.徐建民－出血性疾病1.ppt

DISORDERS OF HEMOSTASIS Dept.of Hematology ZhongShan Hospital,FuDan University Prof. JlAN-MIN XU General Considerations Disorders of hemostasis defects in platelet number or function problems in fibrin clot (coagulation) Bleeding due to platelet disorders is typically mucosal or dermatologic include epistaxis, gum bleeding, menorrhagia, gastrointestinal bleeding, purpura, and petechiae General Considerations Petechiae are seen almost exclusively in conditions of thrombocytopenia and not platelet dysfunction. Bleeding due to coagulopathy may occur as deep muscle hematomas as well as skin bleeding. Spontaneous hemarthroses are seen only in severe hemophilia. General Considerations Definition: disorder of hemostasis spontaneous bleeding abnormal bleeding following trauma Machanism ： vessel wall defect thrombocytopenia, platelet disfunction coagulation disorder Normal hemostasis and coagulation hemostasis: 1. Vessel wall： （1）vessel spasm: reflex spasm S-HT↑ slow down blood flow （2）subendothelial connective tissue： encouraging platelet adhesion, activation, aggregation （3）releasing TF, activating FⅫ： triggering intrinsic and extrinsic pathway （4）pression of haematoma Normal hemostasis and coagulation 2. platelet： （1）adhesion： to subendothelial connective tissue by GPⅠb、vWF （2）aggregation ： formation of platelet thrombus by GPⅡb/Ⅲa （3）release： phosphatide-Arachidonic Acid -TXA2 further platelet activation and adhesion violent vessel spasm Normal hemostasis and coagulation coagulation: （1） Rearrangement of platelet membrane phosphatidate-PF3 （2） Tissue injury- TF release （3） Subendothelial connective tissue-Ⅻ-Ⅻa triggering intrinsic and extrinsic pathway-white thrombus-red thrombus Normal hemostasis and coagulation coagulation： nature: a cascade of enzymes activation