Which of the following is the main activating factor of aldosterone secretion during periods of dehydration?
Which of the following is the main activating factor of aldosterone secretion during periods of dehydration?
The correct option is C Renin
When renal blood flow is reduced, juxtaglomerular cells in the kidneys convert the precursor, in the blood, into renin and secrete it directly into the circulation. Plasma renin then converts angiotensinogen, released by the liver, into angiotensin I. Angiotensin I is then, converted to angiotensin II by the angiotensin-converting enzyme (ACE) found in the lungs. Angiotensin II also stimulates the secretion of the hormone aldosterone from the adrenal cortex. Aldosterone causes the renal tubules to increase the reabsorption of sodium and water into the blood, while at the same time causing the excretion of potassium (to maintain electrolyte balance). This increases the volume of extracellular fluid in the body, which also increases blood pressure.
Renin
When renal blood flow is reduced, juxtaglomerular cells in the kidneys convert the precursor, in the blood, into renin and secrete it directly into the circulation. Plasma renin then converts angiotensinogen, released by the liver, into angiotensin I. Angiotensin I is then, converted to angiotensin II by the angiotensin-converting enzyme (ACE) found in the lungs. Angiotensin II also stimulates the secretion of the hormone aldosterone from the adrenal cortex. Aldosterone causes the renal tubules to increase the reabsorption of sodium and water into the blood, while at the same time causing the excretion of potassium (to maintain electrolyte balance). This increases the volume of extracellular fluid in the body, which also increases blood pressure.
