HEMOSTASIS Flashcards
smooth surface is not conducive to clot formation
has display membrane proteins (thrombomodulin) that inhibit clotting
store von willebrand factor in cytoplasmic alpha granules
intact endothelial cells
contain membrane proteins and extracellular matrix proteins (collagen) that normally do not contact blood
subendothelial cells
enucleated cells that are fragments of larger progenitor cells called megakaryocytes
production is primarily regulated by thrombopoietan and other growth factors
half life in the blood = 8-12days
platelets
vascular spasm/constriction
platelet plug formation
primary hemostasis
clot organization
blood coagulation
secondary hemostasis
fibrinolysis
tertiary hemostasis
reduces the flow of blood from the vessel rupture
vascular constriction
platelet adhesion
platelet secretion
platelet aggregation
formation of platelet plug
binding of platelet to non-platelet surface: sub endothelial collagen
plasma proteins required for normal platelet adhesion:
thrombin
fibronectin
VWF
platelet adhesion
primary ADP stimulates aggregation
Thromboxane A2
serotonin enhance vasoconstriction
platelet secretion
END RESULT: platelet plug
platelet aggregation
formation prothrombin activator in response to rupture of the vessel and damage
catalytic conversion of prothrombin to thrombin
thrombin acts as enzyme to convert fibrinogen into fibrin
clot formation
factors 3 and 4 roman numerals indicate inactive forms as they exist in the _____
plasma
proenzymes
________________ are each activated by proteolytic cleavage to become enzymatically active
factors 12,11, 9, 7, 10, 11
vitamin k dependent clotting factors
2, 7, 9, 10
co factors are non enzymatic proteins that are essential for the optimal activity of the enzymes of the clotting cascade
tissue factor (factor 3), factor 8, factor 4 are cofactors
platelets contain 3 types of secretory granules which are
lysosome
alpha granules
delta granules
__________________ are required for promotion and acceleration of almost all blood clotting reactions
except activation of 12 and 11 (intrinsic mechanism)
calcium ions
physiologic inhibitors of coagulation
antithrombin 3
activated protein c and s
thrombomodulin
prostacyclin
inactivates thrombin
attaches to thrombin 2a and inactivates it preventing thrombin from converting fibrinogen to fibrin
antithrombin 3
inactivates antithrombin 3
binds to activated _________ factors
9a, 10a, 11a, 12a
antithrombin 3 is enhanced and accelerated by presence of ____________ (either naturally released from basophils or given therapeutically as an anticoagulant)
heparin
produced by liver
vitamin K dependent
inactivates factors 5 and 8
stimulates fibrinolysis
activated by thrombin 2a
protein c
protein c inactivates factors ________
factors 5 and 8 inactivated by protein c
cofactor to protein c to enhance its ability to degrade factors 5 and 8
vitamin k dependent and produced by the liver
protein S
binds with thrombin
thrombomodulin - thrombin complex activates protein c which inactivates factors 5 and 8
thrombomodulin
natural anticoagulants
heparin, anti thromboplastin
heparin comes from basophils and mast cells and potentiates effects of antithrombin 3
which inhibits factors ____________
9, 10, 11, 12 and thrombin (activated factor 3)
inhibits factor 3 (tissue factors - tissue thromboplastin)
antithromboplastin
________ is necessary for production of prothrombin, factor 7, 9, 10, & protein c
vitamin k
severe reduction in the number of platelets
bleeding from small venules and capillaries
thrombocytopenia
widespread coagulation which leads to thrombosis in small blood vessels, increased fibrinolysis and depletion of coagulating factors which leads to generalized bleeding
disseminated intravascular coagulation
hemophilia which occurs in males
transmitted by women (X chromosome)
A: Factor 8 deficiency 85%
B: Factor 9 deficiency
Hemophilia
hemophilia A is _______ deficiency
factor 8
hemophilia b is ________ deficiency
factor 9
abnormal blood clot develops in blood vesel
thrombus
freely floating blood clot
embolus
