Question

Explain the pathway that stimulates the release of aldosterone. (chapter on urinary system)

Answer 1

• By the RAS system they regulate the aldosterone release
• Intially with the stimulation of JG apparatus in the kidney by decreased renal blood flow cause the release of renin from the JG cells.
• The released renin is utilised for converting angiotensinogen produced by the liver to angiotensin I
• The surface of pulmonary and renal endothelium contains angiotensin converting enzyme which positively helps in conversion of angiotensin I to angiotensin II
• Angiotensin II causes adrenal cortex of adrenal gland to secrete aldosterone
• The produced aldosterone acts by regulating potassium secretion and sodium reabsorption by acting primarily on principle cells of renal.tubules
• It stimulates sodium potassium ATPase pump present on the basal lateral side, thus increasing permeability of sodium ions
• Thus it increases sodium and water reabsorption and also increases potassium excretion
• That can cause water to retain in the body thereby increasing blood volume and pressure.