Deck 15: Development of the Gastrointestinal Tract

Question 1

Endodermal contact with the notochord during early GI development is essential for the development of what organ?

A) Liver
B) Pancreas
C) Anorectal sphincter
D) Gallbladder

Answer 1

B

Question 2

With regard to cytodifferentiation of the GI glandular epithelium along the radial axis,what cell signaling interaction(s)mediate the proliferation,migration,and differentiation of cells within the glandular epithelium?

A) Ephrin ligands and EphB receptors
B) Wnt ligand and Frizzle receptors
C) Tgfß and their receptors (yes)
D) Shh and Ptch1 receptors
E) All the above

Answer 2

E

Question 3

Which of these organs remains retroperitoneal throughout its development?

A) Transverse colon
B) Pancreas
C) Kidney
D) Stomach
E) Sigmoid colon

Answer 3

C

Question 4

What forms the definitive anorectal canal?

A) It is completely derived from the distal hindgut.
B) Two thirds of the anorectal canal is derived from the hindgut, and one third is from the anal pit.
C) It is completely derived from the anal pit.
D) It is entirely derived from the cloacal membrane.
E) It is entirely derived from the urogenital sinus.

Question 5

What cells serve as the progenitors of hepatocytes?

A) Foregut endodermal cells
B) Mesodermal cells of septum transversum
C) Endothelial precursor cells
D) Cholangiocytes

Question 6

Based on hospital records,a 3-day-old newborn has not had a bowel movement.Upon re-examination,you notice the baby's abdomen appears bloated and the infant is beginning to run a fever.Soon after feeding,the baby also exhibits severe vomiting and can't keep anything down.As a physician,you request abdominal x-rays,and you find that the jejunum is drastically dilated,with the remainder of the lower small large intestines appearing smaller in diameter than expected.What is the likely cause?

A) An umbilical hernia
B) Pyloric atresia
C) Meckel's diverticulum
D) Hirschsprung's disease
E) An annular pancreas

Question 7

Based on animal studies,neural crest cells forming the parasympathetic ganglia of the descending colon,sigmoid colon,and rectum originate from which levels of the axis?

A) Only somite 1-7 axial levels
B) The adrenal gland axial levels
C) Only the sacral axial levels
D) Both vagal and sacral levels

Question 8

Clinical testing shows that a newborn has a bowel obstruction caused by a volvulus.Further assessment reveals that the infant's cecum and colon occupy the left abdominal side.Recognizing this is a congenital rotational anomaly,what patterns of gut rotation during GI development could have led to this situation?

A) The initial 90-degree counterclockwise rotation of the intestinal loop occurred, but subsequent rotational steps failed.
B) The initial 90-degree counterclockwise rotation of the intestinal loop occurred, which was followed subsequently by another 180-degree counterclockwise rotation.
C) Each limb of the intestinal loop rotated separately, with only the cranial intestinal limb rotating 90 degrees counterclockwise in the initial rotational step and only the caudal limb rotating 180 degrees counterclockwise during the second rotational step.
D) The initial 90-degree counterclockwise rotation of the intestinal loop occurred, but the subsequent 180-degree rotational step was in the clockwise direction.

Question 9

A 2-year-old male infant is crying because of abdominal pain.Recently,he also began producing bloody stools.Barium enema and x-ray imaging show a bowel obstruction and intestinal ulceration in the ileum about 2 feet proximal to the ileocecal junction.What is the likely diagnosis?

A) Meckel's diverticulum
B) Hirschsprung's disease
C) Omphalocele
D) Umbilical hernia

Question 10

What structure gives rise to the greater omentum?

A) Ventral mesogastrium
B) Dorsal mesogastrium
C) Transverse mesocolon
D) Septum transversum