B49 Developmental anomalies of the GI tract Flashcards
Omphalocele
Persistent herniation of the intestine into the umbilical cord.
Is covered by the peritoneum and the amnionic membrane of the umbilical cord exteriorly.
exents out of the middle of the abdomen in a bubble.
Gastroschisis
Incomplete closure of the anterior or lateral abdominal wall.
Abdominal contents, intestines will protrude out of it. They are NOT covered by the parietal peritoneum.
List the developmental abdormalities of the GI
Atresia Stenosis Duplication Meckel diverticulum Omphalocerle Gastyroschisis Malrotation Cystic fibrosis, meconium ileus.
What is congenital stenosis and where does it often occur?
Thickening of the wall and narrowed lumen.
Frequently is a Pyloric Stenosis.
Hypertrophic pyloric smooth muscle which is NOT present at birth, but repidly develops and presents at about 2 weeks after birth.
Presents as projectile vomiting which is non-bilious, with no bile.
Is also felt as a palpable ‘olive-like’ mass on the stomach, and sometimes the peristalsis of the stomach is visible on the abdomen.
Atresia
Complete blockage, failure to canalize the intestinal lumen.
Occurs most often in the duodenum
Stenosis
Most often at the pylorus.
Duplication
usually cystic structures or tubular structures that may or may not communicate with the intestine as a diverticulum.
Meckel Diverticulum.
Origin and possible complications
Remnant of the Vitelline duct, aka Omphalomesenteric duct.
The duct extending from the intestine into the yolk sac.
Found on the ileum near the junction with the cecum.
Complications:
- Usually asymptomatic
- Can cause obstruction and intussusception
- Bloody stool
- Can become inflamed and present as acute appendicitis.
- Can harbor excessive bacteria, can consume and deplete vitamin B12 causing pernicious anemia
- Common site for ectoptic tissue rests, Gastric mucosa, Pancreatic tissue, Duodenal tissue with Brunners mucous glands.
Meckel Diverticulum rule of 2’s
occurs in 2% of population
usually 2 inches in length
2 common ectopic tissues, gastric and pancreatic
presents at 2 years of age
2:1 male:female ratio
Cystic fibrosis often presents with what bowel disorder?
Meconium Ileus
What is Hirschsprung disease?
Congenital megacolon.
Failure of neural crest cell migration and lack agenesis of the ENS.
Congenital paralysis of the intestines, functional obstruction,
distention
enterocolitis
perforation
What are the vascular disorders of the GI tract?
Ischemic bowel disease
Angiodysplasia
Hemorroids.
