Answer:
1. Passive ventricular fillings.
2. Ventricular ejection.
3. Atrial contraction
Explanation:
In Human anatomy, cardiac cycle can be defined as a complete heartbeat of the human heart which comprises of sequential alternating contraction and relaxation of the atria and ventricles, therefore causing blood to flow unidirectionally (one direction) throughout the human body.
Generally, the cardiac cycle occurs in two (2) stages;
Diastole : in this stage, the ventricles is relaxed and would be filled with blood.
Systole: at this stage, the muscles contracts and thus, allow blood to be pushed through the atria.
The following terms describe the physical or mechanical events with the correct phases of the cardiac cycle in mammals (human beings).
1. Passive ventricular fillings: is what happens when depolarization of the atria cause the atria to go into atrial systole. Atrial pressure increases and more blood is forced into the ventricles via the AV valves.
2. Ventricular ejection: is the continued contraction of the ventricles that leads to the pressure inside the ventricles to build up and will thus force open the semilunar valves and blood will be ejected out of the heart to the pulmonary and systemic circuits.
3. Atrial contraction: the process that begins when both the atria and the ventricles are in diastole. Blood from the veins are returning to the heart and the pressure within the atria is higher than the ventricular pressure. Causing the AV valves to open and blood will passively fill into the ventricles. It is important to know that the semilunar valves are closed shut because they have higher pressure than both the left and right ventricle.
