Embryology: abdominal wall defects: 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: abdominal wall defects

Sample item

A newborn has a midline defect at the umbilicus through which bowel loops protrude, covered by a thin transparent sac of amnion and peritoneum. What is the embryological basis?

AVascular disruption of the abdominal wall to the right of the umbilicusBFailure of the urachus to obliterateCPersistence of the vitelline ductDFailure of the physiologically herniated midgut loops to return to the abdomen by about 10 to 12 weeks

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

The answer and the reasoning

D. Failure of the physiologically herniated midgut loops to return to the abdomen by about 10 to 12 weeks

The midgut herniates into the umbilical cord at about week 6 and returns to the abdomen by weeks 10 to 12. If it does not return, the viscera lie in a sac of amnion and peritoneum at the umbilicus, which is an omphalocele. It is often linked with other anomalies.

Option by option

A. Vascular disruption of the abdominal wall to the right of the umbilicus
A paraumbilical defect with no sac is gastroschisis, from disruption of the wall, not this picture.
B. Failure of the urachus to obliterate
A patent urachus gives urine discharge from the umbilicus, not herniated bowel.
C. Persistence of the vitelline duct
A persistent vitelline duct gives Meckel diverticulum or an umbilical fistula, not a sac of bowel.
D. Failure of the physiologically herniated midgut loops to return to the abdomen by about 10 to 12 weeks (correct)
Correct. Failure of return of the physiological hernia gives a sac-covered omphalocele.

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 D, Failure of the physiologically herniated midgut loops to return to the abdomen by about 10 to 12 weeks. The midgut herniates into the umbilical cord at about week 6 and returns to the abdomen by weeks 10 to 12.

Why is "Vascular disruption of the abdominal wall to the right of the umbilic…" not the answer?

A paraumbilical defect with no sac is gastroschisis, from disruption of the wall, not this picture.

Why is "Failure of the urachus to obliterate" not the answer?

A patent urachus gives urine discharge from the umbilicus, not herniated bowel.

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

A persistent vitelline duct gives Meckel diverticulum or an umbilical fistula, not a sac of bowel.

What concept does this question test?

It tests Embryology: abdominal wall defects in Anatomy. If it does not return, the viscera lie in a sac of amnion and peritoneum at the umbilicus, which is an omphalocele. It is often linked with other anomalies.

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 Embryology: abdominal wall defects?

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.