General blood analysis. Properties of blood. Formed elements of blood.

Norms of tests for children

A general blood test can be attributed to the functional methods of studying the hematopoietic system, since it reflects the general state of the whole hematopoietic system. Quantitative and qualitative analysis of the blood picture allows us to assess in general terms such functions as providing gas exchange between blood and air, providing immunity and clotting of blood, providing nutrients to the cells of the body, regulating the creator bonds, homeostatic function.

Blood is a colloid - polymer solution, the solvent of which is water, soluble substances - salts and low molecular weight organic compounds - proteins and their complexes.
The blood of higher animals and man consists of a liquid part - plasma and suspended in it shaped elements.

Let us consider the main physicochemical properties of blood:

Density of blood.
The density of blood fluctuates within narrow limits and depends on the content of its constituent elements, proteins and lipids. In humans, the blood density is 1,060-1,064 g ml.

The viscosity of the blood.
This is another physical indicator. It is 3-6 times the viscosity of water and is in direct proportion to the blood levels of red blood cells and proteins. Viscosity increases with thickening of the blood, for example, with abundant sweating.

Osmotic pressure.
The concentration of salts in the blood in mammals is about 0.9%. The osmotic pressure depends on their content in the blood. Osmotic pressure determines the distribution of water between tissues and cells of the body. The osmotic pressure of mammalian blood is at a constant level of 7.3 atm, which corresponds to a freezing point of 0.54 ° C.

Blood reaction.
To evaluate the active reaction of blood, use a hydrogen index, or pH. The active reaction is of great biological importance, because most metabolic processes normally proceed only at certain pH values. The blood of mammals and humans has a slightly alkaline reaction: the arterial blood pH is 7.35 - 7.45, the venous blood - 0.02 units lower.

FORMAL ELEMENTS OF BLOOD.

From the point of view of the functional evaluation, the main value is given to the quantitative characteristics of blood - the number of erythrocytes, leukocytes, platelets, determination of hemoglobin, sedimentation rate of erythrocytes (ESR).
The number of uniform elements in the international system of units (SI) is expressed per 1 liter.
The most simple and informative type of blood test is a blood test from the finger or from the vein in the morning, on an empty stomach. A general blood test demonstrates how things are with the indicators of the so-called "troika": hemoglobin, leukocytes, ESR.

ERYTHROCYTES
Erythrocytes constitute the bulk of the blood. They determine the red color of the blood.
These are specialized cells that carry the transfer of oxygen and carbon dioxide through the body, carry nutrients on their surface, participate in the regulation of acid-base balance and water-salt metabolism in the body, take part in immunity phenomena, adsorb various poisons and in the regulation of the coagulation system . The transfer of gases is due to the presence in them of respiratory pigments (hemoglobin, hemeritin, myoglobin, etc.).
Erythrocytes do not contain nuclei, they have the form of biconcave discs, they are painted in pink or reddish color.
To accurately assess the specific gravity of erythrocytes of different sizes, an erythrocytometric curve is constructed.
In conditions of pathology, the color of erythrocytes can change - hypochromia, hyperchromia. Hypochromia is due to low cell saturation with hemoglobin and occurs in iron deficiency anemia; Hyperchromia - an increase in the content of hemoglobin in the cell with B12-deficiency anemia. With the predominance of erythrocytes of small size, they speak of microcytosis, of large dimensions - of macrocytosis. Microcysts of a spherical spherical shape are called microspherocytes, characteristic of one of the forms of hemolytic anemia. Anisocytosis is the presence in the smear of erythrocytes of different sizes, poikilocytosis - of various forms. These changes are typical for a different nature of anemia. Normoblasts are erythrocytes with preserved nucleus, they testify either to strained, or perverted erythropoiesis in anemia, leukemia. Megaloblasts and megalocytes appear in the peripheral blood for megaloblastic anemias of various origins.
Erythropenia (anemia) indicates insufficient supply of tissues with oxygen and removal of carbon dioxide. Erythrocytosis - the viscosity of the blood is increased The process of destruction of red blood cells, in which hemoglobin enters the plasma, is called hemolysis. Hemolysis can occur under the influence of various factors - physical effects, chemical agents, poisons of plant, animal and bacterial origin, etc.
Hemoglobin - the main "respiratory" component of red blood cells - erythrocytes. It consists of a protein globin and a heme - an iron compound, which supplies the cells with oxygen.

Norm (for the future mother) : 110-130 units.
A decrease in hemoglobin indicates anemia. At 24-25 weeks from the hemoglobin maternal hemoglobin of the fetus is formed. Therefore, during this period, a sharp decrease in the hemoglobin level in the blood is observed in the pregnant woman. In this regard, it is sometimes recommended that a prophylactic intake of iron-containing drugs is recommended.
Hemoglobin binds very easily to carbon monoxide CO. As a result, the body has severe consequences of oxygen starvation (vomiting, headache, loss of consciousness). Formed compounds with hemoglobin can no longer serve to transfer oxygen.
Normal indicators of the amount of hemoglobin for women and men:
Women 120-140 g / l, men 130-160 g / l.
There may be a decrease or increase in hemoglobin. Iron - is actively involved in oxygen metabolism. This element is necessary for normal operation of all organs and tissues. In a general blood test, this level determines the hemoglobin contained in the red blood cells - erythrocytes.
Norm (for the future mother): 9.0-31.0 units.
Decreased iron in the blood indicates the appearance of anemia and inadequate supply of organs and tissues with oxygen. Color indicator - indicates the degree of saturation of erythrocytes with a blood pigment. The norm is 0.9 - 1.0.

ESR - sedimentation rate of erythrocytes.
The normal values ​​for men are 1-10 mm / h, in women it is 2-15 mm / h. Normally, erythrocyte sedimentation should not exceed 15 mm per hour.
Rapid cell sedimentation (30-40 mm / h) indicates the appearance of inflammation, acute infection, poisoning, large blood loss (for example, after surgery). During pregnancy, ESR is accelerated. Low values ​​are characteristic for newborns and with increased muscle activity, viral hepatitis, with the intake of salicylates, calcium chloride.

Reticulocytes are young, immature blood cells, precursors of erythrocytes.
Norm (for the future mother): 2-10 units.
Their level increases with hemolytic anemia, bleeding. A decrease in their content is characteristic of certain types of anemia. Revealed in peripheral blood with a special color - on the greenish background is visible mesh substance - the remnants of the nucleus of erythrocytes. The main importance is the changes in the number of reticulocytes. Reticulocytosis testifies to increased erythropoiesis.

LEUKOCYTES White blood cells belong to white blood cells. They have a nucleus and cytoplasm. These cells are defenders, specialized elements of blood, which are responsible for immune protection. They absorb foreign bacteria and toxins that enter the bloodstream. The number of white blood cells varies during pregnancy and under the influence of external circumstances: seasonal, climatic, periods of solar activity.
Norm (for the future mother): 4.0-9.0 units.

The level of leukocytes increases (leukocytosis) with inflammation, bacterial and viral infections, poisoning, acute blood loss (with trauma) or chronic latent bleeding (with stomach ulcer), kidney colic, allergies, liver diseases after long-term use of medications. As the number of leukocytes increases after eating, with pregnancy, with muscle activity, strong emotions, pain.
Leukopenia characterizes the course of some infectious diseases. Noninfectious leukopenia is associated with an increase in the radioactive background, the use of certain drugs, radiation sickness.
The norm of leukocytes in humans is 4-8.8 x 109 / L. Leukocytes are divided into 2 groups - granulocytes and agranulocytes.
Granulocytes account for about 60% of all blood leukocytes. They are divided into 3 types - neutrophils, basophils and eosinophils. Neutrophils belong to the group of granulocytes, because they contain small granules against the background of the colored cytoplasm, which perceives both basic and acidic dyes. Normally, in a healthy person, there are two types of neutrophils - segmented nuclei, in which the nucleus consists of 3-4 segments - functionally mature neutrophils, completely differentiated; And also stabnuclear (younger) neutrophils with an unsegmented nucleus. Most of the neutrophils are segmented.
Neutrophils can neutralize foreign bodies that the body has not previously met, they release or adsorb on their surface antibodies against microbes and foreign proteins.
Hypersegmented neutrophils contain more than 4 segments in the nucleus, are considered a sign of degeneration, are found with B12-deficient anemias, radiation sickness, septic states. Toxic - more coarse than normal, granularity of neutrophils, is found in severe inflammatory diseases, indicates a severe prognosis. Pelgerian family anomaly of leukocytes by the absence of segmentation of nuclei or their small segmentation (2 segments). Great in pathology does not matter. Eosinophils also belong to granulocytes. They can be stab-and segment-nuclear, but since their number in the smear is small, they are counted together. The cytoplasm contains a large, reddish-colored granularity. In pathology, the change in the number of eosinophils is of primary importance. An increase in their number accompanies allergic and autoimmune diseases, the presence of worms, tumors, childhood infections (scarlet fever), the taking of a number of drugs (antibiotics, sulfonamides), etc. Basophils belong to the group of granulocytes. The cytoplasm contains a large granularity, which is colored violet and dark blue. They produce heparin, which prevents blood clotting. In the pathology, the increase in the number of basophils is important.

Agranulocytes are divided into 2 types - lymphocytes and monocytes . Lymphocytes - do not contain granularity in the cytoplasm. Morphologically distinguish small and large lymphocytes, the first more mature. Lymphocytes carry numerous functions, they are divided into B and T lymphocytes, depending on where they mature and develop.
T-lymphocytes destroy protein bodies-microbes, viruses, cells of transplanted tissue (therefore they are also called T-killers).
B - lymphocytes produce specific antibodies.
Lymphocytes are the central link of the immune system, participate in the processes of cell growth, differentiation, tissue regeneration. Monocytes belong to the group of agranulocytes. The largest cells of peripheral blood. The core is large, friable, often bean-shaped. In the cytoplasm there is no granularity. These cells have amoeboid motions and are characterized by phagocytic activity. In pathology, quantitative changes in the number of monocytes are important. Their number increases with chronic and acute infections.

THROMBOCYTES Platelets are blood plates that actively participate in stopping bleeding (clotting of blood) and in immunobiological reactions of the body.
Norm (for the future mother): 180-320 units.
The obstetrician needs to know the picture of the blood coagulation system in order to make a prediction for the forthcoming birth (especially if a cesarean section is planned). For the same purpose, a prothrombin index is calculated - the time of thrombus formation and the rate of blood coagulation.
Elevated levels of platelets are observed in chronic inflammatory diseases (rheumatoid arthritis, tuberculosis, sarcoidosis), acute infections, certain types of anemia,
A blood test for clotting is needed to determine the duration of bleeding and blood clotting. This knowledge is necessary for doctors to prevent possible bleeding during pregnancy or to cope with great blood loss during childbirth or surgeries.
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