Foundations

How Blood Is Made: Haematopoiesis and Where the Drugs Act

Right now, in the marrow of your bones, roughly two million red cells are being finished every single second — and just as many worn-out ones are being retired. It is the busiest factory in the body, and it never closes. This chapter is the map of that factory: the one stem cell everything descends from, the three signals that drive the main production lines, and — the point of the whole Hematology section — exactly where each drug reaches in to speed the line up, restock its raw materials, or shut it down.

Blood Products and Transfusion: The Components and When to Give Them

A unit of donated blood is almost never given whole. It is spun into parts, and each part is a different "drug" for a different problem: red cells carry oxygen, plasma and cryoprecipitate carry clotting proteins, platelets build the plug. Prescribe the wrong one and you either waste a scarce resource or fail to fix the bleed. This chapter treats each component like a medicine — its indication, its trigger, and its dangers.