cardiac cycle Flashcards
1
Q
what three processes make up the cardiac cycle
A
- atrial systole
- ventricular systole
- diastole
2
Q
what happens during atrial systole
A
- the atrium contract and the ventricles relax
- this increases the pressure in the atrium but decreases the volume
- the pressure of blood due to increased pressure forces the AV valves open and so blood can flow into the ventricles
3
Q
what happens during ventricular systole
A
- the ventricles contract and the atrium relax
- this decreases the volume in the ventricles but increases the pressure
- this pressure forces blood to be pumped up and out forcing the SL valves open and so blood leaves the heart
4
Q
what happens during diasole
A
both the atria and ventricles relax but the pressure in the atria is higher
blood is returned to the heart and the SL valves close
