Phases of cardiac cycle

Question 1

Step A - Atrial systole begins

Answer 1

Atrial contraction forces a small amount of
additional blood into relaxed ventricles

Question 2

Step B

Answer 2

Atrial systole ends,
atrial diastole
begins

Question 3

Step C

Answer 3

Ventricular systole—
first phase: Ventricular
contraction pushes AV
valves closed but does
not create enough
pressure to open
semilunar valves

Question 4

step d

Answer 4

Ventricular systole—
second phase: As
ventricular pressure rises
and exceeds pressure
in the arteries, the
semilunar valves
open and blood
is ejected

Question 5

step e- Ventricular diastole—early:

Answer 5

As ventricles relax, pressure in
ventricles drops; blood flows back
against cusps of semilunar valves
and forces them closed. Blood
flows into the relaxed atria

Question 6

step f Ventricular
diastole—late:

Answer 6

All chambers are
relaxed.
Ventricles fill
passively