Apply your knowledge questions: 1. Blood pressure is too high for homeostasis, baroreceptor is a. High b. low 2. Activation of the sympathetic nerves will cause in vessel radius. a. increase; increase c. decrease; increase CO and b. increase, decrease d. decrease; decrease 3. When the blood pressure is low high for the current activity, the body will parasympathetic activity. sympathetic activity and a. increase; increase b. increase, decrease c. decrease: increase d. decrease; decrease 4. What hormone is released when the sympathetic nerve is activated? Does this hormone cause vasoconstriction or vasodilation.