| Factor Number | Factor name | Nature/Origin | Function/Pathway |
|---|
| I | Fibrinogen | Plasma, synthesised by liver | Common pathway, converted to fibrin, weblike substance of clot |
| II | Prothrombin | Plasma, synthesised by liver, requires vit K | Common pathway, converted to thrombin, which enzymatically converts fibrinogen to fibrin |
| III | Tissue factor (TF)/tissue thromboplastin | Lipoprotein complex, released from damaged tissues | Activates extrinsic pathway |
| IV | Calcium ions Ca2+ | Inorganic ion in plasma, acquired from diet/released from bone | Required for all stages of coagulation process |
| V | Proaccelerin, labile factor or platelet accelerator | Plasma protein, synthesised in liver, released by platelets | Extrinsic and intrinsic mechanisms |
| VII | Serum prothrombin conversion accelerator (SPCA) or stable factor | Plasma protein, synthesised in liver, requires vit K | Extrinsic and intrinsic mechanisms |
| VIII | Antihaemophilic factor (AHF) | Globulin synthesised in liver, deficiency causes haemophilia A | Intrinsic mechanism |
| IX | Plasma thromboplastin component (PTC) | Plasma protein, synthesised in liver requiring vit K, deficiency results in haemophilia B | Intrinsic mechanism |
| X | Thrombokinase | Plasma protein, synthesised in liver requiring vit K | Extrinsic and intrinsic mechanisms |
| XI | Plasma thromboplastin antecedent (PTA) | Plasma protein, synthesised in liver, deficiency results in haemophilia C | Intrinsic mechanism |
| XII | Hageman factor | Plasma protein, proteolytic enzyme, synthesised in liver | Intrinsic mechanism, activates plasmin, activated by contact with glass, may initiate clotting in vitro |
| XIII | Fibrin stabilising factor (FSF) | Plasma protein, synthesised in liver, present in platelets | Cross links fibrin and renders it insoluble |