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. 13.1).

Detailed explanation-2: -Fibrinogen is converted by thrombin into fibrin and stabilized by factor XIII. Fibrin sticks to the tissue and the tissue is adapted by syneresis. Local application of aprotinin to the thrombin solution is necessary in order to inhibit premature lysis of the fibrin film.

Detailed explanation-3: -The thrombin-induced conversion of fibrinogen to fibrin that is the primary subject of this review is essentially the final stage in the complex series of processes involved in blood coagulation.

Detailed explanation-4: -Thrombin acts as an enzyme and almost half in molecular weight compared to prothrombin. Thrombin transforms soluble plasma protein fibrinogen into insoluble polymer called fibrin.