So the blood vessels that carry the blood to our cardiac and skeletal muscle increase in size. They dilate. But the blood vessels that carry the blood to our digestive tract basically decrease in size. They constrict because our rate of activity decreases inside the gastrointestinal system. So now that we know what the job and function of the sympathetic nervous system is let's actually discuss the pathway of the electrical signal along the neurons inside the sympathetic nervous system. So we have two neurons in our pathway.