GI Developmental Defects

Question 1

Congenital omphalocoele

Answer 1

failure of midgut loops to withdraw from umbilical cord;

Question 2

Non-Rotation (anomalies of rotation)

Answer 2

results in small bowel to right and large bowel to left; usually asymptomatic unless there is volvulus (twisting)

Question 3

Reversed rotation (anomalies of rotation)

Answer 3

transverse colon lies posterior to SMA; may result in obstruction of colon by artery; Nutcracker syndrome

Question 4

Subhepatic caecum (anomalies of rotation)

Answer 4

may adhere to liver and not descend into R. iliac fossa; asymptomatic but may create problems with dx of appendicitis

Question 5

Midgut volvulus (anomalies of rotation)

Answer 5

may be constricted & result in decreased blood supply to gut

Question 6

Ileal (Meckel diverticulum)

Answer 6

Rule of 2’s; Yolk stalk anomalies; occurs from persistence of proximal part of omphaloenteric duct; may be connected to umbilicus by fibrous cord or fistula

Question 7

Duodenal obstructions

Answer 7

Bowel stenosis or atresia; Distal to duodenal papilla results in vomitus typically contains bile

Question 8

Hirsprung or congentical megacolon

Answer 8

absence of parasymp ganglia in a segment of descending colon; part of colon proximal to faulty segment enlarges due to back up; failure of neural crest cells to migrate