Q. Which of the following stimulates adrenal cortex to release aldosterone and tackle the water stress condition?
NTA AbhyasNTA Abhyas 2020
Solution:
As a part of Renin-Angiotensin-Aldosterone System (RAAS), renin enzyme (secreted from JG cells) converts angiotensinogen (453 amino acids) into angiotensin I (10 amino acids).
This angiotensin I is converted into angiotensin II (8 amino acids) in presence of enzyme Angiotensin Converting Enzyme (ACE), secreted from lungs.
The angiotensin II is a vasoconstrictor and stimulates adrenal cortex for secretion of hormone aldosterone, which promotes absorption of Na+ ions from nephric filtrate, resulatantly, blood pressure is increased.
Atrial Natriuretic Factor (ANF) is a vasodilator and decreases the absorption of Na+ ions from the nephric filtrate. Anti-Diuretic Hormone (ADH) is secreted from neurohypophysis which promotes the absorption of water in collecting duct and some part of DCT.
This angiotensin I is converted into angiotensin II (8 amino acids) in presence of enzyme Angiotensin Converting Enzyme (ACE), secreted from lungs.
The angiotensin II is a vasoconstrictor and stimulates adrenal cortex for secretion of hormone aldosterone, which promotes absorption of Na+ ions from nephric filtrate, resulatantly, blood pressure is increased.