Embryology: intestinal atresia: practice question

A Anatomy 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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Anatomy · Embryology: intestinal atresia

Sample item

A newborn has bilious vomiting. Laparotomy shows a blind-ending proximal ileum and a V-shaped mesenteric defect, with no features of Down syndrome. Which mechanism most likely caused the atresia?

AIntrauterine mesenteric vascular accidentBFailure of neural crest migrationCPersistence of the vitelline ductDFailed recanalisation of the solid stage

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

The answer and the reasoning

A. Intrauterine mesenteric vascular accident

Jejunoileal atresias are thought to result from an intrauterine interruption of the mesenteric blood supply, such as volvulus or intussusception, leading to infarction and resorption of a bowel segment. Duodenal atresia is the one that results from failed recanalisation.

Option by option

A. Intrauterine mesenteric vascular accident (correct)
Correct. Vascular disruption explains atresia with a mesenteric defect in the jejunum or ileum.
B. Failure of neural crest migration
Failure of neural crest migration causes aganglionosis (Hirschsprung disease), not a blind-ending bowel.
C. Persistence of the vitelline duct
A persistent vitelline duct causes Meckel diverticulum or a fistula at the umbilicus.
D. Failed recanalisation of the solid stage
Failed recanalisation causes duodenal atresia and is associated with Down syndrome.

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.

Questions about this Anatomy question

What is the answer to this Anatomy question?

The best answer is A, Intrauterine mesenteric vascular accident. Jejunoileal atresias are thought to result from an intrauterine interruption of the mesenteric blood supply, such as volvulus or intussusception, leading to infarction and resorption of a bowel segment.

Why is "Failure of neural crest migration" not the answer?

Failure of neural crest migration causes aganglionosis (Hirschsprung disease), not a blind-ending bowel.

Why is "Persistence of the vitelline duct" not the answer?

A persistent vitelline duct causes Meckel diverticulum or a fistula at the umbilicus.

Why is "Failed recanalisation of the solid stage" not the answer?

Failed recanalisation causes duodenal atresia and is associated with Down syndrome.

What concept does this question test?

It tests Embryology: intestinal atresia in Anatomy. Duodenal atresia is the one that results from failed recanalisation.

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 Embryology: intestinal atresia?

Learn every nerve by its route, its muscles and what a lesion looks like at the bedside. That one habit answers a large share of questions. Then use the flashcards and the other Anatomy 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.