The coagulation cascade The coagulation cascade of secondary hemostasis has two pathways which lead to fibrin formation contact activation pathway (the intrinsic pathway) tissue factor pathway(the extrinsic pathway It was previously thought that the coagulation cascade consisted of two pathways of equal importance joined to a common pathway It is now known that the primary pathway for the initiation of blood coagulation is the tissue factor pathwayThe coagulation cascade The coagulation cascade of secondary hemostasis has two pathways which lead to fibrin formation. contact activation pathway (the intrinsic pathway) tissue factor pathway (the extrinsic pathway) It was previously thought that the coagulation cascade consisted of two pathways of equal importance joined to a common pathway. It is now known that the primary pathway for the initiation of blood coagulation is the tissue factor pathway