Which of the following describes the phases of the cardiac cycle?

The phases of the cardiac cycle are accurately described by the terms systole and diastole. Systole refers to the phase of contraction of the heart muscle when blood is pumped out of the chambers, primarily the ventricles, into the arteries. This is when the heart actively ejects blood. In contrast, diastole refers to the relaxation phase, where the heart chambers fill with blood in preparation for the next contraction.

Understanding these phases is crucial because they highlight the rhythmic and repetitive nature of heart function, ensuring that blood circulation is continuous and efficient. This cycle is fundamental in maintaining adequate blood flow throughout the body and is central to cardiovascular physiology.