Chapter 44, Problem 5TYK

The heartbeat includes:

a. the systole when the heart relaxes and fills.

b. the diastole when the heart contracts and empties.

c. pressure that causes the AV valves to open, filling the ventricles.

d. rising pressure in the ventricles to open the AV valves and close the SL valves.

e. the “lub” sound when the SL valves open and the “dub” sound when the AV valves close.