Question

Given below are two statements:
Statement (I): During ventricular systole, cuspid valves close both atrioventricular apertures, preventing blood flow into atria.
Statement (II): During ventricular diastole, semilunar valves are closed, preventing backflow of blood from pulmonary trunk and systemic aorta into ventricles.
In light of above statements, choose most appropriate answer from options given below.

• A. Both (I) and (II) are correct.
• B. Both (I) and (II) are incorrect.
• C. Statement (I) is correct; statement (II) is incorrect.
• D. Statement (I) is incorrect; Statement (II) is correct.

Hint:

Cuspid valves close in ventricular systole and semilunar valves close in ventricular diastole.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
The direction of blood flow in the heart is controlled by valves that open and close with changes in pressure.

Step 2: Statement (I)
In ventricular systole, ventricular pressure exceeds atrial pressure, so the tricuspid and bicuspid valves close (first sound, lubb). Blood cannot flow back into the atria. Statement (I) is correct.

Step 3: Statement (II)
In ventricular diastole, pressure in the ventricles falls below that in the pulmonary trunk and aorta, so the semilunar valves close (second sound, dup). This prevents backflow. Statement (II) is correct.

Final Answer:
Both statements are correct. \[ \boxed{\text{(A) }\text{Both (I) and (II) are correct}} \]