Blood Coagulation Flashcards
Factor I
Fibrinogen. Liver. 2000-4000 microgram/mL.
To fibrin by IIa, stabilised by XIIIa
Structural mesh work
Acute phase reactant
Factor II
Prothrombin. Activated by Xa Fibrinogen to fibrin Activator of platelets Procarboxypeptidase B, inhibits plasmin mediated fibrinolysis Anticlotting activity Wound healing
Vitamin K dependent
Factor III
Tissue thromboplastin
Extrinsic mechanism of blood coagulation
VII to VIIa, then X to Xa
Factor IV
Calcium, X to Xa, prothrombin to thrombin
Factor V
Proaccelerin
Accelerates prothrombin to thrombin
X to Xa
Factor VII
Proconvertin
Activated to tissue factor
Activates X to Xa
Also IX to IXa
Vitamin K dependant
Factor VIII
Antihemophilic factor
Activated by Xa, thrombin
Converts X to Xa
Bound to vWF
Factor IX
Vitamin K dependent
Christmas factor
Activated by XIa or VIIa/TF complex
X to Xa
Factor X
Stuart Prower factor
Vitamin K dependent
Activated by IXa and VIIa
Converts prothrombin to thrombin
Factor XI
Plasma thromboplastin or Antihemophilic factor C
Activated by XIIa, accelerated by kininogen
Contact factors
Factor XII
Hageman’s factor
Contact actuvation, along with HMW kininogen and prekallikrein
Converts XI to XIa
Factor XIII
Laki-Lorand factor
Fibrin stabilising
Activated by thrombin
HMW kininogen, prekallikrein
HMW- nonenzymatic function in contact activation.
Prekallikrein- complex with factor XI and HMW kininogen
Thrombomodulin
Protein C
Protein S
Tissue factor pathway inhibitor
Thrombomodulin+thrombin- protein C activated.
Protein C- vit K dependent
Protein S- cofactor for protein C, inactivates Va and VIIIa
TFPI- inhibits Xa and VIIa
Mechanism of blood coagulation
Stage 1: Activation of Stuart Prower factor
Stage 2: conversion of prothrombin to thrombin
Stage 3: formation of fibrin from fibrinogen
Intrinsic and extrinsic mode
I: IX, enzyme cascade
E: TPL, VII
Formation of fibrin from fibrinogen
Proteolysis of soluble fibrinogen
Polymerisation of fibrin monomers
Stabilisation of fibrin polymer
Proteolysis- by thrombin
Poly- protofibrils
Stab- XIIIa
Clot retraction
Mechanism, platelet, filipodia, contraction, internalization Thrombin and calcium Function: seal strongly Wound healing Prevent thrombolysis
Anticlotting mechanism naturally occurring
Anticoagulants
Vascular endo
Thromboxane A2 with prostacyclin
Mechanism of fibrinolysis
Activation of protein C
Activation of plasmin
Fibrinolysis
Thrombomodulin, inactivate inhibitors of plasmin activator, inactivate Va and VIIIa
Fibrin to fibrin degradation products (FDP) by cofactors thrombin, tissue type plasminogen activator, urokinase type plasminogen activator
