<P> When the ventricles of the heart contract in ventricular systole , the increased blood pressures in both chambers push the AV valves to close simultaneously , preventing backflow of blood into the atria . Since the blood pressure in atria is much lower than that in the ventricles , the flaps attempt to evert to the low pressure regions . The chordae tendineae prevent the eversion , prolapse , by becoming tense thus pulling the flaps , holding them in closed position . </P>
<P> When the ventricles of the heart contract in ventricular systole , the increased blood pressures in both chambers push the AV valves to close simultaneously , preventing backflow of blood into the atria . Since the blood pressure in atria is much lower than that in the ventricles , the flaps attempt to evert to the low pressure regions . The chordae tendineae prevent the eversion , prolapse , by becoming tense thus pulling the flaps , holding them in closed position . </P>
valve responsible for preventing backflow of blood from the lungs into the heart
valve responsible for preventing backflow of blood from the lungs into the heart
chordae tendineae
chordae tendineae