This document discusses recent changes in transfusion medicine regarding the use of blood components instead of whole blood. It notes that high income countries now process 97% of donated blood into components, while low income countries only process 28% into components. Component therapy allows one blood donation to help multiple patients. The document then provides details on the coagulation cascade and factors, describing the intrinsic, extrinsic, and common pathways. It also briefly discusses the fibrinolytic system and the historical naming of coagulation factors.