Question

Which one is an important constituent of renin angiotensinogen-aldosterone system?

• A. JGA cell
• B. Macular cell
• C. Erythropoietin
• D. Plasma cell

Answer 1

Answer: (A)

JGA cell

When blood volume is low, juxtaglomerular cells in the kidneys secrete renin directly into circulation. Plasma renin converts angiotensinogen to angiotensin I, which is converted to angiotensin II. Angiotensin II is a vasoconstrictor, which causes blood vessels to constrict, resulting in increased blood pressure. Angiotensin II also stimulates the secretion of the hormone aldosterone from the adrenal cortex. Aldosterone causes the tubules of the kidneys to increase the reabsorption of sodium and water into the blood. This increases the volume of fluid in the body, which also increases blood pressure.

So, the correct answer is option A.