Cardiac Cycle: Phases and Pressure Changes

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During which phase of the cardiac cycle are all valves closed?

Isometric contraction (correct)

Slow filling

Rapid ejection

Atrial systole

What is the characteristic sound heard at the end of the second heart sound?

Snap

Murmur

Click (correct)

Gurgle

In aortic stenosis, why does the left ventricle have to generate more pressure?

To open the AV valve

To open the semilunar valve

To decrease blood flow to the carotid arteries

To overcome stiffening of the aortic valve (correct)

What does the U wave on an ECG indicate?

Hypokalemia Signup and view all the answers

Which phase of the cardiac cycle sees a marked increase in ventricular volume?

Rapid ventricular filling Signup and view all the answers

Why does a jet of blood radiate to the carotid arteries in aortic stenosis?

Due to increased ventricular pressure after valve opening Signup and view all the answers

During which phase of the cardiac cycle do the AV valves close and the semilunar valves open?

Rapid ejection phase Signup and view all the answers

Which event occurs during the isometric relaxation phase?

Semilunar valve closure Signup and view all the answers

What is the approximate duration of the whole cardiac cycle when the heart rate is 75 beats per minute?

0.8 seconds Signup and view all the answers

During which phase does ventricular filling occur?

Rapid filling phase Signup and view all the answers

Which heart sound is associated with the isometric contraction phase?

Fourth heart sound Signup and view all the answers

What happens to atrial pressure during the atrial systolic phase?

It increases then decreases Signup and view all the answers

What happens during the isometric (isovolumic) contraction phase?

The atrioventricular (AV) valves suddenly close, and the semilunar valves remain closed. Signup and view all the answers

During which phase does the ventricular pressure markedly increase and become greater than the aortic pressure?

Rapid (maximal) ejection phase Signup and view all the answers

What happens to the aortic pressure during the slow (reduced) ejection phase?

It slightly decreases. Signup and view all the answers

When do the semilunar valves close during the cardiac cycle?

During the isometric (isovolumic) relaxation phase Signup and view all the answers

Which phase is characterized by a sharp decrease in aortic pressure followed by an increase (diacrotic notch)?

Isometric (isovolumic) relaxation phase Signup and view all the answers

During which phase does the atrial pressure become greater than the ventricular pressure?

Rapid (maximal) filling phase Signup and view all the answers