The Cardiac Cycle Flashcards
1
Q
3 stages
A
- diastole
- atrial systole
- ventricular systole
2
Q
Describe stage 1
A
- diastole
- relaxation of the heart
- atria and ventricles relax and blood returns from PV and VC
- atria fills with blood and reassure rises
- when pressure bigger in atria bigger than in the ventricles the both valves open this lows blood into the ventricles
- relaxation of the ventricles walls causes them to recoil this reduces pressure in them
- the pressure is lower in the ventricles than aorta and PA causing semi Luna values and PA to close
3
Q
Describe stage 2
A
- atrial systole
- contraction of atria
- atria contract together causing the volume to decrease put the pressure to increase
- atrioventricular valve open for in blood in ventricles down a pressure gradient
- muscles around the PV and VC restrict causing blood to flow in one way
4
Q
Stage 3
A
- ventricular systole
- both ventricles contract together
- pressure in the ventricles increases above atria
- cause atrioventricular valves to close
- after AV to close so pressure in ventricles increases above PA and aorta this open the semi Luna valves
- lows blood flow into vessels