Although the pumping action of your would not ensure effective blood flow heart is certainly effective at ejecting through the figure-eight circulatory blood from the chambers, it alone would not ensure effective blood flow through the circulatory loop. Any pumping system require method to guarantee that the pumped fluid goes in the desired direction. This is the purpose of the valves.

Each valve in your heart opens and closes once with each heartbeat (or about once every second throughout your lifetime).

Location and Structure of the Valves

There are four valves in your heart: the tricuspid, mitral, pulmonary, and aortic (see Figure 3, page A1). The valves are strong, thin leaflets of tissue anchored to the myocardium. The leaflets consist of single sheets of fibrous tissue covered by endocardial cells. At the base of each valve leaflet, the fibrous layer merges with the myocardium to form a flexible hinge, called the annulus.

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Cardio & Blood