Cardiac Cycle Flashcards
When does the Miral valve open?
When the pressure in LV
What happens during rapid filling?
Blood rushes into the ventricles as it relaxes, the Volume increases, and the pressure decreases, cuz it’s relaxing
What happens during the Slow/Reduced filling phase?
- Ventricles Fill
- Slow phase contributes 1/4 to 1/3 LV EDV
- Ventricular pressure rises slightly
What happens during Atrial contraction?
During atrial contraction the Atria delivers the last bit of blood to the the ventricles right before Isovolumic contraction.
What is Isovolumic contraction?
It is when the ventricles contract to pump out a full volume of blood into the aorta, forcing the aortic valves to open
What marks the end of of the Isovolumic contraction?
When the Aortic Valves open
What happens during Systolic Ejection (i.e. Rapid/Reduced ejection)?
The pressures in the Ventricles and Aorta rise and fall together because the Aortic Valve provides an open communication btw the 2 chambers.
What is the End Systolic Pressure Point?
It is when the Aorta Closes, marking the end of the Systolic phase.
What happens during Isovolumic Relaxation?
The is a huge drop in Ventricular pressure and no change of Volume
What is the range of Normal Ejection Fraction?
55 to 80% Avg (67%)
What keeps the Aoritc pressure at 80 mmHg and not anything lower?
The arterioles are partially constricted, which allows the generation of pressure btw the arterioles and the aorta.
Arterioles Dilated= lower Aortic pressure
Arterioles Constricted = higher Aortic pressure
What is the formula for SV?
SV = EDV - ESV
What is the formula for ejection fraction/ CO?
EF = SV/ EDV
What formula would you use to determine the Preload?
LV - EDV
What causes the 1st heart sound?
When the Mitral Valve snaps closed right before Isovolumic Contraction
