Question

How many clotting factors are there in our blood? Name them.

Answer 1

Hint: A blood clot is defined as a coagulated mass of blood cells and other blood components at the site of injury. The blood clot plugs any damaged area of the vessel and prevents blood from leaking out through it. There are several factors involved in the blood clotting process. The factors are named from roman letters I to XIII. When there is an injury, the clotting factors get activated and form a coagulation cascade. At the end of the cascade, fibrinogen is converted into fibrin.

Complete explanation:
There are twelve clotting factors. They are nothing but circulating plasma proteins. Each blood clotting factor plays an important role in the coagulation process. The functions of them are given below.
Factor I or Fibrinogen: It’s a type of plasma protein synthesized in the liver. It is the precursor of fibrin which will be formed at the final stage of blood clotting.
Factor II or Prothrombin: It is also a plasma protein synthesized in the liver. It is the precursor of thrombin, the enzyme which converts fibrinogen into fibrin.
Factor III or Thromboplastin: It is a type of lipoprotein formed from disintegrating platelets or tissues. It combines with calcium to convert inactive prothrombin into active thrombin.
Factor IV or Calcium ions: It is present in the plasma. It is obtained from bones or through diet. It is crucial for the formation of thrombin as well as for all stages of clotting.
Factor V or Proaccelerin: It is produced in liver which is required for the intrinsic and extrinsic pathways of coagulation:
Factor VII or Serum prothrombin conversion accelerator: It is a plasma protein produced in the liver that is required for the first phase of the extrinsic pathway.
Factor VIII or Antihemophilic factor A: It is a plasma protein produced in liver and other tissues which is necessary for the first phase of the intrinsic pathway.
Factor IX or Antihemophilic factor B: It is synthesized in the liver. It is required for the first phase of the intrinsic pathway. Its deficiency causes haemophilia B.
Factor X or Stuart factor: It is required for the early phases of extrinsic and intrinsic pathways.
Factor XI or Antihemophilic factor C: It is required for the first phase of the intrinsic pathway. Its deficiency causes haemophilia C.
Factor XII or Hageman factor: It is a plasma protein, needed for the first phase of an intrinsic pathway. It also activates plasmin. It’s probably involved with clotting outside the body.
Factor XIII or Fibrin stabilizing factor: It’s a protein that is present in plasma and platelets. It is needed for the final phase of clotting.

Note:
There are two pathways that trigger a blood clot- Extrinsic pathway and Intrinsic pathway. The extrinsic pathway is activated when the blood vessels are ruptured and tissues are damaged. It is a rapid clotting system. The intrinsic pathway is activated when the damage occurs in the inner walls of blood vessels. The extrinsic pathway merges with the intrinsic pathway after producing the prothrombin activator. After this, the coagulation cascade starts.