What mechanism states that a greater volume of blood entering the heart leads to a greater volume ejected during contraction?

The Frank-Starling Mechanism is a fundamental principle in cardiac physiology that explains how the heart's stroke volume— the amount of blood ejected with each heartbeat—increases in response to an increase in the volume of blood filling the heart, known as preload. Essentially, as more blood enters the heart during the diastolic phase, the myocardial fibers are stretched to a greater extent. This stretching optimizes the overlap of actin and myosin filaments in the cardiac muscle cells, resulting in a more forceful contraction during systole.

This relationship highlights the heart's ability to adapt its pumping effectiveness based on the volume of incoming blood, ensuring that it can efficiently manage varying levels of venous return. The Frank-Starling Mechanism is crucial for maintaining cardiovascular stability, particularly during activities that cause fluctuations in blood flow.

The other options refer to aspects of cardiac function but do not specifically articulate the relationship between the volume entering the heart and the volume ejected during contraction as precisely as the Frank-Starling Mechanism does. For instance, the cardiac cycle describes the complete sequence of events in a single heartbeat, while atrial contraction and ventricular filling refer to specific phases within the cycle without encapsulating the overarching mechanism that governs the relationship between preload and stroke volume