Embryology of the GI Tract Flashcards Preview

Gastro > Embryology of the GI Tract > Flashcards

Flashcards in Embryology of the GI Tract Deck (57):
1

What happens by week 4

Endodermal tube running thought the centre of the emrbyo is present

2

What happens to the cloaca

develops into both parts of the urinary system and also for the hind gut

3

What are the 2 origins of the GI Tract

Endoderm and Visceral mesoderm

4

What does the endoderm form

Epithelium of mucosa and associated ducts and glands

5

What does the visceral mesoderm surround

Lamina propria
Muscularis mucosa and muscularis externa
CT of submucosa and External CT

6

What is the endoderm suspended in a bit of?

The mesoderm

7

What is the dorsal mesogastrium associated with?

Stomach, duodenum and mesentery proper (largest part of the dorsal mesentery associated with the small intestine

8

What happens to the dorsal mesogastrium

Moves downwards and forwards to become the greater omentum

9

How are the mesenteries brought into their final positions

Rotation of different parts of the gut

10

When is the oesophagus distringuishable by?

End of week 4

11

What develops in terms of the oesophagus in week 5

Circular muscle

12

What develops in terms of the oesophagus in week 8

Longitudinal muscle

13

What does the dilatation indicate at the end of week 4?

The stomach

14

How is the unusual shape of the stomach brought about

Swelling is not growing at a uniform rate - quicker on the left border. As it grows it starts to undergo a rotation

15

Where will the original left side of the stomach lie

Anteriorly

16

Where will the original right side of the stomach lie

Posteriorly

17

What also rotates at the same time as the stomach

Vagus nerves

18

Where does the greater curvature move

Slightly inferiorly pointing down

19

Where does the lesser curvature end up pointing

Slightly downwards

20

What forms the lesser sac

Growth and rotations of the stomach

21

What else does the growth and rotation of the stomach cause

The dorsal mesentery to bulge

22

What forms the greater omentum

Continued growth of the dorsal mesentery

23

What 2 things form from the ventral mesentery

Lesser omentum and falciform ligament

24

What 3 parts make up the duodenum and what do they make up

Caudal portion of foregut - parts 1 and 2 of duodenum
Cranial portion of midgut - parts 3 and 4 of duodenum
Duodenal loop is directed to the right due to the rotation of the stomach

25

Describe the growth of the liver bud

Into the mesoderm of the septum Transversum

26

What is the duodenum closely associated with

The liver, gall bladder and pancreas

27

What is important for the formation of the diaphragm

septum transversum

28

What is the gall bladder associated with

The posterior aspect of the liver

29

What does the mesoderm of septum transversum give rise to

The development of hepatocytes and the lining of the biliary tree

30

What does either side of the liver go on to be?

The lesser omentum

31

Where do the pancreas and the common bile duct form from?

Proliferation of the endoderm

32

What gives rise to the gall bladder

Diverticulum

33

Name the two buds of the pancreas

Ventral pancreatic bud and dorsal pancreatic bud

34

What supplies the dorsal pancreatic bud

The celiac axis

35

What supplies the ventral pancreatic bud

Superior mesenteric artery

36

HOw does the ventral pancreatic duct migrate?

It twists so that it lies adjacent to the dorsa pancreatic duct

37

What happens as the ventral pancreatic duct migrates?

It pulls the common bile duct and the gall bladder closer together

38

In what direction does the pancreas move?

Clockwise

39

Where is the spleen derived from?

Mesoderm (not gut tube)

40

When does the spleen develop

week 5

41

What is the position of the spleen dictated by

The rotation of the stomach

42

When does the spleen develop into a lymphatic organ?

Weeks 15-18

43

What comprises the midgut

Second half of duodenum
Jejunum
Ileum
Caecum and appendix
Ascending colon
Proximal 2/3rd of transverse colon

44

What happens at the beginning of week 4 in the midgut

Communicates with the yolk sac along its length

45

What happens during week 4 in the midgut

Connection with the yolk sac narrows

46

What happens to the midgut by the end of week 4

Connected to the yolk sac via narrow vitelline duct

47

What happens in week 5 in terms of the midgut

The midgut has outgrown the embryo and bulges ventrally into the umbilicus

48

What occupies the majority of the abdominal space

The liver

49

What direction does the midgut rotate as you look at it

Anticlockwise

50

What acts as an axis for the rotation to occur around

Superior mesenteric artery

51

What does the caecal bud develop into and when does this happen

Caecum and the appendix
Week 8

52

When does re-entry of the midgut into the body cavity occur

Around week 10

53

What returns first?

Small intestine

54

Describe the movement of the caecum

It moves back in last and lies below the liver in the Upper right quadrant. It will then move down towards the right ileac fossa.

55

What is a vitelline cyst

A fibrous plaque

56

When does the formation of the definitive gut lumen occur?

Weeks 5-9

57

Why does the lumen of the gut initially become ecluded

The endodermal lining is going to proliferate

Decks in Gastro Class (67):