Why can’t the leaflet valves open towards the atria? And what happens if they don’t open well?

The leaflet valves obstruct the return flow of blood from the ventricles to the atria. To ensure the vital activity of the body, blood must always move in only one direction. The leaflet valves are limited by special outgrowths of the endocardium – chords. Chords are threads that are attached at one end to the endocardium inside the ventricle and at the other to the valve leaflet. When the ventricle contracts, the pressure inside the ventricle rises, the blood pressure leads to the closure of the valves, but the chord is not allowed to turn into the atrial cavity. Therefore, blood rushes from the ventricle to the arteries.

If the valve flaps open poorly, heart failure will occur: blood will begin to accumulate in the atrial cavity, it will begin to increase in size, then stagnation of blood in the veins that bring blood to this atrium develops, then stagnation in the circulatory system related to this atrium. If the situation does not change, stagnation will begin in the second circle of blood circulation.