyevolved due to the fact that our ancient ancestors ate fruits. It will sound a little strange, but it is beneficial for the fruits to be eaten, so there was a joint evolution: the more pleasant the smell, the more likely they are to be found by an animal that, in the process of digestion, spreads the seeds over a large area.
The human nose is a unique instrument thatanalyzes the state of the environment, and not just to choose safe food. For example, there is interesting evidence that the smell of women's tears reduces the production of the “male” hormone testosterone in men by 30%. This probably also has an evolutionary meaning (tears are a signal that it’s time to reduce the level of aggression).
- Why is the spinal cord called that? Does he think and make decisions?
In ancient times, people called the word “brain” anysoft substance in our body. They used this word to denote the contents of the hard skull, vertebrae, and bones. Our ancestors did not immediately guess the purpose of the brain.
With regard to the functions of the spinal cord, init is basically a conductor between the brain and other parts of the body. But he can "make" some decisions himself. For example, when we pull our hand away from something hot, the corresponding command is given to us by the spinal cord (because this must be done quickly and there is no time to consult with the main command center - the brain).
The structure of the spinal cord
- Why does my head continue to spin after the carousel has already stopped?
Inside the ear (deep in the skull) there is a special organ -inner ear. Its structure includes semicircular canals filled with fluid that moves when a person turns his head. After the carousel stops, this liquid overflows by inertia, so it seems to people that the movement in a circle has not stopped.
It is part of the vestibular system, whichallows you to coordinate eye movements, posture and balance. By the way, the carousel is not the only thing that can be disorienting. For example, astronauts have a hard time in weightlessness - their vestibular apparatus "fails" without gravity. Those who spend a lot of time in orbit even form new neural connections in the brain, as they have to focus only on sight.
- Is it true that at the end of the day we are lower than in the morning?
Truth. In a vertical position, under the influence of gravity, the intervertebral discs become thinner, and “straighten out” overnight.
Height difference due to changes in the spine
- Which bacteria is more: beneficial or dangerous?
There are many more “good” useful things on Earthbacteria than are dangerous to people. In addition to human microflora, there are cyanobacteria, which, like plants, produce oxygen. Iron bacteria form deposits of metal that is so necessary for industry. In addition, man has learned to use microorganisms to produce medicines. Bacteria “transplant” the gene of some protein, which starts the chain of its production. For example, all the insulin used by people with diabetes is made this way today. Bacteria are also actively used in food production, in particular fermented and fermented milk products.
It is worth mentioning the global mission of bacteria onEarth. When any organism dies, its constituent particles must be returned to the circulation of substances. This task is performed by bacteria together with fungi. If all bacteria disappear, the circulation of substances will stop and all living things will die.
Today scientists are trying to figure out howbacteria outside the planet, because humanity is actively exploring outer space. It has been discovered that "bad" bacteria like salmonella become more infectious in lower gravity. And Pseudomonas aeruginosa grows additional “armor”, which conventional means are no longer suitable for combating. Let's hope that “good” bacteria will acquire superpowers in space to protect humans.
The human body is very complexa system that should be learned from childhood. 95% of the respondents of the Uchi.ru survey conducted among parents of preschoolers and primary school students agree with this. Six out of ten would like to see schoolchildren given more knowledge in the field of anatomy and a healthy lifestyle during the lessons of the world around them. Most parents actively discuss these issues with their children. Adults draw information mainly from textbooks and the Internet.
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