What takes place as the blood passes from the atria into the ventricles of the heart?
- Aatrioventricular valves close; muscle wall of the atria relax; muscle wall of the ventricles contract; semi-lunar valves open
- Batrioventricular valves close; muscle wall of the atria relax; muscle wall of the ventricles relax; semi-lunar valves open
- Catrioventricular valves open; muscle wall of the atria contract; muscle wall of the ventricles contract; semi-lunar valves close
- Datrioventricular valves open; muscle wall of the atria contract; muscle wall of the ventricles relax; semi-lunar valves close