1. When you are going for a run, as you start to pick up pace, what is your nerve input (sympathetic or parasympathetic)? What is the affect on heart rate (increase or decrease); stroke volume (increase or decrease); cardiac output (increase or decrease)? 2. JN often feels light-headed and dizzy when she stands up. The sensation does not last long and she has never fainted. She asks her physician about this problem and he says that her body may not be regulating blood pressure as quickly as it should. Complete the physician's explanation of how her blood pressure is changing when she stands. You feel light-headed when you stand because your blood pressure is too low. When blood pressure is low, baroreceptor activity increases / decreases leading to decreased / increased parasympathetic activity and decreased / increased sympathetic activity. These changes in your autonomic nervous system lead to decreased / increased heart rate and contractility, and vasoconstriction/ vasodilation. The net result of these changes is that your blood pressure decreases / increases to homeostasis. 3. Short term control of rising blood pressure involves decreased/increased parasympathetic activity.20-6 which leads to decreased/ increased heart rate, vasoconstriction/ vasodilation, and lower blood pressure.