Question

Name the principal mineralocorticoid secreted by the adrenal cortex. What stimulates its secretion? Give its any two functions. What is the disorder caused due to excessive secretion of this hormone?

Answer 1

Aldosterone is principle mineralocorticoid secreted by the adrenal cortex. Serum potassium concentrations are the most potent stimulator of aldosterone secretion. A fall in glomerular blood flow/glomerular blood pressure/GFR can activate the JG cells to release renin which converts angiotensinogen in blood to angiotensin I and further to angiotensin II. Angiotensin II activates the adrenal cortex to release Aldosterone.

Following are functions of Aldosterone:-

1. Acts mainly at the renal tubules and stimulates the reabsorption of Na+ and water.
2. Excretion of K+ and phosphate ions.
   

Hyperaldosteronism is a disorder characterized by excessive secretion of aldosterone, which causes increases in sodium reabsorption and loss of potassium and hydrogen ions.