Probably everyone, even very young children, knows that blood is a red liquid that is located somewhere inside a person. But what is blood, why is it so important and where does it come from?
Not every adult can answer these questions, so I will try to talk about blood from the point of view of biology and medicine.
So, blood is a liquid that continuously moves through our body and performs a number of vital functions. I think everyone has seen blood and imagines that it looks like a dark red liquid. Blood consists of two main components:
- Blood plasma;
- Formed elements of blood.
Blood plasma
Plasma is the liquid part of blood. If you have ever been to a blood transfusion service, you may have seen bags of light yellow liquid. This is exactly what plasma looks like.
The vast majority of plasma composition is water. More than 90% of plasma is water. The rest is occupied by the so-called dry residue - organic and inorganic substances.
It is very important to note proteins that are organic substances - globulins and albumins. Globulins perform a protective function. Immunoglobulins are one of the most important echelons of our body against enemies such as viruses or bacteria. Albumin are responsible for the physical constancy and homogeneity of blood; it is albumins that maintain the formed elements of blood in a suspended, uniform state.
Another organic component of plasma that is familiar to you is glucose. Yes, it is the glucose level that is measured when diabetes is suspected. It is the glucose level that those who are already sick with it try to control. Normal glucose levels are 3.5 - 5.6 millimoles per liter of blood.
Formed elements of blood
If you take a certain amount of blood and separate all the plasma from it, then the formed elements of blood will remain. Namely:
- Red blood cells
- Platelets
- Leukocytes
Let's look at them separately.
Red blood cells
Red blood cells are also sometimes called "red blood cells". Although red blood cells are often referred to as cells, it is important to note that they do not have a nucleus. This is what a red blood cell looks like:
It is red blood cells that form the red color of blood. Red blood cells perform a function oxygen transport to body tissues. Red blood cells carry oxygen to every cell in our body that needs it. Also red blood cells take away carbon dioxide and carry it to the lungs in order to subsequently completely remove it from the body.
Red blood cells contain a very important protein - hemoglobin. It is hemoglobin that is able to bind with oxygen and carbon dioxide.
By the way, in our body there are special zones that are able to check the blood for the correct ratio of oxygen and carbon dioxide. One of these sites is located on.
Another important fact: it is red blood cells that are responsible for the so-called blood group - the antigenic characteristics of the red blood cells of an individual person.
The normal number of red blood cells in the blood of adults varies by gender. For men, the norm is 4.5-5.5 × 10 12 / l, for women - 3.7 - 4.7 × 10 12 / l
Platelets
They are fragments of red bone marrow cells. Like red blood cells, they are not full-fledged cells. This is what a human platelet looks like:
Platelets are the most important part of the blood, which is responsible for clotting. If you cut yourself, for example, with a kitchen knife, blood will immediately flow from the cut site. The blood will come out for several minutes, most likely you will even have to bandage the cut site.
But then, even if you imagine that you are an action hero and do not bandage the cut with anything, the bleeding will stop. To you, it will simply look like a lack of blood, but in fact, platelets and blood plasma proteins, mainly fibrinogen, will work here. A rather complex chain of interaction between platelets and plasma substances will take place, eventually a tiny blood clot will form, the damaged vessel will “seal” and the bleeding will stop.
Normally, the human body contains 180 - 360 × 10 9 / l platelets.
Leukocytes
Leukocytes are the main defenders of the human body. In common parlance they say: “my immunity has dropped,” “my immunity has weakened,” “I often catch colds.” As a rule, all these complaints are related to the work of leukocytes.
Leukocytes protect us from various viral or bacterial diseases. If you have any acute, purulent inflammation - for example, as a result of a hangnail under the nail, you will see and feel the results of their work. Leukocytes attack pathogenic microorganisms, provoking purulent inflammation. By the way, pus is the fragments of dead leukocytes.
Leukocytes also make up the main anticancer barrier. They control the processes of cell division, preventing the appearance of atypical cancer cells.
Leukocytes are full-fledged (unlike platelets and red blood cells) blood cells that have a nucleus and are capable of movement. Another important property of leukocytes is phagocytosis. If we greatly simplify this biological term, we get “devouring”. White blood cells devour our enemies - bacteria and viruses. They also participate in complex cascade reactions in the development of acquired immunity.
Leukocytes are divided into two large groups: granular leukocytes and non-granular leukocytes. It’s very easy to remember - some are covered with granules, others are smooth.
Normally, a healthy person's blood contains 4 - 10 × 10 9 / l leukocytes.
Where does blood come from?
A fairly simple question that few adults can answer (except for doctors and other natural science specialists). Indeed, there is a whole bunch of blood in our body - 5 liters in men and a little more than 4 liters in women. Where is all this created?
Blood is created in red bone marrow. Not in the heart, as many may mistakenly assume. The heart, in fact, has absolutely nothing to do with hematopoiesis, do not confuse the hematopoietic and cardiovascular systems!
Red bone marrow is a reddish-colored tissue that looks very similar to watermelon pulp. Red bone marrow is found inside the pelvic bones, sternum, and in very small quantities inside the vertebrae, skull bones, and also near the epiphyses of long bones. Red bone marrow is not related to the brain, spinal cord, or nervous system at all. I decided to mark the location of the red bone marrow in the skeleton picture so you have an idea of where your blood is produced.
By the way, if there is a suspicion of serious diseases associated with hematopoiesis, a special diagnostic procedure is performed. We are talking about sternal puncture (from the Latin “sternum” - sternum). A sternal puncture is the removal of a sample of red bone marrow from the sternum using a special syringe with a very thick needle.
All formed elements of blood begin their development in the red bone marrow. However, T-lymphocytes (these are representatives of smooth, non-granular leukocytes) migrate to the thymus halfway through their development, where they continue to differentiate. The thymus is a gland that is located behind the upper part of the sternum. Anatomists call this area the “superior mediastinum.”
Where is the blood destroyed?
In fact, all blood cells have short life spans. Red blood cells live about 120 days, white blood cells - no more than 10 days. Old, poorly functioning cells in our body are usually absorbed by special cells - tissue macrophages (also eaters).
However, blood cells are also destroyed and in the spleen. First of all, this concerns red blood cells. It is not for nothing that the spleen is also called the “graveyard of red blood cells.” It should be noted that in a healthy body, aging and decay of old formed elements are compensated by the maturation of new populations. In this way, homeostasis (constancy) of the content of formed elements is formed.
Blood functions
So, we know what blood consists of, we know where it is created and where it is destroyed. What functions does it perform, what is it needed for?
- Transport, also known as respiratory. Blood carries oxygen and nutrients to the tissues of all organs, taking away carbon dioxide and decay products;
- Protective. As mentioned earlier, our blood is the most powerful line of defense against a variety of misfortunes, ranging from banal bacteria to dangerous oncological diseases;
- Supportive. Blood is a universal mechanism for regulating the constancy of the internal environment of the body. Blood regulates temperature, acidity of the environment, surface tension and a number of other factors.
Any living creature must eat; billions of cells in our body constantly need nutrients that are dissolved in the blood that washes all the organs and all the cells of the body. What is the composition of human blood, and what are its main properties?
Basic properties of blood
The main properties of blood are as follows:
1. It is “living”, that is, it consists of billions of living cells, which are called blood cells;
2. Together with nutrients, blood carries the oxygen taken from the air and the oxygen it needs to the cells;
3. While delivering nutrients to the cells of the body, the blood simultaneously removes harmful substances from them;
4. With the help of blood, the body’s organs “exchange” various useful substances;
5. Among the blood cells (blood cells), there are those that can be called “doctors” of our body, because they fight viruses and microbes that have entered it.
6. Among the blood cells there are cells that serve to preserve the blood itself. For example, if you get injured, the liquid blood flowing from the wound very quickly hardens or, in other words, coagulates and, like a plug, plugs the damaged blood vessel. This is facilitated by special blood cells - platelets.
Composition of human blood
The exchange of various substances between blood and cells occurs through the walls of the thinnest blood vessels - capillaries. If you enlarge the capillary 5000 times (about the size of a mosquito to the size of an elephant), then it and the blood flowing through it will look like this:
Blood cells float through the capillary in a clear yellowish liquid called blood plasma. It is plasma that carries nutrients throughout the body and takes away what it no longer needs. That is, plasma brings “food” to cells and removes “garbage” from them.
Human blood also contains red blood cells - it is thanks to them that the blood is red. Red blood cells supply the body with oxygen and remove carbon dioxide from it. First, they deliver oxygen to the cell, which, as it were, “burns”, supplies the cell with energy and turns into carbon dioxide, which is carried away by the same red blood cells.
Human blood also contains white blood cells or white blood cells. They are the ones who fight germs and viruses. But there are thousands of times fewer such “doctors” in the blood than red blood cells that supply the body with oxygen.
Why does a person need blood for children? What does blood consist of and what is its role in the human body?Why does a person need blood for children? What does blood consist of and what is its role in the human body?
The human body is extremely complex. Its elementary building particle is the cell. The union of cells that are similar in their structure and functions form a certain type of tissue. In total, there are four types of tissues in the human body: epithelial, nervous, muscle and connective. It is the latter type that blood belongs to. Below in the article we will discuss what it consists of.
General concepts
Blood is a liquid connective tissue that constantly circulates from the heart to all remote parts of the human body and carries out vital functions.
In all vertebrate organisms, it has a red color (of varying degrees of color intensity), acquired due to the presence of hemoglobin, a specific protein responsible for the transfer of oxygen. The role of blood in the human body cannot be underestimated, since it is responsible for the transfer of nutrients, microelements and gases necessary for the physiological course of cellular metabolic processes.
Main components
The structure of human blood contains two main components - plasma and several types of formed elements located in it.
As a result of centrifugation, you can see that this is a transparent liquid component of a yellowish color. Its volume reaches 52–60% of the total blood volume. The composition of plasma in the blood is 90% water, where proteins, inorganic salts, nutrients, hormones, vitamins, enzymes and gases are dissolved. And what does human blood consist of?
Blood cells are of the following types:
- (red blood cells) - contained most among all cells, their importance is the transport of oxygen. The red color is due to the presence of hemoglobin in them.
- (white blood cells) are part of the human immune system, protecting it from pathogenic factors.
- (blood plates) – guarantee the physiological course of blood clotting.
Platelets are colorless plates without a nucleus. In fact, these are fragments of the cytoplasm of megakaryocytes (giant cells in the bone marrow), which are surrounded by a cell membrane. The shape of platelets is varied - oval, in the form of a sphere or rods. The function of platelets is to ensure blood clotting, that is, to protect the body from.
Blood is a rapidly regenerating tissue. The renewal of blood cells takes place in the hematopoietic organs, the main of which is located in the pelvic and long tubular bones of the bone marrow.
What tasks does blood perform?
There are six functions of blood in the human body:
- Nutritional - blood delivers nutrients from the digestive organs to all cells of the body.
- Excretory – the blood picks up and carries away decay and oxidation products from cells and tissues to the excretory organs.
- Respiratory – transport of oxygen and carbon dioxide.
- Protective – neutralization of pathogenic organisms and toxic products.
- Regulatory – due to the transfer of hormones that regulate metabolic processes and the functioning of internal organs.
- Maintaining homeostasis (constancy of the internal environment of the body) - temperature, environmental reaction, salt composition, etc.
The importance of blood in the body is enormous. The constancy of its composition and characteristics ensures the normal course of life processes. By changing its indicators, it is possible to identify the development of the pathological process in the early stages. We hope you learned what blood is, what it consists of and how it functions in the human body.
Probably everyone, even very young children, knows that blood is a red liquid that is located somewhere inside a person. But what is blood, why is it so important and where does it come from?
Not every adult can answer these questions, so I will try to talk about blood from the point of view of biology and medicine.
So, blood is a liquid that continuously moves through our body and performs a number of vital functions. I think everyone has seen blood and imagines that it looks like a dark red liquid. Blood consists of two main components:
- Blood plasma;
- Formed elements of blood.
Blood plasma
Plasma is the liquid part of blood. If you have ever been to a blood transfusion service, you may have seen bags of light yellow liquid. This is exactly what plasma looks like.
The vast majority of plasma composition is water. More than 90% of plasma is water. The remaining portion is occupied by the so-called dry residue - organic and inorganic substances.
It is very important to note proteins, which are organic substances - globulins and albumins. Globulins perform a protective function. Immunoglobulins are one of the most important echelons of our body against enemies such as viruses or bacteria. Albumin are responsible for the physical constancy and homogeneity of blood; it is albumins that maintain the formed elements of blood in a suspended, uniform state.
Another organic component of plasma that is well known to you is glucose. Yes, it is the glucose level that is measured when diabetes is suspected. It is the glucose level that those who are already sick with it try to control. Normal glucose levels are 3.5 - 5.6 millimoles per liter of blood.
Formed elements of blood
If you take a certain amount of blood and separate all the plasma from it, then the formed elements of blood will remain. Namely:
- Red blood cells
- Platelets
- Leukocytes
Let's look at them separately.
Red blood cells
Red blood cells are also sometimes called "red blood cells". Although red blood cells are often referred to as cells, it is important to note that they do not have a nucleus. This is what a red blood cell looks like:
It is red blood cells that form the red color of blood. Red blood cells perform a function oxygen transport to body tissues. Red blood cells carry oxygen to every cell in our body that needs it. Also red blood cells take away carbon dioxide and carry it to the lungs in order to subsequently completely remove it from the body.
Red blood cells contain a very important protein - hemoglobin. It is hemoglobin that is able to bind with oxygen and carbon dioxide.
By the way, in our body there are special zones that are able to check the blood for the correct ratio of oxygen and carbon dioxide. One of these sites is located at.
Another important fact: it is red blood cells that are responsible for the so-called blood group - the antigenic characteristic of the red blood cells of an individual person.
The normal number of red blood cells in the blood of adults varies by gender. For men, the norm is 4.5-5.5 × 10 12 / l, for women - 3.7 - 4.7 × 10 12 / l
Platelets
They are fragments of red bone marrow cells. Like red blood cells, they are not full-fledged cells. This is what a human platelet looks like:
Platelets are the most important part of the blood, which is responsible for clotting. If you cut yourself, for example, with a kitchen knife, blood will immediately flow from the cut site. The blood will come out for several minutes, most likely you will even have to bandage the cut site.
But then, even if you imagine that you are an action hero and do not bandage the cut with anything, the bleeding will stop. To you, it will simply look like a lack of blood, but in fact, platelets and blood plasma proteins, mainly fibrinogen, will work here. A rather complex chain of interaction between platelets and plasma substances will take place, eventually a tiny blood clot will form, the damaged vessel will “seal” and the bleeding will stop.
Normally, the human body contains 180 - 360×10 9 /l platelets.
Leukocytes
Leukocytes are the main defenders of the human body. In common parlance they say: “immunity has dropped,” “immunity has weakened,” “I often catch colds.” As a rule, all these complaints are related to the work of leukocytes.
Leukocytes protect us from various viral or bacterial diseases. If you have any acute, purulent inflammation - for example, as a result of a hangnail under the nail, you will see and feel the results of their work. Leukocytes attack pathogenic microorganisms, provoking purulent inflammation. By the way, pus is the fragments of dead leukocytes.
Leukocytes also make up the main anticancer barrier. They control the processes of cell division, preventing the appearance of atypical cancer cells.
Leukocytes are full-fledged (unlike platelets and erythrocytes) blood cells that have a nucleus and are capable of movement. Another important property of leukocytes is phagocytosis. If we greatly simplify this biological term, we get “devouring”. Leukocytes devour our enemies - bacteria and viruses. They also participate in complex cascade reactions in the development of acquired immunity.
Leukocytes are divided into two large groups: granular leukocytes and non-granular leukocytes. It’s very easy to remember - some are covered with granules, others are smooth.
Normally, a healthy person's blood contains 4 - 10×10 9 /l leukocytes.
Where does blood come from?
A fairly simple question that few adults can answer (except for doctors and other natural science specialists). Indeed, there is a whole bunch of blood in our body - 5 liters in men and a little more than 4 liters in women. Where is all this created?
Blood is created in red bone marrow. Not in the heart, as many may mistakenly assume. The heart, in fact, has absolutely nothing to do with hematopoiesis, do not confuse the hematopoietic and cardiovascular systems!
Red bone marrow is a reddish-colored tissue that looks very similar to watermelon pulp. Red bone marrow is found inside the pelvic bones, sternum, and in very small quantities inside the vertebrae, skull bones, and also near the epiphyses of long bones. Red bone marrow is not related to the brain, spinal cord, or nervous system at all. I decided to mark the location of the red bone marrow in the skeleton picture so you have an idea of where your blood is produced.
By the way, if there is a suspicion of serious diseases associated with hematopoiesis, a special diagnostic procedure is performed. We are talking about sternal puncture (from the Latin “sternum” - sternum). A sternal puncture is the removal of a sample of red bone marrow from the sternum using a special syringe with a very thick needle.
All formed elements of blood begin their development in the red bone marrow. However, T-lymphocytes (these are representatives of smooth, non-granular leukocytes) migrate to the thymus halfway through their development, where they continue to differentiate. The thymus is a gland that is located behind the upper part of the sternum. Anatomists call this area the “superior mediastinum.”
Where is the blood destroyed?
In fact, all blood cells have short life spans. Red blood cells live about 120 days, white blood cells - no more than 10 days. Old, poorly functioning cells in our body are usually absorbed by special cells - tissue macrophages (also eaters).
However, blood cells are also destroyed and in the spleen. First of all, this concerns red blood cells. It is not for nothing that the spleen is also called the “graveyard of red blood cells.” It should be noted that in a healthy body, aging and decay of old formed elements are compensated by the maturation of new populations. In this way, homeostasis (constancy) of the content of formed elements is formed.
Blood functions
So, we know what blood consists of, we know where it is created and where it is destroyed. What functions does it perform, what is it needed for?
- Transport, also known as respiratory. Blood carries oxygen and nutrients to the tissues of all organs, taking away carbon dioxide and decay products;
- Protective. As mentioned earlier, our blood is the most powerful line of defense against a variety of misfortunes, ranging from banal bacteria to dangerous cancer diseases;
- Supportive. Blood is a universal mechanism for regulating the constancy of the internal environment of the body. Blood regulates temperature, acidity of the environment, surface tension and a number of other factors.
Olga Sokolova
"What is blood for?" Summary of an open lesson in the preparatory group
Subject: "For what do you need blood for?» .
(V preparatory group)
Tasks:
Give an idea of what it does blood in the body,
Develop attention, memory, thinking.
Develop hygienic skills to protect your health.
Result:
blood distributes nutrition to all organs,
blood carries oxygen throughout the body,
Fights germs that enter the body.
Activating the dictionary: nutrition, oxygen, spreads, germs
Concepts: heart, arteries, veins, kidneys.
Actions: manipulation of a boat using a poster.
I draw the guys’ attention to the bottle with the inscription “Water of Life”.
Guys, in which fairy tale did we meet “Water of Life” (the tale of “Ivan Tsarevich and the Gray Wolf”).
Why did the gray wolf need “Living Water”? (to revive Ivan - Tsarevich)
I would like to invite you on an interesting journey through our body, along two large rivers.
Look at the poster.
Our main port is “Heart”. One red river flows down from the port “Heart” to the small station “Palchiki”. This river carries oxygen to all cells, it is called “Artery”. Repeat.
Another river, blue in color, is called "Vein". Repeat. It flows from the "Palchiki" station to the "Heart" port and carries the gas exhausted by the cells - carbon dioxide, so the river becomes a different color. The water in these rivers is not simple, but living, it is called - blood. Repeat.
- Heart is beating: "Knock Knock" like the engine of a car, it pushes day and night blood with oxygen into the river “Artery”, it never rests, Listen to yourself how the main port “Heart” works with your hand,
Remember from what are our muscles made of?., bones, hair? (from cells)
Yes, that's right, if a little blood If you look at it under a microscope, you can see that it consists of boat cells. These boats are red, white and purple.
Why do you think red blood? (more red cage ships).
Right. (To play out the actions, I suggest paper boats in red, white and purple colors).
I suggest the children take red boats.
Red ships are merchant ships, carrying the most valuable cargo - oxygen.
We set off from the port "Heart" down the river "Arteriya" - we brought oxygen to the cells, gave it to and collected the waste gas - carbon dioxide,
What river do you think we will return along? (on the blue line, we took the exhaust gas. We arrived and put the boats in the port.
While the red boats are carrying valuable cargo - oxygen, what are the white and purple boats doing? Here's what.
As soon as we cut our hand, microbes try to penetrate the wounds, and then the white boats begin to work (the model shows a wound).
I suggest taking white boats.
They surround microbes in a tight ring and eat them, “devour” them, they are called devourers. (game moment with germs)
At this time, purple ships, they are called repairmen, close the entrance to the wound, do not let germs in. This is the kind of fight-battle that happens in our body if we cut ourselves. Many cell ships die in the battle, they need to be removed, cleaned blood. This is done in our body by the orderlies - the kidneys, which are located on both sides of the rivers. Here they are. Repeat "Kidneys" blood cleanses itself of everything harmful, poisonous and returns to the main port - “Heart”.
Guys, what do you think will happen to us if our heart stops? (the artery will become empty, cells without oxygen will begin to die, which means we will die). The heart and all organs must be protected.
Fizminutka "We are fearless sailors"
Do you want to become captains and sail along these rivers?
Put on your caps (headbands), take the boats and place them in the main port "Heart", to the river “Artery”. We swam down (working with a poster on the floor).
What are we bringing about you? (oxygen)
Well done! We sailed to the port “Zheludok”, “Intestines”.
What are we giving away? (part of oxygen)
What does the intestine give us? (food for cells).
I hear a signal from the port "Leg": “Germs crawl into a scratch on a finger...” Give commands to the ships!
What kind of cargo was brought to the port of Noga? (food, oxygen).
We collect the exhaust gas from the dead cell ships.
Which river will we return by? (vein)
What will we bring? (exhaust gas, food, lost ships).
Which port should you go to to get medical treatment? (port "Kidneys")
Guys, now let’s go for valuable cargo to the port “Lungs” - for oxygen, and from there to the port “Heart”.
For why do we need blood in the body?
Bottom line:
Our journey has ended.
Which captain himself wants to sail his ship along this route? (we provide assistance).
Well done! You can apply to the school of real captains.
Blood is a liquid substance in the human body that performs transport functions for oxygen and nutrients from the intestines to all organs and systems of the body. Toxic substances and metabolic products are also eliminated through the blood. Blood provides a person with normal functioning and life in general.
Composition of blood and a brief description of its constituent elements
Blood has been studied quite well. Today, by its composition, doctors can easily determine a person’s health status and possible diseases.
Blood consists of plasma (the liquid part) and three dense groups of elements: red blood cells, white blood cells and platelets. The normal composition of blood contains approximately 40-45% dense elements. An increase in this indicator leads to thickening of the blood, and a decrease leads to thinning. An increase in blood density/thickness occurs due to a large loss of fluid from the body, for example, due to diarrhea, profuse sweating, and so on. Liquefaction occurs, on the contrary, due to fluid retention in the body and when drinking heavily (in the case when the kidneys do not have time to remove excess water).
What does blood plasma consist of?
Blood plasma contains up to 92% water, the rest is fats, proteins, carbohydrates, minerals and vitamins.
Proteins in plasma ensure normal blood clotting, transport various substances from one organ to another, and support various biochemical reactions of the body.
What proteins are included in blood plasma?
- albumins (are the main building material for amino acids, preserve blood inside the vessels, transport some substances);
- globulins (divided into three groups, two of them transport various substances, the third is involved in the formation of the blood group);
- fibrinogens (take part in the process of blood clotting).
In addition to proteins, the blood plasma may also contain amino acid residues in the form of nitrogenous compounds, chains. There are also some other substances in the plasma that should not exceed certain levels. Otherwise, when the indicators increase, a violation of the excretory functions of the kidneys is diagnosed.
Other organic compounds in plasma are glucose, enzymes and lipids.
Dense elements of human blood
Red blood cells are cells without a nucleus. The description was given in the previous article.
Leukocytes are responsible for. The task of leukocytes is to capture and neutralize infectious elements, as well as create a database that is passed on to subsequent generations. In this way, either illnesses or immunity are transmitted from parents to children.
Platelets keep blood in the bloodstream. The peculiarity of these cells is that they do not have a nucleus, like red blood cells, and they are able to stick anywhere. They provide blood clotting in case of damage to blood vessels and skin, creating thrombotic seals and preventing blood from leaking out.
Blood consists of 60% plasma. This is a yellowish-white liquid, which in turn consists mainly of water, as well as various proteins, salts, trace elements and vitamins***. About 40% of blood is made up of cells [ ] called blood corpuscles or blood cells. There are three types of blood cells, which are found in different numbers and perform different tasks:
- red blood cells (erythrocytes)
- white blood cells (leukocytes)
- blood platelets (platelets)
Erythrocytes (red blood cells)
Most of the human blood contains s, which are also called red blood cells or red blood cells. They make up 99% of all blood cells. In one microliter of blood (that is, in one millionth of a liter) there are from 4 to 6 million red blood cells.
The most important task of red blood cells is to carry vital oxygen through the blood vessels (which enters the lungs) to the organs and tissues of the body. They perform this task with the help of the red blood pigment - hemoglobin.
If the number of red blood cells in the blood is not enough, or if there is little hemoglobin in the red blood cells and therefore they cannot fully perform their work, then we are talking about anemia, or anemia. “Anemic” people often have very pale skin. Since their body does not receive enough oxygen, they also experience symptoms such as fatigue, weakness, shortness of breath, decreased performance, headache or back pain.
The main thing in assessing the work of red blood cells is, first of all, not their number in the blood, but their volume, the so-called hematocrit*** (abbreviated in Ht tests), and the level of hemoglobin (abbreviated in Hb tests). For children older than infancy, the normal hemoglobin level is considered to be between 10 and 16 g/dl, and the hematocrit level is between 30 and 49% ( details see table) .
If these indicators are significantly lower than normal and at the same time the child develops symptoms of anemia [ ], for example, due to leukemia, or after chemotherapy [ ], then a transfusion (transfusion) of red blood cell concentrate (packed red blood cells, abbreviated as “ermass”) may be required. to stabilize the child's condition.
Leukocytes (white blood cells)
White blood cells or white blood cells, also called ami, together with platelets in healthy people, make up only 1% of all blood cells. A level of 5,000 to 8,000 leukocytes per microliter of blood is considered normal.
Leukocytes are responsible for the body's immune defense. They recognize “strangers”, for example, bacteria*** , s or fungi, and neutralize them. If there is , the number of white blood cells can increase greatly in a short time. Thanks to this, the body quickly begins to fight pathogens.
These three types of cells fight pathogens in different ways, while simultaneously complementing each other's work. Only due to the fact that they work in harmony, the body is provided with optimal protection against infections. If the number of white blood cells decreases or they cannot work normally, for example in leukemia, then the body's defense against “foreigners” (bacteria, viruses, fungi) can no longer be effective. Then the body begins to pick up various infections.
The total number of white blood cells is measured in a blood test [blood test***]. The characteristics of the different types of white blood cells and their percentage can be examined in a so-called differential blood test ( leukocyte formula***).
Granulocytes
Granulocytes are so-called phagocytes. They capture an enemy that has entered the body and digest it (phagocytosis). In the same way, they cleanse the body of dead cells. In addition, granulocytes are responsible for working with allergic and inflammatory reactions, and with the formation of pus.
The level of granulocytes in the blood is very important in the treatment of cancer. If during treatment their number becomes less than 500 - 1,000 in 1 microliter of blood, then, as a rule, the danger of infectious infections increases greatly, even from pathogens that are usually not dangerous at all for a healthy person.
Lymphocytes
Lymphocytes are white blood cells, 70% of which are found in the tissues of the lymphatic system. Such tissues include, for example, the spleen, pharyngeal tonsils (tonsils) and .
Groups of lymph nodes are located under the jaws, in the armpits, on the back of the head, in the groin area and in the lower abdomen. The spleen is an organ that is located on the left side of the upper abdomen under the ribs; The thymus gland is a small organ behind the breastbone. In addition, lymphocytes are found in lymph. Lymph is a colorless, watery fluid found in lymphatic vessels. It, like blood, covers the entire body with its branches.
Lymphocytes recognize and destroy body cells affected by the virus, as well as cancer cells, and remember those pathogens with which they have already been in contact. Experts distinguish between s and s, which differ in their immunological characteristics, and also identify some other, rarer subgroups of lymphocytes.
Monocytes
Monocytes are blood cells that go into tissues and there begin to work as “large phagocytes” (macrophages), absorbing pathogens, foreign bodies and dead cells, and clearing them from the body. In addition, they present part of the absorbed and digested organisms on their surface and thus activate lymphocytes for immune defense.
Platelets (blood platelets)
Blood plates, also called s, are primarily responsible for stopping bleeding. If damage occurs to the walls of blood vessels, they clog the damaged area in the shortest possible time and thus stop the bleeding.
Too low a platelet level (occurs, for example, in patients with cancer) is manifested in nosebleeds or bleeding gums, as well as small hemorrhages on the skin. Even after the most minor injury, bruises may appear, as well as hemorrhages in the internal organs.
The platelet count in the blood may also drop due to chemotherapy. Thanks to the transfusion (transfusion***) of blood platelets (thrombotic concentrate), as a rule, it is possible to maintain an acceptable level of platelets.
Consisting of 90% water with proteins, minerals and organic substances (proteins, anions, cations, etc.) dissolved in it. And about 40-50% comes from shaped elements, which are represented by:
Red blood cells - erythrocytes (the most numerous components);
- blood platelets - platelets;
- blood cells - leukocytes.
This ratio of plasma and formed elements received a hematocrit number. The phrase is formed from two Greek words - “blood” and “indicator”. A change in this number is observed with erythremia and anemia.
Blood functions
Blood circulates in the circulatory system uninterruptedly, constantly being renewed and performing a number of important functions. Formally, blood functions can be divided into two groups.
Transport function
The first one is transport. This function has several subfunctions. First, blood provides tissues with oxygen. From the lungs to various tissues, blood carries oxygen, and from them to the lungs - carbon dioxide. Nutrients are also delivered to the tissues with blood.
Blood transports waste products from tissues to the lungs and kidneys. This subfunction is called excretory.
Another important part of blood work is regulating body temperature. Blood carries heat. And finally, it is the connecting link between all body systems. It is the signal substances () that regulate all the activities of the body that are distributed.
Protective function
Blood is an important element of the body's defense. It is the determining factor of immunity. Leukocytes (white blood cells) protect the body from germs, foreign substances, pathogenic bacteria, and viruses.
Thus, neutrophils, which make up 50-70% of leukocytes, protect the body from microbes and their toxins. Eosinophils, which account for 1-5% of leukocytes, are busy destroying foreign proteins and neutralizing their toxins. Basophils (about 1% of all leukocytes) are involved in immediate hypersensitivity reactions. Monocytes (2-10% of white blood cells) are called the body's wipers. Their main function is to cleanse foci of inflammation and prepare tissues for regeneration.
And finally, lymphocytes (20-40% of leukocytes). Their functions: destruction of the body’s own mutant cells, provision of immune memory, synthesis of antibodies, etc. Platelets also perform a protective function, preventing large blood loss from various injuries and wounds.
Olga Sokolova
"What is blood for?" Summary of an open lesson in the preparatory group
Subject: "For what do you need blood for?» .
(V preparatory group)
Tasks:
Give an idea of what it does blood in the body,
Develop attention, memory, thinking.
Develop hygienic skills to protect your health.
Result:
blood distributes nutrition to all organs,
blood carries oxygen throughout the body,
Fights germs that enter the body.
Activating the dictionary: nutrition, oxygen, spreads, germs
Concepts: heart, arteries, veins, kidneys.
Actions: manipulation of a boat using a poster.
I draw the guys’ attention to the bottle with the inscription “Water of Life”.
Guys, in which fairy tale did we meet “Water of Life” (the tale of “Ivan Tsarevich and the Gray Wolf”).
Why did the gray wolf need “Living Water”? (to revive Ivan - Tsarevich)
I would like to invite you on an interesting journey through our body, along two large rivers.
Look at the poster.
Our main port is “Heart”. One red river flows down from the port “Heart” to the small station “Palchiki”. This river carries oxygen to all cells, it is called “Artery”. Repeat.
Another river, blue in color, is called "Vein". Repeat. It flows from the "Palchiki" station to the "Heart" port and carries the gas exhausted by the cells - carbon dioxide, so the river becomes a different color. The water in these rivers is not simple, but living, it is called - blood. Repeat.
- Heart is beating: "Knock Knock" like the engine of a car, it pushes day and night blood with oxygen into the river “Artery”, it never rests, Listen to yourself how the main port “Heart” works with your hand,
Remember from what are our muscles made of?., bones, hair? (from cells)
Yes, that's right, if a little blood If you look at it under a microscope, you can see that it consists of boat cells. These boats are red, white and purple.
Why do you think red blood? (more red cage ships).
Right. (To play out the actions, I suggest paper boats in red, white and purple colors).
I suggest the children take red boats.
Red ships are merchant ships, carrying the most valuable cargo - oxygen.
We set off from the port "Heart" down the river "Arteriya" - we brought oxygen to the cells, gave it to and collected the waste gas - carbon dioxide,
What river do you think we will return along? (on the blue line, we took the exhaust gas. We arrived and put the boats in the port.
While the red boats are carrying valuable cargo - oxygen, what are the white and purple boats doing? Here's what.
As soon as we cut our hand, microbes try to penetrate the wounds, and then the white boats begin to work (the model shows a wound).
I suggest taking white boats.
They surround microbes in a tight ring and eat them, “devour” them, they are called devourers. (game moment with germs)
At this time, purple ships, they are called repairmen, close the entrance to the wound, do not let germs in. This is the kind of fight-battle that happens in our body if we cut ourselves. Many cell ships die in the battle, they need to be removed, cleaned blood. This is done in our body by the orderlies - the kidneys, which are located on both sides of the rivers. Here they are. Repeat "Kidneys" blood cleanses itself of everything harmful, poisonous and returns to the main port - “Heart”.
Guys, what do you think will happen to us if our heart stops? (the artery will become empty, cells without oxygen will begin to die, which means we will die). The heart and all organs must be protected.
Fizminutka "We are fearless sailors"
Do you want to become captains and sail along these rivers?
Put on your caps (headbands), take the boats and place them in the main port "Heart", to the river “Artery”. We swam down (working with a poster on the floor).
What are we bringing about you? (oxygen)
Well done! We sailed to the port “Zheludok”, “Intestines”.
What are we giving away? (part of oxygen)
What does the intestine give us? (food for cells).
I hear a signal from the port "Leg": “Germs crawl into a scratch on a finger...” Give commands to the ships!
What kind of cargo was brought to the port of Noga? (food, oxygen).
We collect the exhaust gas from the dead cell ships.
Which river will we return by? (vein)
What will we bring? (exhaust gas, food, lost ships).
Which port should you go to to get medical treatment? (port "Kidneys")
Guys, now let’s go for valuable cargo to the port “Lungs” - for oxygen, and from there to the port “Heart”.
For why do we need blood in the body?
Bottom line:
Our journey has ended.
Which captain himself wants to sail his ship along this route? (we provide assistance).
Well done! You can apply to the school of real captains.
