Blood Coagulation Factors

List of Clotting Factors

Factor I

Name : Fibrinogen
Source : Liver
Pathway : Both extrinsic and intrinsic
Activator : Thrombin
Actions : When fibrinogen is converted into fibrin by thrombin, it forms long strands that compose the mesh network for clot formation.

Factor II

Name : Prothrombin
Source : Liver
Pathway : Both extrinsic and intrinsic
Activator : Prothrombin activator
Actions : Prothrombin is converted into thrombin which then activated fibrinogen into fibrin.

Factor III

Name : Thromboplastin / Tissue factor
Source : Platelets (intrinsic) and damaged endothelium (cells) lining the blood vessel (extrinsic).
Pathway : Both extrinsic and intrinsic
Activator : Injury to blood vessel
Action : Activates factor VII (VIIa).

Factor IV

Name : Calcium
Source : Bone and absorption from food in gastrointestinal tract
Pathway : Both extrinsic and intrinsic
Action : Works with many clotting factors for activation of the other clotting factors. These are called calcium-dependent steps.

Factor V

Name : Proaccerin / Labile factor / Ac-globulin (Ac-G)
Source : Liver and platelets
Pathway : Both extrinsic and intrinsic
Activator : Thrombin
Action : Works with Factor X to activate prothrombin (prothrombin activator).

Factor VI

Name : Proconvertin / Serum prothrombin conversion accelerator (SPCA) / stable factor
Source : Liver
Pathway : Extrinsic
Activator : Factor III (tissue factor)
Actions : Activates Factor X which works with other factors to convert prothrombin into thrombin.

Factor VIII

Name : Anti-hemoplytic factor / Antihemophilic factor (AHF) or globulin (AHG) / antihemophilic factor A
Source : Endothelium lining blood vessel and platelets (plug)
Pathway : Intrinsic
Activator : Thrombin
Actions : Works with Factor IX and calcium to activate Factor X.
Deficiency : Hemophilia A

Factor IX

Name : Christmas factor / Plasma thromboplastin component (PTC) / Antihemophilic factor B
Source : Liver
Pathway : Intrinsic
Activator : Factor XI and calcium
Actions : Works with Factor VIII and calcium to activate Factor X.
Deficiency : Hemophilia B

Factor X

Name : Stuart Prower factor / Stuart factor
Source : Liver
Pathway : Extrinsic and intrinsic
Activator : Factor VII (extrinsic) / Factor IX + Factor VIII + calcium (intrinsic)
Actions : Works with platelet phospholipids to convert prothrombin into thrombin. This reaction is made faster by activated Factor V.

Factor XI

Name : Plasma thromboplastin antecedent (PTA) / antihemophilic factor C
Source : Liver
Pathway : Intrinsic
Activator : Factor XII + prekallikrein and kininogen
Actions : Works with calcium to activate Factor IX.
Deficiency : Hemophilia C

Factor XII

Name : Hageman factor
Source : Liver
Pathway : Intrinsic
Activator : Contact with collagen in the torn wall of blood vessels
Actions : Works with prekallikrein and kininogen to activate Factor XI. Also activates plasmin which degrades clots.

Factor XIII

Name : Fibrin stabilizing factor
Source : Liver
Activator : Thrombin and calcium
Actions : Stabilizes the fibrin mesh network of a blood clot by helping fibrin strands to link to each other. Therefore it also helps to prevent fibrin breakdown (fibrinolysis).

Prekallikrein

Source : Liver
Pathway : Intrinsic
Actions : Works with kininogen and Factor XII to activate Factor XI.

Kininogen

Source : Liver
Pathway : Intrinsic
Actions : Works with prekallikrein and Factor XII to activate Factor XI.