T Flashcards
Function of hemostasis
Limit blood loss
Define thrombosis
Formation of blood clot inside the vessel
Endothelium has a non-thrombogenic surface
If this is intact, it generates prostaglandin and nitric oxide which inhibits platelet aggregation
When endothelium is damaged, sub-endothelial collagen is exposed and platelets will adhere to this - this will activate the platelets
The platelets will begin to Aggregate
Platelets release agents which promote vasoconstriction and platelet aggergation
Then fibrin will form through enzymatic reaction, these get meshed within the platelet plug, which stops the flow
Haemostatic plug is dissolved by fibrinolytic system
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“Blood clot” slide
Shows EMG of RBC in fibrin mesh
Calcium is required for clotting
Calcium chelators can be used to prevent clotting
Thrombin acts on
Fibrinogen to form fibrin
Extrinsic factor = the Easy pathway
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Blood clotting disorders
Learn
Fibrinolytic system stops the clotting cascade overrunning
Plans in breaks down fibrin polymers
Venous thrombosis vs arterial thrombosis
Problem with venous thrombosis - can break off and enter pulmonary circulation
Anticoagulants are involved in vitro storage of blood, as well as in vivo
Heparin - is polyanionic (has lots of negative charges)