Module 8 ML-6 Flashcards
What are the two phases of the cardiac cycle
systole and diastole
What is diastole?
relaxation and ventricular filling
What is the length of diastole
longer 2/3 of time 600-800msec
What is systole
contraction, ventricular pressure (squeezing)
What is the length of systole
short 1/3 of time 200-400msec
What are the 4 period within the two phases
ventricular filling
isovolumetric contraction
ejection
Isovolumetric relaxation
What are the two parts of ventricualr filling?
passive and active
Passive filling
rapid and most filling occurs passively and rapidly
Active filling
this is shown by the P wabe and involved the atrial kick
Atrial kick
active contraction and adds 10-20% more blood to ventricle at rest
In order for filling to occur what has to happen
AV valves are open and SL valves are closed
How is EDV achieved
by both passive and active filling and the final voltume is 135 mL
What is isovolumetric contraction
ventricles contract (on 135 ml) and tension and pressure develop
What are the valved doing durin isovolumetric contraction
AV and SL valves are closed
What causes SL valves to be closed
Pressure in ventricles are less than pressure in aorta