3. Please explain what is specifically happening in each of the following 4 phases of the cardiac
cycle (including any contractions occurring, the direction blood is flowing if it flows at all, and if
the valves are open or closed - including specific valve names:
a. Ventricular filling phase =
b. Isovolumetric contraction phase =
c. Ventricular ejection phase =
d. Isovolumetric relaxation phase =