Gastrointestinal: paralytic ileus: 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: paralytic ileus

Sample item

On the second day after major abdominal surgery, a patient has abdominal distension, absent bowel sounds and no flatus. Which physiological mechanism contributes to this paralytic ileus?

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

The answer and the reasoning

A. Reflex sympathetic inhibition of enteric neurons and smooth muscle

Surgical handling and pain increase sympathetic outflow through spinal reflexes, which inhibits the enteric neurons and gut smooth muscle, and opioids add to the effect. Peristalsis stops and gas and fluid accumulate in the bowel.

Option by option

  • A. Reflex sympathetic inhibition of enteric neurons and smooth muscle (correct)

    Correct. Increased sympathetic tone inhibits motility.

  • B. Increased gastrin release

    Gastrin affects acid secretion and has only a minor effect on motility.

  • C. Stimulation of the migrating motor complex by motilin

    Motilin stimulates the migrating motor complex in the fasting state and promotes motility.

  • D. Excess parasympathetic stimulation of the gut

    Parasympathetic stimulation increases, rather than inhibits, gut motility.

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 A, Reflex sympathetic inhibition of enteric neurons and smooth muscle. Surgical handling and pain increase sympathetic outflow through spinal reflexes, which inhibits the enteric neurons and gut smooth muscle, and opioids add to the effect.

Why is "Increased gastrin release" not the answer?

Gastrin affects acid secretion and has only a minor effect on motility.

Why is "Stimulation of the migrating motor complex by motilin" not the answer?

Motilin stimulates the migrating motor complex in the fasting state and promotes motility.

Why is "Excess parasympathetic stimulation of the gut" not the answer?

Parasympathetic stimulation increases, rather than inhibits, gut motility.

What concept does this question test?

It tests Gastrointestinal: paralytic ileus in Physiology. Peristalsis stops and gas and fluid accumulate in the bowel.

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: paralytic ileus?

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.