Module 19 Cardiac Cycle

Question 1

When the pressure in the ventricles is greater than in the atria?

Answer 1

1. AV valves close
2. Ventricles are contracting

Question 2

When the pressure of the ventricles is greater than in the arteries?

Answer 2

1. Blood flows from ventricles into arteries
2. Semilunar valves open

Question 3

What is happening during the filling phase of the cardiac cycle?
Dystole

Answer 3

1. Ventricular Filling: Blood enters into atria and ventricles passively filling. The AV valves are open the whole time.
2. Atrial Contraction: SA node depolarizes and pushes the last of the blood out of the atria into the ventricles

Question 4

What is happening during the systole isovolumetric phase of the cardiac cycle?
Systole

Answer 4

Blood is now in the ventricles
1. Depolarization spreads to the the rest of the heart causing contractions
2. Pressure in ventricle rises and the AV valves shut (LUB sound)
3. Blood volume remains the same.

Question 5

What are the names of the cardiac cycle phases?

Answer 5

1. Filling Phase
2. Isovolumetric Contraction
3. Ventricular Ejection
4. Isovolumetric Relaxation

Question 6

What happens during ventricular ejection
Systole

Answer 6

1. Contractions in the ventricle cause the pressure to increase.
2. Semilunar valves open
3. Blood enters the arteries
4. Pressure builds in the arteries and decreases in the ventricles

Question 7

What happens during isovolumetric relaxation?
Dystole

Answer 7

1. Ventricles repolarize and are lower pressure than arteries.
2. Semilunar valves close causing the dub sound.
3. Ventricles are ready for ventricular filling and the AV valves open to start the cycle over again