Stroke volume is most accurately defined as which statement?

• A. Amount of blood ejected from the heart with one contraction
• B. Total blood volume in the circulatory system
• C. Heart rate multiplied by stroke volume
• D. Pressure generated during ventricular contraction

Answer: (A)

Stroke volume is the amount of blood ejected from the heart with each contraction. It is measured in milliliters per beat and reflects how much blood the ventricle pumps with every heartbeat. This description is the best fit because it focuses on the volume moved per beat. By comparison, total blood volume refers to the entire amount of blood in the circulatory system, cardiac output is heart rate multiplied by stroke volume (volume per minute, not per beat), and the pressure generated during ventricular contraction is the systolic pressure, not the amount ejected. Stroke volume is influenced by preload, afterload, and contractility, which helps explain why it can change with fluid status, vascular resistance, or myocardial performance.