Question

Which of the following statements best describes the relationship between the hormones ANF and Angiotensin 2 in terms of their physiological effects on the body?

• A. ANF promotes sodium reabsorption, while Angiotensin 2 dilates blood vessels.
• B. ANF dilates blood vessels, while Angiotensin 2 promotes sodium reabsorption.
• C. Both ANF and Angiotensin 2 promote sodium reabsorption.
• D. Both ANF and Angiotensin 2 dilate blood vessels.

Hint:

ANF and Angiotensin 2 perform opposing roles: ANF lowers blood pressure and promotes sodium excretion. Angiotensin 2 raises blood pressure and promotes sodium retention. Understanding these roles helps clarify their effects in the regulation of blood pressure and fluid balance.

Answer 1

The Correct Option is B

Step 1: Role of ANF (Atrial Natriuretic Factor)
ANF is secreted by the atrial cells of the heart in response to increased blood pressure and blood volume. Its physiological effects include: Dilating blood vessels (vasodilation) to reduce blood pressure. Promoting sodium excretion by reducing sodium reabsorption in the kidneys. Decreasing blood volume by promoting water excretion. Step 2: Role of Angiotensin 2
Angiotensin 2 is a key hormone in the Renin-Angiotensin-Aldosterone System (RAAS). Its physiological effects include: Causing vasoconstriction to increase blood pressure. Promoting sodium reabsorption in the kidneys, which helps retain water and increase blood volume. Stimulating the release of aldosterone, which enhances sodium and water reabsorption. Step 3: Comparing ANF and Angiotensin 2
ANF primarily acts to lower blood pressure and reduce sodium levels by promoting vasodilation and sodium excretion. Angiotensin 2 acts to increase blood pressure and sodium levels by causing vasoconstriction and promoting sodium reabsorption. Thus, ANF and Angiotensin 2 have opposite physiological effects. {The correct answer is: ANF dilates blood vessels, while Angiotensin 2 promotes sodium reabsorption.}