The stage of the heart cycle in which the heart muscle contracts and the chambers pump blood is called what?

• A. Systolic Pressure
• B. Hypertension
• C. Pulse
• D. Systole

Answer: (D)

During the cardiac cycle the heart alternates between contracting and relaxing. The contraction phase, when the heart muscle tightens and the chambers push blood out to the lungs and the rest of the body, is called systole. Systolic pressure refers to the arterial pressure measured during this contraction, but the stage itself is named systole, not the pressure. A pulse is the palpable result of this beating, not the phase name. The relaxation phase, when the chambers refill with blood, is called diastole. So the stage described—when the heart muscle contracts and the chambers pump blood—is systole.