7.5 The cardiac cycle Flashcards
1
Q
What is the relaxation of the heart?
A
Diastole
2
Q
What are the contractions of the heart?
A
- atrial systole
- ventricular systole
3
Q
What happens during atrial systole?
A
- atria contract (higher pressure)
- ventricles relaxed (lower pressure)
- atrioventricular valves open
- blood flows from atria to ventricles
4
Q
What happens during ventricular systole?
A
- ventricles contract (higher pressure)
- atria relaxed (lower pressure)
- atrioventricular valves close to prevent backflow of blood
- semilunar valves open
- blood flows from ventricles to arteries
5
Q
What happens during diastole?
A
- atria relaxed - begin to fill with blood
- atrioventricular valves open
- ventricles relaxed (lower pressure) blood enters from atria
- arterial pressure high
- semilunar valves close to prevent backflow of blood
6
Q
How do you calculate cardiac output?
A
Cardiac output = heart rate x stroke volume
