fibrinogen

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the blood coagulation cascade

fibrinogen

biochemistry

Also known as: factor I

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June 26, 2026

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the blood coagulation cascade — the blood coagulation cascade Figure 1: The blood coagulation cascade. Each protein circulates in the blood in an active form.

Fibrinogen is a soluble protein produced by the liver and found in blood plasma. It plays a crucial role in blood clotting. When bleeding occurs due to tissue damage, an enzyme called thrombin converts fibrinogen into fibrin. Fibrin is an insoluble protein that forms long, fibrous chains. These fibrin threads create a mesh that traps platelets and blood cells, forming a spongy mass that hardens into a blood clot. This process is essential for stopping blood loss. Rare hereditary disorders can affect fibrinogen levels or function, leading to difficulties in blood clotting.12345

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blood transfusion
Transfusion procedures and blood storage
Exchange transfusion is a procedure in which much or all of a patient’s blood is gradually removed and replaced with donor blood. It is used for specialized clinical situations, particularly severe cases of hemolytic disease…
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Exchange transfusion is a procedure in which much or all of a patient’s blood is gradually removed and replaced with donor blood. It is used for specialized clinical situations, particularly severe cases of hemolytic disease…
Read More

fibrin
…chains; it is formed from fibrinogen, a soluble protein that is produced by the liver and found in blood plasma. When tissue damage results in bleeding, fibrinogen is converted at the wound into fibrin by the action of thrombin, a clotting enzyme. Fibrin molecules then combine to form long fibrin…
Read More
…chains; it is formed from fibrinogen, a soluble protein that is produced by the liver and found in blood plasma. When tissue damage results in bleeding, fibrinogen is converted at the wound into fibrin by the action of thrombin, a clotting enzyme. Fibrin molecules then combine to form long fibrin…
Read More

bleeding and blood clotting
Platelets and their aggregation
…after platelet activation that binds fibrinogen (a bivalent molecule with two symmetrical halves that is found in relatively high concentration in plasma). Fibrinogen can bind simultaneously to two platelets. Thus, fibrinogen links platelets together (aggregation) through the glycoprotein IIb–IIIa complex that serves as the fibrinogen receptor.
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…after platelet activation that binds fibrinogen (a bivalent molecule with two symmetrical halves that is found in relatively high concentration in plasma). Fibrinogen can bind simultaneously to two platelets. Thus, fibrinogen links platelets together (aggregation) through the glycoprotein IIb–IIIa complex that serves as the fibrinogen receptor.
Read More