This question-specific review guide is tied to the answer reasoning for a PracticeTestVault item. Use it after you answer the question so the review stays focused on what the prompt actually tested.
What this question is testing
Objective: Physiology
Prompt focus: A patient develops diabetes insipidus after head trauma. The kidneys produce large volumes of dilute urine because of a deficiency or reduced action of which hormone?
Why the correct answer works
Antidiuretic hormone from the pituitary
Lack of antidiuretic hormone prevents water reabsorption, causing dilute high-volume urine.
Why the tempting wrong answer fails
Aldosterone regulates sodium and potassium, not free water reabsorption in diabetes insipidus.
Plain-language takeaway
Antidiuretic hormone promotes water reabsorption in the collecting ducts by inserting aquaporin channels. A deficiency of antidiuretic hormone, as in central diabetes insipidus, causes the kidneys to excrete large volumes of dilute urine.
Simple analogy
Think of physiology like following a short checklist: identify the clue, confirm the rule, and then make the move that fits this exact scenario.
How to review it before a retake
- Underline the command word and name what the question is asking before rereading the choices.
- Compare the correct answer against the closest distractor and write the exact detail that separates them.
- Retest this objective with a fresh question without looking at the rationale first.