What happens to the heart during atrial systole?

During atrial systole, the atria contract, which causes blood to be pushed from the atria into the ventricles. This phase is essential for completing ventricular filling and occurs just before the ventricles contract. The contraction of the atria increases the pressure within them, enabling the blood to be effectively transferred into the relaxed ventricles.

This process is vital as it ensures that the ventricles are adequately filled with blood, ready for the next phase of the cardiac cycle when they will contract during ventricular systole. By understanding this mechanism, one can appreciate the coordinated nature of the cardiac cycle and the importance of each phase in maintaining efficient blood circulation throughout the body.