Definition
noun, plural: blood clotting factors
Any of the many plasma components involved in blood clot formation
Supplement
Coagulation, the process of clot formation, involves platelet and blood clotting factors. In humans, the coagulation mechanism is comprised of two processes. The first is the so-called primary hemostasis wherein the platelets form a plug at the site of injury. This is then followed by secondary hemostasis, which is comprised of cascading events involving the clotting factors to ultimately form fibrin strands that strengthen the platelet plug. This secondary hemostasis has two initial pathways that end in the formation of fibrin. These two pathways are: (1) intrinsic pathway (contact activation pathway) and (2) extrinsic pathway (tissue factor pathway).
Examples of blood clotting factors in humans are as follows:
- Fibrinogen (factor I)
- Prothrombin (factor II)
- Tissue factor or thromboplastin (factor III)
- Calcium ions (factor IV)
- Proaccelerin (factor V)
- Accelerin
- Proconvertin (factor VII)
- Antihaemophilic factor (factor VIII)
- Christmas factor (factor IX)
- Stuart factor (factor X)
- Plasma prothromboplastin antecedent (factor XI)
- Hageman factor (factor XII)
- Fibrin-stabilizing factor (factor XIII)
The lack of, or insufficiency of, blood clotting factors may lead to inefficient blood clotting. Haemophilia is a condition characterized by excessive bleeding due to a defective blood clot formation caused by faulty genes associated with the production of blood clotting factors, e.g. factor VIII (antihaemophilic factor).
Also called:
- coagulation factor
