Systole : It is contraction phase of heart. It is the phase of the heartbeat when the heart muscle contracts and pump blood in to the ventricles (atrial systole) or the arteries (ventricular systole)

Diastole : It is the relaxation phase of heart. It is that phase of the heartbeat when the heart muscle relaxes and allows the chambers to fill with blood.

Pulmonary circulation : It is the circulation of impure blood from right ventricle to lungs via pulmonary artery and collection of pure blood from lungs and pouring that to left auricle by pulmonary veins.