<unk>  is the term referring to all or any of the events related to the flow of blood that occur from the beginning of one heartbeat to the beginning of the next. The frequency of the<unk>  is the heart rate. Throughout the<unk> , the blood pressure increases and decreases.
Every single 'beat' of the heart involves three major stages that together form one<unk> :
1- Atrial systole
2- Ventricular systole
3- Complete<unk>  diastole
While the term systole is synonymous  with contraction (movement or stretching) of a muscle, the term diastole is synonymous with relaxation of a muscle.
Cardiac cycle
Hemodynamics
Cerebral circulation
Circulatory system
Coronary circulation
Muscle tone
Electrical conduction system of the heart
Autonomic nervous system