Which term describes the total volume of blood pumped by the heart per minute?

• A. Stroke volume
• B. Cardiac output
• C. End-diastolic volume
• D. Heart rate

Answer: (B)

Cardiac output is the total volume of blood the heart pumps each minute. It reflects how much blood moves through the circulation per minute by combining how much blood is ejected with each beat (stroke volume) and how many beats occur each minute (heart rate). CO equals stroke volume times heart rate, so a typical resting value is about 5 liters per minute when SV is around 70 mL per beat and HR is about 70/min. End-diastolic volume is simply the amount of blood in the ventricle before contraction and relates to preload, not the flow rate. Heart rate alone measures frequency but not how much blood is pumped with each beat. Stroke volume is the amount ejected per beat, not per minute. Therefore, the term describing the total blood pumped per minute is cardiac output.