What is the definition of stroke volume?

• A. The volume of blood in the left ventricle
• B. The volume of blood pumped by the left ventricle per beat
• C. The total amount of blood in circulation
• D. The amount of plasma in blood

Answer: (B)

Stroke volume is defined as the volume of blood pumped by the left ventricle of the heart with each heartbeat. This measurement is crucial in understanding how effectively the heart is functioning, as it reflects the amount of blood being delivered to the body and is an important factor in calculating cardiac output, which is the total volume of blood the heart pumps in a minute.

In contrast, the other definitions provided do not accurately describe stroke volume. The volume of blood in the left ventricle refers to the amount of blood present at a specific moment rather than the amount pumped per contraction. The total amount of blood in circulation pertains to the entire blood volume within the vascular system but does not indicate how much is pumped with each heartbeat. Lastly, the amount of plasma in blood specifically refers to the liquid component of blood, which is unrelated to stroke volume as it does not account for the blood pumped by the heart.