The aortic semilunar valve controls flow between which two structures?

• A. Left atrium and ventricle
• B. Right ventricle and pulmonary artery
• C. Right atrium and ventricle
• D. Left ventricle and aorta

Answer: (D)

The main idea is identifying where the aortic semilunar valve sits and what it regulates. This valve is at the junction of the left ventricle and the aorta, serving as the gateway that lets blood be ejected from the heart into the systemic circulation. It opens during ventricular systole when the left ventricle contracts to push blood into the ascending aorta and closes during diastole to prevent blood from flowing back into the ventricle.

So, the flow controlled by the aortic semilunar valve is between the left ventricle and the aorta. For context, the other valves include the mitral valve between the left atrium and left ventricle, the tricuspid valve between the right atrium and right ventricle, and the pulmonic valve between the right ventricle and the pulmonary artery.