Gastrointestinal hormones: practice question

A Physiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Physiology · Gastrointestinal hormones

Sample item

A woman on long-term high-dose proton pump inhibitor therapy has a raised fasting serum gastrin level, with no gastrinoma. What is the best explanation?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. Reduced gastric acid removes negative feedback on antral G cells

Antral acidity normally inhibits gastrin release, partly through somatostatin from D cells. When a proton pump inhibitor lowers gastric acid, this inhibition is lost and G cells release more gastrin, producing hypergastrinaemia.

Option by option

  • A. Increased somatostatin release from D cells

    Somatostatin release falls rather than rises when antral acid falls, which also contributes to higher gastrin.

  • B. Reduced gastric acid removes negative feedback on antral G cells (correct)

    Correct. Less acid means less feedback inhibition, so gastrin rises.

  • C. Increased secretin release from the duodenum

    Secretin release depends on duodenal acid and, if anything, would fall; it does not raise gastrin.

  • D. The drug directly stimulates G cells

    Proton pump inhibitors block the parietal cell H+/K+ ATPase and do not act directly on G cells.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Physiology question

What is the answer to this Physiology question?

The best answer is B, Reduced gastric acid removes negative feedback on antral G cells. Antral acidity normally inhibits gastrin release, partly through somatostatin from D cells.

Why is "Increased somatostatin release from D cells" not the answer?

Somatostatin release falls rather than rises when antral acid falls, which also contributes to higher gastrin.

Why is "Increased secretin release from the duodenum" not the answer?

Secretin release depends on duodenal acid and, if anything, would fall; it does not raise gastrin.

Why is "The drug directly stimulates G cells" not the answer?

Proton pump inhibitors block the parietal cell H+/K+ ATPase and do not act directly on G cells.

What concept does this question test?

It tests Gastrointestinal hormones in Physiology. When a proton pump inhibitor lowers gastric acid, this inhibition is lost and G cells release more gastrin, producing hypergastrinaemia.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Gastrointestinal hormones?

For each system, sketch the key graph (pressure–volume loop, oxygen dissociation curve, nephron handling) and explain it aloud. Then use the flashcards and the other Physiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.