Embryo of the GI Tract Flashcards Preview

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Flashcards in Embryo of the GI Tract Deck (42)
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1
Q

Time frame for development of the GI tract

A

4th to 10th weeks

2
Q

Txn factor for the esophagus

For the duodenum and pancreas

For the SI

For the LI

A

SOX2

PDX1

CDXC

CDXA

3
Q

The development of the GI tract requires the communication between what two embryonic layers?

A

Endoderm (epithelium) and splanchnic mesoderm (mesenchyme)

4
Q

How might epithelium cause an atresia in the gut tube?

A

Temporarily occludes it, but then never re-canalizes

5
Q

Where is the oblique muscle layer when it is included in the GI wall?

A

Innermost, just after the submucosa

6
Q

The mesentery is made from what layer?

A

Parietal peritoneum (splanchnic mesoderm)

7
Q

Where is the only place where ventral mesentery can be seen in an adult?

A

Falciform ligament and lesser omentum

8
Q

Innervation of the foregut

Spinal roots

A

Greater splanchnic n. and celiac plexus

T5-9

9
Q

Innervation of the midgut

Spinal nerve roots

A

Lesser splanchnic n. and superior mesenteric plexus

T9-12

10
Q

Innervation of the hindgut

Spinal nerve roots

A

Least splanchnic n. and inferior mesenteric plexus

T12-L2

11
Q

In the pathway of sympathetic innervation, the “prevertebral ganglia” that the splanchnic nn. go to after leaving the abdominal sympathetic trunk are where?

A

Celiac, SM, and IM plexuses

12
Q

Parasympathetic innervation of foregut

Midgut?

A

Vagus n.

SAME

13
Q

Parasympathetic innervation of hindgut (w/ levels)

A

Pelvic splanchnic nn. (S2-4)

14
Q

If urine is leaking from an umbilicus, what is the problem?

A

Patent allantois (to become the urachus)

15
Q

If feces is leaking from an umbilicus, what is the problem?

A

Patent vitelline duct (to be Meckel’s diverticulum)

16
Q

3 Tx’s for a double tracheoesophageal fistula

What is crucial to these?

A

Colon interposition
Gastric tube esophagoplasty
Gastric transposition

MUST KEEP BLOOD SUPPLY IN TACT

17
Q

Esophageal diverticulum

A

Blind benign pouch off the side of the esophagus that could collect food/liquid

18
Q

Why does the stomach turn?

A

Posterior grows faster than anterior, so needs more space to keep growing

19
Q

If, 2-3 weeks after birth, a baby is vomiting NON-GREEN stuff after feeding, what is most likely the problem?

What can sometimes be seen externally?

A

Hypertrophic pyloric stenosis

Bloated stomach and/or duodenum poking through ant. abd. wall

20
Q

Double bubble sign

A

2 bloated areas on x-ray (stomach and duodenum) due to a duodenal atresia (occlusion)

21
Q

What organs develop in the ventral mesentery?

A

Liver and gall bladder

Stomach and part of duodenum

22
Q

Why are there often 2 duodenal papillas?

A

B/c ventral and dorsal “buds” of pancreas were both connected until they fused

23
Q

What 2 areas signal the liver to develop in the right place?

Where does it end up coming from?

A

Heart and septum transversum

Posterior endoderm

24
Q

Why does the lesser sac become so small?

A

The liver grows into the right “sac” and fills it in

25
Q

If someone presents w/ jaundice, dark urine, and pale stool, what is a likely Dx?

A

Extrahepatic biliary atresia (incomplete formation of bile duct)

26
Q

Normal level of referred pain for the GB

A

L1

27
Q

Txn factor for inducing islets of langerhaans, D-cells, and pancreatic acinar cells to form

A

Pax 4

28
Q

Txn factor for making glucagon-producing cells

A

Pax 6

29
Q

Cause of annular pancreas

A

Does not rotate w/ stomach

30
Q

Most common places for accessory pancreatic tissue

A

Near stomach or ileum

31
Q

Most common cause of gut atresias or stenoses in the duodenum

In the SI and LI?

A

Failure to re-canalize

Vascular compromise

32
Q

Apple peel atresia

A

Vascular issue leads to short jejunum and small coiled ileum and LI around the SMA or its branches

33
Q

At about what time is the midgut expected to “herniate” into the umbilical cord?

Why?

About when does it come back into the body?

A

6 weeks

Growing faster than the body has space for

10 weeks

34
Q

Common problem w/ twisting of midgut after it comes out of the umbilical cord

A

Volvulus

35
Q

When one part of the GI tract is shoved within that of another, what is that called?

Often affects what?

A

Intussuseption

Blood supply

36
Q

Omphalocele

A

Unresolved umbilical herniation

37
Q

Gastroschisis

Maybe linked to what behavior by mom?

A

Body wall doesn’t fuse, abdomen is protruding through a “hole” in the body wall w/o being in the cord

Cocaine use

38
Q

Prune Belly / Eagle-Barrett syndrome

Involved w/ what layer?

Often what other abnormality?

A

Lack of abdominal wall muscles, abdomen is very large and unrestrained in size

Mesoderm

Cryptorchidism

39
Q

Ileal fistula

A

Fecal matter discharges through patent vitelline duct

40
Q

Hirschprung’s Disease

A

Megacolon

Lack of migration of neural crest cells to the hindgut, so no enteric NS for peristalsis

41
Q

Name when anus does not reach the external environment

A

Imperforate anus

42
Q

High anorectal malformation

Low

A

No musculature for defecation (anorectal agenesis)

Blind sac below pelvic diaphragm (anal agenesis)