Therefore, although the coagulation cascade can be triggered in vitro through the intrinsic pathway only, in vivo coagulation is triggered by the extrinsic pathway. However, the model better describing how coagulation works is the so-called cell-based model, a more integrated picture of the whole process, in which phospholipid surfaces, such as those provided by platelets, are a key component.
Consequently, although the blood clotting process can be initiated in a laboratory setting via the intrinsic pathway alone, in real-life situations, coagulation is triggered by the extrinsic pathway. However, the model that more accurately depicts how coagulation functions is the so-called cell-based model, which presents a more comprehensive and integrated view of the entire process, with phospholipid surfaces, such as those supplied by platelets, playing a crucial role.