Increased return of the blood to the heart stretches the muscle,thereby
A) stimulating the sympathetic nerve.
B) activating the beta1-adrenergic receptors.
C) closing the AV valves.
D) increasing stroke volume.

Question

Quizplus · Accepted Answer

When the muscle of the heart is stretched due to an increased return of blood to the heart, it leads to an increase in the stroke volume (the amount of blood ejected from the heart with each contraction). This occurs due to an increase in the force of contraction of the heart muscle, which is known as the Frank-Starling mechanism. The other options (stimulating the sympathetic nerve, activating the beta1-adrenergic receptors, closing the AV valves) are not directly related to the increase in stroke volume from increased venous return.

Increased Return of the Blood to the Heart Stretches the Muscle,thereby