What physiological effect does angiotensin II have on the sympathetic nervous system?

Angiotensin II is a potent vasoconstrictor and plays a significant role in the regulation of blood pressure and fluid balance. One of its key physiological effects is the stimulation of the sympathetic nervous system, which leads to increased activity.

When angiotensin II is released, it acts on specific receptors in the brain and other tissues, prompting the sympathetic nervous system to become more active. This heightened activity results in several downstream effects, including increased heart rate, enhanced cardiac contractility, and vasoconstriction, all of which contribute to an elevation in blood pressure. Additionally, angiotensin II can lead to the release of norepinephrine from sympathetic nerve terminals, further amplifying its effects on blood pressure regulation.

The physiological consequence of this increased sympathetic nervous system activity correlates with the body’s response to low blood volume or pressure, promoting mechanisms that restore homeostasis. This adaptation aims to support adequate organ perfusion in times of stress or fluid loss. Thus, the correct answer reflects the direct influence of angiotensin II as a facilitator of sympathetic nervous system activity.