Heart Valve States During Ventricular Systole

Steps:

• In the right heart, valve X is the pulmonary semilunar valve (between ventricle and pulmonary artery); valve Y is the tricuspid atrioventricular (AV) valve (between atrium and ventricle).
• During ventricular relaxation (diastole), AV valves open to fill ventricles, while semilunar valves stay closed.
• When the ventricle contracts (systole), pressure rises in the ventricle, closing AV valves to prevent backflow into the atria.
• Simultaneously, high ventricular pressure opens semilunar valves, ejecting blood into the pulmonary artery.

Why B is correct:

• B (open closed) matches systole: semilunar valve (X) opens for outflow, AV valve (Y) closes per the one-way flow principle in cardiac cycle.

Why the others are wrong:

• A (closed open): Describes diastole, not contraction.
• C (open open): Impossible, as both open would allow backflow and inefficient pumping.
• D (open open): Same as C; both open disrupts unidirectional blood flow.

Final answer: B