Question

During mid-to-late diastole, blood flows from the atria to fill their respective ventricles to prepare for systole. What is happening during this time? Choose all that apply.

A) Atrioventricular (AV) valves are open.

B) Atria contract to force the remaining blood into the ventricles.

C) Semilunar valves are open.

D) Blood flows passively from veins through atria into ventricles.

E) Pressure in the heart is high.

Answer 1

During mid-to-late diastole, blood flows from the atria into the ventricles as a result of the pressure difference between the two chambers. The atrioventricular (AV) valves are open, while the semilunar valves are closed. The pressure in the heart is not high during this time.

Step-by-step explanation:

During mid-to-late diastole, blood flows from the atria to fill their respective ventricles to prepare for systole. This happens because the pressure within the ventricles drops below the pressure in the atria. As a result, the atrioventricular (AV) valves are open, allowing blood to flow from the atria into the ventricles. At the same time, the semilunar valves remain closed to prevent backflow of blood into the ventricles. The high pressure in the heart occurs during systole, not during diastole. Therefore, options A) and C) are correct, while options B), D), and E) are not applicable during mid-to-late diastole.

Answer 2

During mid-to-late diastole, the following events are occurring:

A) Atrioventricular (AV) valves are open.
D) Blood flows passively from veins through atria into ventricles.

Option A is correct because during mid-to-late diastole, the atrioventricular (AV) valves are open to allow blood to pass from the atria into the ventricles.

Option D is correct because during diastole, the atria are relaxed, and blood flows passively from the veins through the atria into the ventricles due to the pressure difference.

Options B, C, and E are not correct:

B) Atria contract to force the remaining blood into the ventricles is not accurate because during diastole, the atria are in a state of relaxation and filling, not contraction.

C) Semilunar valves are open is not accurate during mid-to-late diastole. Semilunar valves are closed during diastole to prevent blood from flowing back into the ventricles.

E) Pressure in the heart is high is not accurate during mid-to-late diastole. The pressure in the heart is relatively low during diastole as the chambers are filling with blood.