Which one of the following statements is correct with respect to kidney function regulation?
- When someone drinks a lot of water, ADH release is suppressed.
- Exposure to cold temperature stimulates ADH release.
- An increase in glomerular blood flow stimulates formation of angiotensin II.
- During summer when body loses a lot of water by evaporation, the release of ADH is suppressed.
Answer
(1) When someone drinks a lot of water, ADH release is suppressed.
Solution
As per NCERT, an excessive loss of fluid from the body activates osmoreceptors, which stimulate the hypothalamus to release ADH (vasopressin); ADH increases water reabsorption from the latter parts of the tubule.
⇒ An increase in body fluid volume switches off the osmoreceptors and suppresses ADH release. So drinking a lot of water suppresses ADH (option 1 correct), and water loss in summer increases ADH (option 4 wrong).
⇒ Cold exposure does not stimulate ADH; urine output rises in cold (option 2 wrong).
⇒ A fall in glomerular blood flow activates the JG cells to release renin, which leads to angiotensin II; an increase does not (option 3 wrong).
Answer: (1)