Why is it a bad idea to hold your breath when you strain? Why does dust collect on the blades of a fan? These seemingly unrelated questions--and many, many more--are answered in the pages of Vital Circuits, an original and often witty guide to the workings of the circulatory system. Vogel ranges across physics, fluid mechanics, and chemistry to show how an enormous--and enormously complex--system of pumps and pipes works to keep the human body functioning, offering insight into such items as how heart disease develops and how other animals' systems differ from ours.