The formation of fibrin involves three interconnected biochemical pathways: intrinsic, extrinsic, and common. These pathways allow for the interaction of coagulation factors via a finely tuned sequence of chemical processes, where the factors control the pathway's activity.
Most coagulation factors are stimulated and activated by the preceding factor, hence the term "coagulation cascade." Since factor activation requires the activation of a preceding factor, a deficiency in the functionality or availability of any factor would seriously impact the effectiveness of the coagulation process. Factor deficiencies, however, often lead to impaired vascular repair and depressed hemostatic activity.
