Cardiac Cycle: Ventricular Contraction and Ejection

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During which phase of ventricular filling does the AV valve open?

Ventricular systole

Atrial contraction

Ventricular diastole (correct)

Diastasis

What is the term for the volume of blood in the ventricles at the end of the filling period?

Stroke volume

End-diastolic volume (correct)

End-systolic volume

Cardiac output

What percentage of each cardiac cycle at rest does systole last in the atria?

90%

40%

10% (correct)

80%

Which valve closes during ventricular systole to prevent the backward flow of blood from the ventricle into the atrium?

AV valve Signup and view all the answers

During which phase of ventricular filling is the atrium contracting to push the last 25% of blood into the ventricles?

Atrial contraction phase Signup and view all the answers

What is the typical pressure range that ventricular pressure climbs towards during ventricular systole?

Up to 80 mmHg Signup and view all the answers

What is the name of the period when ventricular pressure exceeds aortic pressure and the aortic valve opens?

Isovolumetric contraction Signup and view all the answers

What is the approximate volume of blood that remains in the ventricle following contraction?

50-60 ml Signup and view all the answers

What causes the closure of the aortic valve?

Backflow of blood from the aorta into the ventricle Signup and view all the answers

During which phase are both the aortic and AV valves closed with no change in ventricular volume?

Isovolumetric relaxation Signup and view all the answers

What property of arterial walls allows for continuous blood flow to the tissues despite the heart pumping blood intermittently?

Elasticity Signup and view all the answers

What happens to the arteries during diastole?

They recoil and regain their original shape Signup and view all the answers

What is the primary function of the electrocardiogram?

To represent the sum of all electrical activity throughout the heart at any given moment Signup and view all the answers

During which phase of the cardiac cycle is the heart completely depolarized?

Plateau phase of the ventricular action potential Signup and view all the answers

What is the term for a rapid heart rate?

Tachycardia Signup and view all the answers

During which phase of the cardiac cycle do the ventricles relax and fill with blood?

Ventricular diastole Signup and view all the answers

What is the term for a slow heart rate?

Bradycardia Signup and view all the answers

During which phase of the cardiac cycle do the ventricles contract and pump blood out of the heart?

Ventricular systole Signup and view all the answers