Microcirculation Disorders – Intravascular, and Extravascular Disorders

MICROCIRCULATION DISORDERS


In Microcirculation Disorders, The microcirculatory bed is considered as a subsystem within a single circulatory system. Microhemocirculation is a basic element of blood circulation, a constituent element of organs and tissues.

Disorders of blood flow in the microcirculation system are an inevitable component of almost every pathological process.

Disorders of microcirculation that are of general pathological significance are divided into:

  1. intravascular changes;
  2. disorders associated with changes in the vessels themselves;
  3. extravascular changes.

Intravascular disorders (Microcirculation Disorders):

  1. disorders of the rheological properties of blood;
  2. blood coagulation disorders and thromboembolism;
  3. change in blood flow rate, i.e. violation of blood perfusion through the microvasculature.

VIOLATIONS OF THE VESSELS ITSELF (Microcirculation Disorders):

  1. damage and change in the shape and location of endothelial cells in the walls of microvessels;
  2. change in the permeability of the capillary and venular walls;
  3. adhesion (adhesion) of leukocytes, platelets and foreign particles to the endothelium;
  4. diapedesis of blood cells through the wall of capillaries and venules;
  5. microbleeds.


EXTERNAL CHANGES:

  1. damage to the connective tissue and parenchymal cells of organs surrounding the microvessels;
  2. the reaction of mast cells to pathological stimuli;
  3. disorders (difficulties) of lymph formation;
  4. involvement of the microvascular bed in the neurodystrophic tissue process.

The phenomenon of erythrocyte aggregation. Aggregates of erythrocytes in pathological conditions clog small vessels, worsen the nutritive (metabolic) blood flow, adversely affect trans-

capillary exchange. Aggregation in microvessels is accompanied by

slowing down of blood flow, phenomena of vasoconstriction and vasodilation. Violations are manifested by widespread aggregation of erythrocytes, embolothrombus formation, plasma separation (separation), opening of arteriovenular anastomoses. Stasis, thrombophlebitis, tissue acidosis, tissue necrosis develop. The functions of many organs (heart, brain, liver, kidneys, intestines, endocrine glands, etc.) are upset.

Aggregation of erythrocytes is a secondary process, a systemic reaction of the body to various damaging factors.

Etiological factors are trauma in the broadest sense of the word (mechanical, thermal, chemical, vibration), the antigen-antibody reaction, autoimmune processes, the influence of microbes, etc.

It is necessary to distinguish aggregation from agglutination. If aggregation is a reversible process, then agglutination is always irreversible and is usually caused by immune factors.

Sludge is a blood condition caused by the aggregation of red blood cells. The development of sludge is an extreme degree of expression of the aggregation of blood corpuscles.

Main features of blood sludge: sticking to each other

to another shaped elements and an increase in plasma viscosity. WHO-

diminishing blood condition makes it difficult to perfusion through microvessels.

Depending on the structural features of the aggregates, the following types of sludge are distinguished .

  1. Classic.
  2. Dextran.
  3. Amorphous.