What is intrinsic pathway and extrinsic pathway?
The intrinsic pathway is activated through exposed endothelial collagen, and the extrinsic pathway is activated through tissue factor released by endothelial cells after external damage. Intrinsic Pathway. This pathway is the longer pathway of secondary hemostasis.
What is the main coagulation pathway?
The coagulation pathway is a cascade of events that leads to hemostasis. The intricate pathway allows for rapid healing and prevention of spontaneous bleeding. Two paths, intrinsic and extrinsic, originate separately but converge at a specific point, leading to fibrin activation.
What pathway is Factor 3?
Coagulation Factor III, also known as Tissue Factor (TF), Thromboplastin, and CD142, is the primary initiator of the extrinsic coagulation pathway. It is a transmembrane protein that is consitutively expressed in subendothelial cells throughout the vasculature and is inducible on endothelial cells and monocytes.
What is the extrinsic pathway of coagulation?
The extrinsic pathway consists of the transmembrane receptor tissue factor (TF) and plasma factor VII/VIIa (FVII/FVIIa), and the intrinsic pathway consists of plasma FXI, FIX, and FVIII. Under physiological conditions, TF is constitutively expressed by adventitial cells surrounding blood vessels and initiates clotting.
What is the difference between intrinsic and extrinsic coagulation pathways?
The clotting cascade occurs through two separate pathways that interact, the intrinsic and the extrinsic pathway. The extrinsic pathway is activated by external trauma that causes blood to escape from the vascular system. This pathway is quicker than the intrinsic pathway. It involves factor VII.
Where is factor 3 synthesized?
Tissue factor, also called platelet tissue factor, factor III, or CD142, is a protein encoded by the F3 gene, present in subendothelial tissue and leukocytes. Its role in the clotting process is the initiation of thrombin formation from the zymogen prothrombin.
What is Factor 4 in blood coagulation?
Factor IV is a calcium ion. Calcium is an element essential in various bodily functions such as neurotransmission, muscle contraction, and blood coagulation. It works with other clotting factors by acting as a cofactor and is involved in both extrinsic and intrinsic pathways.
Why extrinsic pathway is called extrinsic?
Tissue factor is found in many of the cells of the body but is particularly abundant in those of the brain, lungs, and placenta. The pathway of blood coagulation activated by tissue factor, a protein extrinsic to blood, is known as the extrinsic pathway (Figure 1).