Blood. Erythrocytes, protein and leukocytes in the urine

Translated from Greek, these are “red cells”, the most numerous blood cells, in an adult there are about 25 trillion of them. The number of red blood cells in the blood changes, for example, with a lack of oxygen, in rarefied mountain air or during physical exertion, it increases.

The shape of an erythrocyte is a biconcave disk - this shape significantly increases its surface, oxygen quickly and evenly enters the cell. Erythrocytes are also elastic, due to which they penetrate even the smallest capillaries. An erythrocyte does not live long - from 100 to 125 days. It is formed in the red bone marrow and destroyed in the spleen.

About a third of an erythrocyte cell consists of hemoglobin, a complex compound consisting of protein (globin) and ferrous iron (heme). Hemoglobin is found only in erythrocytes and is absent in the free state in the blood of healthy people.

Each red blood cell contains approximately 200-300 hemoglobin molecules.. Due to its structure, hemoglobin is ideal vehicles for gases. In the capillaries of the lungs, oxygen molecules join it, the erythrocyte acquires a bright red color. Having given oxygen to cells, hemoglobin attaches carbon dioxide molecules, changing its color to dark red.

In addition to transporting oxygen and carbon dioxide, erythrocytes also transport amino acids, lipids, proteins, help the body get rid of various poisons that are formed as a result of metabolism and the vital activity of microorganisms. Erythrocytes are also involved in maintaining acid-base, ionic balance, and in blood coagulation.

Red blood cells are very sensitive to changes in the chemical composition of the plasma, and in some cases, their premature destruction, called hemolysis, occurs. This happens when the plasma concentration of sodium chloride increases, under the influence of ether, chloroform. erythrocytes are sensitive to temperature regime, therefore, when hypothermia or overheating of the body, they are destroyed in the first place. Hemolysis also occurs during the transfusion of incompatible blood, with violations immune system, under the influence of poisons of snakes, bees.

Size and shape of erythrocytes. Anisocytosis– heterogeneity of erythrocyte samples in peripheral blood smears by cell size. Normally dominated normocytes with a diameter of 7.8 µm (68 ± 0.4%).

Pathological cells include microcytes (< 6,5 мкм), macrocytes(8.9 µm) and megalocytes(> 12 µm).

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Normally, the proportion of microcytes and macrocytes is 15.3 ± 0.4% and 16.7 ± 0.5%; megalocytes are not normal.

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Along with this, erythrocytes of elongated, pear-shaped, oval, spindle-shaped and other forms (poikilocytosis) can be found in blood smears.

A number of reversible poikilocytes(normally no more than 3%, which is associated with cell aging) includes echinocytes, i.e. dentate cells, and stomatocytes with a central enlightenment in the form of a mouth.

Irreversibly altered erythrocytes are divided into 6 groups:

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1. Microcytes, leptocytes (thin cells with a normal diameter), anulocytes (wide enlightenment) and macrocytes.
2. Crescent.
3. Plantocytes (increased diameter, but not volume) are target-shaped, acanthocytes without enlightenment with numerous spines and drop-shaped.
4. Xerocytes, compacted, irregular in shape.
5. Spherocytes (transformation of echinocytes, acanthocytes and stomatocytes), ovalocytes.
6. Bitten cells and schistocytes.

Regenerative changes in circulating red blood cells. The regenerative forms of erythrocytes include immature elements of erythropoiesis - nucleated erythrocytes: normoblasts and megaloblasts, as well as erythrocytes with inclusions of nuclear or cytoplasmic origin.

The first ones include jolly bodies (Gowell) - one or two small dark purple inclusions (rarely found in single erythrocytes of healthy people, although when an erythron is irritated, the frequency of erythrocytes marked by them ranges from 1 to 5%).

Among the second - basophilic puncture(dark-colored granules scattered over the surface of the erythrocyte and associated with RNA-containing organelles) and siderosomes, detected by the reaction with Prussian blue inclusion of non-hemoglobin iron in erythroblasts (sideroblasts) and in erythrocytes (siderocytes).

Ineffective erythropoiesis. Ineffective erythropoiesis is due to the fact that part of erythroblasts and normoblasts (usually no more than 3-8%) does not complete the differentiation cycle and is destroyed in the bone marrow.

Normally, this process is one of physiological mechanisms regulation of equilibrium in the erythron system with a constantly changing need of the body for erythrocytes. When living conditions change, the bone marrow production of erythrocytes increases or decreases depending on the needs of the body.

Defective, doomed to destruction in the bone marrow, erythronormoblasts accumulate polysaccharides (detected by the PAS reaction), which, when pathological conditions exceeds the normal healthy person values ​​and can manifest itself at all stages of differentiation of erythroid cells.

For the formation of full-fledged erythrocytes in the body, there must be:

- 3.7 g of active iron, 70% of which is bound by hemoglobin, and almost everything else is stored by ferritin;

- 3-5 mg of vitamin B12 (cobalamin initiates the transcription of erythropoietin);

- 2.5 U / ml of erythropoietin.

Erythropoiesis Control Factors. The main stimulating factor for erythropoiesis is hypoxia.

It is believed that the decrease in the level of oxygen observed in this case in specific sensory cells of the cortical part of the kidneys (the area most low pressure oxygen) enhances the production of prostaglandins in the cells of the glomeruli of the kidneys and the simultaneous release of neutral proteases and lysosomal hydrolases. All together stimulates production erythropoietin(EP). The biosynthesis of erythropoietin is also stimulated by hormones of the hypothalamic-pituitary system, thyroid gland and some steroid hormones. The EP gene is located on the long arm of chromosome 7. Proerythroblasts and erythroblasts, which carry hormone receptors on their surface, are sensitive to EP. With further differentiation in the erythron, the number of such receptors on the cells decreases.

These cells are also called white blood cells.. Their content in the blood is much less, about 60 billion. The content of leukocytes in the blood of an adult can change under the influence of the most various factors. For example, after eating, digestive leukocytosis occurs and the number of leukocytes increases significantly.

By appearance and structure, two main groups of leukocytes are distinguished:

grainy (granulocytes), containing small grains in the cytoplasm. Depending on the color in which the granules of leukocytes are stained with laboratory research, allocate basophils(stained with alkaline dyes), neutrophils(neutral dyes) and eosinophils(acid dyes);

nongranular leukocytes (lymphocytes and monocytes).

There is a certain ratio of leukocytes in the blood - the leukocyte formula, which is indicated on the leaflet with the results of a blood test. According to its changes, a specialist can judge the processes taking place in the body. The leukocyte formula also changes with age. In blood small child there are more lymphocytes than neutrophils, somewhere by the age of 6 their number levels off, and then gradually neutrophils begin to prevail over lymphocytes.

What role do leukocytes play? Their main task is protection. Due to their structure, they absorb and destroy foreign elements - bacteria, viruses, toxins. This phenomenon, discovered by I.I. Mechnikov, was called phagocytosis, and the cells themselves - phagocytes.

Each of the leukocytes performs its own clear tasks. Neutrophils are the most active phagocytes, one neutrophil is able to absorb 20-30 microbes. They are also involved in the resorption and digestion of dead blood cells, in cleansing the body of dead tissue. Lymphocytes and monocytes capture invading bacteria and microbes, as well as destroyed neutrophils, and absorb them.

Eosinophils are involved in the transport of a special substance - histamine, the excess of which causes allergies. Increased content eosinophils in the blood just indicates an allergic reaction in the body. Basophils, also involved in the regulation of histamine levels, also play a role in blood clotting.

Platelets are the smallest blood cells. Their main task is to participate in blood coagulation, more precisely, in the formation of a blood clot, which, like a cork, closes the lumen in the vessel wall and prevents the outflow of blood from the body.

Platelet formation- cells, in combination with other factors that ensure blood clotting, is carried out through megakaryocytopoiesis. The first in this series of hematopoiesis are megakaryoblasts, then - megakaryocytes, as a result of the detachment of the cytoplasm of which platelets arise.

The origin of platelets from the cytoplasm of megakaryocytes has been proven by immunological, radioisotope methods and confirmed both by direct observation and time-lapse filming.

Factors controlling megakaryocytopoiesis. The formation of precursor cells of megakaryocytopoiesis is carried out according to the principle common to all granulocytes: an excess of platelets in the bloodstream inhibits megakaryocytopoiesis, thrombocytopenia stimulates (through platelet caylon).

Regulates platelet production thrombopoietin, whose molecular weight is 80-90 kDa, and the half-life is 20-40 hours. Thrombopoietin receptors (c-mpl) are detected on platelets, megakaryocytes and a small number of progenitor cells.

The fastest way to increase the number of platelets is the final endomitosis of megakaryocytes. The patterns of maturation of megakaryocytes, as found experimentally, are that it accelerates with enhanced regeneration, for example, after blood loss, and slows down under conditions of deficiency of vitamins, food ingredients, or when exposed to antiplatelet antibodies, chemotherapy. The restored bone marrow reserve of megakaryocytes, according to the feedback principle, slows down the rate of cell proliferation in the germ.

The cytoplasm of mature megakaryocytes always contains fully mature platelets, which, however, lack a wide loose layer of the outer membrane ( glycocalyx). It is the unique ability of nuclear division in the morphologically mature cytoplasm of a megakaryocyte, i.e., final endomitosis, that completes the formation of the glycocalyx and makes the platelets complete.

In addition to platelets, a protein is involved in the formation of a thrombus fibrin. Its threads, precipitating, form a dense network in the damaged wall of the vessel, which blocks the path of blood. In addition to platelets, erythrocytes and leukocytes are also driven into this network. A clot forms and the bleeding stops. After the restoration of damaged tissues begins, the thrombus gradually resolves, fibrin dissolves (fibrinolysis).

The process of blood coagulation to a mild degree occurs constantly, even in intact vessels. This is necessary for education inner surface vascular fibrin film, which prevents the release of erythrocytes and blood plasma proteins from the vessels. To prevent the film from filling the entire lumen of the vessel, blood coagulation is constantly accompanied by fibrinolysis.

The activity and number of platelets in the blood is very dependent on the state of health. Both low and high numbers are bad.

In the first case, the blood coagulation process is disrupted. This happens, for example, with aplastic anemia.

An excess of platelets increases the risk of heart attack and stroke, and it can signal certain infectious diseases, such as mosquito-borne dengue fever. Therefore, it is very important to have regular blood tests to monitor platelets.

Blood is an important ingredient human body. It transports oxygen throughout the body, removing carbon dioxide, is directly involved in cellular respiration, provides the body's immune defense and maintains the constancy of the internal environment.

The formed elements of blood include erythrocytes,. For a clear idea of ​​the state of the human body, a certain norm for the content of these cells has been established, the slightest deviation from it can indicate inflammatory and other pathological processes occurring in the body. In the article, we will consider what erythrocytes and leukocytes are, what functions each of the elements performs, and how they differ from each other.

Erythrocytes are the main elements of blood. They originate in the red bone marrow and are destroyed in the spleen and liver. The cells have the shape of a biconcave disk, they are elastic, therefore they are able to squeeze even into the smallest capillaries. Erythrocytes in the blood are colored red. This is due to the content of hemoglobin protein in them, the main component of which is iron, in contrast to leukocytes, in which this component is not present. Red blood cells acquire a rich red color at a mature stage of development, when they are saturated with hemoglobin. Otherwise, the color of the cells is blue.

One of the main elements of blood - erythrocytes

In humans, red blood cells do not have formed nuclei and organelles. Outside, the erythrocyte is covered with an elastic cell membrane, which is capable of passing gas, water, hydrogen ions and glucose.

The cell diameter is equal to 7 µm, the thickness is 2 µm. In women, the norm of erythrocyte content is 3.7 10 12 / l. - 4.7 10 12 / l., for men - 4.5 10 12 / l. - 5.5 10 12 / l. But this indicator may vary depending on many factors: age, physical activity, physiological features, psychological stress and other external factors.

However, it is worth remembering that large deviations from the norm may indicate a course in the body inflammatory processes which lead to various kinds of complications.

The main function of erythrocytes is that they carry oxygen from the lungs to tissues and organs and remove carbon dioxide, that is, they participate in cellular respiration. The task is performed thanks to hemoglobin, which passes through the capillaries of the lungs. In this case, hemoglobin forms a combination with oxygen and turns into oxyhemoglobin, which is then broken down in the organs, while producing oxygen.

Further, the protein, freed from oxygen, absorbs carbon dioxide, removing it from the body. The lifespan of cells is about 120 days. During the day, 200 billion red blood cells are destroyed and the same amount is formed. In total, there are 25 trillion red blood cells in the human body, if you unfold them in a chain, its length will be 200,000 km. The area of ​​erythrocytes that participate in gas exchange is also very large - 3200 sq. m.

Leukocytes are colorless blood cells. Due to their lack of coloration, they are called white blood cells. Unlike erythrocytes, leukocytes contain all cellular structures: the nucleus, organelles, cytoplasm, they are able to move independently and enter the intercellular space, penetrating through the capillary wall, while erythrocytes differ from leukocytes in that they move only with blood flow.

White cells are also formed in the red bone marrow and perform mainly protective function. With skin lesions, leukocytes are sent to the site of the lesion, protecting the wound from the ingress of pathogens.

Some leukocytes secrete substances due to which "alien guests" die, another species pounces on them and absorbs them. The process of protection - phagocytosis - is the digestion of cells, and leukocytes eaters are called phagocytes.

Leukocyte cells, in particular, lymphocytes, play an important role in the formation of specific immunity.

Cells without hemoglobin are called white blood cells or leukocytes.

Now it becomes clear why the blood of a person whose body is affected by an infection contains so many white cells. The body fights the infection by trying to clear it of the pathogen.

The leukocyte norm for an adult is 4 × 10 9 - 8.51 × 0 9 / l. But the indicators are not absolute, it all depends on the time of day and the state of human health. The level of white cells rises slightly after eating, physical exertion, emotional experiences, and also during inflammatory processes in the body.

RBC fluctuations

An excess of red blood cells in the blood indicates dehydration, an inflammatory process, or malignant formations, reduced level about anemia. Various factors can influence the deviation from the norm:

• Avitaminosis.
• body intoxication.
• Diseases internal organs.
• Abuse of alcoholic beverages.
• Insufficient fluid intake.

If we talk about the content of red blood cells in the urine, they should not be there. However, there is a "non-dangerous" indicator - 1-2 units. In case of a significant excess, we can talk about problems with the kidneys or heart, or poor blood clotting.

Fluctuations in the level of leukocytes

A deviation from the norm in the content of white blood cells indicates inflammation, even in the case of an insignificant process, the cells quickly fight the problem. Increased rates can be caused by the following factors:

• Binge eating;
• The introduction of the vaccine;
• menstruation in women;
• Wounds on the skin.

Elevated leukocytes are observed, as a rule, in diseases of internal organs, oncological pathologies, infections, in postoperative period. A decrease is observed with viral infections, beriberi, taking certain medicines, decreased immunity.

The level of neutrophils - one of the types of white blood cells - almost always changes when the body is defending itself from infections. In addition, an increase in the level of these cells occurs when:

• Injuries;
• osteomyelitis;
• Inflammatory processes in the internal organs;
• diabetes;
• Vaccinations;
• tumors;
• Taking medications to support the immune system.

A decrease in the number of neutrophils in the blood is noted after undergoing chemotherapy procedures, with hormonal disorders, sepsis.

It is worth remembering that the content of red and white blood cells must comply with the norm. If changes are found in the results of the analyzes, it is necessary to identify the cause that gave rise to the deviation, and direct all efforts to eliminate the problem. After all, a bad analysis is not a joke, but often the first “bell” about problems in the body.

More:

Varieties of leukocytes in the blood, what is their importance for a person? How is the measurement of erythrocytes in human blood carried out and when is it necessary to diagnose and treat?

Each person, receiving test results in his hands, is worried, and if the doctor talks about increased red blood cells and white blood cells in the urine, there is reason to think about your health. After all, their increased content may indicate the presence of diseases of various organs.

What are leukocytes?

Leukocytes are the shaped elements of the blood, namely, white blood cells that have a nucleus. They are formed in the bone marrow and lymph nodes. The main function of leukocytes is to protect the body from foreign agents. Leukocytes are phagocytically active, and in addition, they are involved in the formation of immunity, as well as in the exchange of heparin and histamine, due to which such components are realized. immune reactions, as antibody-forming, antimicrobial, antitoxic and others.

What is the normal content of leukocytes in the blood?

To talk about whether erythrocytes and leukocytes are elevated in the urine, one should understand what norms for the content of these bodies in the blood are acceptable for different age groups. The norm may vary depending on the age of the subject, as well as on the rate of cell influx from the bone marrow.

An increase in the content of leukocytes over 10 * 10 9 indicates the development of a disease such as leukocytosis, and a decrease below 4 * 10 9 indicates leukopenia.

What are erythrocytes?

Erythrocytes are the main elements of the blood, their presence in the blood is significant, but they can also be contained in other formed elements. These blood cells look like a disk, which is slightly thickened at the edges. This structure allows them to freely and quickly pass through the circulatory system.

The task of erythrocytes is to saturate organs and cells with oxygen. Their number in the blood and urine should be normal, and if a person has protein, leukocytes and erythrocytes elevated in the urine, this may be an indicator of the development of a serious disease, such as pyelonephritis.

The formation of red blood cells occurs in the bone marrow. They include hemoglobin (two-thirds). Each erythrocyte functions for one hundred and twenty days.

Rates of erythrocytes in urine

If a person does not have health problems and inflammatory processes, then the number of red blood cells in urine should be within certain limits. The norms of the content of red blood cells in the urine for men and women are different. For the fair sex, the norm is 0-3, and for the stronger sex - 1-2 units. in sight.

If the analysis shows that the number of red blood cells is high, then this indicates hematuria. Is urine brown or red? This indicates an increase in the value of red blood cells. Per day when emptying Bladder about two million red blood cells are excreted.

What diseases are indicated by the appearance of an admixture of erythrocytes in the urine?

Let's say you have elevated red blood cells and white blood cells in your urine. The reasons may be different. But you need to understand what diseases such a deviation can indicate.

First of all, the presence increased amount erythrocytes indicates kidney disease, urethra, prostate, ureters and bladder. Kidney tumor, cystitis, pyelonephritis, nephrosis, hypertonic disease, urolithiasis disease- it is with such diseases that the level of erythrocytes can be increased.

What does an increase in erythrocytes and leukocytes in the urine of a woman indicate?

If a doctor detects increased red blood cells and white blood cells in the urine of a woman, then he may suspect a disease such as endometriosis. Also, an increase in blood cells sometimes indicates the presence of menstruation. In this case, a more detailed examination may be necessary. genitourinary system women. If there are no erythrocytes in the urine, which was taken with a catheter, then this indicates a gynecological disease.

The causes of pathological hematuria are different. It can indicate diseases such as:

• Pyelonephritis, which provokes infection kidneys and blood vessels. Here, blood seeps through the urinary tract and walls.
• Tumors of the kidneys that destroy blood vessels and provoke bleeding.
• Kidney stones, which have a traumatic effect on organs and blood vessels.
• Glomerulonephritis, in which the body completely loses the ability to filter out substances.
• Hydronephrosis, in which there is a stagnation of the excreted fluid with a bubble. The pressure rises, which causes bleeding.
• Kidney injury.

Also, erythrocytes, leukocytes and protein in the urine can be increased in diseases of the bladder and urethra. It's about about ailments such as:

• Cystitis is an infectious disease that affects the bladder, in which its strength is reduced, which contributes to the seepage of blood particles into it.
• Tumor of the urethra and bladder.
• Stones in the urinary canal.

Increased red blood cells in diseases of the reproductive system

Erythrocytes and leukocytes may increase due to the presence of diseases of the reproductive system in humans. For example, when:

• Erosion of the cervix.
• Infectious processes in the uterus (adenomyosis, endometriosis and others).

Attention! If the erythrocytes in the urine are elevated, the leukocytes are normal, then such an analysis result may indicate the presence of any mechanical damage.

Non-pathological hematuria

As mentioned above, an increase in red blood cells in the urine in women can be observed during menstruation, which is not a deviation from the norm. But there are other reasons that cause an increase in blood cells in the urine.

Far from always, elevated erythrocytes and leukocytes in the urine are an indicator of a pathological process in the human body, and therefore this does not require immediate treatment. It happens that the reason for the increase in erythrocytes in urine is a physiological increase allowable rate blood cells.

The increase in the indicator can be affected by:

• Alcohol intoxication.
• Severe stressful situation.
• Taking medicines that prevent the formation of blood clots.
• Excessive physical activity.
• Eating spices and hot spices in large quantities.

Increase in leukocytes in the urine

The first cause of an increase in the level of leukocytes in the urine can be an acute inflammatory process. By leukocyte, you can determine the localization of inflammation. For example, if leukocytes with one nucleus have increased, then this indicates an exacerbation of kidney disease. If the inflammation is located in urinary tract, then the analysis will show leukocytes with several nuclei.

If inflammation in the kidneys is accompanied by a dystrophic disorder or metabolic defects, then fatty connections are found in leukocytes.

In diseases of the kidneys such as pyelonephritis, the most big number"renal" leukocytes. With glomerulonephritis, an increase in the number of leukocytes of this type is observed much less frequently.

If an increase in the number of leukocytes is accompanied by eosinophils, then this indicates that the inflammatory process is accompanied by an allergic reaction.

The cause of an increase in leukocytes in the urine can be diseases such as cystitis and urethritis.

Other reasons

In addition to the occurrence of inflammatory processes of the genitourinary system, an increase in leukocytes in human urine can be caused by other reasons.

For example, which is absolutely normal. But if you are in a position and your red blood cells are elevated, you need to be wary.

Activities during pregnancy hormonal system women is activated. Therefore, there is an increase in leukocytes in the urine. However, it doesn't have to be high all the time. The norm is only those periods when there is a fluctuation in the level of leukocytes, that is, they either decrease or increase. Constantly high level these bodies indicates an infectious disease. Elevated erythrocytes and leukocytes in the urine, which do not decrease for a long time, is a cause for concern.

Child - what to look for?

An increased content of leukocytes and erythrocytes in the urine occurs not only in adults, but also in children. Pay attention if the child has problems with urination, for example, he began to complain of pain when emptying the bladder or going to the toilet too often.

A change in the color of urine can also indicate a problem. Even if it is insignificant.

An increase in leukocytes in the urine is indicated by turbidity of the urine. Therefore, if you notice that the urine has become cloudy and there is sediment in it, sound the alarm.

An increase in the number of blood cells in the urine is not always due to pathological processes in the human body. But it is better to monitor your well-being and the color of urine. This will help you to see a doctor in time and prevent acute infectious disease go to chronic form. Are leukocytes and erythrocytes in the urine elevated? Don't worry, just go for a full examination. Carry out treatment chronic illness much more difficult.

White (colorless) blood cells. Provide immunity - protection of the body from foreign particles. Produced in red bone marrow. Life span - from several days (phagocytes) to several years (memory cells). 1 ml of blood of an adult healthy person contains 5-8 thousand leukocytes.

Unlike erythrocytes, they have a nucleus (capable of active metabolism and division) and do not have a specific shape (they are able to move amoeba-like, including leaving the blood vessels to the outside).

Phagocytes are white blood cells that absorb and digest foreign particles, as well as dead and mutant cells of their own body.

B-lymphocytes are white blood cells that produce antibodies (gamma globulins are proteins that can combine with antigens that are on the surface of foreign particles). Attachment of the antibody leads to gluing of foreign particles and marks them for phagocytosis, the cells are destroyed under the action of antibodies.

Tests

1. Protect the human body from foreign bodies and microorganisms carry out
A) leukocytes or white blood cells
B) erythrocytes or red blood cells
B) platelets or platelets
D) the liquid part of the blood - plasma

2. What is the function of blood leukocytes?
A) transport gases
B) provide immunity
B) carry nutrients
D) provide blood clotting

3. What cells destroy bacteria that have entered the human body?
A) white blood cells
B) red blood cells
B) kidney nephron cells
D) cells of the alveoli of the lungs

4. Participate in the formation of antibodies
A) platelets
B) lymphocytes
B) erythrocytes
D) phagocytes

6. Leukocytes, unlike other blood cells, are capable of
A) maintain the shape of your body
B) enter into an unstable combination with oxygen
C) enter into an unstable combination with carbon dioxide
D) exit the capillaries into the intercellular space

7. Some leukocytes are called phagocytes for
A) their production of antibodies
B) their production of fibrinogen
C) the ability to absorb and digest foreign particles
D) the ability to move and leave blood vessels

8. Leukocytes are able to move due to
A) pseudopods
B) contractile fibers
C) the presence of air bubbles in the cytoplasm
D) contraction of contractile vacuoles

9. What is phagocytosis?
A) release of blood cells from metabolic products
B) interaction of hemoglobin with oxygen
B) destruction of red blood cells
D) active capture of foreign cells by leukocytes

10. Blood cells capable of phagocytosis,
A) cause the formation of fibrinogen
B) provide immunity
B) contribute to its clotting
D) contain hemoglobin

12. How many leukocytes are contained in a milliliter of blood
A) several tens of thousands
B) several million
B) several hundred thousand
D) several thousand

They are derivatives of the mesenchyme. Together with the organs of hematopoiesis and immunopoiesis, lymphoid formations associated with the structures of non-hematopoietic organs, they are genetically and functionally linked, ensuring the maintenance of the constancy of the internal environment (homeostasis), internal respiration, trophism, regulation and integration of all body systems, excretion of toxins and protection (phagocytosis , cellular and humoral immunity, thrombosis).

Blood morphology

Blood consists of plasma (55-60%) and formed elements (40-45%).

Plasma is the liquid part of blood. It contains proteins (more than 100 varieties), fats, carbohydrates, salts, hormones, enzymes, antibodies, dissolved gases, etc. The dry residue of plasma accounts for 7-10%, the rest is water (90-93%). The main component of the dry residue are proteins (6.5-8.5%). Its medium is slightly alkaline (pH 7.4). Plasma proteins are divided into 2 fractions: light fraction albumins (60%) and heavy - globulins (40%).

Albumins are synthesized in the liver. They provide colloid osmotic blood pressure, retain water in the bloodstream (with their deficiency - edema), perform a transport function, adsorbing a number of compounds.

Globulins have two origins. Some of them, γ-globulins (antibodies), are produced by B-lymphocytes and plasma cells, while others, β-globulins, fibrinogen and prothrombin, are formed in the liver. β-globulins are able to bind and transport ions of Fe, Cu, Zn, etc., and fibrinogen and prothrombin are involved in thrombus formation.

Formed elements of blood. D. L. Romanovsky in 1891 proposed staining blood smears with a mixture of two dyes - eosin and azure-II, which made it possible to differentiate blood cells, which include erythrocytes, leukocytes, stem cells and platelets.

Erythrocytes. In mammals, these are non-nuclear cells; in birds, reptiles, amphibians, and fish, they contain nuclei. The sizes of erythrocytes have specific features and in each case they are divided into normocytes, microcytes and macrocytes (the variety of sizes of erythrocytes is called anisocytosis).

Normally, erythrocytes have the shape of a biconcave disc (discocytes). However, with aging and various kinds of pathological conditions, they can change their shape, and therefore they are distinguished: planicites - with a flat surface, stomatocytes - dome-shaped, spherocytes - spherical, echinocytes - spiky, etc.

- (the variety of forms of erythrocytes is called poikilocytosis - Greek poikilis - varied).

Functions of erythrocytes: transport of O2 and CO2 (respiratory), amino acids, antibodies, toxins, medicinal substances through adsorption. Respiratory function is related to the ability of hemoglobin (Hb) to attach oxygen (O2) and carbon dioxide (CO2) to itself. However, Hb can form strong bonds with other chemical compounds:

Hb - deoxyhemoglobin,

HbO - oxyhemoglobin,

HbCO2 - carbhemoglobin,

HbCO - carboxyhemoglobin (CO - carbon monoxide, the bond strength with Hb is 300 times higher than with O2),

Hb + strong oxidizing agents (KMnO4; aniline, nitrobenzene, etc.) → HbOH - methemoglobin (in these cases, Fe + 2 → Fe + 3, as a result of which the ability of Hb to attach oxygen is lost).

Features of the structure of the plasmolemma of erythrocytes. The erythrocyte plasmalemma is a typical biological membrane consisting of a bilipid layer and proteins in combination with carbohydrates. The ratio of lipids and proteins in it is 1:1. Carbohydrates are part of the glycocalyx. Phospholipids, sialic acid, antigenic oligosaccharides, and adsorbed proteins are located on the outer surface of the membrane. On the inside - glycolytic enzymes, Na + -ATPase and K + -ATPase, glycoproteins and cytoskeletal proteins.

The lipid composition of the outer layer of the plasmalemma includes phosphatidylcholine and sphingomyelin containing choline, and the inner layer contains phosphatidylserine and phosphatidylethanolamine, which carry an amino group at the end of the molecule. FROM outside there are glycolipids (5%). Glycophorin is a transmembrane glycoprotein. Its 16 oligosaccharide chains are located in the glycocalyx. Among them, sialic acid provides a negative charge to the outer surface of the membrane of mature erythrocytes. This allows mature cells to emerge from the red bone marrow. Antigenic properties of various blood groups are associated with glycophorins.

The membrane protein spectrin is part of the cytoskeleton and is involved in maintaining the shape of the erythrocyte. Spectrin, together with another protein, actin, is linked by the 4.1 band protein into a “nodal complex” that is connected to the glycophorin protein. A change in the amount of spectrin leads to a change in the shape of the erythrocyte (spherocytes).

The spectrin cytoskeleton is connected to the plasmolemma by another protein, ankyrin, in the zone of localization of the transmembrane protein of band 3, which is involved in the exchange of O2 and CO2. It also forms hydrophilic "pores" - water ion channels.

The composition of the erythrocyte cytoplasm: Water - 66%, hemoglobin - 33% (heme in it is - 4%).

Under various pathological conditions, erythrocytes can undergo:

1. gluing, forming coin columns (due to the loss of the charge that provides surface tension);

2. hemolysis (when exposed to a hypotonic solution, plasma of other types, snake venom hemoglobin enters the plasma, while the shell remains intact);

3. rolling - wrinkling (when exposed to hypertonic solution); from the Greek crena - tenderloin;

Aging erythrocytes are phagocytosed by macrophages. The lifespan of red blood cells is 120 days

Leukocytes. Unlike erythrocytes, which "work" directly in the blood, leukocytes "work" in body tissues, migrating (by diapedesis) through the walls of capillaries. These are nucleated cells.

Leukocytes are classified into granular (granulocytes) and non-granular (agranulocytes).

Granulocytes. Granular leukocytes (granulocytes) got their name due to the ambiguity of staining of their granules with dyes at different pH values ​​of the medium, in connection with which basophilic, eosinophilic and neutrophilic granular leukocytes are distinguished.

Basophils – cells spherical shape, up to 10–12 µm in diameter. The nucleus has a lobed or bean-shaped shape (depending on the degree of cell maturity). Their basophilic cytoplasm contains rather large granules stained with basic dyes. One of the features of the content of basophil granules is their metachromatic staining with thiazine dyes (methylene blue, toluidine blue, etc., while instead of blue color, the granules become purple, pink or red).

Basophil granules contain biologically active substances: proteoglycans, GAGs (including heparin), vasoactive histamine, neutral proteases, serotonin, peroxidases, acid phosphatase, serotonin (pineal gland hormone that weakens or inhibits the secretion of gonadoliberins in the hypothalamus), histidine decarboxylase (histamine synthesis enzyme), etc.

Functions of basophils. Basophils can phagocytize bacteria, prevent blood clotting (heparin), promote vasodilation and increase the permeability of their walls (histamine), resulting in edema. They mediate inflammation, activate macrophages, participate in immunological reactions allergic nature: secrete eosinophilic chemotactic factor, which stimulates the migration of eosinophils. Asthma, anaphylaxis, rash observed immediate type degranulation triggered by the IgE receptor for IgE. Together with mast cells, they participate in the anticoagulant system of the blood and regulate the permeability of the vascular wall; together with neutrophils, they form biologically active metabolites of arachidonic acid - leukotrienes and prostaglandins. Basophilic granulocytes are not active inducers in the development of delayed-type hypersensitivity.

In the peripheral blood, basophils stay for about 1-2 days, and then migrate into the intercellular substance. connective tissue where their life expectancy is not great.

Eosinophils . The sizes of these cells reach 12-17 microns. The nucleus of mature cells usually contains 2 segments, but in sheep it has more. Band and young eosinophils are very rare. The granules in the cytoplasm are quite large. There are two varieties of them: primary azurophilic and secondary - eosinophilic (modified lysosomes). The center of the eosinophilic granule contains a crystalloid that contains the main basic protein rich in arginine, cationic protein, lysosomal hydrolytic enzymes, peroxidase, histaminase, etc. The peroxidase activity of eosinophilic granulocytes is not associated with the presence of myeloperoxidase, which is strictly specific for the neutrophilic granulocyte system.

AT allergic reactions the Fc-receptor of the plasmalemma for IgE, as well as C3- and C4- receptors are involved.

Eosinophilic granulocytes stay in the blood for about 12 hours, and then migrate to the intercellular substance of the connective tissue, where they function for up to 8-12 days (there are 500 times more of them in the connective tissue than in the blood). The peroxidase activity of eosinophilic granulocytes is not associated with the presence of myeloperoxidase, which is strictly specific for the neutrophilic granulocyte system.

Neutrophils . The sizes of these cells vary within 9–12 µm. The shape of the nucleus is not constant and depends on the degree of maturity of the cells. In this regard, young, stab and segmented neutrophilic granulocytes are distinguished. In young neutrophils, the nucleus has a bean-shaped form, there are relatively few granules in the cytoplasm. The nuclei of stab neutrophils look like varying degrees curved rod, and in mature cells it is fragmented into segments interconnected by thin bridges. The cytoplasm of neutrophils contains 2 types of granules:

1) primary azurophilic non-specific (PAN), their size is 0.4-0.8 microns (up to 20%), they are primary lysosomes containing ß-glucuronidase, acid ß-glycerophosphate dehydrogenase, acid protease, lysozyme (muramidase), acidic phosphatase, myeloperoxidase (turns hydrogen peroxide into molecular oxygen).

2) secondary neutrophil specific granules (VNS), the size of which is 0.1-0.3 microns; they contain alkaline phosphatase, phagocytins, aminopeptidases, lysozyme, cationic proteins and the protein lactoferrin, which ensures bacterial adhesion (bacterial multiplication) and inhibition of the formation of leukocytes in the red bone marrow.

The description of neutrophilic granulocytes should be supplemented with modern data on tertiary granules, secretory vesicles, and adhesive molecules.

Function of neutrophils- non-specific antibacterial protection by phagocytosis and release of bactericidal substances, participation in inflammatory reactions (carried out outside the vessels, in the intercellular substance of connective tissues). In the formation of endogenous pyrogen, which is now identified as interleukin-1, neutrophilic granulocytes do not participate, it is produced by cells of the monocyte-macrophage system. In the blood, they are up to 8-12 hours, and in the tissues - up to 9 days, where they die.

Agranulocytes. Nongranular leukocytes include lymphocytes and monocytes. Both of these groups of cells are actively involved in the body's immune responses. Immunity is a way of protecting the body from living bodies and substances that bear signs of genetic alienness.

Lymphocytes . By degree of maturity lymphocytes are divided into large (10 microns), medium (7-10 microns) and small (4.5-6 microns). Small lymphocytes are mature. They contain a large round nucleus with a slight depression, which occupies almost the entire cell. It is surrounded by a narrow rim of basophilic cytoplasm. By origin and functional properties There are 4 main groups of lymphocytes: B-lymphocytes, T-lymphocytes, natural killer (NK) and K-cells. All of them are involved in providing immune responses, protecting against everything foreign that enters from the outside and is formed in the body itself.

B-lymphocytes They are formed in the lymph nodes and carry out specific humoral immunity (they supply antibodies to the blood, lymph and tissue fluid). On the surface of the plasmolemma of B-lymphocytes there are antigen-specific receptors, which are antibodies - immunoglobulins (Ig) of classes M and D, or surface immunoglobulins (SIg). The antigens recognized by the receptors attach to them, as a result of which B-lymphocytes are activated, proliferate many times and differentiate into effector cells - plasma cells, or antibody-forming cells (AFCs), capable of producing antibodies (immunoglobulins). Antibodies have binding sites on their surface for that particular antigen.

The process of lymphocyte activation can be represented in the following sequence: Activated B-lymphocyte→ plasmablast (diameter up to 30 µm) → proplasmocyte → mature plasma cell (diameter about 10 µm).

B-lymphocytes - live from several weeks to tens of months.

T-lymphocytes, natural killers ( NK ) and K cells are formed in the thymus. They carry out reactions of specific cellular immunity and regulate humoral immunity. The plasmolemma of T-lymphocytes contains surface antigenic markers (histocompatibility antigens) and many receptors with which they recognize foreign antigens and immune complexes. After encountering antigens, T-lymphocytes turn into T-effectors: T-killers, T-helpers and T-suppressors.

Effector cells of T-lymphocytes T-killers (cytotoxic) - provide cellular immunity. Possessing a cytotoxic effect, they interact with target cells due to direct contact with them or due to the short-acting toxic mediators produced by them. As a result of this interaction, the permeability of the target cell membrane changes, which leads to its death.

Under the action of antigens in T-lymphocytes, special soluble substances, lymphokines, are produced, which transmit information about antigens to B-lymphocytes.

T-helpers are helpers of B-lymphocytes, they recognize the antigen and increase the production of antibodies; T-suppressors, on the contrary, suppress the production of antibodies by B-lymphocytes.

The life span of T-lymphocytes is up to 10 years.

AT recent times in scientific publications (G. M. Mogilnaya et al., 2002) it is indicated that the classification of T-lymphocytes accepted by immunologists should be introduced, which is based on the determination of surface differentiation antigens (cluster of differentiation - CD) using immunocytochemistry.

The thymus leaves two subpopulations of native T-lymphocytes with the CD23 antigen. T-helpers are marked with the CD4 antigen, and T-killers are marked with CD8. It has been established that during the immune response, CD4+ T-helpers (ThO) give rise to two subpopulations of Th1- and Th2-helpers, with the predominance of one of them, depending on the intra- or extracellular localization of the pathogen, or on the characteristics of the antigen. By producing different sets of cytokines Th1 (interferon gamma, tumor necrosis factor-alpha, lymphotoxin, interleukin-2) and Th2 (interleukins -4, -5, -6, -10, -13 and transforming growth factor - beta) regulate the development immune inflammation. T-lymphocytes of hypersensitivity belong to the class of Th1-helpers, so they do not have to be isolated in a separate cell form. It should be noted that after contact with the antigen and the synthesis of cytotoxins (perforin, granzymes), the CD8+ T-killer is called the cytotoxic T-lymphocyte (CTL).

In the process of local contact of CTL with the target cell, there is a strict direction of the release of cytotoxins into the zone of spatial connection T cell receptor and antigen. In addition, osmotic lysis of the cell is observed, due to the independent effect of perforin, which leads to the release and dispersion of the intracellularly localized pathogen. It is worth pointing out that the death of a target cell by apoptosis, which occurs with the combined effect of perforin and granzymes, is biologically expedient, since it leads to membrane isolation of a degraded pathogen or other antigen.

T and B memory cells - lymphocytes that return to an inactive state, but have already acquired information (memory) from a meeting with a specific antigen. When they encounter this antigen again, they quickly provide an immune response of considerable intensity.

T - and B-lymphocytes in the vascular bed - functionally relatively inactive. Their activation is carried out by antigens, as a result of which these cells turn into effector forms of cellular and humoral immunity, thereby increasing the fund of memory cells.

Monocytes - enough large cells, in a blood smear their sizes reach 15-20 microns. They contain large nuclei of lobed, bean-shaped and other shapes. The cytoplasm is basophilic. Despite the fact that these cells belong to agranulocytes, small amounts of small azurophilic granules, which are lysosomes, can be found in their cytoplasm. In functional terms, these are typical macrophages, which are located in the peripheral bloodstream on the way from the red bone marrow to the tissues, where they perform specific protective functions.

Percentage various kinds leukocytes in the peripheral bloodstream (leukocyte formula) varies in different animal species (Table 2):

Table 2. Leukocyte formula (in%)

Note : B – Basophilic granulocyte; E – Eosinophilic granulocyte ; YU – Young neutrophilic granulocyte; P – stab neutrophilic granulocyte;FROM – Segmented neutrophilic granulocyte.

As can be seen from the table, in some animal species, lymphocytes are predominant among leukocytes, while in others, granular leukocytes.

Thus, a number of cells circulate in the peripheral blood, which have specific functions aimed at protecting the body from foreign factors (antigens). These include various populations of lymphocytes, descendants of monocytes - macrophages and granular leukocytes.

Blood plates. Blood plates. In mammals, these are fragments of the cytoplasm of megakaryocytes. In birds, these are nucleated cells - platelets. The sizes of platelets vary within 2-4 microns. They consist of a peripheral zone - a hyalomere and a central zone - a granulomere. The hyalomere stains basophilically in young platelets, and oxyphilically in old platelets. The hyalomere contains actin, which is involved in the retraction (volume reduction) of platelets.

On the surface of the platelet plasmolemma there is glycolix, the glycoproteins of which are receptors involved in the adhesion and aggregation of platelets (platelet aggregation - their gluing).

According to the degree of maturity, 5 types of platelets are distinguished: young, mature, old, degenerative and giant forms of irritation.

The function of platelets: They contain approximately 12 blood clotting factors. They take part in fibrinogen coagulation: fibrin → prothrombin → thrombin.

Blood plasma contains the von Willebrand coagulation factor (vWF), for which there is a special P Ib receptor in the platelet plasma membrane. Another receptor P IIb - IIIa binds fibrinogen, as a result of which platelets aggregate.

In addition, the tubular system of the platelet cytoplasm synthesizes cyclooxygenases and prostaglandins. It is also a reservoir for Ca ions.

Platelets of birds and reptiles perform similar functions.