Embryology of the Gastrointestinal System

Question 1

In addition to regionalization, development of the gut tube also involves what?

Answer 1

continuous elongation, herniation past the body wall, oration and folding for efficient packing

Question 2

What are reflections of parietal peritoneum onto the gut tube called?

Answer 2

mesenteries

Question 3

esophagus, stomach, 1/2 duodenum, liver, gall bladder, pancreas, and spleen make up the foregut, midgut, or hindgut?

Answer 3

foregut

Question 4

1/2 duodenum, jejunum, ileum, cecum, appendix, ascending colon, 2/3 transverse colon make up the foregut, midgut, or hindgut?

Answer 4

midgut

Question 5

1/3 transverse colon, descending colon, sigmoid colon, rectum, and upper part of the anal canal make up the foregut, midgut, or hindgut?

Answer 5

hindgut

Question 6

Foregut derivatives are supplied by branches of what artery?

Answer 6

celiac artery

Question 7

Midgut derivatives are supplied by branches of what artery?

Answer 7

superior mesenteric artery

Question 8

HIndgut derivatives are supplied by branches of what artery?

Answer 8

inferior mesenteric artery

Question 9

List the preganglionic cell bodies of the foregut, midgut, and hindgut

Answer 9

foregut: T5-T9
midgut: T9-T12
hindgut: T12-L2

Question 10

Esophageal stenosis or atresia is caused by what?

Answer 10

narrowed or occluded esophagus due to incomplete recanalizaiton, usually found in the lower 1/3

Question 11

True or False?

In stomach development, the ventral surface grows faster than the dorsal surface

Answer 11

false; dorsal surface grows faster than ventral surface

Question 12

The dorsal left side of the tube (developing stomach) grows rapidly, expands and there is a simultaneous clockwise rotation of how many degrees?

Answer 12

90

Question 13

After rotation of the stomach, the left side lies ___ and the right side lies ___

Answer 13

anterior; posterior

note: causes the left vagus nervier to become anterior vagal trunk and the right vagus nerve to become the posterior vagal trunk

Question 14

Hypertrophic pyloric stenosis usually presents how soon after birth?

Answer 14

2-3 weeks, accompanied by projectile vomiting, small palpable mass at right costal margin

Question 15

In regards to liver development, the endoderm of the foregut develops the hepatic ___

Answer 15

diverticulum

Question 16

the liver grows into the ___ of the septum transversum

Answer 16

mesoderm

Question 17

the liver divides ventral mesentery into what?

Answer 17

falciform ligament and the lesser omentum

Question 18

Action of inhibiting factors that block liver tissue differentiation are in turn blocked in the area of the liver by ___ which is secreted by cardiac mesoderm and BMPs secreted by the septum transversum

Answer 18

FGF2

Question 19

The cyclic diverticulum forms what two things

Answer 19

gall bladder and cystic duct

Question 20

the bile duct forms between what two developing things

Answer 20

liver and duodenum

Question 21

What is extrahepatic biliary atresia?

Answer 21

incomplete canalization of the bile duct

symptoms: jaundice, dark urine, pale stool

Question 22

This organ develops from buds in both ventral and dorsal mesenteries

Answer 22

pancreas

Question 23

What is an annular pancreas?

Answer 23

occurs when ventral and dorsal pancreatic buds form a ring around the deuodenum

Question 24

Gut atresias and stenoses caudal to the duodenum are probably due to what?

Answer 24

vascular compromise

Question 25

Gut atresias and stenoses in the upper duodenum are probably due to what?

Answer 25

failure to recanalize

Question 26

When does rapid growth of the midgut start?

Answer 26

about 6 weeks

Question 27

Rapid growth of the midgut produces a physiologic herniation - gut loops into the umbilical cord- as this happens, the loop rotates how many degrees and which direction around the superior mesenteric a.

Answer 27

90 degrees counterclockwise

Question 28

At the 10th week, the herniated loops of the midgut return to the abdominal cavity and rotate an addition how many degrees?

Answer 28

180

Question 29

What is a volvulus?

Answer 29

abnormal twisting god the intestine causing obstruction which compromises blood flow

Question 30

What is it called when abdominal contents remain herniated into the umbilical cord?

Answer 30

omphalocele

Question 31

What is it called when the abdominal contents of the ventral abdominal wall have herniated into the amniotic cavity?

Answer 31

gastroschisis

note: organs on outside of body

Question 32

What is an ileal (Meckel’s) diverticulum or fistula?

Answer 32

out-pouching of ileum

note: patient presents with fecal matter leaking from umbilicus

Question 33

This disease is a motor disorder of the colon that causes functional intestinal obstruction. The pathogenesis of the disease is failure of migration of the neural crest cells that form the colonic ganglion cells

Answer 33

Hirschsprung’s Disease

note: patients have no parasympathetic innervation in colon - colon can’t relax

Question 34

Define primary retroperitoneal

Answer 34

any organ that developed outside the abdominal cavity (kidney) which never had a mesentery to begin with

Question 35

Define secondary retroperitoneal

Answer 35

portions of the gut tube whose mesentery has fused with the lining peritoneum

Question 36

Define intraperitoneal

Answer 36

organs with a mesentery

Question 37

In regards to anorectal malformations, the rectum may end in a blind pouch that does not connect with the ___ ____ or it may have openings to the urethra, bladder, or vagina

Answer 37

external environment

Question 38

Imperforate anus symptoms are…

Answer 38

no passage of stool in first 24-48 hours

passage of feces through penis/vagina/scrotum

Question 39

Anal agenesis occurs when the anal canal ends as blind sac ___ pelvic diaphragm

Answer 39

below

Question 40

Anorectal agenesis occurs when the rectum ends as blind pouch ___ the pelvic diaphragm

Answer 40

above