What is the Frank-Starling Mechanism?
The stroke volume of the heart increases in response to an increase in the volume of blood filling the heart. The increased volume of blood stretches the ventricular wall, causing cardiac muscle to contract more forcefully. The stroke volume may also increase as a result of greater contractility of the cardiac muscle during exercise, independent of the end-diastolic volume. The Frank-Starling mechanism appears to make its greatest contribution to increasing stroke volume at lower work rates, and contractility has its greatest influence at higher work rates.