Small changes in ________ will have a large impact on the heart's pumping effectiveness, while large changes in ________ do not impact the effectiveness much.
A) afterload; preload
B) preload; afterload
C) contractility; preload
D) afterload; contractility
E) contractility; afterload

Question

Quizplus · Accepted Answer

Preload refers to the initial stretching of the cardiac myocytes prior to contraction, and small changes in preload can significantly affect the heart's stroke volume and pumping effectiveness. Afterload, on the other hand, is the pressure the heart must work against to eject blood, and large changes in afterload do not have as significant an impact on the heart's pumping effectiveness.

Small Changes in ________ Will Have a Large Impact on the Heart's