Coagulation Cascade and Fibrinolysis - clotting factors, regulation and control mechanism

The classic coagulation cascade is divided into the extrinsic and intrinsic pathways which both lead to what is called the common pathway. The hallmark of both intrinsic and extrinsic pathway of coagulation is the sequential activation of a series of clotting factors. Clotting factors are shown as Roman numerals, and numerals followed by the alphabet represents an active clotting factor. For example X --: Xa (Xa being the active factor) The classical view of coagulation is very useful to interpret coagulation tests and identifying bleeding disorders based on coagulation factors. However physiologically the coagulation cascade is much more confusing. There is a cell based model of coagulation which involves 3 steps: initiation, amplification and propagation.