• Heat labile protein Synthesis in Liver.


• Absent from serum.

Accelerin -

• Hypothetical activation product of Proaccelerin.

Stable factor or Proconvertin or autoprothrombin or Serum prothrombin accelerator (SPCA) -

• Plasma protein of mol. wt. 63,000.


• Requires vit. K for its Synthesis. (In Liver) Associated with prothrombin. Accelerates tissue thromboplastin formation from damaged tissues.

Anti haemophilic factor (AHC) or Antihaemophilic globulin (AHG) or platelet Cofactor 1

• Glycoprotein, mol. wt. 1.1 million.


• Synthesis Liver, Required for prothrombin activator formation from blood constituents. Deficiency causes Haemophilia A.

Christmas factor or plasma thromboplastin component (PTC) or platelet Cofactor II or Anti prothrmbin II -

• Glycoprotein of mol. wt. 55,400.


• Synthesis Liver, requires vit. K for Synthesis


• Deficiency causes Haemophilia B

Stuart factor or stuart power factor

• Glycoprotein of mol. wt. 55,000,


• Synthesis Liver, in the presence of vit K;


• Deficiency results in nose bleeding

Plasma thromboplastin antecadent

• Glycoprotein of molecular weight 1,60,000


• Synthesis in Liver,Required for stage 1 of intrinsic pathway


• Deficiency results in haemophilia C.

Hageman factor or surface factor

• A glycoprotein of uncertain mol. wt. in plasma and serum & is required for the formation of prothrombin activator complex from blood constituents. In its deficiency blood clots very slowly.

Fibrin stabilizing factor

• Glycoprotein of mol. wt. 3,20,000


• Causes polymerization of soluble fibrinogen to insoluble fibrin.


• Deficiency causes heamorhagic state.

Platelet coagulation factors

• Platelet Accelerator or PF₁ Essentially same as plasma coagulation factor V.


• PF₂or Thrombin accelertor Accelerates thrombin formation in stage I of Intrinsic pathway. + Conversion of fibrinogen to fibrin.


• PF₃(Platelet thromboplastin factor)


• PF₄(Binds heparin)

complex of substances called prothrombin activator complex is formed in response to rupture of the vessel or damage to the blood itself

These activators catalyze the conversion of Prothrombin to thrombin

This thrombin act as an enzyme to convert fibrinogen into fibrin threads. Ý Clot formed

Development of THROMBOPLASTEIN from tissues [EXTRINSIC PATHWAY] with the help of factors4, 5, 7, 10.or from platelets [INTRINSIC PATHWAY] with the help of all platelet cofactors and plasma factors 4, 5, 9, 10, 11, 12