The microcirculatory bed is not a mechanical sum of various vessels, but a complex anatomical and physiological complex consisting of 7 links (5 blood vessels, lymphatic and interstitial) and providing the main vital process of the body – metabolism. Therefore, V. V. Kupriyanov regards it as a microcirculation system.
The structure of the microvasculature has its own characteristics in different organs, corresponding to their structure and function. Thus, in the liver there are wide capillaries – hepatic sinusoids, which receive arterial and venous (from the portal vein) blood. In the kidneys there are arterial capillary glomeruli. Special sinusoids are characteristic of the bone marrow, etc.
Microcirculation fluid is not limited to microscopic blood vessels. The human body is 70% composed of water, which is contained in cells and tissues and makes up the bulk of blood and lymph. Only xls of the whole fluid is in the vessels, and the remaining 4/5 of it is contained in the plasma of cells and in the extracellular medium. Microcirculation of the fluid is carried out, in addition to the circulatory system, also in the tissues, in the serous and other cavities, and in the path of transport of lymph.
From the microvasculature, blood flows through the veins, and lymph through the lymphatic vessels, which ultimately fall into the cardiac veins. Venous blood containing lymph that has joined it, flows into the heart, first into the right atrium, and from it into the right ventricle. From the latter, venous blood enters the lungs through the small (pulmonary) circulation.