Hi! I am having trouble understanding the SNS regulation of blood pressure.
So in response to low arterial pressure, the SNS becomes activated which causes the release of norepinephrine and epinephrine. Norepinephrine acts on the alpha receptors to cause systemic vasoconstriction, which increases SVR, which will lead to an increase in blood pressure. I am having trouble understanding epinephrine's action on the beta receptors. So with decreased arterial pressure, SNS is stimulated and epinephrine released; epinephrine stimulates the beta receptors which causes an increase in heart rate, speed of conduction and force of contraction, but also causes vasodilation. This is the part I am confused about. With vasodilation, wouldn't the BP decrease? Or is the vasodilation used to accommodate an increased heart rate and increased cardiac output to protect the blood pressure from becoming too high? Any help and clarification would be great!