Which of the Following Increases Systemic Vascular Resistance,stroke Volume,and Heart

Question

Which of the following increases systemic vascular resistance,stroke volume,and heart rate?
A) Stimulation of the vagus nerve
B) Stimulation of the parasympathetic nervous system
C) Administration of a sympatholytic drug
D) Stimulation of the sympathetic nervous system

Accepted Answer

Stimulation of the sympathetic nervous system increases systemic vascular resistance, stroke volume, and heart rate by releasing norepinephrine, which activates alpha and beta adrenergic receptors in the heart and blood vessels. The parasympathetic nervous system, activated by the vagus nerve, has the opposite effect, decreasing heart rate and contractility. Administration of a sympatholytic drug, which inhibits sympathetic nervous system activity, would also decrease these parameters.