GI embryology

Question 1

T or F: the Faciform ligament is a adult remnant of the dorsal embryonic mesentery

Answer 1

False, it is a remnant of the ventral embryonic mesentery

Question 2

Would failure of differentiation of the individual organs derived from the embryonic foregut cause malformation of the gallbladder?

Answer 2

Yes

Question 3

T or F: Meckel’s diverticulitis affects the lower duodenum.

Answer 3

False it affects the lower ileum

Remember: the rule of 2’s (2 feet from ileocecal valve)

Question 4

A child is fed for the first time and immediately starts choking. What might be the issue?

Answer 4

Esophageal Atresia causes by a trachesophageal fistula

Question 5

A man has constipation from a neural crest defect in his small intestine, he would likely have a deficiency in what type of neuronal cells?

Answer 5

• Parasympatheic Postganglionic
• Must be postganglionic if it is neural crest associated because NC cells only give rise to structures of the PNS.

Note: these bodies would be located in a terminal ganglia

Question 6

T or F: a defect in the development of the dorsal embryonic mesentery would affect the ligamentum venosum.

Answer 6

False, Ligamentum Venosum is part of the ventral mesentery.

• Something like the greater omentum would more likely be affected.

Question 7

A 2-day old child is breastfed and 20 minutes later projectile vomits nonbiliary vomitis. What is likely the problem with the infant?

Answer 7

Pyloric Stenosis - happens before the bile duct so it results in vomit that has no bile

Question 8

A 2 inch fingerlike pouch stick out from someone’s ileum 2 feet proximal to the ileocecal junction. What embryonic structure failed to completely degenerate?

Answer 8

Vitelline Duct

Question 9

Why don’t babies born between 24th and 25th weeks typically survive?

Answer 9

They lack type II pneumocytes that are needed to secrete surfactant

Question 10

Development of what GI portion involves herniation of the gut tube into the umbilical stalk?

Answer 10

Midgut developement

Question 11

An aganglionic colon may result from a defect in which type of neural crest cells?

Answer 11

Postsynaptic parasympathetic neurons

Question 12

A stillborn infant has intestine protruding covered by a thin membrane. What is the diagnosis?

Answer 12

Omphalocele

Question 13

The site of the cleocal membrane is represented in the adult by…

Answer 13

Anal valves

Question 14

Would you expect elevated AFP to accompany omencephaly?

Answer 14

Yes, its a body wall defect

Question 15

A fetal defect is observed where viscera protrude into the amniotic cavity. What causes this condition.

Answer 15

Describes gastroischisis

• this is caused by incomplete closure of the lateral body folds.

Question 16

T or F: the pancreatic duct is derived from both dorsal and ventral pancreatic buds.

Answer 16

True

Question 17

What is caused by failure of the pericardioperitoneal folds to close?

Answer 17

Heriation of abdominal viscera into the diaphragm

• causes cyanosis because lung is compressed

Question 18

Projectile vomiting with presence of bile and double bubble on the ultrasound showing distention of stomach and upper duodenum indicate what?

Answer 18

Duodenal Atresia