| 1. | Lub | : | First heart sound associated with closure of tricuspid and bicuspid valves |
| 2. | Cardiac output | : | Stroke volume multiplied by heart rate |
| 3. | Dub | : | Second heart sound, due to opening of semilunar valves |
| 4. | Duration of cardiac cycle | : | 0.8 seconds |
| 1. | Atrioventricular node |
| 2. | Purkinje fibre network |
| 3. | Sinoatrial node |
| 4. | Bundle of His |