Blood, like any tissue, consists of cells and the intercellular substance that metabolizes them. At the same time, their ratio is such that it is more like a suspension of shaped elements (cells) in a liquid medium.
Cells are formed in the bone marrow from red and white sprouts, and then through multiple sinusoidal capillaries they enter the general circulation, where they perform their highly specialized functions. However, before that, they undergo a multistage differentiation from a common precursor cell of a pluripotent stem cell to mature cells: leukocytes, thrombocytes, and erythrocytes; the norm of all these cells may fluctuate as a manifestation of compensation or pathology. The latter of them are the main oxygen transporters, while the remaining white blood cells (leukocytes, consist of 5 classes) and lamellar bodies (platelets) carry out multifaceted protective reactions. So, lymphocytes provide immunity, neutrophils and monocytes - phagocytosis and proteolysis, baso- and eisonophils - the secretion of biologically active substances: histamine, thromboxanes, prostaglandins and leukotrienes, PAF,promoting vasoconstriction and activation of other cells. Platelets form a kind of “plug” when the vascular wall is damaged.
Erythrocytes, norm: structure and functions
RBCs are one of the most highly specialized cells. Their young precursors are called reticulocytes, as they mature, the cell gradually loses the nucleus and replaces it with hemoglobin, a quaternary protein capable of forming a weak compound with oxygen in order to easily capture it in the pulmonary capillaries and also easily release it in the tissues. RBCs normally have a biconcave shape, as it provides them with a number of advantages, increasing the surface area to bind more oxygen and allowing them to "fold" as they pass through the smallest caliber vessels of the microvasculature. Since men expend more energy and, accordingly, oxygen, erythrocytes also have a higher concentration in their blood.
The norm for women is 3.9 - 4.710^12/l, for men the same norm is 4.0-5.010^12/l. This is also due to a higher level of androgens, which have a stimulating effect on erythropoiesis. Another important component of the KLA is the level of hemoglobin, since with a decrease in its concentration per unit volume of blood, a pathological state of "anemia" occurs, accompanied by increasing hypoxia and organ ischemia. The color indicator reflects how erythrocytes are saturated with hemoglobin. The norm of thisthe indicator is 0.8-1.05 units, and when it decreases, we can talk about hypochromic anemia. Also, anemia can be normochromic, as with increased hemolysis, when it is erythrocytes that undergo increased destruction in the tissues, the norm of which is maintained by the balance of their synthesis in the RMC, destruction occurs in the liver and spleen after 90-110 days. Hyperchromic anemia is observed with the so-called. megaloblastic anemia that develops with a lack of vitamin B12 or H4-folate, the most important components of erythropoiesis.
