Coagulation Flashcards
Process of Hemostasis
1) Constriction of the blood vessel.
2) Formation of a temporary “platelet plug.”
3) Activation of the coagulation cascade.
4) Formation of “fibrin plug” or the final clot.
Primary Hemostasis
Vasocontraction
Platelet adhesion
PlateletSe aggregation to form primary hemostatic plug at injury site
Secondary Hemostasis
-Interaction of Coag Factors to produce fibrin (secondary hemostatic plug)
-Fibrin stabilization by Factor 13
Fibrinolysis
-Release of tissue plasminogen activator
-Conversion of plasminogen to plasmin
-Conversion of fibrin-fibrin degradation products
Factor I
Fibrinogen (I, E, C)
Converts to fibrin by thrombin
Factor II
Prothrombin (I, E, C)
Precursor of thrombin
Factor III
Tissue Factor (E)
Phospholipid released from injured vessel wall, not normally in blood
Factor IV
Calcium Ions Ca2= (I, E, C)
Bound by anticoagulant sodium citrate.
Factor V
Liable Factor (I, E, C)
Factor VII
Stable Factor (E)
Factor VIII
Antihemophilic Factor (I)
Critical in Hemophilia A deficiency
Circulates in association with VWF. VWF stabilizes VIII prolonging half life. VIII:C = Coagulant portion.
Factor IX
Christmas Factor (plasma thromboplastin component) (I)
Critical in hemophilia B deficiency
Factor X
Stuart Factor (I , E, C)
Factor XI
Plasma thromboplastin antecedent (I)
Rare but critical in hemophilia C
Factor XII
Hegeman Factor (I)
Factor XIII
Fibrin stabilizing factor ( I, E, C)
Stabilizes fibrin clot
HMWK
High molecular weight kiniogen (I)
Non part of the in vivo coagulation
PK
Prekallikrein (Fletcher factor) (I)
Not part of in vivo coagulation
Contact Group
PK, HMWK, XII, XI
Involved in initiation of intrinsic pathway
Prothrombin Group
II, VII, IX, X
Vitamin K-Dependent Factors
Fibrinogen Group
I, V, VIII, XIII
Factors acted on by thrombin (V, VII & XIII are activated; I is converted to fibrin)
Factors in extrinsic pathway
TF, VII
Factors in intrinsic pathway
PK, HMWK, XII,XI, IX, VIII
Factors in the common pathwau
X, V, II, I
extrinsic tenase complex
VIIa/TF
Acts on X
Intrinsic tenase complex
IXa/VIIIa
Acts on X
Prothombinase complex
Xa/Va
Acts on prothrombin
Factor VIII complex
VIII:C and von willebreand factor
VIII:C is the procoagulant, VWF is the carrier rotein
Where are all the factors produced?
In the liver
Requires Vitamin K for synthesis
II, VII, IX, X
Affected by the anticoagulant therapy (Coumadin)
II, VII, IX, X
All the require Vitamin K, warfarin is an vitamin K antagonist
Consumed during clotting
I, II, V, VIII, XIIII
Not present in serum
Labile Factors
V, VIII
