The normal circulation is one of the essential requirement to maintain the normal metabolism and functional activities of body. The health of cell and tissue depends not only on an intact circulation to deliver oxygen and remove waste but also on fluid homeostasis. Normal homeostasis encompasses maintenance of vessel wall integrity as well as changes in vascular volume,coagulability, intravascular pressure and osmolarity within certain physiology ranges .When these are out of balance ,hemodynamic disorders will occur . Hemodynamic disorders can have an effect on the metabolism ,function and morphology of its relevant organism and tissue .They can lead to atrophy ,degeneration and necrosis ,even if death . Hemodynamic disorders are major factor in much of human diseases.
Hemodynamic disorders can be all over or local . Here mainly introduce disturbances of local flow and body fluids . Hyperemia and congestion indicate a local increased volume of blood in particular tissue .Hyperemia is an active process resulting from augmented blood flow due to arteriolar dilation .Congestion is an passive process resulting from impaired venous obstruction .The usual congestions we meet in clinic are lung congestion from lefe-side heart failure and liver congestion from right-side heart failure .The latter often take a nutmeg–like look in naked eye. Normal fluid homeostasis maintains blood as a liquid until such time as injury necessitates clot formation.When this balance is destroyed ,clotting and hemorrhage can take place. Clotting can be normal and abnormal. Production of an intravascalar clot (thrombus) during life is an abnormal response to a change in a vessel or its contents .This is so-call thrombosis. It can be caused by changes in the vessel wall ,changes in the blood flow and changes in coagulability of blood. Hemorrhage generalily indicates extravasation of blood due to rupture of blood vessels .Hemorrhage may be external or may be enclosesd winthin a tissue .So it is divided into external hemorrhage and internal hemorrhage. Abnormal intravascular thing obstructs blood flow and can be carried by the blood to a site distant from its point of origin. It is so called embolism . The abnormal intravascular thing being named embolus can be solid ,liquid ,or gaseous and so on .It is so-call infarction that any cause hampers blood flow into tissue then lead to single cell,tissue or organism taking place atrophy ,degeneration and necrosis ,even if death. Maily according to its color , infarction is classified as three types :red infarction, white infarction ,septic infarction . Edema refer to too much water accumulation of fluid in body cavities, cells or tissue spaces. It can be all over or local . And edema usual takes place with the other fluid imbalance and worsens its condition.
Hemodynamic disorders are major factor in much of human diseases nowadays.In clinic we can see that many diseases deal with hemodynamic disorders .They can display deferent symptoms in deferent organisms. What effect it takes place in our body usually is up to what extent it is ,which organism it is in or how long it is enduring and so on .For example when an absolutely embolism take place in the coronary can usually lead to myocardial infarction .It will probably display a great pain in the front of chest ,hypotension ,shock and heart-failure .We can diagnose the disease according to its symptoms and it pathology.