Cardiac Cycle Flashcards
(24 cards)
At 75 bpm, how long are ventricular diastole and systole?
Diastole = 0.5 secs, systole = 0.3 secs
In systole, where does the left ventricle pump blood?
Aorta
In systole, where does the right ventricle pump blood?
Pulmonary artery
What is the pressure in the atria and ventricles during passive filling?
Close to 0
Describe what occurs in passive filling.
AV valves open, venous return flows into ventricles
How full do ventricles become during passive filling?
80%
In passive filling, are pressures higher on left or right side of the heart?
left
Is the aortic valve opened or closed in passive filling?
Closed
What in the ECG signals atrial depolarization?
P waves
When in the ECG do atria contract?
Between p wave and QRS
What is the end diastolic volume in normal adults?
130ml
When does ventricular contraction start in an ECG?
After QRS
When do AV valves shut and what does this produce?
When ventricular pressure exceeds atrial pressure, producing 1st heart sound
What is isovolumetric contraction?
Tension rises around closed volume, and ventricular pressure rises
In ventricular ejection, which valves open?
Aortic and pulmonary
What is ejected by the ventricle to leave behind the end systolic volume?
Stroke volume
After ventricular ejection, what happens to aortic pressure?
rises
What do T-waves signal?
ventricular repolarization
What happens to ventricular pressure after ventricular ejection?
falls
When do Aortic and pulmonary valves shut?
After ventricular ejection, when ventricular pressure falls below aortic
What produces the dicrotic notch in an aortic pressure curve?
valve vibrations
When does isovolumetric ventricular relaxation start?
after closure of aortic and pulmonary valves
What occurs in isovolumetric ventricular relaxation?
Tension falls around close volume
When do AV valves open?
After isovolumetric ventricular relaxation
