Development of The Gut

1. Foregut: celiac artery

-esophagus, stomach, liver, gallbladder, pancreas, upper duodenum

2. Midgut: superior mesenteric artery

-lower duodenum, jejunum, ileum, cecum, appendix, ascending colon, proximal 2/3 transverse colon

3. Hindgut: inferior mesenteric artery

-distal 1/3 of transverse colon, descending colon, sigmoid colon, upper anal canal

4. Lower anal canal = surface ectoderm (think squamous cell carcinoma)



Congenital anomalies


1. Esophageal atresia – malformed tracheoesophageal septum

2. Hypertrophic pyloric stenosis – hypertrophy of muscularis externa; projectile vomiting and small, palpable mass at right costal margin

3. Extrahepatic biliary atresia – incomplete canalization > occlusion of biliary duct; jaundice, pale feces, dark urine

4. Annular pancreas – ventral and dorsal pancreatic buds form ring around duodenum; obstruction

5. Duodenal atresia – failed recanalization; polyhydramnios, bile-containing vomit, stomach distention

6. Omphalocoele – midgut loop fails to return to abd. cavity; light gray sac at base of umbilical cord

7. Meckel’s diverticulum – remnant of yolk sac b/t umbilicus and ileum; drainage of meconium from umbilicus

8. Hirschsprung’s – failure of neural crest cells to form myenteric plexus in sigmoid colon and rectum; loss of peristalsis, fecal retention, abd. distention

Tags: Omphalocele, Duodenal atresia, embryology

Category: Anatomy Notes