What occurs during the rapid filling phase of the left ventricle?

During the rapid filling phase of the left ventricle, the key event is that the atrial pressure increases, which leads to the opening of the mitral valve. This phase occurs immediately after the filling of the left atrium from the pulmonary veins and precedes the left ventricle's contraction. As the left atrial pressure rises due to blood returning from the lungs, it surpasses the pressure in the left ventricle, resulting in the opening of the mitral valve. This allows blood to flow quickly from the left atrium into the left ventricle, filling it rapidly before the next contraction occurs.

In this context, pushing blood out of the aorta pertains to the ejection phase rather than the filling phase. The contraction of the left atrium happens with the atrial systole, which occurs after the rapid filling phase. Closing of the tricuspid valve relates to the right side of the heart and is not directly involved in the left ventricular rapid filling phase. Understanding these mechanisms is crucial for a comprehensive grasp of cardiac physiology and the dynamics of heart function.