Exam Tips: Water Regulation

Always name the source of ADH: Many students write "the kidneys release ADH." This is wrong — ADH is produced in the hypothalamus and released by the pituitary gland. The kidneys are the target organ, not the source.

Use "permeability" precisely: ADH increases the permeability of the collecting duct to water. Avoid saying ADH "opens channels" or "makes the kidney work harder" — use the specific word permeability.

Negative feedback direction: Always state what the original change was AND how the response reverses it. E.g., "Blood water concentration falls, ADH is released, water is reabsorbed, blood water concentration rises back to normal."

Dialysis vs transplant questions: Give a balanced comparison with specific named advantages AND disadvantages for each. Vague answers (e.g., "dialysis is worse") score zero. Use the words: lifestyle, rejection, immunosuppressants, donor shortage.

Osmosis link: When explaining water movement in the kidney, say water moves by osmosis along a concentration gradient. This earns an extra mark in extended response questions.