Question

During the ventricular systole, the atrioventricular valves (P) ________ and the semilunar valves (Q) _________.

• A. P - close and Q - open
• B. P - close and Q - close
• C. P - open and Q - close
• D. P - open and Q - open

Hint:

During ventricular systole, the atrioventricular valves close and the semilunar valves open to allow blood to flow into the arteries.

Answer 1

The Correct Option is A

Step 1: Understanding ventricular systole.
During ventricular systole, the ventricles contract, leading to an increase in ventricular pressure. This pressure causes the atrioventricular (AV) valves (P) to close, preventing the backflow of blood into the atria. At the same time, the semilunar valves (Q) open, allowing blood to be ejected from the ventricles into the pulmonary artery and the aorta.
Step 2: Analyzing the options.

• (A) P - close and Q - open: Correct. During ventricular systole, the AV valves close, and the semilunar valves open, as explained above.
• (B) P - close and Q - close: Incorrect. The semilunar valves should open during ventricular systole.
• (C) P - open and Q - close: Incorrect. The AV valves open only during ventricular diastole.
• (D) P - open and Q - open: Incorrect. The AV valves should be closed during ventricular systole, not open.

Step 3: Conclusion.
The correct answer is (A) because during ventricular systole, the AV valves close and the semilunar valves open to allow blood flow from the ventricles. Final Answer: P - close and Q - open.