Question

Which of the following statements is FALSE regarding the cardiac cycle?

A) As blood flows from the atria into the ventricles, the ventricular pressure rises.
B) After the atria contract, the ventricles reach their EDV.
C) When the LV contracts, the pressure rises in the ventricle until it overcomes the aortic pressure and it begins ejecting blood into the aorta.
D) Systole is defined as when the ventricles begin to relax.
E) None of the above.

Answer 1

The FALSE statement regarding the cardiac cycle is that systole is when the ventricles begin to relax, which is incorrect as systole is the phase when the ventricles contract and pump blood out.

Step-by-step explanation:

The statement that is FALSE regarding the cardiac cycle is "D) Systole is defined as when the ventricles begin to relax." Systole actually refers to the phase of the cardiac cycle when the ventricles contract and pump blood out of the heart. The phase when the ventricles relax is called diastole. During atrial systole, the atria contract and push blood into the ventricles. As this happens, the end-diastolic volume (EDV) of the ventricles is reached. As the ventricles contract (ventricular systole), the pressure inside them increases, eventually overtaking the pressure in the arteries, such as the aorta, which leads to the ejection of blood into the circulation.