Edema with hypoproteinemia
Allergic edema. Acute allergic reactions cause a local release of vasoactive substances such as histamine, which
expand the lumen of the vessels of the microcirculatory bed and cause an increase in capillary permeability.
Edema due to venous stasis. The degree of venous stasis depends onintensity of collateral venous circulation in this area. In those cases when venous congestion is accompanied by complete failure of the drainage function of the veins, severe swelling and hemorrhage develops, as hydrostatic pressure accompanied by rupture of capillaries is increased. When the drainage function of the veins is partially broken, the swelling is less pronounced.
Edema due to lymphatic stasis. When the lymphatic drainage is broken, a small amount of protein that leaves the capillaries by pinocytosis and as a result of ultrafiltration, it is not removed and accumulates in the interstitial space.
General edema is the result of an increase in the total number ofsodium ions and water in the body when they are delayed by the kidneys, when the level of glomerular filtration is reduced or increased secretion of aldosterone. The balance of sodium ions is regulated by many mechanisms:
• filtration of sodium ions in the glomeruli and reabsorption of sodium ions in the proximal and distal convoluted tubules;
• its further utilization in the distal convoluted tubules is regulated by the renin-angiotensin-aldosterone system.
Cardiac edema. Heart failure is accompanied byreduction of left ventricular ejection of blood. Reduction of the release of blood into the large circle of blood circulation leads to a decrease in filtration pressure in the glomeruli, stimulation of the juxtaglomerular apparatus and renin secretion. Renin, in turn, stimulates an increase in the production of aldosterone via angiotensin, providing a retention of sodium and water ions, which leads to the appearance of a general edema.
Hypoproteinemic edema. With hypoproteinemia, the osmoticcolloid pressure of plasma. As a result of fluid loss in the vascular system and a decrease in the volume of the plasma, reflex spasm of the renal vessels occurs, leading to hypersecretion of renin, secondary aldosteronism, retention of sodium and water ions by the kidneys, and development of a general edema.
Renal edema. In acute glomerulonephritis, the level of glomerularfiltration is markedly reduced, which leads to the retention of sodium and water ions and the development of moderate edema. Unlike other types of general edema in acute glomerulonephritis, usually
first there are swelling in the tissues surrounding the eyes, on the eyelids, and then they spread to the hands, feet.
Other kidney diseases, accompanied by nephrotic syndrome and a significant loss of protein in the urine, lead to hypoproteinemia and are accompanied by massive general edema.
Pulmonary edema. Pulmonary circulation functions at lowhydrostatic pressure. When it becomes higher than the colloid osmotic pressure of the plasma, a small amount of fluid exits the pulmonary capillaries. The outlet of fluid from the pulmonary capillary into the alveoli is called pulmonary edema. The lungs are swollen when swelling is heavy, increases in size, acquires a testic consistency, and a large amount of transparent, pinkish, small foam liquid drains from the surface of the incision.The edematic fluid first accumulates in the interstitial tissue (stroma), and then in the alveoli, edema disrupts gas exchange in the lungs and severe cases cause hypoxia and death.
Edema of the brain observed in a wide variety of injuriesbrain. The liquid is collected in the extracellular space of the white matter. The edema fluid physically ruptures the neural connections, causing transient acute brain disturbances. Increased intracranial pressure leads to headache and edema of the optical disk of the optic nerve (papilledema). The brain is enlarged, the subarachnoid spaces and ventricles are enlarged and filled with a clear liquid. Edema of the brain is often combined with its swelling, which in some cases dominates. When the brain swells, there is a sharp hydration of its substance, the gyrus is smoothed, the cavities of the ventricles are reduced. With edema of the brain, the fluid accumulates around the vessels and cells (perivascular and pericellular edema), swelling of the brain marked astrocyte swelling, destruction of glial fibers, decomposition of myelin. There is an increase in intracerebral and intracranial pressure. A significant increase in pressure can move the temporal lobe downward into the opening of the cerebellum nest (hernia of the nest) or move the amygdala of the cerebellum into the large occipital foramen (almond hernia), which can cause death due to compression of the vasomotor center in the brainstem.
Edema of serous cavities. The accumulation of edematous fluid within the cardiac and pleural cavities can disrupt the normal functioning of the heart and the spreading of the lungs. Fluid, accumulating in the abdominal cavity (ascites), causes stretching of the abdominal wall and usually does not significantly disturb the normal function of the abdominal organs.