Page 90 - Veterinary Immunology, 10th Edition
P. 90
VetBooks.ir The Coagulation System
When blood vessels dilate and fluid leaks from the bloodstream
into the tissues, the blood coagulation system is activated. Platelet
aggregation accelerates this process. Activation of the coagulation
system generates large quantities of thrombin, the main clotting
enzyme. Thrombin acts on fibrinogen in tissue fluid and plasma to
produce insoluble fibrin. Fibrin is therefore deposited in inflamed
tissues, where it forms a barrier to the spread of infection.
Activation of the coagulation cascade also initiates the fibrinolytic
system. This leads to activation of plasminogen activator, which in
turn generates plasmin, a potent fibrinolytic enzyme. In destroying
fibrin, plasmin releases peptide fragments that attract neutrophils.
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