GI Diseases

Question 1

Achlasia

Answer 1

Affects the esophagus. Lower esophageal sphincter fails to relax, or literally just has a higher tension than it should be, so food bolus is not allowed to progress into the stomach. In addition to this, there is NO peristaltic activity present in the esphophagus…loss of upper esophageal sphincter with esophageal distention. Result: dilated esophagus. Patients present with difficulty swallowing and regurg of the food.

Question 2

VIPomas

Answer 2

1:10000000 exceptionally rare neuroendocrine tumor located in the pancreas. Leads to excessive, unregulated vasoactive intestine peptide secretion. results in watery diarrhea that persists with fasting, stool volume exceeding 3k mL/day, and hypokalemia and dehydration.

Question 3

Omphalocele

Answer 3

cele = seal = what happened to the gut tube. It is still sealed away. Associated with other SERIOUS issues. Reason of occurrence is that intestines do not retract from vitelline duct before birth.

Question 4

Tracheoesophageal fistula (TEF)

Answer 4

Note that respiratory system is still derived from the gut tube…foregut. Remember that the lung buds project off the foregut and give rise to the respiratory system. In this particular issue, the distal part of the esophagus is still attached to the lungs. The proximal part has a dead end (Atresia occurs at this point). EXPECT POLYHYDRAMNIOS!!!!! Reason: fetus swallows amnionic fluid, but it does not progress through the digestive system. You can expect vomiting because of this. Gastric contents may pass through the fistula and into the respiratory tract as well. You can expect to find fluid in the lungs because of this.

Question 5

Annular pancreas

Answer 5

Ring of pancreatic tissue around the duodenum. occurs when ventral and dorsal buds of pancreas do not wrap around and completely migrate during gut rotation. Expect obstruction of duodenum in this area.

Question 6

Duodenal atresia

Answer 6

Duodenum is stenotic. Remember that it formed as a solid structure (as in, there is no lumen!!!) and then catalyzes (and lumen is formed). If catalysis does not occur, this is the end result, as there is no lumen. Double bubble = gas in the stomach and gas in the proximal side of where the atresia occurred in duodenum. Neonate would have distension and associated vomiting

Question 7

Gastroschisis

Answer 7

Intestines are not covered by membranes of vitellin duct…exposed to amnionic fluid…when the intestines leave through umbillical cord. Intestines are exposed to amnionic fluid. Caused by improper VENTRAL body folding in development. Note: endoderm is on VENTRAL SIDE

Question 8

Meckel’s ileal diverticulum

Answer 8

Vitelline duct connects midgut to the yolk sac. It is supposed to digress and degenerate. Sometimes it does not. Multiple variations. This occurs in the ilium.

Question 9

Imperforate anus

Answer 9

No A-hole. Failure of anal membrane to degenerate.

Question 10

Hirschprung’s disease

congenital megacolon

Answer 10

Aganglionosis. Faulty neural crest migration to the colon. Usually occurs in the distal part of the colon (desending). Result is a distended sigma colon proximal to the aganglionosis. Expect distended belly due to missing nervous innervation.