Assignment 5

Exercise-induced effects on the cardiovascular system are largely due to changes in electrical impulses coming from neurons of the autonomic nervous system (ANS). These changes are designed to ensure adequate delivery of blood to exercising muscles. The following exercise will help you learn about the effects of exercise on the cardiovascular system. Working within CardioLab and referring to the detailed instructions on Assignment 5, answer the questions below.


1 .		Based on what you already know about the cardiovascular system and based on what happens to your heart rate when you exercise, think about how the ANS is responsible for exercise-induced changes. What role does the sympathetic division of the ANS play in the cardiovascular response to exercise? How does this occur?

2 .		Click on the Start button to monitor cardiovascular parameters in a normal human. Allow this to proceed for a few seconds, then in the Interventions view, select Treadmill from the popup menu and click on the Apply Intervention button four or five times in rapid succession to simulate strenuous exercise. Notice what happens to each cardiovascular parameter. Record any changes that occur and explain these results.

3 .		Repeat the experiment as before; however, before you apply the treadmill intervention, be sure to switch to the Nerve Impulses view to examine normal impulse activity. Once you have done this, apply the treadmill intervention as before, then return to the Nerve Impulses view to look at exercise–induced changes in nerve impulse activity. What happened to impulse activity from each set of neurons? Describe your results.

4 .		Follow the activity of these neurons for several minutes until homeostasis of blood pressure and heart rate is achieved, then answer the following questions: Describe the role of each set of neurons in blood pressure homeostasis. Which components of the cardiovascular system were affected by each group of neurons?