Stroke Volume describes the amount of blood pumped per heartbeat. Which term best matches this description?

• A. Blood Pressure
• B. Stroke Volume
• C. Cardiac Output
• D. Ejection Fraction

Answer: (B)

Stroke volume is the amount of blood ejected by the heart with each beat, usually expressed in milliliters per beat. This makes it the exact term that describes the amount pumped per heartbeat. Blood pressure is a measure of the force against vessel walls, not the volume per beat. Cardiac output is the total volume pumped per minute and equals stroke volume times heart rate, so it’s a rate over time rather than the per-beat amount. Ejection fraction is the percentage of blood in the ventricle that is ejected during systole, not the absolute volume per beat. Typical resting stroke volume is about 70 mL per beat and can rise with increased venous return and contractility during exercise.