In a healthy subject, running is usually associated with a decrease in the end-systolic volume of the right and left ventricles and with an increase in their stroke volume. What is the probable mechanism for this response?
A) A decrease in catecholamine release
B) An increase in sympathetic tone to the ventricles
C) An increase in parasympathetic tone to the ventricles
D) A decrease in venous return of blood to the heart
E) An increase in pulmonary and systemic resistance

Question

Quizplus · Accepted Answer

An increase in sympathetic tone to the ventricles during running enhances myocardial contractility, which decreases end-systolic volume and increases stroke volume. This is part of the body's natural response to exercise, allowing more blood to be pumped to meet the increased oxygen demand.

In a Healthy Subject, Running Is Usually Associated with a Decrease