Antidiuretic hormone controls the water content of the blood by
- A. increasing the rate of glomerular filtration
- B. making the walls of the distal tubule and collecting duct more permeable to water
- C. actively pumping water out of the tubule
- D. reducing the reabsorption of sodium ions
Explanation
ADH from the posterior pituitary inserts water channels into the tubule walls, so more water is reabsorbed by osmosis into the salty medulla and a small volume of concentrated urine is produced. It is released when osmoreceptors in the hypothalamus detect that the blood is too concentrated, a textbook negative feedback loop. Alcohol suppresses ADH, which is why it causes dehydration.
Related questions
Ultrafiltration in the glomerulus is driven by
Which of the following is normally absent from glomerular filtrate?
All the glucose in the filtrate is normally reabsorbed in the
A desert mammal can produce very concentrated urine because it has
A patient passes very large volumes of dilute urine but the urine contains no glucose. The most likely condition is