I know that, vasoconstriction results in increased total peripheral resistance which is responsible for the rise in diastolic blood pressure. Also, cardiac output is responsible for the systolic blood pressure. But there are conditions, as in administering nor adrenaline, where there is severe vasoconstriction and a fall in cardiac output but a rise in both systolic and diastolic blood pressure. In this case, I understand that the rise in diastolic blood pressure is due to vasoconstriction produced by nor adrenaline. I am not able to account for the rise in systolic blood pressure in the setting of falling cardiac output. Can severe vasoconstriction also influence the systolic blood pressure?