| Most of the cells have a similar structure. There is a boundary wall along the surface of each cell, or cell membrane containing a jelly-like substance - cytoplasm... Inside it is cell nucleus containing genetic material (chromosomes), nucleolus where ribosomes and structures are formed that govern cell growth and division. The kernel controls protein synthesis... The cytoplasm of the cell, although it contains from 70 to 80 percent of water, plays a far from passive role. Various chemical reactions take place between substances dissolved in water; in addition, the cytoplasm contains many tiny structures called organelles, due to which the functions of the cell are realized, including the consumption and production of energy. TO the flyworm also has a certain structure: it is porous and somewhat resembles a sandwich of protein and fat, where fat is, as it were, a filling. In the process of passing various substances through the cell, some of them dissolve in fat, while others leave the cell through a porous, semi-permeable membrane. |
On the cell wall are receptors that allow cells to "recognize" each other, and special channels. Cell receptors also respond to substances produced in the body and to drugs taken by humans, and channels selectively allow these substances and drugs to enter or exit the cell. The reactions triggered by the interaction of substances with receptors control the functions of cells.
Some cells have hairy processes on their membranes, called cilia... In the nose, for example, dust particles are captured by the eyelashes. These cilia can move in waves in one direction, directing any substance.
Cytoplasm of all cells contains microscopic, sausage-like organs called mitochondria which convert oxygen and nutrients into the energy needed for all cell actions.
These "energy houses" work with enzymes- complex proteins that accelerate chemical reactions in cells and are the most numerous elements in muscle cells.
Lysosomes- another type of microscopic organs in the cytoplasm - are tiny sacs filled with enzymes that enable the cell to process nutrients. Most of the lysosomes are in liver cells. Lysosomes also contain enzymes that can destroy large particles that enter the cell. For example, these enzymes destroy bacteria captured by white blood cells.
The substances produced by the cell that are necessary for other parts of the body, such as hormones, for example, are first accumulated and then stored in other tiny organs called Golgi apparatus(intracellular mesh apparatus).
Many cells have a whole system of small tubes, which are considered as a kind of internal "skeleton" of the cell, but all cells contain a system of channels - endoplasmic reticularis. Endoplasmic reticulum is a structure that provides the synthesis of various substances inside the cell.
Along the entire mesh formation are the smallest spherical structures called ribosomes... In ribosomes, proteins are synthesized, which either remain in the cell or are "packed" in the Golgi apparatus (lamellar complex) and are released from it.
Proteins are required for the repair of structures and (in the form of enzymes) for chemical processes in the cell and the production of complex molecules such as hormones.
Centrioli are necessary for cell division.
Our body is magnificent and ingenious. What we only need is not to interfere with his work. And of course, do not feed him any poisonous muck.
Having given up poisons and starting to eat healthy food, after a while we will get a completely healthy body, unless, of course, we have not had any very serious diseases before. But my favorite scientists say that even serious illnesses can be significantly alleviated and cured over time by switching to proper nutrition.
So that's what I'm all about.
All cells of our body are constantly renewed, and we have, with some periodicity (each organ has its own period), completely new organs.
Leather: the outermost layer of the skin that is in contact with the environment is renewed the fastest. Epidermal cells are renewed every 2-3 weeks. The deeper layers are a little slower, but on average, a complete skin renewal cycle occurs in 60-80 days. By the way, interesting information: the body produces about two billion new skin cells per year.
But then the question arises, why does the skin of a one-year-old child and a sixty-year-old person look completely different. There is a lot that is not studied in our body, but so far it is believed that the skin is aging due to the deterioration (over the years) in the production and renewal of collagen, with which this is still under study.
At the moment, it has only been established that factors such as improper and poor (lack of fats and lack of proteins) nutrition, as well as too aggressive environmental influences, are very significant.
They impair collagen production and quality. An excess of ultraviolet radiation also negatively affects skin regeneration. But, 20-30 minutes in the sun is considered a therapeutic dose that has a beneficial effect on many processes in the body, including skin renewal.
The cells of the epithelium covering the stomach and intestines come into contact with the most aggressive environment (gastric juices and enzymes that process food) and become thinner, food constantly passing through them. They are updated every 3-5 days!
The structure of the mucous membrane of the tongue is very complex, and we will not go into details. The rate of renewal of various cells that make up the mucous membrane of the tongue (receptors) is different. Simplified we can say that the cycle of renewal of these cells is 10-14 days.
Blood- the liquid on which our whole life depends. About half a trillion different blood cells die in the body of the average person every day. They must die in time for new ones to be born. In the body of a healthy person, the number of dead cells is equal to the number of newborns. Complete blood renewal occurs within 120-150 days.
Bronchi and lungs they also come into contact with an aggressive environment, therefore they renew their cells relatively quickly. The outer cells of the lungs, which are the first layer of defense against aggressors, are renewed in 2-3 weeks. The rest of the cells, depending on their functions, are updated at different rates. But in general, the body needs a little less than a year to completely renew the lung tissues.
Alveoli of the bronchi updated every 11-12 months.
Hair grow on average by 1-2 cm per month. That is, after some time we have completely new hair, depending on the length.
The life cycle of eyelashes and eyebrows is 3-6 months.
Nails grow on the fingers at a rate of 3-4 mm per month, the cycle of complete renewal is 6 months. On the toes, nails grow at a rate of 1-2 mm per month.
Liver, truly the most magical organ in our body. Not only does it cleanse us all our life of all that garbage that we put into our body, but it is also a champion of regeneration. It has been established that even with the loss of 75% of its cells (in case of surgery), the liver is able to recover completely, and after 2-4 months we have its full volume.
Moreover, at the age of up to 30-40 years, it regenerates volume even with interest - by 113%. With age, liver recovery occurs only 90-95%.
Complete renewal of liver cells occurs in 150-180 days. It has also been established that if one completely abandons poisonous products (chemicals, medicines, fried foods, sugar and alcohol), the liver independently and completely (!) Is cleared of harmful effects in 6-8 weeks.
Our health depends a lot on liver health. But even such a hardy organ as the liver, we (by trying) can kill. Large amounts of sugar or alcohol can cause irreversible effects in the liver in the form of cirrhosis.
Kidney and spleen cells updated every 300-500 days.
Skeleton our body produces hundreds of millions of new cells every day. It constantly regenerates, and has both old and new cells in its structure. But the complete cellular renewal of the bone structure occurs in 7-10 years. With significant nutritional imbalances, cells are produced much less and of inferior quality, and as a result, over the years, we have such a problem as osteoporosis.
Cells of all types of muscle tissue completely renewed in 15-16 years.
Heart, eyes and brain are still the least studied by scientists.
For a very long time, it was believed that the muscles of the heart are not renewed (unlike the rest of the muscle tissue), but recent discoveries have shown that this is a misconception, and the muscle tissue of the heart is renewed in the same way as the rest of the muscles.
The studies have just begun, however, according to preliminary data, it is known that complete renewal of heart muscles occurs approximately (there is no exact data yet) for 20 years. That is 3-4 times in an average life.
The mystery is still the fact that lens of the eye does not update at all, or rather, why the lens is not updated. Only the cells of the cornea of the eye are restored and renewed. The update cycle is fast enough - 7-10 days. In case of damage, the cornea is able to recover in just a day.
However, this does not negate the fact that lens cells are never renewed at all! The central part of the lens is formed in the sixth week of intrauterine development of the fetus. And for the rest of its life, new cells “grow” to the central part of the lens, which makes it thicker and less flexible, deteriorating the focusing quality over the years.
Brain- that's a riddle of riddles ...
The brain is the least studied organ in our body. Of course, this is associated with a number of objective factors. The brain of a living person is very difficult to study without harming it. Experiments on humans are prohibited in our country (at least officially). Therefore, studies are carried out on animals and terminally ill human volunteers, which is not at all equivalent to a healthy, normally functioning person.
Until recently, it was believed that brain cells never renew. In principle, things are still there. The brain, which controls our entire complex system called the organism, the brain, which gives signals for regeneration to all our organs, itself does not renew itself at all ... Hmm.
Back in the 60s of the last century, Joseph Altman discovered neurogenesis (the birth of new neurons) in the thalamus and cerebral cortex. The scientific world, as usual, reacted to this discovery very skeptically and forgot about it. In the mid-80s, this discovery was "rediscovered" by another scientist - Fernando Notteboom. And again silence.
But since the end of the 90s of the last century, full-scale studies of our brain have finally begun.
At the present moment (in the course of the latest research), several discoveries have been made. It has already been reliably established that the hippocampus and the olfactory bulb, nevertheless, regularly renew their cells. In birds, lower vertebrates and mammals, the rate of emergence of new neurons is quite high. In adult rats, approximately 250,000 new neurons are formed and replaced within a month (this is approximately 3% of the total number).
The human body also renews the cells of these parts of the brain. It has also been established that the more active the physical and brain activity, the more actively new neurons are formed in these areas. But still under study. We wait, sir ...
Over the past 20 years, science has made huge strides in studying our nutrition and the dependence on it for our health. We finally found out that a big role in the correct proper nutrition plays a role in the work of organs. It has been reliably found out - what we need to eat and what is not worth eating if we want to be healthy. But in general? What comes out in general? And it turns out that "in detail" we are renewed without stopping, all our life. So what makes us sick, grow old and die?
We fly into space, think about the conquest and colonization of other planets. But at the same time, we know so little about our body. Scientists, both in ancient times and now, have absolutely no idea why, with such a huge capacity for renewal, we are aging. Why wrinkles appear and muscle condition worsens. Why we lose flexibility and our bones become brittle. Why do we become deaf and stupid ... Nobody, as before, can say anything intelligible.
Some people say that aging is in our DNA, but this theory has no evidence base to support it.
Others believe that aging is inherent in our brain and psychology, that we, as it were, force ourselves to grow old and die. That in our subconsciousness there are aging programs. Also just a theory without any proof or confirmation.
Still others (very recent theories) believe that this is due to the "accumulation" of certain mutations and damage in mitochondrial DNA. But why there is an accumulation of these damages and mutations, they do not know.
That is, it turns out that, contrary to the theory of evolution of comrade Darwin, cells, renewing themselves again and again, resume a deteriorated version of themselves, instead of an improved one. Strange ...
Optimistic "alchemists" believe that we are endowed with the elixir of youth from birth, and there is no need to look for it on the side. He is within us. You just need to choose the right keys to our body and learn how to properly and fully use your brain.
And then our body will be, if not immortal, then very, very long-lived!
Let's feed our body properly. We will help him a little, or rather, we will not interfere with him with all sorts of poisons, and in return it will thank us with good work and a long, HEALTHY life! published by
Yul Ivanchey
P.S. And remember, just by changing our consumption - together we are changing the world! © econet
The number of cells in the human body roughly corresponds to the number of our symbiont bacteria.
When it comes to the gastrointestinal microflora, you can often hear that the number of bacterial cells living in our digestive tract is 10 times the number of cells that make up our body. The ratio is certainly impressive - it immediately becomes clear how many bacteria we have and what a great role they play in our life.
Percentages of different cells in the human body. (Illustration by R. Sender, S. Fuchs and R. Milo /bioRov.org 2016.)
Lactobacillus rhamnosus bacteria are one of the useful symbionts of the human and animal digestive systems, suppressing the growth of their pathogenic “colleagues”. (Photo by Visuals Unlimited / Corbis.)
Red blood cells are the most numerous human cells. (Photo by Visuals Unlimited / Corbis.)
The ratio "10 to 1" is quite old, it has long been recognized by all biologists (and some even said that it is actually even, more, that microbes outnumber our own cells by 100 times). Recently, however, experts are increasingly talking about the fact that the proportion is greatly exaggerated and that it needs to be revised. Let's say, according to the American Microbiological Society, the actual ratio corresponds to only three bacterial cells per human. And in 2014, Judah Rosner ( Judah rosner) from the National Institute of Diabetes and Kidney and Digestive System Diseases in his letter to the journal Microbe in general, he spoke in the sense that the notorious "10 to 1" is not true, and the popularity of these numbers speaks only of the researchers' love for round numbers.
Researchers from the Weizmann Institute undertook to accurately recalculate the unfortunate proportion again. In an article published on the site bioRxiv.org, the authors of the work write that the "average" human body weighing 70 kg contains about 30 trillion of its own cells and about 40 trillion of bacteria, that is, the ratio is about 1.3 - a striking difference from the previous tenfold prevalence of microbes. The bacteria estimate allows a 25% deviation, that is, they can be 30 trillion or 50 trillion, but this does not reach "10 to 1" in any case.
In the work of Ron Sender ( Ron sender) and his colleagues, you can find other surprising numbers. For example, the most numerous cells in our body were erythrocytes: they account for 84%. On the other hand, if you count by mass, then muscles and fat lead here - they account for 75% of the body weight, however, muscle and fat cells are quite large and therefore account for only 0.1% (!) Of the total cellular number. Of course, do not forget that everything here is calculated for an "average human body weighing 70 kg", and, for example, for women whose blood volume is less, the ratio between body cells and bacteria will shift by about a third in favor of the latter, and in growing in children, the proportion of bacteria will naturally decrease. But with obesity, the cellular proportion does not change too much (which is understandable if we remember that fat cells, along with muscle cells, constitute a minority).
Cell counting was carried out on the basis of the data available to date, so in the future, when rechecking the ratio, it is likely that the experimental methods of "census of the cell population" will also be used. Some experts, in their responses to the above work, pointed out that only bacteria were taken into account, while archaea, fungi, viruses and other microorganisms also live in us and on us; and if we take into account, for example, viruses that outnumber bacteria, then the ratio of "1.3 microorganisms per human cell" will clearly shift in favor of the microbiome. As for how, from a practical point of view, it is necessary to find out the complete balance between the cells of the body and microbes, then opinions may differ, and many believe that knowing the total figure here is certainly interesting, but useless. However, one important benefit should be pointed out here: when you want to refer to some well-known information that you learned more than a dozen years ago (especially if the information is of a medical or paramedical nature), it is useful to ask what modern science thinks about this.
