The exodus was a journey that moses had lead his people out of. To the Hebrews the release from slavery proved that God was protecting and watching over them.
The left and right ventricles are stronger pumps. The left ventricle is the strongest because it has to pump blood out to the entire body. When your heart functions normally, all four chambers work together in a continuous and coordinated effort to keep oxygen-rich blood circulating throughout your body.
The heart is a two stage electrical pump. The upper chambers of the heart, the atria, (single= atrium) collect blood from the body and pump it into the lower chambers, or ventricles. There is a little delay for the ventricles to fill, and then they pump the blood out of the heart and back to the body.