Medical Laboratory Scientist ASCP Practice Exam 2025 – Complete Study Guide

In hemostasis, the fibrin clotting cascade is a critical component of the coagulation process, ultimately resulting in the formation of a stable fibrin clot. The clotting factors involved in this cascade include prothrombin (Factor II), proaccelerin (Factor V), and thrombin (which is produced from prothrombin and plays a significant role in converting fibrinogen (Factor I) into fibrin, the essential protein that forms the structural framework of the clot).

Factor II, known as prothrombin, is essential for the generation of thrombin, which catalyzes the conversion of fibrinogen into fibrin. Factor V serves as a cofactor that enhances the activity of Factor X, which is crucial in converting prothrombin to thrombin in the presence of factor Xa and calcium ions.

This combination of factors—prothrombin, factor V, and factor X—highlights the cascade's dependency on both intrinsic and extrinsic pathways, with each factor having a specific role in promoting the steps leading to clot formation. Therefore, the inclusion of these factors in the answer accurately represents the crucial components that initiate and propagate the clotting cascade, culminating in fibrin clot formation.