Which of the following is true?
A)Blood enters the right and left atria only during diastole.
B)Most ventricular filling occurs before the atria contract.
C)During ventricular systole,the AV valves open.
D)The semilunar valves remain closed throughout ventricular systole.
E)Most of end-diastolic volume comes from active filling.

Question

Quizplus · Accepted Answer

During diastole, both the atria and ventricles relax, allowing blood to flow into the atria. However, most of the filling of the ventricles occurs during early diastole, before the atria contract to push the remaining blood into the ventricles. This is known as passive filling. Therefore, option B is correct. Option A is incorrect because blood can enter the atria during both diastole and atrial systole. Option C is incorrect because during ventricular systole, the AV valves are closed to prevent backflow of blood into the atria. Option D is incorrect because the semilunar valves open during ventricular systole to allow blood to be ejected from the ventricles into the arteries. Option E is incorrect because end-diastolic volume includes both passive and active filling of the ventricles.

Which of the Following Is True