GI Development

Question 1

Anganglionosis

Answer 1

New ganglion cells in entering nervous system - causing Hirschsprung’s disease

Question 2

Ventral mesogastrium

Answer 2

Becomes lesser omentum and falciform ligament
Only in foregut

Question 3

Dorsal mesogastrium

Answer 3

Becomes greater momentum

Question 4

Trachea & esopahgus

Answer 4

Split at week 4
Fistula if they stay connected

Question 5

Achalasia cardia

Answer 5

LES doesn’t relax
Dysphagia

Question 6

Stomach rotation

Answer 6

Turns 90 degrees clockwise
Forms omental bursa and greater omentum

Question 7

Pyloric stenosis

Answer 7

Pyloric sphincter muscle hypertrophy
Projective vomiting
Olive mass above umbilicus

Question 8

Duodenal atresia

Answer 8

Defect in canalization of bowel - obstruction

Question 9

Liver

Answer 9

Arises from ventral mesentery/mesogastrium

Question 10

Spleen

Answer 10

Arises from dorsal mesentery/mesogastrium

Question 11

Pancreas

Answer 11

Arises from ventral pancreatic bud and dorsal pancreatic bud

Question 12

Annular pancreas

Answer 12

Abnormal ring of pancreatic tissue encircles duodenum, can constrict duodenum

Question 13

Physiological herniation

Answer 13

Occurs during weeks 6-10, thru umbilical ring

Question 14

Persistence of mesentery

Answer 14

Can cause volvulus, abnormal gut movement

Question 15

Gastroschisis

Answer 15

Viscera not covered in amnion
Incomplete closure of abdominal wall

Question 16

Omphalocele

Answer 16

Physiological herniation doesn’t reverse
Contained within amniotic sac

Question 17

Meckel’s diverticulum

Answer 17

Vitelline duct persists
Can contain GI tissue
Can be asymptomatic or cause problems later

Question 18

Vitelline duct abnromalities

Answer 18

Umbilical sinus
Vitelline cyst
Umbilicoileal fistula

Question 19

Cloaca

Answer 19

Split by urorectal septum
Cavity at end of GI tract in embryos
Intestinal, urinary, and reproductive tracts open Terminal part of the hindgut

Question 20

Imperforate anus

Answer 20

No anal opening

Question 21

Congenital megacolon (Hirschsprung disease)

Answer 21

Absence of autonomic ganglia
Failure or neural crest cells to migrate into wall of colon

Question 22

Axis of rotation for midgut

Answer 22

SMA

Question 23

Vitelline duct

Answer 23

Connects yolk sac to developing gut

Question 24

Vitelline fistula

Answer 24

Persistence of developing gut, open tract between ileum and umbilicus, persistent discharge from the umbilical stump