When the ventricles are full, the mitral and tricuspid valves shut. This prevents blood from flowing backward into the atria while the ventricles contract (squeeze)., the aorta, and the body.When the ventricles finish contracting and begin to relax, the aortic and pulmonic valves snap shut. These valves prevent blood from flowing back into the ventricles.This pattern is repeated over and over, causing blood to flow continuously to the heart, lungs and to the body hope this helps. could you answer my zebra question