Ventricular systole pumps blood into the aorta

Steps:

• Ventricular systole is the contraction phase of the ventricles in the cardiac cycle.
• Ventricular walls contract, raising pressure inside the ventricles.
• This pressure exceeds that in the atria, closing atrioventricular (AV) valves to prevent backflow.
• High ventricular pressure then opens semilunar valves, ejecting blood into the aorta and pulmonary artery.

Why A is correct:

• Blood ejection from contracting ventricles into the aorta directly increases aortic pressure, as defined by the pressure-volume relationship in cardiac output.

Why the others are wrong:

• B: Atrioventricular valves close during systole to block backflow into atria.
• C: Semilunar valves open during systole to allow blood outflow.
• D: Ventricular pressure rises during systole due to contraction.

Final answer: A