1- Haemostatic Mechanism3

Amplification
The initiation pathway or extrinsic Xase is rapidly inactivated by
tissue factor pathway inhibitor (TFPI). Thrombin generation
is now dependent on the traditional intrinsic pathway In this factor
VIII and V are converted to VIIIa and Va by the small amounts of
thrombin generated during initiation. In this amplification phase the
intrinsic Xase, formed by IXa and VIIIa on phospholipid surface in
the presence of Ca2+, activates sufficient Xa, which then, in
combination with Va, PL and Ca2+, forms the prothrombinase
complex and results in the explosive generation of thrombin which
acts on fibrinogen to form the fibrin clot.