Cardiac Cycle - Video Tutorials & Practice Problems
Systole, Diastole, Pressure, & Valves
Cardiac Cycle Example 1
When the pressure inside the ventricle causes the atrioventricular valve to close and the semilunar valve to open, which statement about the heart is true?
The ventricles are in systole.
The ventricles are in diastole.
The pressure in the left ventricle is greater than in the aorta.
Both A & C are correct.
For the atrioventricular valves to be open, the pressure in the ventricles must be:
Greater than the pressure in the pulmonary artery.
Greater than the pressure in the aorta.
Greater to the pressure in the atria.
Less than the pressure in the atria.
Events in the Cardiac Cycle
Cardiac Cycle Example 2
What event immediately follows the closure of the atrioventricular valves and coincides with the onset of ventricular systole?
Isovolumetric contraction.
Atrial systole.
Ventricular ejection.
Isovolumetric relaxation.
During which following phase (or phases) of the cardiac cycle is the blood volume in the ventricles constant?
Isovolumetric contraction.
Isovolumetric relaxation.
Ventricular Ejection.
A & B are correct.
If the pressure in the ventricles is higher than in the atria, which of the following statements must be true?
I. The atrioventricular valves are closed.
II. The semilunar valves are open.
III. The ventricles are in systole.
I only.
I and II.
I and III.
II and III.
True or False: if false, choose the answer that best corrects the statement.
Ventricular filling is defined as the period that the atria are in systole.
True.
False; ventricular filling is defined as the period that the semilunar valves are open.
False; ventricular filling is defined as the period when the AV valves are open, and the SL valves are closed.
False; ventricular filling is defined as the period when the pressure in the ventricles is greater than in the atria.
Sounds in the Cardiac Cycle
Cardiac Cycle Example 3
Using a stethoscope, you listen to the heart of a patient in their early forties. You hear a clear 1st heart sound (lub), but the second heart sound is muffled and followed by a whooshing noise. What structure could be dysfunctional in this patient?
Mitral valve.
Right atrioventricular valve.
Aortic valve.
Both A & B could be the cause.
Cardiac Cycle: Putting It All Together
During which phase or phases of the cardiac cycle does the ventricular pressure change the least?
Ventricular filling.
Isometric contraction.
Isometric relaxation.
Both B & C are correct.
During which phase of the cardiac cycle do you hear the second heart sound?
Ventricular filling.
Isometric contraction.
Isovolumetric relaxation.
Ventricular ejection.
You are listening to the heart through a stethoscope. When you hear the first heart sound, which of the following options correctly matches the structure to the pressure change that would be most responsible for producing that sound?
Ventricles: pressure increasing.
Aorta: pressure decreasing.
Ventricles: pressure decreasing.
Atria: pressure increasing.
Do you want more practice?
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