coagulation Flashcards
types of tests used in haematology
to predict bleeding to predict clotting to monitor drugs used to manipulate the haemostatic system
initiation phase of the coagulation cascade involves what?
injury of vessel wall leads to contact between blood and subendothelial cells TF exposed and starts off the system
What is the “starter motor” for coagulation cascade?
tissue factor
specific assays for bleeding
factor assays VWF AG Collagen binding assays fibrinogen
what does secondary haemostasis involve?
activation of coagulation factors formation of fibrin (bulk of clot that covers hole)
Virchow’s triad
three things that are involved in blood clotting - vessel wall - blood flow - blood composition any of these three things can cause abnormal blood blotting
key principles of most coagulation tests
- sample integrity crucial - standard curve developed (for interpretation) - control samples - duplicate testing - multiple consistent tests before labelling a patient
What is special about the endothelium around your body?
it acts differently in arteries and veins, and in every specific site within your body
coagulation system involves
a complex series of proteins in plasma that interact with platelets and blood vessel walls
What is the main action of thrombin?
converts fibrinogen to fibrin –> clot formation
3 types of factor assays
functional clot based assays chromogenic assays immunological assays
what does fibrinolysis inolve?
activation of fibrinolysis lysis of the clot
What is the key enzyme in the coagulation cascade?
thrombin
3 main phases of the coagulation cascade
initiation phase amplification phase propagation phase
which factors does walfarin inhibit?
2, 7, 9, 10
