Blood Flashcards
what are anticoagulants?
compounds that prevent blood clotting
what is a clotting factor?
enzymes/proteins that are required for clot formation
coagulation
the conversion of liquid blood to a gel like solid
homeostasis
the stopping of bleeding, blood clotting is only a part of homeostasis
platelets
very small acellular particles, small pieces budded from special cells, found in whole blood which when activated play an important role in clotting
proteases
an enzyme which cleaves peptide bonds in their substrates
proteolysis
cleavage of peptide bonds in proteins
thrombin
an enzyme (clotting factor) which forms clots
thrombosis
formation of dangerous clots
thrombus
a blood clot (generally in medicine a clot which occurs in a disease process eg formation of a clot where it is not wanted)
what are the 3 phases of haemostasis
vasoconstriction, formation of a platelet plug, coagulation
what is used to prevent coagulation when blood is stored?
sodium citrate
what initiates the extrinsic pathway
tissue factor released by damaged cell (can be tested by PT)
what initiates the intrinsic pathway?
activated platelets (can be tested by APPT)
what is fibrinolysis?
the process by which the clot is removed, done by a protein called plasmin
where is plasminogen synthesised
in the liver and then circulates in the plasma