What term describes the rate at which the heart pumps blood?

• A. Heart rate
• B. Stroke volume
• C. Cardiac output
• D. Blood pressure

Answer: (A)

Understanding rate in this context means how often the heart contracts per minute. That measurement is heart rate—how many beats occur each minute. It’s expressed in beats per minute and increases with exercise to help deliver more oxygen-rich blood to working muscles.

The other terms describe different things: stroke volume is the amount of blood ejected with each heartbeat; cardiac output is the total blood pumped per minute and equals heart rate multiplied by stroke volume; blood pressure is the force of blood against the walls of the arteries. For example, if your heart beats 70 times per minute and ejects about 70 mL with each beat, your cardiac output would be about 4900 mL per minute, but the rate itself remains the number of beats per minute.