Human Body
How Blood Works: Red Cells, Plasma, Clotting, and the 5 Liters Cycling Every Minute
Your body contains roughly 5 liters of blood, and every drop of it completes a full circuit through the heart and lungs in about 60 seconds. Blood is not a simple liquid — it is a suspension of at least four distinct components performing oxygen transport, immune defense, wound sealing, and chemical delivery simultaneously. Here is how it all works.