Question

Which of the following represents the negative feedback mechanism on the RAAS loop?

• A. High Angiotensin II $\Rightarrow$decrease in renin $\Rightarrow$Increased blood pressure$\Rightarrow$Secretion of renin stops.
• B. Angiotensin I $\Rightarrow$secretion of Renin $\Rightarrow$ACE $\Rightarrow$Angiotensin II $\Rightarrow$Aldosterone.
• C. Decreased angiotensin II $\Rightarrow$Decreased blood pressure $\Rightarrow$Secretion of renin starts.
• D. Angiotensin $\Rightarrow$Renin $\Rightarrow$Angiotensinogen I$\Rightarrow$ACE $\Rightarrow$Angiotensinogen II$\Rightarrow$Aldosterone.

Answer 1

The correct option is A

High Angiotensin II $\Rightarrow$decrease in renin $\Rightarrow$Increased blood pressure$\Rightarrow$Secretion of renin stops.

The body senses increasing levels of angiotensin II, and this by itself suppresses renin release. This is called an inhibitory feedback loop. As angiotensin II increases, renin decreases, which means angiotensin II also decreases since it depends on renin for its production.