病理学英文课件：Hemodynamic Disorders and Thromboembolic Disease (2).ppt

Effects of Thrombus Arterial: - Atherosclerosis is a major initiator - Infarction of dependent parts - Myocardial infarction, cerebral infarction Venous: - Associated with stasis - Infarction rare due to collateral bypass channels - Local pain and distal edema - Embolization to lungs, causing death ARTERIAL v/s VENOUS THROMBUS At sites of turbulence / damaged endothelium Usually occlusive Grow in retrograde fashion from point of attachment Site / order of frequency: Coronary - Cerebral - Femoral Gray white friable, tangled mass of platelets and fibrin, RBCs and degenerating WBCs At sites of stasis Almost invariably occlusive Extend in the direction of blood flow Most common : veins of lower extremities More RBCs, hence called red / stasis thrombi Hemostasis and Thrombosis Normal Hemostasis Endothelium Platelets Coagulation cascade Thrombosis Mechanism (Virchow’s triad) Morphology Fate of thrombus Disseminated Intravascular Coagulation Disseminated Intravascular Coagulation (DIC) A complication but a disease Disturbance of micro-circulation Hypercoagulability and thrombosis Micro-thrombi in capillaries Fibrin thrombus( Microthrombus) Constitution: fibrin Location: micro-circulation in DIC Especially in capillaries of kidney, lung, brain and liver SUMMARY: Thrombosis Thrombus development depends on the relative contribution of the components of Virchows triad: Endothelial injury; Abnormal blood flow; Hypercoagulability (primary or secondary) Thrombi may propagate, resolve, organization, or embolization Thrombosis causes tissue injury by local vascular occlusion or by distal embolization Question: What is the difference between arterial thrombus (white thrombus) and venous thrombus (mixed thrombus)? Localization Color Attachment Extending Complications Punctate petechial hemorrhages of the colonic mucosa, a consequence of thrombocytopenia. B, Fatal intracerebral hemorrhage. Even relatively inconsequential volumes of hemorrhage