AMCA Clinical Medical Assisting Practice Test

The measurement that reflects the volume of blood pumped by the heart per beat is stroke volume. Stroke volume is a critical parameter in cardiovascular physiology as it indicates how effectively the heart is functioning. This volume is determined by the amount of blood that is ejected from the left ventricle with each contraction.

Understanding stroke volume is crucial for assessing heart performance, particularly in clinical settings where monitoring the heart's pumping ability can inform treatment decisions. It can be influenced by various factors like preload (the volume of blood in the ventricles before contraction), afterload (the resistance the heart must overcome to eject blood), and contractility (the strength of the heart's contraction).

In contrast, cardiac output is a broader measurement that represents the total volume of blood pumped by the heart in one minute, which is calculated by multiplying stroke volume by heart rate. Cardiac index is similar to cardiac output but is adjusted for body surface area, providing a more personalized metric. Blood pressure refers to the force that circulating blood exerts against the walls of blood vessels, which is not a direct measure of blood volume pumped per contraction. Thus, stroke volume specifically focuses on the heart's action during each heartbeat.