Final answer:
After the end systolic volume (ESV), there is typically 50 to 60 mL of blood remaining in each ventricle. The ESV is crucial for calculating the ejection fraction (EF), a measurement of the heart's pumping efficiency, which usually ranges from 55-70 percent.
Step-by-step explanation:
The amount of blood that is left in the ventricles after the end systolic volume (ESV) is the blood that remains following the contraction of the ventricles. During the ventricular ejection phase of ventricular systole, blood is pumped out of the heart through the pulmonary and aortic semilunar valves. Starting with an end diastolic volume (EDV) of approximately 130 mL, a typical stroke volume (SV) ranging from 70 to 80 mL is ejected, leaving an end systolic volume of 50 to 60 mL still within each ventricle.
This remaining ESV is important for understanding the function of the heart, as it factors into the calculation of the ejection fraction (EF), which measures the percentage of blood pumped out of the ventricles with each beat. To determine EF, the stroke volume (SV) is divided by the EDV. The EF is typically between 55-70 percent, indicating efficient cardiac function.