embryo devel of GI Flashcards Preview

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Flashcards in embryo devel of GI Deck (55):
1

SOX2

specifies esophagus

2

PDX2

specifies doudenum

3

CDXC

small intestine

4

CDXA

large intestine

5

Two tissue layers required for embryological dev of GI

splanchnic mesoderm and endoderm

6

Endoderm

epithelial lining and glands

7

Splanchnic mesoderm

lamina propria, submucosa, muscularis layers, serosa/adventitia

8

the gut is suspended initially by a two layered peritoneum. what is it called

dorsal mesentery

9

foregut structures

esophagus
stomach, 1/2 duodenum,
liver, gall bladder, pancreas, spleen

10

midgut structures

1/2 duodenum
jejunum
ileum
cecum and appendix
ascending colon
2/3 transverse colon

11

hindgut

1/3 transverse colon
descending colon
sigmoid colon
rectum
upper part of anal canal

12

foregut sympathetic innervation

preganglionic, splanchnic, preaortic, and postgang nerves follow what arteries?

Pregang: T5-T9
splanch: Greater splanch n.
Preaor: celiac
postgang follow the celiac a.

13

midgut sympathetic innervation

preganglionic, splanchnic, preaortic, and postgang nerves follow what arteries?

pregang: T9-T12
splanchnic n. lesser splanchnic n
preaortic n. superior mesenteric
postgangs follow superior mesenteric a

14

hindgut

preganglionic, splanchnic, preaortic, and postgang nerves follow what arteries?

pregang: T12-L2
splanchnic n: least splanchnic n
preaortic gang: inferior mesenteric n.
postganglionic axons follow: inferior mesenteric a

15

foregut parasym

pregang neuron bodies, nerve, location of ganglia

brainstem,

vagus n.

organ walls

16

midgut parasym

pregang neuron bodies, nerve, location of ganglia

brainstem,

vagus n.

organ walls

17

hindgut

pregang neuron bodies, nerve, location of ganglia

S2-S4
pelvic splanchnic n
organ walls

18

median umbilical ligament is the remnant of the

urachus (the continuation of the allantois)

19

median umbilical ligament is the remnant of the

umbilical arteries

20

lateral umbilical ligament holds the

inferior epigastric a. and v.

21

Describe the basic mechanism of the laryngeotreacheal diverticulum's development in the lungs and the abnormalities that can occur

laryngeotracheal diverticium buds come off a tube of a primitive pharhynx ---> they develop into the lungs while the pharynx tube differentiates into the esophagus/pharhynx. the laryngotracheal tube is the initial bud: between it and the pharynx, a "tracheosophageal fold" splits the laryngeotracheal bud from the esophagus. that split is where things can go wrong.

22

fistulas vs atresia

fistula is an inappropriate connection between tubes
atresia is a tube that inappropriate ends in a blind pouch.

23

esophageal stenosis or atresia

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

24

barrets esophagus

acid reflux changes epithelia lining of the esophagus

stratified squamous to simple columnar with goblet cells

25

Zenker's diverticulum

esophageal diverticulum

26

the midgut of the primitive stomach grows into what structure

the vitelline duct

the DORSAL side of the stomach expands rapidly and twists 90 degrees

27

the abdominal stomach and esophagus are initially suspended by

ventral and dorsal mesentery

28

which side of the stomach expands rapidly, and the twists in what direction

in what direction do the right and left sides of the primitive stomach end up facing, and how does this effect the vagal trunks

stomach's dorsal side
twists 90 degrees clockwise

the stomach's LEFT side is now anterior, and the stomach's right side is now posterior


therefore, the left vagus becomes the anterior vagal trunk and the right vagus the posterior vagal trunk

29

a child 2-3 weeks old comes to the hospital with bile-free projectile emesis and an distended stomach with prominent peristaltic activity

hypertrophic pyloric stenosis

30

double bubble sign

refers to radiograph image in which both proximal duodenum and stomach are distended by gas, which indicates a doudenal atresia

emesis would have bile in it.

31

duodenal duplication cyst

tubular structure containing GI epithelium, smooth muscle and adherence to a part of the alimentary canal

32

gastric duplication cyst

scan shows and abdominal mass, which is suggestive of a meconium pseudocyst

peritonitis and ascites



33

what organs develop in the ventral mesentery

liver, gallbladder, and and some of the pancreas

34

the pancreas develops from what mesenteries

some ventral and some dorsal

35

all foregut endoderm has the potential to express ___ genes and to differentiate into the ____

liver specific genes, differentiate into the liver

hepatic genes are blocked by signals from mesoderm and ectoderm

36

the whole foregut endoderm expresses genes specifying the liver, but are blocked by signals from other tissue layers. what "inhibits these block-signals" in the hepatic area to allow it to grow?

cardiac FGF2
septum transversum BMP

these instruct the gut to express liver specific genes

37

hepatic cord cells coalesce around what in order to form sinusoids ?

extraembryonic veins

38

Right and Left Peritoneal diverticulums

these areas into which the liver and stomach are growing or twisting

39

Growth of the liver divides the ventral mesentery into the

falciform ligament and lesser omentum

40

ventral mesentery (1) --->

falciform ligament

41

ventral mesentery (2) --->

lesser omentum

42

the umbilical vein travels via the

falciform ligament

43

ductus venosus

connects the umbilical vein to the IVC,

becomes the ligamentum venosum

44

Extrahepatic biliary atresia

incomplete recanalization of the bile duct

child is jaundiced, high levels of bilirubin in bloodstream

45

child in the ER has dark urine, pale stool, and is jaundiced. diagnosis

extrahepatic biliary atresia

46

PDX1

regulates pancreas and duodenum development

47

PAX4

cells secreting insulin

48

PAX6

cells secreting glucagon

49

islets of langerhands appear in the

3rd fetal month

50

insulin secretion begins by the

5th month

51

what genes specify endocrine cell lineages??

paired homeobox genes

52

dorsal pancreatic duct ---> ____ papilla

minor

53

major pancreatic duct ---> papilla

major

54

annular pancreas

ventral and dorsal pancreatic buds form a ring around the duodenum

presents as duodenal obstruction

55

ectopic pancreatic tissue

can be found from distal esophagus to the primary intestinal loop (roughly distal part of transverse colon)

most common in stomach or ileum (ileal or MEckel's diverticulum)