PSIO 532 Study Guide - Midterm Guide: Aortic Valve, Tricuspid Valve, Heart Sounds
Graduate Physiology PSL
Cardiac Wiggers
➔ Draw, in correct temporal relationship, the pressure, volume, heart sound, and ECG
changes in the cardiac cycle. Identify the intervals of isovolumic contraction, rapid
ejection, reduced ejection, isovolumic relaxation, rapid ventricle filling, reduced
ventricular filling and atrial contraction
• ***This is all just one heart beat***
• Atria pressure is a little bit helpful; they
do’t geerate a lot of pressure; ad ee he
they do generate pressure, it is small
• The ventricular pressure generates a lot of
pressure → this is so that the valves open up to
the systemic circulation
• Initially, you see a little bump in pressure of
the ventricular pressure (similar to atrial pressure) → this is because the
ventricular pressure rises due to the atria pushing blood into the ventricle; and
since the tricuspid valve is open, at this point, the atrial and ventricular pressure
is similar → a rise in atrial pressure would have no influence on aortic pressure
because the aortic valve would be closed
• Then there is a big spike in ventricular pressure because it contracts on its own
and the pressure rises quickly because the aortic valve is closed, there is no room
for that volume of blood to go anywhere → hence, an increase in pressure
• Then we have an aortic pressure (red); this pressure is already high; the
difference between atria and ventricles vs. aortic pressure is that the aortic
pressure is already very high even when relaxed; atria and ventricular pressure
are low when its relaxed
• The change in the pressure of the ventricle would not influence the aortic
pressure until the aortic valve opens
• For the aortic pressure on the image above, initially the pressure is falling (this is
due to the previous beat); then we have the ventricles contracting, this
generates pressure; then when the ventricle pressure surpasses the aortic
pressure, aortic valve opens and then you see a spike in aortic pressure
find more resources at oneclass.com
find more resources at oneclass.com
