Eli5: What create a heart beat?

Question

Can anyone explain this in more engineering terms? Biology can be difficult for me to read and to understand.

In: 2

Answer 1

There’s a timed pulse generator (SA node) connected to 4 pumps (the heart chambers) via a way to delay the signal (AV node). 2 of these pumps (atria) empty into the other 2 (ventricles), which empty into general circulation (left side of the heart) and an oxygenation chamber (lungs). The delay is between the atria pumping and the ventricles pumping.

There are valves between each of these chambers and both circulations to prevent backflow of blood. The closing of these is what you hear and feel as a heartbeat.