Cardiovascular Physiology Flashcards
How do you calculate cardiac output?
Stroke Volume x Heart Rate
What does the “lub” sound represent during a heart beat?
The atrio-ventricular valves closing during ventricular systole.
What does the “dub” sound represent during a heart beat?
The semi-lunar valves closing in ventricular diastole.
What does EDV stand for? Define it.
End diastolic volume. The maximum amount of blood in ventricles occurs at the end of ventricular relaxation.
What does ESV stand for?
End systolic volume. The minimum amount of blood in ventricles.
How do you calculate stroke volume?
EDV - ESV
Define late diastole.
Both sets of chambers are relaxed and ventricles fill passively.
Define atrial systole.
Atrial contraction forces a small amount of additional blood into ventricles.
What is the value of EDV?
135ml.
Define isovolumic ventricular contraction.
The first phase of ventricular contraction pushes AV valves closed but doesn’t create enough pressure to open semi-lunar valves.
What is the value of ESV?
65ml.
Define ventricular ejection.
As ventricular pressure rises and exceeds pressure in the arteries, the semilunar valves open and blood is ejected.
Define isovolumic ventricular relaxation.
As ventricles relax, pressure in the ventricles falls, blood flows back into cups of semilunar valves and snaps them closed.
What three things does the Wiggers diagram show the relationship between?
- Electrocardiogram (ECG).
- Heart sounds.
- Pressure and volume changes in the left heart and aorta.
Which heart sound, “lub” or “dub”, produces a bigger amplitude on a graph?
“lub”.
