What does systole refer to in the heart's functioning?

Systole specifically refers to the phase of the cardiac cycle when the heart muscle contracts. This contraction is a crucial part of the heart's functioning as it allows the ventricles to pump blood out of the heart—specifically from the right ventricle to the lungs for oxygenation and from the left ventricle to the rest of the body to supply organs and tissues with oxygen-rich blood. This process is essential for maintaining adequate circulation and ensuring that all body cells receive the oxygen and nutrients they need to function properly.

In a broader context, systole follows diastole, which is the phase of relaxation when the heart chambers fill with blood. Understanding this distinction helps clarify the dynamics of cardiac mechanics and the importance of both phases in the overall cardiac cycle.