Development of GI tract

Question 1

What gives rise to epithelial lining and glands of digestive system?

Answer 1

endoderm

Question 2

what surrounds the epithelial tube of the gut?

Answer 2

splanchnic mesoderm

Question 3

What does splanchnic mesoderm form?

Answer 3

the muscle and connective tissue layers, blood vessels and peritoneal components like mesothelium and connective tissue

Question 4

where does the primitive gut tube come from?

Answer 4

from folding and a portion of the endoderm lined yolk sac

Question 5

what is the vitelline duct?

Answer 5

communication between the midgut and the yolk sac, it eventually becomes the core of the umbilical cord

Question 6

What do the oropharyngeal membrane and cloacal membrane do?

Answer 6

they close the ends of the primordial gut

Question 7

what suspends the abdominal viscera in the body cavity?

Answer 7

Bilayered dorsal mesentery

Question 8

what connects the stomach and the liver to the ventral body wall?

Answer 8

Ventral mesentery

Question 9

What is the Foregut?

Answer 9

region of primitive gi tract with a pharyngeal and proper region

Question 10

what is the midgut?

Answer 10

region of primitive gut that is inferior to bile duct/pancreatic duct to the junction of the right 2/3ds and left 1/3rd of the transverse colon

Question 11

What is the hindgut?

Answer 11

left third of transverse colon to cloacal membrane

Question 12

What are derivatives of the foregut?

Answer 12

Lower respiratory tract, esophagus to duodenum (proximal to bile duct) Liver and biliary apparatus, gallbladder and bile duct.

Question 13

What is the artery of the foregut?

Answer 13

celiac trunk

Question 14

Derivatives of the midgut?

Answer 14

inferior duodenum to right 2/3rds of transverse colon

Question 15

what is midgut artery?

Answer 15

Superior mesenteric artery

Question 16

Hindgut derivatives?

Answer 16

left 1/3 of transverse colon, to rectum upper anal canal

Question 17

Artery of Hindgut?

Answer 17

Inferior mesenteric artery

Question 18

by how much does the stomach rotate initially?

Answer 18

90 degrees

Question 19

What happens when the circular layer of muscularis externa hypertophies?

Answer 19

it obstructs passage of food, stomach becomes distended, this is called Pyloric stenosis

Question 20

What does the rotation of the stomach do to the duodenum?

Answer 20

Bends it into a C shape and displaces to the LEFT. It also becomes 2ndarily retroperitoneal

Question 21

What forms Hepatic diverticulum?

Answer 21

Endodermal thickening over ventral duodenum

Question 22

What does the hepatic diverticulum grow into?

Answer 22

The septum transversum

Question 23

what parts of the liver and gallbladder does the endoderm form?

Answer 23

Hepatocytes and biliary apparatus

Question 24

What does support stroma come from in the liver and gallbladder?

Answer 24

from septum transversu and splanchnic mesoderm

Question 25

What two parts do the hepatid diverticulum divide into?

Answer 25

Large cranial portion that will give rise to primordium of the liver, and a small ventral outgrowth of the bile duct that gives rise to the gallbladder and the cystic duct

Question 26

Where do dorsal and ventral bud of pancreas come from?

Answer 26

from endoderm of the duodenum

Question 27

what happens with rotation of gut tube with the forming pancreas>

Answer 27

it moves the ventral bud dorsally and LEFT the ventral and dorsal buds then fuse

Question 28

in what direction does rotation move the common bile duct?

Answer 28

left

Question 29

Which duct of the pancreas usually regresses

Answer 29

the dorsal bud duct

Question 30

What marks the end of foregut and beginning of midgut in an adult?

Answer 30

the junction between the main pancreatic duct and the accessory duct

Question 31

What is the umbilical ring?

Answer 31

junction of embryonic ectoderm and the amnion

Question 32

What passes through the umbilical ring?

Answer 32

connecting stalk/umbilical vessels, yolk stalk, canal connecting intra and extraembryonic cavities, Wharton’s jelly, yolk sac

Question 33

What is physiological herniation

Answer 33

intestines are outside during week 6 because of midgut elongation and size of liver

Question 34

Endoderm of hindgut forms lef 1/3 of transverse colon, descending colon,sigmoid, rectum, upper anal canal as well as?

Answer 34

epithelial lining of bladder and urethra