How many cells die in a person every minute. How long do human body cells live? How are dead and damaged cells removed from the body? The cells that make up our body

Friesen found that body cells for the most part replace themselves every 7 to 10 years. In other words, old cells die and are replaced by new ones during this period of time. The process of cell renewal is faster in some parts of the body, but complete rejuvenation from toes to head takes about ten years.

This explains why our skin scales fall off, our nails grow, and our hair falls out. But if we are constantly filled with new cells, why does the body age? Shouldn't the new cells act like a shot of Botox? When it comes to aging, it turns out that the secret of it lies not in our cells, but in the cellular DNA.

cell lifespan

The body is updated in different ways. How long cells work in certain areas of the body depends on what is required of them. Red blood cells, for example, live for four months because they have to travel the difficult path through the circulatory system and deliver oxygen to tissues throughout the body.

But how long do other cells live.

• Skin: The epidermis undergoes a fair amount of wear and tear as it acts as the body's outer protective layer. These skin cells are renewed every two to four weeks.
• Hair: The body's natural hairline has a lifespan of about 6 years for women and 3 years for men.
• Liver: The liver cleanses the human body by removing a wide range of pollutants from our systems. It promotes a constant blood supply and remains immune to damage from these pollutants and toxins, renewing its cells every 150-500 days.
• Stomach and intestines: The cells that line the surface of the stomach and intestines live short and complex lives. Constantly exposed to corrosive stomach acids, they tend to live only 5 days, no more.
• Bones: Cells in the skeletal system regenerate almost constantly, but the entire process takes up to 10 years. The renewal process slows down as we age, so our bones become thinner.

Despite all this constant regeneration, people who want to live forever must not stop searching for the fountain of youth. The fact is that we continue to grow old and gradually die. Friesen and others think this may be due to DNA mutations that get worse, moving on to new cells over time.

There are also a number of cells that never leave us and can contribute to the aging process, or at least the decay of the body over time. Although the cornea of ​​the eye can regenerate in just one day, the lens and other areas of the eye do not change. It's the same with the neurons in the cerebral cortex - the outer layer of the brain that is responsible for memory, thinking, language, attention and consciousness - they stay with us from birth to death. Since they are not replaced, the loss of these cells leads to serious ailments. The good news is that other areas of the brain, the olfactory bulb, which is responsible for smell, and the hippocampus, which is responsible for learning, can and are being updated.

Take care of yourself. The first person who will live forever has already been born.

What is known about the human body? How many cells are in an adult human body? How do they grow and develop, what are they intended for? Scientists all over the world are trying to unravel these mysteries.

What is a cell?

Scientists study organisms of plants, animals, people. A cell is the smallest part of any organism. There are a lot of them in the human body, more than 100 trillion. The exact number is unknown. How many cells in the human body die daily? The amount depends on the purpose. So, for example, in the intestinal epithelium - 70 billion per day, blood - 2 billion, and the cells of the nervous system do not recover after death.

He first learned about cells in 1665. He realized that the older a person, the more of these structural elements in his body. It is impossible to accurately calculate, because they die and are born every minute.

Structure and functions

It is impossible to say how many cells there are in the human body, but scientists know for sure that they have a complex structure.

Most are made up of:

• nucleus, it is called the heart of the cell;
• cytoplasm;
• nucleolus;
• mitochondria;
• shells of the nucleus;
• endoplasmic reticular formation;
• ribosome;
• lysosomes;
• pits and pores;
• cell membrane, which ensures integrity, regulates intracellular balance.

Functions are associated with the synthesis of substances. produce hormones or enzymes. The mammary glands produce milk, the pancreas produces insulin. Some do not synthesize anything, such as muscle cells.

Regardless of whether how many cells in the human body, without it they will not survive. Cells, like elements of a mosaic, make up a single organism.

blood cells

What is the fluid that flows through the veins of people? It contains plasma and cellular elements:

• red blood cells - erythrocytes;
• platelets;
• white blood cells are leukocytes.

pigment cells

Melanocytes in the human body are responsible for the color of the skin, hair, eyes and some internal organs. Such cells contain pigments in the cytoplasm that determine their action. Melanocytes also perform a protective function against ultraviolet rays, they are responsible for tanning. Cells are woody in appearance.

Cells of the nervous system

This is one of those that do not recover after dying. Their scientific name is neurons. Their task is to process and transmit information using the electrical impulses they produce. Neurons are divided into several types:

• sensory (responsible for the reaction to light, sound);
• motor;
• interneurons.

It contains the axon body. According to their structure, they are also divided into several groups. human nervous system contains about 10 billion neurons. Every year about 10 thousand die and never recover. The older the person, the fewer of them remain.

sex cells

How many cells in the human body are responsible for reproduction? There are two types of them, they are divided into male - sperm - and female - eggs. The male reproductive cell is much larger in size than the female, as it contains a larger amount of cytoplasm. They were first discovered in 1677, and the terms themselves appeared at the beginning of the 19th century.

Although it is impossible to say exactly how many cells in the human body, scientists have studied almost all of their types. Their participation is directly related to the existence of all life on planet Earth. Scientists are trying to learn how to independently grow human cells in research laboratories. Perhaps they can do it.

How many cells are in a person?

In man there is cells about 200 types. The diameter of the largest of them (the female egg) is 0.13 mm (130 microns). BUT erythrocytes, red blood cells, are only 0.008 mm (8 µm) in diameter. In addition, different cells of the body have different lifetimes, they are constantly updated, and a person either grows, then loses weight, then gets fat.

To calculate the number of cells at least approximately tried for a long time, and in different ways. And the numbers were also different: from 1 billion to 10 trillion, depending on the method of calculation. For example, if we assume that the average weight of one cell is 1 nanogram, then for an adult weighing 70 kg, simple arithmetic gives 70 billion cells. You can go the other way and estimate the number of cells through the volume. The average volume of a mammalian cell is approximately 4x10″9 cm3 (0.000004 mm3), the volume of a body weighing about 70 kg is about 65 liters (minus the volume of gas in the lungs and intestines), and then about 16 billion cells are obtained.

And recently, a group of Italian researchers from the University of Bologna, together with colleagues from Spain and Greece, decided to count cells not by weight or volume, but taking into account the individual characteristics of cells of each type for a conditional person with a height of 1 m 72 cm, a weight of 70 kg and a body surface area of ​​1 .85 m2. How to do it? I had to rework a huge amount of scientific literature published from 1809 to 2012, which dealt with the number, size and density of cells of different types.

How trillions of cells, each of which is itself a complex system, manage to work together is one of the greatest mysteries of nature. By the way, if we are not talking about a conventional human body taken for calculations, but about a real person in real conditions, then a significant number of microorganisms living in it should be added to 37.2 trillion of its own cells, the average mass of which is about 2 kg ( of which 1 kg is intestinal microflora, and another 1 kg is distributed to other organs and tissues). Without these beneficial bacteria, it would be difficult for us to resist disease-causing microbes.

And why do you need to know how many cells make up certain organs? Firstly, it's just interesting, and secondly, the day is not far off when scientists will learn how to create artificial organs that can be transplanted into humans. But how to create an artificial organ without knowing how many cells it consists of? This is where cell arithmetic can come in handy.

Ecology of Consciousness: Life. You can often hear that the number of bacterial cells living in our digestive tract is 10 times greater than the number of cells that make up our body. However, experts are increasingly saying that the proportion is greatly exaggerated, and that it should be revised.

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 greater than 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 big role they play in our lives.

The cells that make up our body

Percentages of different cells in the human body. (Illustration R. Sender, S. Fuchs and R. Milo /bioRov.org 2016.)

The 10 to 1 ratio is pretty old, it was recognized by all biologists for a long time (and some even said that it is actually even more, that microbes outnumber our own cells by 100 times).

However, lately experts are increasingly saying that the proportion is greatly exaggerated, and that it should 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 of the National Institute of Diabetes and Kidney and Digestive Diseases, in a letter to Microbe magazine, generally spoke in the sense that the notorious "10 to 1" is not true, and the popularity of these numbers speaks only of love. researchers to round figures.

Researchers from the Weizmann Institute undertook to accurately recalculate the ill-fated proportion again. In an article published on bioRxiv.org, the authors write, that the "average" human body weighing 70 kg contains about 30 trillion of its own cells and about 40 trillion bacteria, that is the ratio is about 1.3 - a striking difference from the previous tenfold predominance of microbes.

Estimates of bacteria allow for a 25% deviation, that is, there may be 30 trillion or 50 trillion, but this is not up to "10 to 1" in any case.

There are other surprising figures to be found in the work of Ron Sender and his colleagues. For example, Red blood cells are the most numerous cells in our body, accounting for 84%. On the other hand, if you count by weight, then muscles and fat lead here - they account for 75% of body weight, but muscle and fat cells are quite large and therefore make up only 0.1% (!) Of the total cell number.

Of course, we should not forget that everything here is calculated for the “average human body weighing 70 kg”, and, for example, for women who have less blood volume, the ratio between body cells and bacteria will shift by about a third in favor of the latter, and for growing children, the proportion of bacteria will naturally decrease.

But with obesity, the cellular proportion does not change too much (which is understandable if you remember that fat cells, along with muscle cells, are a minority).

Cell counting was performed on the basis of currently available data, so that in the future, when rechecking the ratio, most likely, experimental methods of “cellular population census” will also be used.

Some experts, in their reviews of the above work, pointed out that only bacteria were taken into account, and yet archaea, fungi, viruses and other microorganisms also live in us and on us;

and if we take into account, for example, viruses, which outnumber bacteria, then the ratio of "1.3 microorganisms per human cell" will clearly shift in favor of the microbiome. As for how practical it is to find out the complete balance between body cells and microbes, opinions vary, and many people think 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 medical or near-medical in nature), it is useful to ask what modern science thinks about this. published . If you have any questions on this topic, ask them to specialists and readers of our project

P.S. And remember, just by changing your consciousness - together we change the world! © econet

A person is made up of more than 100000000000000 cells (read "one hundred trillion"). For comparison, an elephant has approximately 6,500,000,000,000,000 (six and a half quadrillion) cells,

Man is 60% water. Sleep is unevenly distributed: for example, only 20% of water in fatty tissues, 25% in bones, 70% in liver, 75% in muscles, 80% in blood and 85% of water in the brain of the total weight. When looking at these figures, a seeming paradox strikes - there is less water in liquid blood than in a rather dense brain. But the point is not only in the quantity, but also in the "packaging" of water. It is known that jellyfish are 98-99% water, however, the jellyfish does not dissolve in the sea, it can be picked up.

The remaining 40% of the weight of the human body is distributed as follows: proteins - 19%, fats and fat-like substances - 15%, minerals - 5%), carbohydrates - 1%.

Of the elements that make up our body, oxygen, carbon, hydrogen and nitrogen play the most important role. In the body of an adult, there are about 70 kilograms of them. There is also a lot of calcium and phosphorus - together they are almost 2 kilograms, they are part of the bone, ensuring its strength. Potassium, sulfur, sodium, chlorine are contained in quantities of several tens of grams. Iron in a person is only about 6 grams, but it plays an extremely important role, being part of hemoglobin.

Oddly enough, it is not possible to indicate the exact number of bones in the human skeleton. First, it is somewhat different for different people. Approximately 20% of people have abnormalities in the number of vertebrae. One person out of every twenty has an extra rib, and in men, an extra rib occurs about 3 times more often than in women (contrary to the biblical legend about the creation of Eve from Adam's rib). Secondly, the number of bones changes with age: over time, some bones fuse together, forming tight sutures. Therefore, it is not always clear how to count the bones. For example, the sacrum clearly consists of five fused vertebrae. Count it as one or five? Therefore, reputable manuals carefully indicate that a person has "somewhat more than 200 bones."

The longest bone is the femur, its length is usually 27.5% of a person's height. The shortest is the stirrup, one of the bones that transmit the vibrations of the tympanic membrane to the sensitive cells of the inner ear. It works like a lever, increasing the pressure of sound waves. Its length is only 3-4 mm.

The smallest muscle is the stirrup muscle. When sounds are too strong, she turns the stirrup so that the ratio of the length of the arms of the bone-lever changes, and the sound amplification factor drops.

It is impossible to accurately specify the number of muscles. Specialists count from 400 to 680 muscles in a person. For comparison: grasshoppers have about 900 muscles, some caterpillars have up to four thousand. The total muscle weight in a man is about 40% of body weight, and in a woman it is about 30%.

In a calm state, lying down, a person consumes 400-500 liters of oxygen per day, making 12-20 breaths per minute. For comparison: the respiratory rate of a horse is 12 breaths per minute, rats are 60, and canaries are 108.

In spring, the respiratory rate is on average one third higher than in autumn.

In an adult, the heart pumps about 10,000 liters of blood per day. For one blow, approximately 130 milliliters are ejected into the aorta. The normal pulse at rest is 60-80 beats per minute, and in women the heart beats 6-8 beats per minute more often than in men. With heavy physical exertion, the pulse can accelerate to 200 or more beats per minute. For comparison: the pulse rate of an elephant is 20 beats per minute, that of a bull is 25, that of a frog (cold-blooded animal) is 30, that of a rabbit is 200, and that of a mouse is 500 beats per minute.

The total length of blood vessels in the human body is about one hundred thousand kilometers.

Here is how blood is distributed in the body at rest: a quarter of the total volume is in the muscles, the other quarter is in the kidneys, 15% in the vessels of the intestinal walls, 10% in the liver, 8% in the brain, 4% in the coronary vessels. heart, 13% - in the vessels of the lungs and other organs.

Each red blood cell contains about 270 million hemoglobin molecules.

The lifespan reaches several months (there are several types of leukocytes, which is why their lifespans are so diverse). In an adult, a billion red blood cells, 5 billion white blood cells, and 2 billion platelets die every hour. They are replaced by new cells produced in the bone marrow and spleen. Approximately 25 grams of blood is replaced per day.

The bone marrow of an adult, a loose mass that fills the internal cavities of some bones, weighs an average of 2600 grams. For 70 years of life, he gives 650 kilograms of red blood cells and a ton of white blood cells.

The human nervous system contains about 10 billion neurons and about seven times more serving cells - supporting and feeding. Only one percent of nerve cells is engaged in "independent work" - it receives sensations from the external environment and commands the muscles. Ninety-nine percent are intermediate nerve cells that serve as amplifying and transmitting stations.

The largest human nerve cells are 1000 times larger than the smallest. The thinnest nerve fibers have a diameter of only 0.5 micrometers, the thickest - 20 micrometers.

More than half of all neurons are concentrated in the cerebral hemispheres.

The total area of ​​the cerebral cortex varies from 1468 to 1670 square centimeters.

In the cranial nerves, 2,600,000 nerve fibers enter the brain and 140,000 exit. About half of the outgoing fibers carry orders to the muscles of the eyeball, controlling subtle, fast and complex eye movements. The remaining nerves control facial expressions, chewing, swallowing, and the activity of internal organs. Of the incoming nerve fibers, two million are visual.

In a minute, 740-750 milliliters of blood flows through the brain.

Starting from the thirtieth year of life, 30-50 thousand nerve cells die daily in a person. The main dimensions of the brain are reduced. With age, the brain not only loses weight, but also changes shape - flattens. In men, the weight of the brain is maximum at 20-29 years, in women - at 15-19.

The average normal visual acuity is 0.0003 arc minutes, that is, the eye is able to distinguish a well-lit object with a diameter of one tenth of a millimeter at a distance of 25 centimeters. But if the object itself glows, it can be much smaller. A hole with a diameter of 3-4 thousandths of a millimeter, pierced in a sheet of tin, behind which a light bulb is lit, is clearly distinguished by a normal eye.

Blood cells are constantly dying and being replaced by new ones. The life expectancy of an erythrocyte is 90-125 days, of a leukocyte - from several hours to several days.

The mass of the human brain is 1/46 of the total body weight, the mass of the brain of an elephant is only 1/560 of the body weight.

The eye is able to distinguish 130-250 pure color tones and 5-10 million mixed shades.

The frequency of flashes, at which the flashing light appears to the eye as evenly burning, for rods is 15 per second, for cones - 71-90.

Full adaptation of the eye to the dark takes 60-80 minutes.

The finger is able to feel vibrations with an amplitude of two ten-thousandths of a millimeter.

The average surface of human skin is about 2 square meters. It is necessary to know it when prescribing certain drugs and medical procedures. To calculate the surface of the skin in the clinic, the following formula is usually used:

Body surface == (body weight X 4) + 7

Weight should be taken in kilograms, the surface is obtained in square meters. There are more precise formulas that take into account growth, but the calculation for them is much more complicated, and they are used less frequently.

In one minute, 460 milliliters of blood passes through the skin.

The skin contains 250,000 cold receptors, 30,000 heat receptors, a million pain endings, half a million touch receptors, and three million sweat glands.

The average number of hairs on the head: blondes - 140 thousand, brunettes - 102 thousand, brown hair - 109 thousand, redheads - 88 thousand. The total number of hairs on the body, except for the head, is about 20,000.

Hair grows at a rate of 0.35-0.40 millimeters per day. During the day, our hair lengthens, if we calculate the total increase in hair length, thirty meters.

There are about 25,000 cells in the inner ear that respond to sound. The frequency range perceived by the ear lies between 16 and 20,000 hertz. With age, it decreases, especially due to a decrease in sensitivity to high sounds. By the age of 35, the upper limit of hearing drops to 15,000 hertz.

The ear is most sensitive to the range of 2000-2300 hertz. The best ear for music (the ability to distinguish height) falls on the region of 80-600 hertz. Here our ear is able to distinguish, for example, two sounds with a frequency of 100 hertz and 100.1 hertz. In total, a person distinguishes 3-4 thousand sounds of different heights.

We become aware of a sound 35-175 milliseconds after it has reached the ear. Another 180-500 milliseconds is required for the ear to “tune in” to receiving this sound, to achieve the best sensitivity.

There are about 9,000 taste buds on the tongue. The best temperature for their operation is 24 degrees Celsius. (Gourmets should take this into account!)

The area of ​​the olfactory zone of the nose is 5 square centimeters. There are about a million olfactory nerve endings here. In order for an impulse to arise in the olfactory nerve fiber, approximately 8 molecules of an odorous substance must reach its end. In order for the sensation of smell to arise, at least 40 nerve fibers must be excited.

Nails on the hands grow at a rate of 0.086 millimeters per day, on the legs - 0.05 millimeters. About two grams of nails grow on the fingers per year.

When chewing food, the jaw muscles develop a force of up to 72 kilograms on the molars, and up to 20 kilograms on the incisors. Chewing bread requires an effort of 25 kilograms, chewing roast veal requires 15 kilograms.

For one square millimeter of the gastric mucosa, there are about a hundred glands that secrete digestive juice.

The small intestine, where digested food is absorbed into the blood, has about 5 million villi on its inner surface - the thinnest hair-like outgrowths through which nutrients are absorbed.

A sip of water - is it a lot or a little? Numerous measurements have shown that a man swallows an average of 21 milliliters of liquid in one gulp, and a woman 14 milliliters.

The feeling of thirst appears when the loss of water is equal to one percent of body weight. A loss of more than 5% can lead to fainting, and more than 10% can lead to death from withering.

A fresh fingerprint weighs approximately one millionth of a gram. It consists of water, fats, proteins and salts secreted by the skin,

Even harsh men shed 1-3 milliliters of tears daily. Tears are constantly produced by the lacrimal glands and moisten the cornea of ​​the eye, protecting it from exposure to air and dust.

At least 700 enzymes work in the human body.