Gastrointestinal: serotonin and chemotherapy-induced vomiting: 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: serotonin and chemotherapy-induced vomiting

Sample item

A patient receiving cisplatin develops severe vomiting within a few hours, which is largely prevented by ondansetron. Which cells release the mediator that triggers the vagal afferents?

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

The answer and the reasoning

B. Enterochromaffin cells of the small bowel, releasing serotonin

Chemotherapy damages the mucosa and causes enterochromaffin cells to release serotonin. It stimulates 5-HT3 receptors on vagal afferents that project to the vomiting centre and the area postrema, which is why 5-HT3 antagonists are effective against acute emesis.

Option by option

  • A. G cells, releasing gastrin

    Gastrin from G cells regulates acid secretion, not emesis.

  • B. Enterochromaffin cells of the small bowel, releasing serotonin (correct)

    Correct. Serotonin from enterochromaffin cells activates vagal 5-HT3 receptors.

  • C. Enterochromaffin-like cells of the gastric body, releasing histamine

    Histamine from gastric ECL cells stimulates acid secretion and is not the trigger of cisplatin vomiting.

  • D. I cells, releasing cholecystokinin

    Cholecystokinin from I cells regulates the gallbladder and pancreas, not chemotherapy emesis.

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, Enterochromaffin cells of the small bowel, releasing serotonin. Chemotherapy damages the mucosa and causes enterochromaffin cells to release serotonin.

Why is "G cells, releasing gastrin" not the answer?

Gastrin from G cells regulates acid secretion, not emesis.

Why is "Enterochromaffin-like cells of the gastric body, releasing histamine" not the answer?

Histamine from gastric ECL cells stimulates acid secretion and is not the trigger of cisplatin vomiting.

Why is "I cells, releasing cholecystokinin" not the answer?

Cholecystokinin from I cells regulates the gallbladder and pancreas, not chemotherapy emesis.

What concept does this question test?

It tests Gastrointestinal: serotonin and chemotherapy-induced vomiting in Physiology. It stimulates 5-HT3 receptors on vagal afferents that project to the vomiting centre and the area postrema, which is why 5-HT3 antagonists are effective against acute emesis.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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: serotonin and chemotherapy-induced vomiting?

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.