A group of runners gathers every week to train for long-distance runs. Several students in your anatomy class are part of this group. Your classmates are curious about the physiological changes that occur with exercise. You do a little research in class and find several changes occur as exercise begins. Which of these correctly lists the changes that occur as exercise begins?

A) increased vasodilation, increased cardiac output, increased venous return

B) decreased vasodilation, decreased cardiac output, decreased venous return

C) increased vasodilation, decreased cardiac output, increased venous return

D) increased vasodilation, increased cardiac output, decreased venous return

Increased vasodilation, increased cardiac output, decreased venous return occurs during exercise.

Option D.

Explanation:

Exercise is a condition where the body works more than normal, leading to more consumption of nutrients and oxygen in the active muscles of body. The exercise also produces a lot of carbon dioxide in the muscles.

The increase in carbon dioxide and the need of oxygen and nutrients in the muscles lead to the para sympathetic stimulation which leads to the increase in vasodilation. This increase in vasodilation leads to reduced peripheral resistance which in turn reduces the venous return.

While, heart has sympathetic stimulation which causes the heart rate to increase and as a result cardiac output to increase too. But due to reduced venous return, the stroke volume increases up to a certain limit from where it remains still, because of the reduced blood in heart.