- •13. Disturbances of the peripheral blood circulation
- •13.1. Name the main forms of the local disturbances of blood circulation:
- •13.2. What is arterial hyperemia?
- •13.3. What functional changes and clinical attributes characterize arterial hyperemia?
- •13.4. What factors can be a cause of arterial hyperemia? What mean the physiological and pathological arterial hyperemia?
- •13.5. Name the main mechanisms of the pathological arterial hyperemia development.
- •13.6. What is the essence of the neurotonic mechanism of development of the arterial hyperemia ?
- •13.7. Explain the neuroparalytic mechanism of development of the arterial hyperemia.
- •13.8. What humoral factors can be the cause of development of arterial hyperemia?
- •13.9. What is the role of endothelium of blood vessels in development of arterial hyperemia?
- •13.10. Name possible outcomes of arterial hyperemia.
- •13.11. What is venous hyperemia?
- •13.12. What factors can be the cause of venous hyperemia?
- •13.13. What attributes display venous hyperemia?
- •13.14. What local and common violations can be consequence of venous hyperemia?
- •13.15. What is ischemia?
- •13.16. What attributes are typical for ischemia?
- •13.17. Name the main types of ischemia depending on the reason and mechanisms of its occurrence.
- •13.18. How are defined the character of metabolic, functional and structural disturbances in a tissue in case of its ischemia?
- •13.19. What consecutive stages characterize the pathogenesis of alterations in ischemic tissues?
- •13.20. What is stasis?
- •13.21. Name the main variants of stasis and their reasons.
- •13.22. What is the thrombosis?
- •13.23. Name three major factors, promoting thrombosis formation (Virhov’s triad).
- •13.24. What phases is the process of blood clot forming consists of? What is their essence?
- •13.25. What negative consequences can thrombosis formation in pathology have?
- •13.26. What is embolism?
- •13.27. What kinds of embolism are assigned?
- •13.28. Name principal causes of embolism exogenous.
- •13.29. Name the principal causes of embolism of endogenous origins.
- •13.31. What is the essence of a phenomenon called "sludge"?
- •13.32. How the exchange of water between plasma of blood and an interstitial liquid is carried out?
- •13.33. How does hydrostatic and oncotic pressure of blood and an intercellular liquid changes influence on intensity of processes of a filtration-reabsorption of water in capillaries?
- •13.34. What is the insufficiency of lymphokinesia? Name its main forms.
13.20. What is stasis?
Stasis is a delay and a stop of a current of blood in capillaries, fine arteries and veins.
13.21. Name the main variants of stasis and their reasons.
There is distinguishing ischemic, venous and true (capillary) stasis.
Ischemic and venous stasis develops as consequence of an ischemia and venous hyperemia and consequently has the same reasons, as the specified local frustration of blood circulation.
The reason of true stasis can be physical (a cold, it is warm), chemical (the poisons, the concentrated solution of sodium of chloride and other salts, turpentine) and biological (toxins of microorganisms) factors.
In pathogenesis of true stasis the great value is given to two factors: 1) intracapillary aggregation of erythrocytes, i.e. to their pasting and formation of the conglomerates complicating a blood-groove; 2) to delay of a blood-groove in capillaries owing to a condensation of blood. In the latter case the leading part belongs to increase of permeability of a wall of the vessels located in a zone of stasis.
13.22. What is the thrombosis?
The thrombosis is a process of lifetime formation on an internal surface of a wall of vessels of the blood clots consisting of its elements. These clots have received the name of blood clots.
Blood clots can be a parietal (in part reduce a gleam of a vessel) and stopples.
Depending on a structure can be distinguished the white, red and mixed blood clots. In the first case the blood clot is formed by thrombocytes, with leukocytes, and also a small amount of fibers of plasma; in the second - erythrocytes connected among themselves strings of fibrin; the mixed blood clots will consist of alternating white and red layers.
13.23. Name three major factors, promoting thrombosis formation (Virhov’s triad).
1. Damage of vascular wall. It can arise under action of the physical (a mechanical trauma, an electric current), chemical, biological (endotoxins of microorganisms) factors, and also as a result of violation of a feeding and metabolism of the vascular wall.
2. Disturbances of activity of coagulative and anticoagulative systems of blood and vascular wall. For formation of blood clots, the great value has an increase of activity of the coagulative systems of blood due to increasing its concentration of procoagulants, and downturn of activity of anticoagulative and fibrinolytic systems.
3. Delay of blood flow. This factor allows to explain, why in veins blood clots are formed more often, than in arteries, in veins of the legs - is more often, than in veins of the hands; and also high frequency of thrombosis formation at decompensation blood circulations, stay on a long confinement to bed.
13.24. What phases is the process of blood clot forming consists of? What is their essence?
Process of thrombosis formation includes two phases: cellular and plasmatic.
The essence of a cellular phase are: the adhesion, aggregation and agglutination of trombocytes (detailed watch chapter 26).
The plasmatic phase (phase of coagulation of blood) represents a circuit of consecutive biochemical reactions of curtailing of blood which the end result is formation of fibrin which is the important component of blood clots.