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13.25. What negative consequences can thrombosis formation in pathology have?

At various diseases, formation of blood clots can be accompanied by the heavy consequences caused by sharp violation of blood circulation in a zone of a thrombosed vessel (an ischemia at a thrombosis of arteries and stagnation of blood at a thrombosis of veins). A final stage can be development of necrosis (infarction) in area of thrombosed vessel without collaterals. The role of a thrombosis of coronal arteries in development of a heart attack of a myocardium is especially great. The thrombosis of arteries can result in trophic disturbances with the subsequent development of gangrene of legs, in case of atherosclerosis, endarteritis obliterans, or diabetes.

13.26. What is embolism?

Embolism is an occlusion of vessels by the bodies brought by blood flow or by lymph. These bodies are called embolus.

13.27. What kinds of embolism are assigned?

Depending on character of embolus and their origins, they can be distinguished into exogenous embolism and endogenous embolism.

Depending on localization embolism are distinguished as such as the big and small circle of blood circulation, and also system of portal vein.

Very seldom so-called retrograde embolism happens - when movement of embolus submits not to hemodynamic laws, but embolus’ own weight, and paradoxical embolism which is observed at nonclosure interatrial or interventricular partitions therefore embolus from veins of the big circle of blood circulation and the right half of heart pass in left, passing a small circle.

13.28. Name principal causes of embolism exogenous.

Depending on nature and character of embolus, which come from the outside, they can be distinguished into the following kinds of exogenous embolism: air, gas, bacterial, parasitic, embolism dense alien bodies.

Air embolism arises at wound of large veins of head and neck which are poorly fallen down also pressure close to zero or negative. As a result, the damaged veins air is sucked in, especially during inhaling, with the subsequent embolism of vessels of pulmonar circle of blood circulation.

Gas embolism develops at sharp difference of atmospheric pressure from raised to normal (at working caissons and divers) or from normal to lowered (at fast rise, on height or during time decompression cabins of the high-altitude flying apparatus). Thus solubility of gases in tissues and blood decreases, there is desaturation, i.e. a transition of gases from the dissolved condition in gaseous, and corking bubbles these gases (first of all nitrogen) the capillaries located mainly in system of the big circle of blood circulation.

13.29. Name the principal causes of embolism of endogenous origins.

Endogenous embolism includes embolism by a blood clot (thromboembolism), fatty embolism, tissue embolism, embolism of amniotic waters.

Source of thromboembolism is the particle of the come off blood clot, more often at aseptic or its purulent fusion.

Fatty embolism arises at hit in a blood-groove of drops of fat. More often the reason of it is damage (crushing, strong concussion) of bone marrow, hypodermics or pelvic fat.

Tissue embolism can be caused by entering in a blood channel parts of various tissues of an organism at their damage. Special value has embolism vessels cells of malignant tumours as it is the main mechanism of formation of metastasis.

Embolism of amniotic waters results from hit amniotic waters during sorts in the damaged vessels of a uterus on a site of the separated placenta.

13.30. What is the microcirculation? Name the main types of disturbances of microcirculation.

Microcirculation is a movement of blood and lymph on microcirculatory blood and lymphatic vessels.

Microcirculatory blood channel consists of vessels which diameter does not exceed 100 microns, i.e. arterioles, metaarterioles, capillary vessels, venules and arteriolo-venulous anastomosis (fig. 38).

Microcirculatory lymphatic vessels are begins in the initial part of lymphatic system in which there is a formation of the lymph and its receipt in lymphatic capillaries.

Disturbances of microcirculation divide into three types: intravascular; the disturbances connected to changes of vessels, and extravascular.

The big successes in studying laws of microcirculation in norm and in pathology are connected to A.M. Chernuh's name.

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