What do anti-diuretics do?

What do anti-diuretics do?

• A. Stimulate water retention in the kidneys
• B. Promote water excretion
• C. Decrease electrolyte reabsorption
• D. Increase urine production

Answer: (A)

Anti-diuretics reduce urine output by increasing the kidney’s reabsorption of water. When the body needs to conserve water, the hormone vasopressin (antidiuretic hormone) is released and acts on the collecting ducts of the nephron, triggering the insertion of aquaporin-2 water channels. With more channels, water moves from the filtrate back into the bloodstream, producing less urine and a more concentrated urine. This is why anti-diuretics promote water retention rather than excretion. They don’t primarily alter electrolyte reabsorption, and they don’t increase urine production.

Anti-diuretics reduce urine output by increasing the kidney’s reabsorption of water. When the body needs to conserve water, the hormone vasopressin (antidiuretic hormone) is released and acts on the collecting ducts of the nephron, triggering the insertion of aquaporin-2 water channels. With more channels, water moves from the filtrate back into the bloodstream, producing less urine and a more concentrated urine. This is why anti-diuretics promote water retention rather than excretion. They don’t primarily alter electrolyte reabsorption, and they don’t increase urine production.