Final answer:
The volume of blood ejected from the ventricle with each heartbeat is described by the difference between end-diastolic volume and end-systolic volume, which is known as the stroke volume.
Step-by-step explanation:
The volume of blood ejected from the ventricle with each contraction can be described by the equation A) (end-diastolic volume) - (end-systolic volume). This is because the amount of blood in the ventricles at the end of atrial systole just prior to ventricular contraction, known as the end diastolic volume (EDV) or preload, is reduced by the amount of blood remaining in each ventricle after the contraction, which is the end systolic volume (ESV). Consequently, the difference between these two volumes is the stroke volume (SV), which is the actual volume of blood that is pumped out of the heart during systole.
Stroke volume and EDV are also used to calculate the ejection fraction, which is the portion of blood that is ejected from the heart with each contraction. To find the ejection fraction, SV is divided by EDV and is typically expressed as a percentage, ranging from approximately 55-70 percent with a mean of 58 percent for a healthy heart.