Final answer:
The volume of blood in the ventricle during isovolumetric contraction is the end-diastolic volume (EDV). This is the amount of blood in the ventricle at the end of atrial systole just prior to ventricular contraction.
Step-by-step explanation:
The volume of blood in the ventricle during isovolumetric contraction is the end-diastolic volume (EDV).
During isovolumetric contraction, the ventricles contract and the pressure within the ventricle rises, but it is not yet high enough to open the semilunar valves and be ejected from the heart. Since no blood is being ejected from the ventricle during this phase, the volume of blood within the chamber remains constant, which is the end-diastolic volume (EDV).
An example of the end-diastolic volume would be approximately 130 mL of blood at the end of atrial systole just prior to ventricular contraction.