What is the name for the contraction phase of the cardiac cycle?

The contraction phase of the cardiac cycle is known as systole. During systole, the heart muscle contracts, pushing blood out of the chambers. Specifically, the ventricles contract to send blood into the aorta and pulmonary artery. This phase is critical for maintaining adequate blood flow throughout the body and ensuring that oxygen-rich blood reaches the organs and tissues. The contraction that occurs during this phase is a rhythmic process that is key to the overall function of the heart.

In contrast, diastole, which is the phase immediately following systole, involves the relaxation of the heart muscle, allowing the chambers to fill with blood before the next contraction. Other terms like peristole and cardio phase are not recognized in standard cardiac physiology terminology and do not accurately represent the phases of the cardiac cycle. Thus, understanding the definition and importance of systole clarifies why it is the correct answer.