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Lymph circulation

Lymph circulation is the movement of lymph through lymphatic vessels and capillaries. The main condition for the movement of lymph (see) through the lymphatic capillaries into the large lymphatic vessels and further into the venous bed is a constant flow of fluid from tissue spaces (see Tissue fluid ), which creates pressure in the capillaries of the lymphatic system (see). Of great importance for lymphatic circulation is the physiological activity of individual organs, the contractile ability of the walls: lymphatic vessels, pulse movements of arterial vessels, etc.

Disorders of lymph circulation are observed in various pathological. conditions and, as a rule, are the result of previous diseases. Violations of lymph circulation are manifested in a change in the qualitative composition of the lymph, an increase in its quantity. The nature of the change in the qualitative composition of the lymph depends on the pathological process in the area of ​​the tissue or organ from which the lymph flows. So, when a tumor contains lymph cells in the composition of the tumor, and during inflammation there are significant amounts of leukocytes and fibrinogen . A pathological increase in the amount of lymph is a consequence of obstacles in the way of its outflow or an increase in its production (insufficiency of lymph circulation). There are mechanical insufficiency of lymph circulation that occurs when the lymphatic vessels are blocked by “fibrinous” thrombi formed as a result of the inflammatory process, when the vessels are squeezed by a nearby tumor, etc., and dynamic insufficiency associated with an increase in the permeability of blood capillaries, which leads to a significant increase in the amount of tissue fluid which does not have time to flow through the lymphatic vessels. In addition, there is a resorption insufficiency of lymph circulation that occurs when the absorption capacity of the endothelium of the lymphatic capillaries is impaired. Lymph circulation disorders are clinically expressed in an increase and swelling of the affected organ, sometimes there is a rupture of the lymphatic vessels and lymph flow (lymphorrhagia, lymphorrhea). The most common X-ray method is the study of lymph circulation (see Angiography ).

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Lymph circulation is the circulation of lymph and tissue fluid in the body. The true internal environment for all cells of the body is tissue fluid (see), through which the exchange of substances between the blood and tissues. Lymph circulation, causing, together with the blood circulation, a constant renewal of tissue fluid, plays a huge role in the metabolism of the cells of the whole organism.

Lymph circulation consists of: 1) the formation of tissue fluid by blood capillaries and tissues of organs; 2) the flow of excess tissue fluid from the intercellular spaces into the system of lymphatic capillaries; 3) movement of the lymph (see) through the lymphatic vessels (see) to the lymph nodes (see); 4) lymph flow through the main lymphatic ducts [thoracic duct (see), right lymphatic duct] into the large venous vessels of the neck.

The flow of tissue fluid through the endothelium of lymphatic capillaries occurs when the amount of its filtration from the arterial part of the blood capillary into the interstitial spaces prevails over reabsorption in the venous part of the same capillary. For example, with the active activity of an organ (muscle), the level of blood pressure in the arterial section of the capillary sharply increases and there is a continuous accumulation of tissue fluid. Increasing its pressure in the intercellular spaces leads to a continuous flow of tissue fluid into the cavity of lymphatic capillaries.

The movement of the lymph through the lymphatic vessels is caused by: a higher level of lymph pressure in the lymphatic capillaries than in the thoracic duct and large veins; the presence in the lymphatic vessels of a large number of valves that prevent the movement of the lymph in the retrograde direction; contractions of the surrounding skeletal muscles, as well as peristaltic movements of the intestine, contractions of the heart muscle, pulsation of large arteries. In some organs (mesentery) their own peristaltic movements of the lymphatic vessels were also found.

The study of lymph circulation is carried out by X-ray (introduction of contrast agents) and radiological (introduction of radioactive isotopes) methods, as well as vivisection experiments (using cannulas inserted into the thoracic duct, and the introduction of vital dyes on the periphery).

Disorders of lymph circulation (ascites, edema) are often accompanied by circulatory disorders (with heart failure), as well as certain metabolic pathologies (myxedema). The formation of edema during inflammation is caused by the cessation of the outflow of lymph from the focus of inflammation. Lymphostasis in this case is due to spasm of the lymphatic vessels distant from the center of inflammation, and their thrombosis in the area of ​​the center.