Circulatory Disturbances PDF

-Thrombosis -Embolism -Ischemia - Definition, causes, pathogenesis, types, classification and fate of thrombosis. - Definition and types of embolism. - Definition, types and fate of ischemia. Normally, the blood is kept in a fluid, clot-free state in the vessels Definition: Formation of thr...

-Thrombosis -Embolism -Ischemia - Definition, causes, pathogenesis, types, classification and fate of thrombosis. - Definition and types of embolism. - Definition, types and fate of ischemia. Normally, the blood is kept in a fluid, clot-free state in the vessels Definition: Formation of thrombus (solid mass formed of the elements of circulating blood inside the cardiovascular system during life) Causes & pathogenesis: Causes & pathogenesis: 1- Endothelial injury:(most important cause that can act alone or with combination with other factors causing activation of : 1-Platelets 2- Coagulation cascade Causes of Endothelial Injury: ▪ Mechanical: trauma, ligature, pressure. ▪ Degenerative: atherosclerosis & aneurysm. ▪ Inflammation: Arteritis, phlebitis (veins) , endocarditis (endocardium lining heart) Causes & pathogenesis: (slowing) (Bleeding factors)  Causes & pathogenesis: 3- Hypercoagulability Coagulation Bleeding factors factors Causes & pathogenesis: Coagulation 3- Hypercoagulability factors 1. Acquired causes: ▪ RBCs: polycythemia Bleeding factors ▪ WBCs: leukemia. ▪ Platelets: increase number: postoperative. ▪ Fibrinogen: late pregnancy, lobar pneumonia ▪ Plasma: decrease post hemorrhage, dehydration, persistent vomiting, diarrhea 2. Inherited causes : - Mutations in the factor V gene and prothrombin gene causing increase in their activities Types of thrombi: 1- Platelet thrombus: - Formed only of platelets - Weak, pale - Can be easily washed by normal blood flow Types of thrombi: 2- Mixed thrombus: - Formed of platelet, fibrin network, RBCS & WBCs - larger and more stable Types of thrombi: 3- Propagating thrombus: - Spread of thrombus inside the blood vessel until it reaches area of normal blood flow where it stops  Thrombophlebitis Phlebothrombosis Definition Thrombosis in an inflamed -Thrombosis in non inflamed vein vein Cause Inflammation cause -Stasis endothelial injury - Hypercoagulability Incidence Less common More common Types (Sites) -Septic (bacteria): in case of Calf veins: in varicose vein or appendicitis…vein heart failure. - Aseptic: may be due irradiation Complication Septic thromboembolism Thromboembolism Septic thrombi: Fragmentation septic emboli in the circulation multiple pyemic abscesses Definition : A process at which the blood losses its fluidity and form jelly- like mass. Causes: It is a natural process occur due to stasis with activation of coagulation cascade with no platelet activation Inside CVS Outside CVS (living) During the process of After death. thrombosis During In vitro Propagating thrombus. (lab)  Most common During labor Definition: Cutting of arterial blood supply to tissue Types: Sudden and complete Acute obstruction of artery Gradual and incomplete Chronic occlusion of artery Acute ischemia: Sudden and complete obstruction of artery Causes 1-Thrombus 2-Embolus 3-Surgical ligature 4-Ergot poisoning leading to arterial spasm (vasoconstriction) 5-Twisting of vessels as in ovary and testis. 6- Frost bite: occlusion of capillaries and arterioles in severe cold due to spasm Chronic ischemia: Gradual and incomplete obstruction of artery Causes: 1-Atherosclerosis 2-Compression from outside by enlarged lymph node, gravid uterus or tumors. Efeects: according to a. Type of ischemia: acute or chronic b. Degree of organ vascularity regarding number of arterial blood supply and efficiency of collaterals c. Vulnerability of tissue to hypoxia, CNS tissues are very sensitive to hypoxia and rapidly undergo necrosis after cut of blood supply d. Oxygen concentration in blood, so occlusion of small vessel may lead to marked damage if the condition is associated with anemia  Effects chronic acute Good Bad Good Bad collaterals collaterals collaterals collaterals Degeneration of tissue (small Degeneration (Necrosis) No effect and subsequent number of cells) fibrosis and scarring Enumerate the components of Virchow’s triad? Enumerate types of emboli?