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How does fibrin strengthen a platelet plug?
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bleeding and blood clotting
Red blood cells (erythrocytes) trapped in a mesh of fibrin threads. Fibrin, a tough, insoluble protein formed after injury to the blood vessels, is an essential component of blood clots.
Fibrin strengthens a platelet plug by transforming it into a more resilient, stable structure through the following process:
- Conversion: In response to vessel injury, the enzyme thrombin converts soluble fibrinogen into long, sticky threads of insoluble fibrin.12
- Entanglement: These fibrin threads form a meshwork that entangles platelets and other blood cells, building a spongy mass.12
- Stabilization: The meshwork is further reinforced through the formation of intermolecular and intramolecular cross-links. This process is stabilized by fibrin-stabilizing factor (factor XIII).31
- Contraction: The resulting fibrin mesh contracts, squeezing out fluid and hardening the mass. This creates a resilient, insoluble blood clot capable of withstanding the mechanical stress and friction of blood flow.12