Question

What are the 5 stages of the cardiac cycle?

Answer 1

Cardiac cycle:

1. A cardiac cycle is a period that begins with atrioventricular contraction and concludes with ventricular relaxation.
2. The cardiac cycle describes how the human heart works from the start of one heartbeat to the start of the next.
3. It comprises two phases: systole, when the heart muscle is strongly contracted and pumps blood; and diastole when the heart muscle relaxes and fills with blood.
4. The heart quickly relaxes and expands after emptying to take in the second rush of blood coming from the lungs and other systems of the body, before contracting once again to pump blood to those organs.

5 stages of the cardiac cycle:

1. Atrial systole - atria contract which power blood into the ventricles. The AV valve opens while the semilunar valves close.
2. Early ventricular systole - ventricle contracts, atria unwind, semilunar valves shut.
3. Late ventricular systole - withdrawal of ventricles, atria unwind, blood powers into the pneumonic conduit and aorta.
4. Early ventricular diastole - ventricles and atria unwind, and atria latently start loading up with blood.
5. Late ventricular diastole - atria and ventricles unwind, AV valves open, and semilunar valves shut.