Define a cardiac cycle and the cardiac output.

The sequential events taking place in the heart which is the contraction or systole and relaxation or diastole of both the atria and ventricles is called cardiac cycle. The amount of blood pumped by the ventricle during this cardiac cycle is approximately 70 ml which is called as the stroke volume. The stroke volume multiplied by the heart rate gives the cardiac output. Cardiac output can be defined as the volume of blood pumped out by each ventricle per minute which is around 5000 ml or 5 litres in a healthy individual.