A 7-year-old boy is brought to the emergency department by his parents due to complaints of abdominal pain and bloody stools. The pain is intermittent and located around the umbilical area. His past medical history is unremarkable. On physical examination, the abdomen is soft with mild tenderness near the umbilicus. An abdominal ultrasound is performed, revealing a small outpouching in the distal ileum. The pediatric surgeon suspects Meckel’s diverticulum and recommends further imaging to confirm the diagnosis.
Meckel’s diverticulum is a remnant of which embryological structure?
A. Stenson’s duct
B. Wolffian duct
C. Mullerian duct
D. Vitello-intestinal duct
The correct answer is: D. Vitello-intestinal duct.
Explanation:
Meckel’s diverticulum is the most common congenital anomaly of the gastrointestinal tract, resulting from the incomplete obliteration of the vitelline duct (also known as the omphalomesenteric duct or vitello-intestinal duct) during embryonic development. Here’s a detailed explanation of each option:
Vitello-intestinal Duct (D):
– The vitello-intestinal duct connects the yolk sac to the midgut lumen in the developing embryo.
– Normally, this duct obliterates between the 5th and 7th weeks of gestation. If it fails to obliterate completely, it can result in Meckel’s diverticulum.
– Meckel’s diverticulum is typically located in the ileum, about 2 feet from the ileocecal valve, and can present with symptoms such as bleeding, obstruction, or inflammation.
Other Options:
– Stenson’s duct (A): This is the duct of the parotid gland, which opens into the mouth near the upper second molar. It has no relation to Meckel’s diverticulum.
– Wolffian duct (B): Also known as the mesonephric duct, it develops into male reproductive structures such as the epididymis, vas deferens, and seminal vesicles. It is unrelated to the formation of Meckel’s diverticulum.
– Mullerian duct (C): Also known as the paramesonephric duct, it develops into female reproductive structures such as the fallopian tubes, uterus, and the upper portion of the vagina. It is not involved in the development of Meckel’s diverticulum.
In summary, Meckel’s diverticulum is a remnant of the vitello-intestinal duct, making D. Vitello-intestinal duct the correct answer.