MICROANATOMY

Detailed explanation-1: -Fibrinogen is a soluble macromolecule, but forms an insoluble clot or gel on conversion to fibrin by the action of the serine protease thrombin, which is activated by a cascade of enzymatic reactions triggered by vessel wall injury, activated blood cells, or a foreign surface (Fig.

Detailed explanation-2: -1) Constriction of the blood vessel. 2) Formation of a temporary “platelet plug.” 3) Activation of the coagulation cascade. 4) Formation of “fibrin plug” or the final clot.

Detailed explanation-3: -When blood clotting is activated, fibrinogen circulating in the blood is converted to fibrin, which in turn helps to form a stable blood clot at the site of vascular disruption. Coagulation inhibitor proteins help to prevent abnormal coagulation (hypercoagulability) and to resolve clots after they are formed.

Detailed explanation-4: -During coagulation, fibrinogen is converted into insoluble fibrin (Figure 1). Fibrin formation involves thrombin-mediated proteolytic cleavage and removal of N-terminal fibrinopeptides from the A and B chains.