What is the relaxation phase of the heart called?

What is the relaxation phase of the heart called?

• A. Diastole
• B. Systole
• C. Mitral
• D. Aortic

Answer: (A)

During the cardiac cycle, the heart relaxes after each beat to allow the chambers to fill with blood. This relaxation phase is called diastole. In diastole, the ventricles relax and expand, the atrioventricular valves (mitral and tricuspid) are open, and blood flows from the atria into the ventricles. The semilunar valves (aortic and pulmonary) are closed to keep blood from flowing back into the ventricles. Systole is the contraction phase when the ventricles pump blood out. Terms like mitral and aortic refer to valves or arteries, not a phase of relaxation.

During the cardiac cycle, the heart relaxes after each beat to allow the chambers to fill with blood. This relaxation phase is called diastole. In diastole, the ventricles relax and expand, the atrioventricular valves (mitral and tricuspid) are open, and blood flows from the atria into the ventricles. The semilunar valves (aortic and pulmonary) are closed to keep blood from flowing back into the ventricles. Systole is the contraction phase when the ventricles pump blood out. Terms like mitral and aortic refer to valves or arteries, not a phase of relaxation.