What is the function of the aortic semilunar valve?

What is the function of the aortic semilunar valve?

• A. It separates the right ventricle from the pulmonary artery.
• B. It separates the left ventricle from the aorta.
• C. It receives blood from the right atrium.
• D. It prevents backflow into the ventricle.

Answer: (B)

The aortic semilunar valve sits between the left ventricle and the aorta, opening to allow blood to flow into the aorta during systole and then closing to prevent blood from flowing back into the ventricle during diastole. This unidirectional flow hinges on pressure changes: when the left ventricle ejects, its pressure exceeds aortic pressure to open the valve, and after ejection, the aorta’s pressure keeps the valve closed to stop regurgitation. That’s why the best description is that it separates the left ventricle from the aorta. The other options point to different valves (pulling in the wrong chamber pair), or describe a more general function of preventing backflow without naming the specific location.

The aortic semilunar valve sits between the left ventricle and the aorta, opening to allow blood to flow into the aorta during systole and then closing to prevent blood from flowing back into the ventricle during diastole. This unidirectional flow hinges on pressure changes: when the left ventricle ejects, its pressure exceeds aortic pressure to open the valve, and after ejection, the aorta’s pressure keeps the valve closed to stop regurgitation.

That’s why the best description is that it separates the left ventricle from the aorta. The other options point to different valves (pulling in the wrong chamber pair), or describe a more general function of preventing backflow without naming the specific location.