Final answer:
Diastole is the filling stage when the heart's chambers relax and fill with blood, while systole is the pumping stage when the heart contracts and pumps blood out. These phases must be well-coordinated to maintain proper blood flow and blood pressure.
Step-by-step explanation:
Diastole vs. Systole
Diastole and systole are two phases of the cardiac cycle. Diastole is the period of time when the heart muscle is relaxed and the chambers fill with blood; it is also known as the filling stage. During atrial diastole, the heart chambers are relaxed and blood flows into both the atria and ventricles. During the second part of diastole, the atria contract, pumping blood into the ventricles, which remain relaxed. In contrast, systole is the period when the heart muscle contracts and pumps blood out of the chambers - the pumping stage. Specifically, during ventricular systole, the ventricles contract, pushing blood out of the heart, while the atria are relaxed and start filling with blood again.
These stages are crucial for maintaining blood pressure and ensuring efficient blood flow throughout the body. Systole and diastole must be carefully regulated and coordinated, which is achieved through the electrical stimulation of the heart. The sound of the heart beats that can be heard during auscultation corresponds to the closing of the heart valves that occurs at the transitions between diastole and systole.