Cardiac Cycle Wiki

Question 1

#1 Atrial Systole
Valves

Answer 1

AV open

Semilunar closed

Question 2

#1 Atrial Systole
What happens

Answer 2

Atria contract and pump blood

Ventricle (partially filled) received last 30% of blood –> 140 mL total

Question 3

#2 Isovolumetric contraction
Valves

Answer 3

AV closed

Semilunar closed

Question 4

#2 Isovolumetric contraction
What happens

Answer 4

Ventricles begin contract (pressure rises rapidly)

Volume unchanged

Question 5

#3 Ventricular ejection
Valves

Answer 5

AV closed

Semilunar open

Question 6

#3 Ventricular ejection
what happens

Answer 6

Pressure in LV and RV > aortic and pulmonic pressures

Rapid ejection first then slows down (but some blood remains in ventricle at the end)

Question 7

#4 isovolumetric relaxation
valves

Answer 7

AV closed

Semilunar closed

Question 8

#4 isovolumetric relaxation
what happens

Answer 8

Ventricles relax and ventricular pressure decreases until drop below atrial pressure

blood spread and pumped to rest of body

Question 9

#5 ventricular filling
valves

Answer 9

AV open

Semilunar closed

Question 10

#5 ventricular filling 
what happens

Answer 10

ventricles relaxed

ventricles passively fill to ~70% max volume

as fill, rate of filling decr and AV valves start closing as atria fill