Also what prevents this from occuring? I have a lab due tomorrow for my biology class this is one of the questions. the answer is no where in my book, and we haven't discussed this in class. im also having a hard time finding the answer online. i would assume it would have something to do with the elasticity of the valves, and i know that when valves are weak sometimes blood can flow back into the artium when the ventricle contracts causing a heart murmur and other problems, but i haven't came across any information that talks about the valve being pushed backwards. if you can help me out that would be awesome! thanks =]
Valves, because they open when your heart pumps and close, not allowing blood to flow backwards after the pump.
the heart valves maintain the unidirectional flow of blood in the heart by opening and closing depending on the difference in pressure on each side. (wiki) So I would assume that the pressure of blood flow is what prevents the valve from pushing backwards. ALSO Atrioventricular valves These are small valves that prevent backflow from the ventricles into the atrium during systole. They are anchored to the wall of the ventricle by chordae tendineae, which prevent the valve from inverting. The chordae tendineae are attached to papillary muscles that cause tension to better hold the valve. Together, the papillary muscles and the chordae tendineae are known as the subvalvular apparatus. The function of the subvalvular apparatus is to keep the valves from prolapsing into the atria when they close. The subvalvular apparatus have no effect on the opening and closure of the valves, however. This is caused entirely by the pressure gradient across the valve.