Gastrointestinal physiology: effects of truncal vagotomy: 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.

Try it

Physiology · Gastrointestinal physiology: effects of truncal vagotomy

Sample item

After truncal vagotomy without a drainage procedure, a patient has early satiety and postprandial fullness, with retention of solid food, while liquids empty rapidly. Which explanation is correct?

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

The answer and the reasoning

D. Loss of vagal receptive relaxation and antral pump function, so liquids empty quickly and solids slowly

Vagal fibres mediate receptive relaxation of the proximal stomach and strong antral contractions that grind solids. Without them the fundus has increased tone, which expels liquids quickly, whereas poorly ground solids empty slowly. This is why a pyloroplasty is usually combined with vagotomy.

Option by option

  • A. Hypergastrinaemia raising pyloric tone and delaying both liquids and solids

    Hypergastrinaemia does not explain this differential effect on liquids and solids.

  • B. Loss of the enterogastric reflex, so both solids and liquids empty rapidly

    Solids do not empty rapidly after vagotomy, so this does not fit the picture.

  • C. Increased acid output delaying emptying of solids only

    Acid output falls after vagotomy and does not explain the pattern.

  • D. Loss of vagal receptive relaxation and antral pump function, so liquids empty quickly and solids slowly (correct)

    Correct. Impaired accommodation speeds liquids and impaired antral grinding delays solids.

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.

More Physiology questions

Questions about this Physiology question

What is the answer to this Physiology question?

The best answer is D, Loss of vagal receptive relaxation and antral pump function, so liquids empty quickly and solids slowly. Vagal fibres mediate receptive relaxation of the proximal stomach and strong antral contractions that grind solids.

Why is "Hypergastrinaemia raising pyloric tone and delaying both liquids and…" not the answer?

Hypergastrinaemia does not explain this differential effect on liquids and solids.

Why is "Loss of the enterogastric reflex, so both solids and liquids empty ra…" not the answer?

Solids do not empty rapidly after vagotomy, so this does not fit the picture.

Why is "Increased acid output delaying emptying of solids only" not the answer?

Acid output falls after vagotomy and does not explain the pattern.

What concept does this question test?

It tests Gastrointestinal physiology: effects of truncal vagotomy in Physiology. Without them the fundus has increased tone, which expels liquids quickly, whereas poorly ground solids empty slowly. This is why a pyloroplasty is usually combined with vagotomy.

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 physiology: effects of truncal vagotomy?

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.