During systole,what happens in the heart?

Define a cardiac cycle and the cardiac output.

$A$: Isovolumetric systole of a normal cardiac cycle is responsible for the opening of semilunar valves causing the blood flow into aortic aorta and pulmonary aorta.
$R$: During isovolumetric systole,intraventricular pressure increases as semilunar and $AV$ valves are closed and ventricles are contracting.

Calculate the cardiac output of an individual having $70$ heart beats/min with a stroke volume of $55 \ mL$.

What is the cardiac output of blood?

What is meant by cardiac cycle?