Blood under a microscope. Human blood under a microscope The smallest blood cells

They are small and can only be viewed under a microscope.

All blood cells are divided into red and white. The first are erythrocytes, which make up the majority of all cells, the second are leukocytes.

It is customary to classify platelets as blood cells. These small platelets are not actually complete cells. They are small fragments detached from large cells - megakaryocytes.

Erythrocytes

Red blood cells are called red blood cells. This is the largest group of cells. They carry oxygen from the respiratory system to the tissues and take part in the transport of carbon dioxide from the tissues to the lungs.

The place of erythrocyte formation is the red bone marrow. They live for 120 days and are destroyed in the spleen and liver.

Formed from precursor cells - erythroblasts, which pass through different stages development and are divided several times. Thus, up to 64 red blood cells are formed from erythroblast.

Erythrocytes are devoid of a nucleus and in shape resemble a disc concave on both sides, the average diameter of which is about 7-7.5 microns, and the thickness at the edges is 2.5 microns. This shape helps to increase the plasticity required for passage through small vessels and the surface area for the diffusion of gases. Old erythrocytes lose their plasticity, which is why they are retained in small vessels spleens are also destroyed there.

Most of erythrocytes (up to 80%) has a biconcave spherical shape. The remaining 20% may have another: oval, cup-shaped, spherical simple, sickle-shaped, etc. The violation of the shape is associated with various diseases(anemia, vitamin B 12 deficiency, folic acid, iron, etc.).

Most of the erythrocyte cytoplasm is occupied by hemoglobin, which consists of protein and heme iron, which gives the blood a red color. The non-protein portion consists of four heme molecules with an Fe atom in each. It is thanks to hemoglobin that the erythrocyte is able to carry oxygen and remove carbon dioxide. In the lungs, an iron atom binds to an oxygen molecule, hemoglobin is converted into oxyhemoglobin, which gives the blood a scarlet color. In tissues, hemoglobin gives up oxygen and attaches carbon dioxide, turning into carbohemoglobin, as a result, the blood becomes dark. In the lungs, carbon dioxide is separated from hemoglobin and is excreted by the lungs to the outside, and the incoming oxygen is again bound to iron.

In addition to hemoglobin, the erythrocyte cytoplasm contains various enzymes (phosphatase, cholinesterase, carbonic anhydrase, etc.).

The erythrocyte membrane has a fairly simple structure compared to the membranes of other cells. It is an elastic thin mesh that provides fast gas exchange.

In blood healthy person in small quantities there may be immature red blood cells called reticulocytes. Their number increases with significant blood loss, when red cells are required to be replaced and the bone marrow does not have time to produce them, therefore it releases immature ones, which are nevertheless capable of performing the functions of red blood cells for transporting oxygen.

Leukocytes

Leukocytes are white blood cells, the main task of which is to protect the body from internal and external enemies.

They are usually divided into granulocytes and agranulocytes. The first group is granular cells: neutrophils, basophils, eosinophils. The second group does not have granules in the cytoplasm; it includes lymphocytes and monocytes.

Neutrophils

This is the most numerous group of leukocytes - up to 70% of the total number of white cells. Neutrophils got their name due to the fact that their granules are stained with dyes with a neutral reaction. Its granularity is fine, the granules have a violet-brownish tint.

The main task of neutrophils is phagocytosis, which consists in capturing pathogenic microbes and tissue breakdown products and their destruction inside the cell with the help of lysosomal enzymes in the granules. These granulocytes fight mainly bacteria and fungi and, to a lesser extent, viruses. Pus is composed of neutrophils and their remnants. Lysosomal enzymes are released during the breakdown of neutrophils and soften nearby tissues, thus forming a purulent focus.

Neutrophil is a round-shaped nuclear cell, reaching a diameter of 10 microns. The nucleus can be in the form of a rod or consist of several segments (from three to five), connected by strands. An increase in the number of segments (up to 8-12 or more) indicates pathology. Thus, neutrophils can be stab or segmented. The first are young cells, the second are mature. Cells with a segmented nucleus make up up to 65% of all leukocytes, stab cells in the blood of a healthy person - no more than 5%.

In the cytoplasm there are about 250 varieties of granules containing substances due to which the neutrophil performs its functions. These are protein molecules that affect metabolic processes (enzymes), regulatory molecules that control the work of neutrophils, substances that destroy bacteria and other harmful agents.

These granulocytes are formed in the bone marrow from neutrophilic myeloblasts. A mature cell stays in the brain for 5 days, then enters the bloodstream and lives here up to 10 hours. From the vascular bed, neutrophils enter the tissues, where they stay for two or three days, then they enter the liver and spleen, where they are destroyed.

Basophils

There are very few of these cells in the blood - no more than 1% of the total number of leukocytes. They have a rounded shape and a segmented or rod-shaped nucleus. Their diameter reaches 7-11 microns. Inside the cytoplasm there are dark purple granules of various sizes. The name was given due to the fact that their granules are colored with dyes with an alkaline, or basic, reaction. Basophil granules contain enzymes and other substances involved in the development of inflammation.

Their main function is the release of histamine and heparin and participation in the formation of inflammatory and allergic reactions, including immediate type(anaphylactic shock). In addition, they are able to reduce blood clotting.

Formed in the bone marrow from basophilic myeloblasts. After maturation, they enter the bloodstream, where they are for about two days, then go into the tissues. What happens next is still unknown.

Eosinophils

These granulocytes make up approximately 2-5% of the total white cell count. Their granules are stained with an acidic dye - eosin.

They have a rounded shape and a weakly colored nucleus, consisting of segments of the same size (usually two, less often three). In diameter, eosinophils reach µm. Their cytoplasm turns pale blue and is almost invisible among a large number of large round yellow-red granules.

These cells are formed in the bone marrow, their precursors are eosinophilic myeloblasts. Their granules contain enzymes, proteins and phospholipids. The matured eosinophil lives in the bone marrow for several days, after entering the blood it is in it for up to 8 hours, then moves to tissues in contact with the external environment (mucous membranes).

These are round cells with a large nucleus that occupies most of the cytoplasm. Their diameter is 7 to 10 microns. The kernel is round, oval or bean-shaped and has a rough structure. They consist of lumps of oxychromatin and basiromatin, resembling lumps. The nucleus can be dark purple or light purple, sometimes there are light blotches in the form of nucleoli. The cytoplasm is light blue; it is lighter around the nucleus. In some lymphocytes, the cytoplasm has azurophilic granularity, which turns red when stained.

There are two types of mature lymphocytes circulating in the blood:

Narrow plasma. They have a rough, dark purple nucleus and cytoplasm in the form of a narrow blue rim.
Wide plasma. In this case, the kernel has a paler color and bean-like shape. The rim of the cytoplasm is wide enough, gray-blue in color, with rare ausurophilic granules.

From atypical lymphocytes in the blood, you can find:

Small cells with barely visible cytoplasm and pyknotic nucleus.
Cells with vacuoles in the cytoplasm or nucleus.
Cells with lobular, kidney-shaped, barbed nuclei.
Bare kernels.

Lymphocytes are formed in the bone marrow from lymphoblasts and in the process of maturation they undergo several stages of division. Its full maturation occurs in the thymus, lymph nodes and spleen. Lymphocytes are immune cells that provide immune responses. Distinguish between T-lymphocytes (80% of the total) and B-lymphocytes (20%). The first passed maturation in the thymus, the second - in the spleen and lymph nodes. B-lymphocytes are larger in size than T-lymphocytes. The life span of these leukocytes is up to 90 days. For them, blood is a transport medium through which they get to the tissues where their help is needed.

The actions of T-lymphocytes and B-lymphocytes are different, although both are involved in the formation of immune responses.

The former are engaged in the destruction of harmful agents, usually viruses, by phagocytosis. The immune responses in which they are involved are nonspecific resistance because the actions of T-lymphocytes are the same for all harmful agents.

According to the actions performed, T-lymphocytes are divided into three types:

T-helpers. Their main task is to help B-lymphocytes, but in some cases they can act as killers.
T-killers. Destroy harmful agents: foreign, cancerous and mutated cells, infectious agents.
T-suppressors. They inhibit or block too active reactions of B-lymphocytes.

B-lymphocytes act differently: against pathogens, they produce antibodies - immunoglobulins. This happens as follows: in response to the actions of harmful agents, they interact with monocytes and T-lymphocytes and turn into plasma cells that produce antibodies that recognize the corresponding antigens and bind them. For each type of microbes, these proteins are specific and can only destroy certain kind, therefore, the resistance that these lymphocytes form is specific, and it is directed mainly against bacteria.

These cells provide the body's resistance to certain harmful microorganisms, which is commonly called immunity. That is, having met a harmful agent, B-lymphocytes create memory cells that form this resistance. The same thing - the formation of memory cells - is achieved by vaccinations against infectious diseases. In this case, a weak microbe is introduced so that a person can easily endure the disease, and as a result, memory cells are formed. They can remain for life or for a certain period, after which the vaccination must be repeated.

Monocytes

Monocytes are the largest of the white blood cells. Their number ranges from 2 to 9% of all white blood cells. Their diameter reaches 20 microns. The nucleus of a monocyte is large, occupies almost the entire cytoplasm, it can be round, bean-shaped, in the form of a mushroom, a butterfly. When stained, it turns red-violet. The cytoplasm is smoky, bluish-smoky, less often blue. It usually has azurophilic fine grain. It may contain vacuoles (voids), pigment grains, phagocytosed cells.

Monocytes are produced in the bone marrow from monoblasts. After maturation, they immediately appear in the blood and stay there for up to 4 days. Some of these leukocytes die, some move to tissues, where they mature and turn into macrophages. These are the most large cells with a large round or oval nucleus, blue cytoplasm and a large number of vacuoles, which makes it appear foamy. The life span of macrophages is several months. They can be constantly in one place (resident cells) or move (wandering).

Monocytes form regulatory molecules and enzymes. They are capable of generating an inflammatory response, but they can also inhibit it. In addition, they participate in the process of wound healing, helping to speed it up, contribute to the restoration of nerve fibers and bone tissue... Their main function is phagocytosis. Monocytes destroy harmful bacteria and inhibit the proliferation of viruses. They are able to execute commands, but cannot distinguish between specific antigens.

Platelets

These blood cells are small, nuclear-free plates and can be round or oval in shape. During activation, when they are at the damaged vessel wall, they form outgrowths, so they look like stars. Platelets contain microtubules, mitochondria, ribosomes, specific granules containing substances necessary for blood clotting. These cells are equipped with a three-layer membrane.

Platelets are produced in the bone marrow, but in a completely different way than the rest of the cells. Platelets are formed from the largest brain cells - megakaryocytes, which, in turn, are formed from megakaryoblasts. Megakaryocytes have a very large cytoplasm. After the maturation of the cell, membranes appear in it, dividing it into fragments, which begin to separate, and thus platelets appear. They leave the bone marrow into the blood, stay in it for 8-10 days, then die in the spleen, lungs, and liver.

Platelets can be of different sizes:

the smallest are microforms, their diameter does not exceed 1.5 microns;
normoforms reach 2-4 microns;
macroforms - 5 microns;
megaloforms - 6-10 microns.

Platelets perform a very important function - they participate in the formation of a blood clot, which closes the damage in the vessel, thereby preventing blood from flowing out. In addition, they maintain the integrity of the vessel wall, contribute to its fastest recovery after damage. When bleeding begins, platelets adhere to the edge of the lesion until the hole is completely closed. The adhered plates begin to break down and secrete enzymes that affect the blood plasma. As a result, insoluble fibrin filaments are formed, tightly covering the site of injury.

Conclusion

Blood cells have complex structure, and each kind performs a certain job: from the transportation of gases and substances to the development of antibodies against foreign microorganisms. Their properties and functions are currently not fully understood. For normal life a person needs a certain amount of each type of cells. According to their quantitative and qualitative changes, physicians have the opportunity to suspect the development of pathologies. The composition of the blood is the first thing that a doctor examines when a patient applies.

Human blood cells. The structure of blood cells

V anatomical structure the human body distinguishes between cells, tissues, organs and organ systems that carry out all vital important functions... There are about 11 such systems in total:

nervous (central nervous system);
digestive;
cardiovascular;
hematopoietic;
respiratory;
musculoskeletal;
lymphatic;
endocrine;
excretory;
genital;
musculocutaneous.

Each of them has its own characteristics, structure and performs certain functions. We will consider that part circulatory system, which is its foundation. It's about liquid tissue human body... Let's study the composition of blood, blood cells and their significance.

Anatomy of the human cardiovascular system

The most important organ forming this system, is the heart. It is this muscle sac that plays a fundamental role in blood circulation throughout the body. Different sizes and directions depart from it. blood vessels, which are divided into:

veins;
arteries;
the aorta;
capillaries.

The listed structures carry out a constant circulation of the special tissue of the body - blood, which washes all cells, organs and systems as a whole. In humans (as in all mammals), two circles of blood circulation are distinguished: large and small, and such a system is called closed.

Its main functions are as follows:

gas exchange - the implementation of transport (that is, movement) of oxygen and carbon dioxide;
nutritious, or trophic - delivery of the necessary molecules from the digestive organs to all tissues, systems, and so on;
excretory - the withdrawal of harmful and waste substances from all structures to the excretory;
delivery of products endocrine system(hormones) to all cells of the body;
protective - participation in immune reactions through special antibodies.

The features are obviously very significant. That is why the structure of blood cells, their role and, in general, characteristics are so important. After all, blood is the basis of the activity of the entire corresponding system.

The composition of blood and the value of its cells

What is this red liquid with a specific taste and smell that appears on any part of the body at the slightest wound?

By its nature, blood is a type of connective tissue, consisting of a liquid part - plasma and shaped elements of cells. Their percentage is approximately 60/40. In total, there are about 400 different compounds in the blood, both of a hormonal nature and vitamins, proteins, antibodies and trace elements.

The volume of this fluid in the body of an adult is about 5.5-6 liters. The loss of 2-2.5 of them is deadly. Why? Because blood has a number of vital functions.

Provides homeostasis of the body (the constancy of the internal environment, including body temperature).
The work of blood and plasma cells leads to the spread of important biologically active connections: proteins, hormones, antibodies, nutrients, gases, vitamins, as well as metabolic products.
Due to the constancy of the blood composition, a certain level of acidity is maintained (pH should not exceed 7.4).
It is this tissue that takes care of removing unnecessary, harmful compounds from the body through excretory system and sweat glands.
Liquid solutions of electrolytes (salts) are excreted in the urine, which is provided exclusively by the work of the blood and excretory organs.

It is difficult to overestimate the importance of human blood cells. Let's consider in more detail the structure of each structural element this important and unique biological fluid.

Plasma

Viscous liquid yellowish, occupying up to 60% of the total blood mass. The composition is very diverse (several hundred substances and elements) and includes compounds from various chemical groups... So, this part of the blood includes:

Protein molecules. It is believed that every protein that exists in the body is present initially in the blood plasma. There are especially many albumin and immunoglobulins, which play an important role in defense mechanisms... In total, about 500 names of plasma proteins are known.
Chemical elements in the form of ions: sodium, chlorine, potassium, calcium, magnesium, iron, iodine, phosphorus, fluorine, manganese, selenium and others. Almost everything is present here. Periodic system Mendeleev, about 80 items of it are in the blood plasma.
Mono-, di- and polysaccharides.
Vitamins and coenzymes.
Hormones of the kidneys, adrenal glands, gonads (adrenaline, endorphin, androgens, testosterones and others).
Lipids (fats).
Enzymes as biological catalysts.

The most important structural parts of plasma are blood cells, of which there are 3 main types. They are the second component of this type of connective tissue, their structure and functions performed deserve special attention.

Erythrocytes

The smallest cell structures, the size of which does not exceed 8 microns. However, their number is over 26 trillion! - makes you forget about the insignificant volumes of a single particle.

Erythrocytes are blood cells that are devoid of conventional component parts structures. That is, they have no nucleus, no EPS (endoplasmic reticulum), no chromosomes, no DNA, and so on. If you compare this cell with anything, then a biconcave porous disc - a kind of sponge - is best suited. All inner part, each pore is filled with a specific molecule - hemoglobin. It is a protein, the chemical basis of which is an iron atom. It is easily able to interact with oxygen and carbon dioxide, which is the main function of red blood cells.

That is, red blood cells are simply filled with hemoglobin in the amount of 270 million per unit. Why red? Because it is this color that iron, which is the basis of protein, gives them, and because of the overwhelming majority of red blood cells in the composition of human blood, it acquires the appropriate color.

By appearance When viewed through a special microscope, red blood cells are rounded structures, as if flattened from the top and bottom to the center. Their precursors are stem cells produced in the bone marrow and the spleen depot.

Function

The role of red blood cells is explained by the presence of hemoglobin. These structures collect oxygen in pulmonary alveoli and carry it to all cells, tissues, organs and systems. In this case, gas exchange takes place, because giving oxygen, they take carbon dioxide, which is also transported to the places of excretion - the lungs.

V different ages erythrocyte activity is not the same. So, for example, the fetus produces a special fetal hemoglobin, which carries out the transport of gases an order of magnitude more intensive than the usual one typical for adults.

There is a common disease that red blood cells provoke. Blood cells, produced in insufficient quantities, lead to anemia - a serious disease of general weakening and thinning of the vitality of the body. After all, the normal supply of oxygen to tissues is disrupted, which causes their starvation and, as a result, rapid fatigability and weakness.

The lifespan of each red blood cell is from 90 to 100 days.

Platelets

One more important cells human blood - platelets. These are flat structures that are 10 times smaller than erythrocytes. Such small volumes allow them to quickly accumulate and stick together to fulfill their intended purpose.

In the body of these guards, there are about 1.5 trillion pieces, the number is constantly replenished and updated, since their lifespan, alas, is very short - only about 9 days. Why law enforcers? This has to do with the function they are performing.

Meaning

Focusing on the parietal vascular space, blood cells, platelets, carefully monitor the health and integrity of organs. If suddenly somewhere there is a rupture of tissues, they react immediately. Sticking together, they seem to seal the damage and restore the structure. In addition, it is they who largely owe the merit of blood coagulation in the wound. Therefore, their role is precisely to ensure and restore the integrity of all vessels, integuments, and so on.

Leukocytes

White blood cells, which got their name for their absolute colorlessness. But the lack of color does not diminish their importance in the least.

Rounded bodies are divided into several main types:

The sizes of these structures are quite significant in comparison with erythrocytes and platelets. They reach 23 microns in diameter and live only a few hours (up to 36). Their functions vary depending on the variety.

White blood cells live not only in it. In fact, they only use liquid in order to get to the desired destination and perform their functions. Leukocytes are found in many organs and tissues. Therefore, specifically in the blood, their number is small.

Role in the body

The general importance of all varieties of white bodies is to provide protection against foreign particles, microorganisms and molecules.

These are the main functions that leukocytes perform in the human body.

Stem cells

The life span of blood cells is insignificant. Only a few types of leukocytes, which are responsible for memory, can exist for a lifetime. Therefore, a hematopoietic system functions in the body, consisting of two organs and ensuring the replenishment of all formed elements.

These include:

Especially great importance has bone marrow. It is located in the cavities of flat bones and produces absolutely all blood cells. In newborns, tubular formations (shin, shoulder, hands and feet) also take part in this process. With age, such a brain remains only in pelvic bones, but it is enough to provide the entire body shaped elements blood.

Another organ in which they are not produced, but are stored for emergency cases sufficiently large amounts of blood cells - spleen. This is a kind of "blood depot" of each human body.

Why are stem cells needed?

Blood stem cells are the most important undifferentiated formations that play a role in hematopoiesis - the formation of the tissue itself. Therefore, their normal functioning is a guarantee of health and quality work of the cardiovascular and all other systems.

In cases where a person loses a large number of blood, which the brain itself cannot replenish or does not have time to, selection of donors is necessary (it is also necessary in the case of blood renewal in case of leukemia). This process is complex, it depends on many characteristics, for example, on the degree of kinship and comparability of people with each other in terms of other indicators.

Norms of blood cells in medical analysis

For a healthy person, there are certain norms for the amount of formed blood cells per 1 mm 3. These indicators are as follows:

Erythrocytes - 3.5-5 million, protein hemoglobin g / l.
Platelets thous.
Leukocytes - from 2 to 5 thousand.

These rates can vary depending on the age and health of the person. That is, blood is an indicator of the physical condition of people, therefore its timely analysis is the key to successful and high-quality treatment.

Blood under a microscope and human blood types

Since ancient times, human blood has been endowed with mystical properties. People made sacrifices to the gods with the indispensable rite of bloodletting. With the touch of freshly cut wounds, sacred oaths were sealed. A wooden idol "crying" with blood was the last argument of the priests in an attempt to convince their fellow tribesmen of something. The ancient Greeks considered blood to be the guardian of the properties of the human soul.

Modern science has penetrated many of the secrets of blood, but research continues to this day. Medicine, immunology, genogeography, biochemistry, genetics study biophysical and Chemical properties blood in the complex. Today we know what human blood groups are. The optimal composition of the blood of a person adhering to healthy way life. It was revealed that the level of sugar in a person's blood changes depending on his physical and mental state... Scientists have found an answer to the question "how much blood is in a person and what is the blood flow rate?" not out of idle curiosity, but for the purpose of diagnosing and treating cardiovascular and other diseases.

The microscope has long become an indispensable human assistant in many areas. In the lens of the device, you can see what is not visible with the naked eye. The most interesting object for research is blood. Under a microscope, you can see the main elements of the composition of human blood: plasma and corpuscles.

For the first time, the composition of human blood was investigated by an Italian doctor, Marcello Malpighi. He mistook the shaped elements floating in the plasma for fat globules. Blood cells have more than once been called either balloons or animals, mistaking them for intelligent beings. The term "blood cells" or "blood balls" was introduced into scientific use by Anthony Levenguk. Blood under a microscope is a kind of mirror of the state of the human body. One drop at a time can determine that in this moment worries the person. Hematology or a science that studies blood, hematopoiesis and specific diseases, today is experiencing a boom in its development. Thanks to the study of blood, new high-tech methods of diagnosing diseases and their treatment are being introduced into the practice of doctors.

The blood of a sick person

Healthy person's blood

Blood of a healthy person (electron microscope)

You too can join the world of science with optical instruments Altami. Microscopic histological slides, which include blood samples, can be prepared at home without special processing. To do this, wash and degrease the slides on which you place a drop of blood. With a momentary motion of another slide or spatula, spread a thin layer of the liquid. For home experiments, the use of special dyes is unnecessary. Dry the preparation in air until the gloss disappears and fix it on the stage, first placing a cover glass on top. The temporary biological product is usable for only a few hours, but it will also be enough to unravel the mysteries of blood with our hint.

By the way, in order to see what is part of a person's blood, it is not at all necessary to cut a finger. It is enough to use ready-made Altami micropreparations.

So, if you look at blood under a microscope, under high magnification, then we will see that it contains a lot different cells... Today it is known that blood in the human body is a type of connective tissue. It consists of the liquid part of the plasma and the corpuscular elements suspended in it: erythrocytes, leukocytes and platelets. Blood cells are produced in the red bone marrow. Interestingly, in a child, the entire bone marrow is red, while in an adult, blood is produced only in certain bones.

Pay attention to the pink flattened balls - red blood cells. They carry molecules of the protein hemoglobin, which gives red blood cells a delicate shade. With the help of protein, red blood cells enrich every cell of the human body with oxygen and remove carbon dioxide. If a person drinks a little water, then the red blood cells stick together and do not tolerate hemoglobin. In certain diseases, not enough red blood cells are produced, which leads to oxygen starvation fabrics. If the blood is infected with a fungus, these blood cells will resemble gears or be shaped like curved hooks.

Blood coagulation (electron microscope)

It is common knowledge that there are different groups human blood and Rh factor, positive or negative. It is the erythrocytes that make it possible to classify a person's blood as one or another group and Rh belonging. The revealed various reactions between the erythrocytes of one person and the blood plasma of another made it possible to systematize the blood by groups and rhesus. The development of a blood compatibility table is on a par with such a great discovery as the periodic system. chemical elements Mendeleev.

Today, the blood type is determined in the first days of a newborn's life. Like fingerprints, a person's blood types remain unchanged throughout their lives. Back in 1900, the world did not know what blood types were. A person who needed a blood transfusion was subjected to the procedure, unaware that his blood might be incompatible with the donor's blood. Austrian immunologist, nobel laureate Karl Landsteiner initiated the classification of fluid connective tissue and discovered the Rhesus system. The blood compatibility table acquired its final form thanks to the research of the Czech doctor Jakob Jansky.

Blood leukocytes are represented by several types of cells. Neutrophils or granulocytes are cells with a multi-part nucleus inside. Fine granularity is scattered around large cells. Lymphocytes have a smaller round nucleus, but it occupies almost the entire cell. The bean-shaped nucleus is characteristic of monocytes.

Red blood cells or red blood cells (electron microscope)

Red blood cells or red blood cells

White blood cells protect us from infections and diseases, including such formidable ones as cancer. At the same time, the functions of warrior cells are strictly delineated. If T-lymphocytes recognize and remember what various microbes look like, then B-lymphocytes develop antibodies against them. Neutrophils "devour" substances foreign to the body. In the fight for human health, both microbes and lymphocytes die. Increased white blood cells indicate the presence inflammatory process in organism.

Platelets or platelets are responsible for creating dense blood clots that stop minor bleeding. Platelets do not have cell nucleus and are clusters of small granular cells with a coarse membrane. As a rule, platelets "walk in formation", in the amount of 3 to 10 pieces.

The liquid portion of the blood is called plasma. Erythrocytes, leukocytes and platelets together with plasma make up important component blood systems - peripheral blood. You are already tormented by the question: "How much blood is in a person?" Then it will be interesting for you to know that the total amount of blood in an adult body is 6–8% of body weight, and in a child’s body - 8–9%. Now you yourself can calculate how much blood is in a person, knowing his weight.

In addition to blood cells, plasma contains proteins, minerals in the form of ions. Other inclusions, harmful, which should not be in the blood of a healthy person, are visible under the Altami microscope lens. Thus, uric acid salts are presented in the form of crystals resembling shards of glass. Crystals mechanically damage blood cells and peel off the film from the walls of blood vessels. Cholesterol looks like flakes that accumulate on the walls of the blood vessel and gradually narrow its lumen. The presence of bacteria and fungi of various irregular shapes indicates serious violations immune system person.

Leukocytes or white blood cells (electron microscope)

Macrophages destroy foreign elements. They are good.

You can find irregularly shaped crystalloids in the blood - this is sugar, an excess of which leads to metabolic disorders. Human blood sugar - the most important indicator v clinical analysis blood. Avoid diseases such as diabetes, some diseases of the central nervous system, hypertension, atherosclerosis and others is possible if you take a blood test for glucose once a year. A person's blood sugar level, high or low, directly indicates a predisposition to a particular disease.

Thanks to the fascinating lesson - the study of a drop of blood under the Altami microscope - you made a journey into the world of hematology: you learned about the composition of blood and the important role it plays in the human body.

Almost all of the images presented here were taken with a scanning electron microscope(SAM). The electron beam emitted by such a device interacts with the atoms of the desired object, resulting in 3D images of the highest resolution. A magnification of 250,000 times allows you to see details in the size of 1-5 nanometers (that is, billionths of a meter).

The first SEM image was obtained in 1935 by Max Knoll, and already in 1965 the Cambridge Instrumentation Company offered its Stereoscan to DuPont. Now such devices are widely used in research centers.

Taking a look at the pictures below will take you on a journey through your body, from your head to your intestines and pelvic organs. You will see what normal cells look like and what happens to them when cancer affects them, and you will also get a visual idea of how, say, the first meeting of an egg and a sperm cell occurs.

Shown here is, you might say, the basis of your blood - red blood cells (RBC). These pretty biconcave cells are responsible for carrying oxygen throughout the body. Usually in one cubic millimeter of blood such cells are 4-5 million in women and 5-6 million in men. People living in the highlands, where there is a lack of oxygen, have even more red cells.

To avoid being so invisible to ordinary eye splitting hair, you need to regularly cut and use good shampoos and air conditioners.

Of the 100 billion neurons in your brain, Purkinje cells are among the largest. Among other things, they are responsible for motor coordination in the cerebellar cortex. They are destructively affected by both alcohol or lithium poisoning, and autoimmune diseases, genetic abnormalities (including autism), as well as neurodegenerative diseases (Alzheimer's, Parkinson's, multiple sclerosis, etc.).

This is what stereocilia look like, that is, the sensory elements of the vestibular apparatus inside your ear. By capturing sound vibrations, they control the reciprocal mechanical movements and actions.

Shown here are retinal blood vessels emerging from a black-painted optic nerve head. This disc is a "blind spot" since there are no light receptors in this area of the retina.

There are about 10,000 taste buds on the tongue that help identify salty, sour, bitter, sweet and spicy tastes.

To avoid such deposits similar to unmilled spikelets on the teeth, it is advisable to brush your teeth more often.

Remember how beautiful healthy red blood cells looked. Now look at how they become in the web of the deadly blood clot... In the very center is a white blood cell (leukocyte).

This is a view of your lung from the inside. Empty cavities are the alveoli, where oxygen is exchanged for carbon dioxide.

Now take a look at how deformed lungs differ from healthy ones in the previous picture.

Villi small intestine increase its area, which contributes better assimilation food. These are outgrowths of an irregular cylindrical shape up to 1.2 millimeters high. The basis of the villi is loose connective tissue. In the center, like a rod, passes a wide lymphatic capillary, or lactiferous sinus, and on the sides of it there are blood vessels and capillaries. Fats enter the lymph through the lactiferous sinus, and then fats enter the bloodstream, and proteins and carbohydrates enter the bloodstream through the blood capillaries of the villi. On closer inspection, you can see food debris in the grooves.

Here you see a human egg. The egg cell is covered with a glycoprotein membrane (zona pellicuda), which not only protects it, but also helps to capture and retain the sperm. Two coronal cells are attached to the shell.

The picture captures the moment when several sperm are trying to fertilize an egg.

It looks like a war of the worlds, in fact, in front of you is an egg 5 days after fertilization. Some spermatozoa are still retained on its surface. The image was taken with a confocal (confocal) microscope. The oocyte and sperm nuclei are purple, while the sperm flagella are green. Blue areas are nexuses, intercellular gap junctions that communicate between cells.

You are present at the beginning of a new life cycle... A six-day-old human embryo is implanted into the endometrium, the lining of the uterine cavity. Let's wish him good luck!

Blood is the most important system in the human body that performs many different functions. Blood is a transport system through which vital substances are transferred to the organs and waste substances, decay products and other elements that are to be excreted from the body are removed from the cells. The blood also circulates substances and cells that provide protection for the body as a whole.

Blood consists of cells and a liquid part - serum, consisting of proteins, fats, sugars and trace elements.

Three main types of cells are distinguished in the blood:

Erythrocytes;
Leukocytes;

Red blood cells - cells that transport oxygen to tissues

Erythrocytes are highly specialized cells that do not have a nucleus (lost during maturation). Most of the cells are represented by biconcave discs, the average diameter of which is 7 μm, and the peripheral thickness is 2-2.5 μm. There are also spherical and domed erythrocytes.

Due to the shape, the cell surface is significantly increased for gas diffusion. Also, this shape contributes to an increase in the plasticity of the erythrocyte, due to which it deforms and moves freely through the capillaries.

In pathological and old cells, plasticity is very low, and therefore they are retained and destroyed in the capillaries of the reticular tissue of the spleen.

The erythrocyte membrane and non-nuclear cells provide the main function of erythrocytes - the transport of oxygen and carbon dioxide. The membrane is completely impermeable to cations (except for potassium) and highly permeable to anions. The membrane is 50% composed of proteins that determine the blood group and provide a negative charge.

Erythrocytes are different from each other in:

Size;
Age;
Resistance to adverse factors.

Video: Erythrocytes

Red blood cells are the most numerous cells in the human blood

Erythrocytes are classified according to the degree of maturity into groups that have their own distinctive features.

ripening stage	features
Erythroblast	diameter - 20-25 microns; the nucleus occupying more than 2/3 of the cell with nucleoli (up to 4); the cytoplasm is brightly basophilic, purple in color.
Pronormocyte	diameter - 10-20 microns; nucleus without nucleoli; rough chromatin; the cytoplasm brightens.
Basophilic normoblast	diameter - 10-18 microns; segmented chromatin; zones of bazochromatin and oxychromatin are formed.
Polychromatophilic normoblast	diameter - 9-13 microns; destructive changes in the nucleus; oxyphilic cytoplasm due to high content hemoglobin.
Oxyphilic normoblast	diameter - 7-10 microns; the cytoplasm is pink.
Reticulocyte	diameter - 9-12 microns; the cytoplasm is yellow-green.
Normocyte (mature erythrocyte)	diameter - 7-8 microns; the cytoplasm is red.

V peripheral blood there are both mature and young and old cells. Young erythrocytes, which contain remnants of nuclei, are called reticulocytes.

The number of young erythrocytes in the blood should not exceed 1% of the total mass of red cells. An increase in reticulocyte count indicates increased erythropoiesis.

The formation of red blood cells is called erythropoiesis.

Erythropoiesis occurs in:

Bone marrow of the skull bones;
Pelvis;
Torso;
Sternum and vertebral discs;
Before the age of 30, erythropoiesis also occurs in the humerus and femur bones.

Bone marrow produces more than 200 million new cells every day.

After full maturation, cells enter the circulatory system through the capillary walls. The life span of red blood cells is 60 to 120 days. Less than 20% of erythrocyte hemolysis occurs inside the vessels, the rest is destroyed in the liver and spleen.

Function of erythrocytes

Carry out a transport function. In addition to oxygen and carbon dioxide, cells carry lipids, proteins and amino acids;
Promote the elimination of toxins from the body, as well as poisons that are formed as a result of metabolic and life processes microorganisms;
They are actively involved in maintaining the balance of acid and alkali;
Participate in the process of blood clotting.

The composition of the erythrocyte includes a complex iron-containing protein hemoglobin, the main function of which is to transport oxygen between tissues and lungs, as well as partial transport of carbon dioxide.

The composition of hemoglobin includes:

A large protein molecule is globin;
The non-protein structure built into the globin is heme. An iron ion is located in the core of the heme.

In the lungs, iron binds to oxygen, and it is this bond that contributes to the acquisition of a characteristic shade of blood.

Blood groups and Rh factor

On the surface of red blood cells are antigens, of which there are several varieties. That is why the blood of one person can be different from the blood of another. Antigens form the Rh factor and blood group.

antigen	blood type
0	I
0A	II
0B	III
AB	IV

The presence / absence of the Rh antigen on the surface of the erythrocyte determines the Rh factor (in the presence of Rh, Rh is positive, in the absence - negative).

Determination of the Rh factor and group affiliation of human blood is of great importance for transfusion donated blood... Some antigens are incompatible with each other, causing destruction of blood cells, which can lead to the death of the patient. It is very important to transfuse blood from a donor whose blood group and Rh factor match those of the recipient.

Leukocytes - blood cells that perform the function of phagocytosis

Leukocytes, or white blood cells, are blood cells that perform protective function... Leukocytes contain enzymes that destroy foreign proteins. Cells are able to detect harmful agents, "attack" and destroy them (phagocytose). In addition to eliminating harmful microparticles, leukocytes take an active part in cleansing the blood from decay products and metabolism.

Thanks to antibodies produced by leukocytes, the human body becomes resistant to certain diseases.

Leukocytes have a beneficial effect on:

Metabolic processes;
Providing organs and tissues with the necessary hormones;
Enzymes and other essential substances.

Leukocytes are divided into 2 groups: granular (granulocytes) and non-granular (agranulocytes).

Granular leukocytes include:

The group of non-granular leukocytes includes:

Varieties of leukocytes

The largest group of leukocytes in terms of number, accounting for almost 70% of their total. Its name given view leukocyte received due to the ability of cell granularity to stain with paints that have a neutral reaction.

Neutrophils are classified according to the shape of the nucleus into:

Young that do not have a kernel;
Stab, the core of which is represented by a stick;
Segmented, the core of which consists of 4-5 segments interconnected.

When counting neutrophils in a blood test, the presence of no more than 1% of young, no more than 5% of stab cells and no more than 70% of segmented cells is permissible.

The main function of neutrophilic leukocytes is protective, which is realized through phagocytosis - the process of detecting, capturing and destroying bacteria or viruses.

1 neutrophil is able to "neutralize" up to 7 microbes.

The neutrophil is also involved in the development of inflammation.

The smallest subspecies of leukocytes, the volume of which is less than 1% of the number of all cells. Basophilic leukocytes are called because of the ability of cell granularity to stain only with alkaline dyes (basic).

The functions of basophilic leukocytes are due to the presence of active biological substances... Basophils produce heparin, which prevents blood clotting at the site of the inflammatory reaction, and histamine, which dilates the capillaries, which leads to early resorption and healing. Basophils also contribute to the development of allergic reactions.

A subspecies of leukocytes, which got its name due to the fact that its granules are stained with acidic dyes, the main of which is eosin.

The number of eosinophils is 1-5% of the total number of leukocytes.

Cells have the ability to phagocytosis, but their main function is to neutralize and eliminate protein toxins, foreign proteins.

Also, eosinophils are involved in the self-regulation of body systems, produce detoxifying inflammatory mediators, and participate in blood purification.

Eosinophil

A subspecies of leukocytes that does not have granularity. Monocytes are large cells that resemble a triangle in shape. Monocytes have a large nucleus of various shapes.

Monocyte formation occurs in the bone marrow. In the process of maturation, the cell goes through several stages of maturation and division.

Immediately after the young monocyte matures, it enters the circulatory system, where it lives for 2-5 days. After that, some of the cells die, and some leave to "ripen" to the stage of macrophages - the largest blood cells, whose lifespan is up to 3 months.

Monocytes perform the following functions:

Produce enzymes and molecules that contribute to the development of inflammation;
Participate in phagocytosis;
Promote tissue regeneration;
Helps in the restoration of nerve fibers;
Promotes bone tissue growth.

Macrophages phagocytose harmful agents in tissues and suppress the reproduction of pathogenic microorganisms.

The central link in the defense system, which is responsible for the formation of a specific immune response and provides protection against all foreign bodies in the body.

The formation, maturation and division of cells occurs in the bone marrow, from where they are sent through the circulatory system to the thymus, lymph nodes and spleen for full maturation. Depending on where full maturation occurs, T-lymphocytes (matured in the thymus) and B-lymphocytes (matured in the spleen or in the lymph nodes) are secreted.

The main function of T-lymphocytes is to protect the body through the participation of cells in immune responses. T-lymphocytes phagocytose pathogenic agents and destroy viruses. The reaction carried out by these cells is called "nonspecific resistance".

B-lymphocytes are cells that are capable of producing antibodies - special protein compounds that prevent the multiplication of antigens and neutralize toxins released by them in the course of their vital activity. For each type pathogenic microorganism B-lymphocytes produce individual antibodies that eliminate a specific species.

T-lymphocytes phagocytose, mainly viruses, B-lymphocytes destroy bacteria.

What antibodies do lymphocytes form?

B-lymphocytes produce antibodies that are found in cell membranes and in the serum of the blood. When an infection develops, antibodies begin to rapidly enter the bloodstream, where disease-causing agents are recognized and the immune system is "informed" about it.

Allocate the following types antibodies:

Immunoglobulin M- makes up 10% of the total amount of antibodies in the body. They are the largest antibodies and are formed immediately after the introduction of the antigen into the body;
Immunoglobulin G- the main group of antibodies, which plays a leading role in the protection of the human body and forms immunity in the fetus. The cells are the smallest among antibodies and are able to cross the placental barrier. Together with this immunoglobulin, immunity from many pathologies is transmitted to the fetus from the mother to her unborn child;
Immunoglobulin A- protect the body from the influence of antigens entering the body from external environment... The synthesis of immunoglobulin A is produced by B-lymphocytes, but is found in large quantities not in the blood, but on the mucous membranes, breast milk, saliva, tears, urine, bile and secretions of the bronchi and stomach;
Immunoglobulin E- antibodies released during allergic reactions.

Lymphocytes and immunity

After a meeting of a microbe with a B-lymphocyte, the latter is able to form "memory cells" in the body, which makes it resistant to pathologies caused by this bacterium. For the appearance of memory cells, medicine has developed vaccines aimed at the formation of immunity to especially dangerous diseases.

Where are leukocytes destroyed?

The process of destruction of leukocytes is not fully understood. To date, it has been proven that of all the mechanisms of cell destruction, the spleen and lungs are involved in the destruction of white blood cells.

Platelets - cells that protect the body from fatal blood loss

Platelets are blood cells that are involved in ensuring hemostasis. Presented by small cells biconvex without a kernel. The platelet diameter varies between 2-10 microns.

Platelets are produced by the red bone marrow, where they undergo 6 maturation cycles, after which they enter the bloodstream and stay there for 5 to 12 days. The breakdown of platelets occurs in the liver, spleen, and bone marrow.

While in the bloodstream, platelets have the shape of a disk, but when activated, the platelet takes the shape of a sphere on which pseudopodia are formed - special outgrowths with the help of which platelets are connected to each other and adhere to the damaged surface of the vessel.

In the human body, platelets perform 3 main functions:

They create "plugs" on the surface of the damaged blood vessel, helping to stop bleeding (primary thrombus);
Participate in blood clotting, which is also important for stopping bleeding;
Platelets provide nutrition to vascular cells.

Platelets are classified into:

Microforms- platelet with a diameter of up to 1.5 microns;
Normoforms- platelet with a diameter of 2 to 4 microns;
Macroforms- platelet with a diameter of 5 microns;
Megaloforms- platelet up to 6-10 microns in diameter.

The norm of erythrocytes, leukocytes and platelets in the blood (table)

age	floor	erythrocytes (x 10 12 / l)	leukocytes (x 10 9 / l)	platelets (x 10 9 / l)
1-3 months	husband	3,5 - 5,1	6,0 - 17,5	180 - 490
	wives
3-6 months	husband	3,9 - 5,5
	wives
6-12 months	husband	4,0 - 5,3		180 - 400
	wives
1-3 years	husband	3,7 - 5,0	6,0 - 17,0	160 - 390
	wives
3-6 years old	husband		5,5 - 17,5
	wives
6-12 years old	husband		4,5 - 14,0	160 - 380
	wives
12-15 years old	husband	4,1 - 5,5

In the anatomical structure of the human body, cells, tissues, organs and organ systems are distinguished, which carry out all vital functions. There are about 11 such systems in total:

nervous (central nervous system);
digestive;
cardiovascular;
hematopoietic;
respiratory;
musculoskeletal;
lymphatic;
endocrine;
excretory;
genital;
musculocutaneous.

Each of them has its own characteristics, structure and performs certain functions. We will consider that part of the circulatory system, which is its basis. It will be about the liquid tissue of the human body. Let's study the composition of blood, blood cells and their significance.

Anatomy of the human cardiovascular system

The most important organ forming this system is the heart. It is this muscle sac that plays a fundamental role in blood circulation throughout the body. Blood vessels of different sizes and directions depart from it, which are divided into:

veins;
arteries;
the aorta;
capillaries.

The listed structures carry out a constant circulation of the special tissue of the body - blood, which washes all cells, organs and systems as a whole. In humans (as in all mammals), two circles of blood circulation are distinguished: large and small, and such a system is called closed.

Its main functions are as follows:

gas exchange - the implementation of transport (that is, movement) of oxygen and carbon dioxide;
nutritious, or trophic - delivery of the necessary molecules from the digestive organs to all tissues, systems, and so on;
excretory - the withdrawal of harmful and waste substances from all structures to the excretory;
delivery of endocrine system products (hormones) to all cells of the body;
protective - participation in immune reactions through special antibodies.

The composition of blood and the value of its cells

What is this red liquid with a specific taste and smell that appears on any part of the body at the slightest wound?

The volume of this fluid in the body of an adult is about 5.5-6 liters. The loss of 2-2.5 of them is deadly. Why? Because blood has a number of vital functions.

Provides homeostasis of the body (the constancy of the internal environment, including body temperature).
The work of blood and plasma cells leads to the spread of important biologically active compounds throughout all cells: proteins, hormones, antibodies, nutrients, gases, vitamins, and metabolic products.
Due to the constancy of the blood composition, a certain level of acidity is maintained (pH should not exceed 7.4).
It is this tissue that takes care of removing unnecessary, harmful compounds from the body through the excretory system and sweat glands.
Liquid solutions of electrolytes (salts) are excreted in the urine, which is provided exclusively by the work of the blood and excretory organs.

It is difficult to overestimate the importance of human blood cells. Let's consider in more detail the structure of each structural element of this important and unique biological fluid.

Plasma

Viscous yellowish liquid, occupying up to 60% of the total blood mass. The composition is very diverse (several hundred substances and elements) and includes compounds from various chemical groups. So, this part of the blood includes:

Protein molecules. It is believed that every protein that exists in the body is present initially in the blood plasma. There are especially many albumin and immunoglobulins, which play an important role in defense mechanisms. In total, about 500 names of plasma proteins are known.
Chemical elements in the form of ions: sodium, chlorine, potassium, calcium, magnesium, iron, iodine, phosphorus, fluorine, manganese, selenium and others. Almost the entire Periodic Table of Mendeleev is present here, about 80 items from it are in the blood plasma.
Mono-, di- and polysaccharides.
Vitamins and coenzymes.
Hormones of the kidneys, adrenal glands, gonads (adrenaline, endorphin, androgens, testosterones and others).
Lipids (fats).
Enzymes as biological catalysts.

Erythrocytes

The smallest cell structures, the size of which does not exceed 8 microns. However, their number is over 26 trillion! - makes you forget about the insignificant volumes of a single particle.

Erythrocytes are blood cells that are devoid of the usual constituent parts of the structure. That is, they have no nucleus, no EPS (endoplasmic reticulum), no chromosomes, no DNA, and so on. If you compare this cell with anything, then a biconcave porous disc - a kind of sponge - is best suited. The entire inner part, each pore, is filled with a specific molecule - hemoglobin. It is a protein, the chemical basis of which is an iron atom. It is easily able to interact with oxygen and carbon dioxide, which is the main function of red blood cells.

In appearance, when viewed through a special microscope, red blood cells are rounded structures, as if flattened from the top and bottom to the center. Their precursors are stem cells produced in the bone marrow and the spleen depot.

Function

The role of red blood cells is explained by the presence of hemoglobin. These structures collect oxygen in the pulmonary alveoli and carry it to all cells, tissues, organs and systems. In this case, gas exchange takes place, because giving oxygen, they take carbon dioxide, which is also transported to the places of excretion - the lungs.

At different ages, the activity of erythrocytes is not the same. So, for example, the fetus produces a special fetal hemoglobin, which carries out the transport of gases an order of magnitude more intensive than the usual one typical for adults.

The lifespan of each red blood cell is from 90 to 100 days.

Platelets

Another important human blood cell is platelets. These are flat structures that are 10 times smaller than erythrocytes. Such small volumes allow them to quickly accumulate and stick together to fulfill their intended purpose.

Meaning

Leukocytes

White blood cells, which got their name for their absolute colorlessness. But the lack of color does not diminish their importance in the least.

Rounded bodies are divided into several main types:

eosinophils;
neutrophils;
monocytes;
basophils;
lymphocytes.

Role in the body

The general importance of all varieties of white bodies is to provide protection against foreign particles, microorganisms and molecules.

These are the main functions that leukocytes perform in the human body.

Stem cells

These include:

red bone marrow;
spleen.

The bone marrow is especially important. It is located in the cavities of flat bones and produces absolutely all blood cells. In newborns, tubular formations (shin, shoulder, hands and feet) also take part in this process. With age, such a brain remains only in the pelvic bones, but it is enough to provide the entire body with blood corpuscles.

Another organ that does not produce enough blood cells for emergencies is the spleen. This is a kind of "blood depot" of each human body.

Why are stem cells needed?

In cases where a person loses a large amount of blood, which the brain itself cannot replenish or does not have time to, selection of donors is necessary (this is also necessary in the case of blood renewal in case of leukemia). This process is complex, it depends on many characteristics, for example, on the degree of kinship and comparability of people with each other in terms of other indicators.

Norms of blood cells in medical analysis

For a healthy person, there are certain norms for the amount of formed blood cells per 1 mm 3. These indicators are as follows:

Erythrocytes - 3.5-5 million, hemoglobin protein - 120-155 g / l.
Platelets - 150-450 thousand
Leukocytes - from 2 to 5 thousand.