hyytymisreaktioon

Hyytymisreaktio is a Finnish term that translates to "coagulation reaction" or "clotting reaction" in English. It refers to the complex biological process that occurs in the blood of vertebrates when a blood vessel is injured. This process is essential for hemostasis, which is the cessation of bleeding.

The coagulation cascade involves a series of enzymatic reactions, where inactive clotting factors (proteins) are sequentially activated. This cascade can be initiated through two main pathways: the intrinsic pathway and the extrinsic pathway. The intrinsic pathway is activated by damage to the blood vessel wall itself, while the extrinsic pathway is triggered by tissue factor released from damaged cells outside the blood vessel. Both pathways ultimately converge on a common pathway.

The end result of the coagulation cascade is the formation of a fibrin clot. Thrombin, a key enzyme in the cascade, converts soluble fibrinogen into insoluble fibrin strands. These fibrin strands then form a meshwork that traps blood cells, forming a stable clot. This clot seals the injured blood vessel and prevents further blood loss.

Once the injured vessel has healed, the clot is broken down by another process called fibrinolysis. This ensures that blood flow is restored and that clots do not form inappropriately within the circulatory system. Disorders of blood coagulation, such as hemophilia or thrombosis, can have serious health consequences.