Control of Water Levels

• The pituitary gland constantly releases ADH depending on how much water the kidneys should reabsorb from the filtrate.
• If the water content in the blood is too high: The pituitary gland releases less ADH so the tubules become less permeable to water, therefore less water is reabsorbed.
• If the water content in the blood is too low: The pituitary gland releases more ADH so the tubules become more permeable to water, therefore more water is reabsorbed.