Lesson 10.2 - Cardiac Cycle

Question 1

Systole

Answer 1

Contracting

Question 2

atrial systole

Answer 2

Contracting of atrium

Question 3

Diastole

Answer 3

Relaxing

Question 4

Ventricular diastole

Answer 4

Relaxing of the ventricles

Question 5

How does heart diagram look when a cardiac cycle has finished?

Answer 5

Both atria and ventricles are in diastole (relaxation)

Question 6

Step 1 - Blood into atria

Answer 6

Blood flows into the atria through the pulmonary vein and vena cava. Pressure in the atria rises. Pressure in the atria is greater than the pressure in the ventricles.

Question 7

Step 2 - What happens when the pressure in the atria is greater than in the ventricles?

Answer 7

The atrioventricular valves open. This allows blood to flow down from the atria into the ventricles.

Question 8

Step 3 - What happens when blood has flowed into the ventricles?

Answer 8

Atria systole takes place.
This pushes the remaining blood from the atria into the ventricles.

Question 9

Step 4 - When all blood in heart are in the ventricles?

Answer 9

The ventricles contract. (Ventricular systole). Pressure in the ventricles rises rapidly. As the ventricular pressure is greater than the atrial pressure, atrioventricular valves are close (prevents backflow).

Question 10

Step 5 - After the ventricles contract?

Answer 10

The semilunar valves in aorta and pulmonary artery open. Blood is pumped from the ventricles out of the heart.

Question 11

Step 6 - Final step

Answer 11

Ventricular diastole. At some point the pressure in the ventricles falls below pressure in the aorta and pulmonary artery. This causes the semilunar valves to close.