- •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.
13.12. What factors can be the cause of venous hyperemia?
Violation of outflow of blood on veins can be connected to the following factors:
1) intravascular (obstruction of veins by blood clot or embolus);
2) extravascular (compression of veins by a tumour, scar, increased uterus, edematic liquid);
3) factors of the vascular wall itself (constitutional weakness of the elastic components of the veins, insufficient development and the lowered tone smooth muscle’s elements of blood vessel wall;
4) disturbances of the general hemodynamics (slackening of function of right ventricle of heart, reduction of sticking activity of the thorax, disturbances of blood flow in the pulmonar circle of blood circulation).
13.13. What attributes display venous hyperemia?
For venous hyperemia increasing of volume of organ or the site of tissue, cyanosis, local downturn of temperature, a hypostasis, increase of pressure in veins and capillaries of stagnant area, delay of the blood flow, an output of erythrocytes from blood vessels (diapedesis) are characterized. At the last stage of hyperemia oscillating of blood and stasis are possible. Long expansion of veins results the stretching of their wall that can be accompanied by a hypertrophy of a muscular layer of venous wall, the phenomenons of phlebosclerosis and varicose expansions of veins.
13.14. What local and common violations can be consequence of venous hyperemia?
Local changes at venous hyperemia are initiated on the whole by the oxygen starvation (hypoxia) of the tissues. Hypoxia thus is originally caused by restriction of inflow of arterial blood, and then by influence on tissue enzyme systems of products of the broken metabolism, consequence of these are disturbances of oxygen using.
Oxygen starvation at venous hyperemia causes frustration of the tissue metabolism, causes atrophic and dystrophic changes, superfluous growth of the connective tissue (for example, a cirrhosis of a liver at the venous stagnation caused by insufficiency of function of heart).
If venous hyperemia has generalized character, some common hemodynamic violations with heavy consequences is possible. More often they arise at corking large venous vessels - portal, bottom hollow veins. The congestion of blood in the specified vascular tanks (up to 90 % of all blood) is accompanied by sharp decrease in arterial pressure, violation of the feeding of the vital important organ (heart, brain), that can lead to death.
13.15. What is ischemia?
Ischemia is a reduction of blood filling of the organ or site of a tissue as a result of restriction or the full stop of inflow of arterial blood. Ischemia is also called a local anemia.
13.16. What attributes are typical for ischemia?
Ischemia is characterized by paleness of part of organ, decrease of its temperature, violations of sensitivity (sensation of anesthesia, pricking, crawling "the creeps"), a painful syndrome, reduction of speed of a blood-groove and body in volume, downturn of arterial pressure on the site of an artery located below of an obstacle; decreasing of the pressure of oxygen in ischemical part of the organ or tissue, reduction of formation of the tissue fluid and decrease of turgor of tissues, dysfunction of the organ or tissue, dystrophic changes.