3) Development of Foregut Flashcards Preview

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Flashcards in 3) Development of Foregut Deck (34):
1

What does lateral folding of the embryo achieve?

Creates ventral body wall
Primitive gut becomes tubular

2

What does craniocaudal folding of the embryo achieve?

Creates cranial and caudal pockets from yolk sac endoderm

3

What are the three regions of the primitive gut tube?

Foregut
Midgut
Hindgut

4

Where does the primitive gut tube run from?

From future mouth to future anus with opening at umbilicus

5

What is the internal lining of the primitive gut tube derived from and what will this become?

Endoderm, will become epithelial lining

6

What is the external lining of the primitive gut tube derived from and what will this become?

Splanchnic mesoderm
Will become future musculature and visceral peritoneum

7

What are the adult derivatives of the foregut?

Oesophagus, stomach, pancreas, liver, gall bladder and duodenum (proximal to bile duct entrance)

8

What are the adult derivatives of the midgut?

Duodenum (distal to bile duct entrance), jejunum, ileum, caecum, ascending colon, proximal 2/3rds transverse colon

9

What are the adult derivatives of the hindgut?

Distal 1/3rd transverse colon, descending and sigmoid colon, rectum, upper anal canal and internal lining of bladder & urethra

10

What is each region of the gut tube's blood supply?

Foregut - celiac trunk
Midgut - SMA
Hindgut - IMA

11

What is the intraembryonic coelom divided by?

Diaphragm

12

What do the abdominal muscles develop from?

Somatic mesoderm

13

What does the inguinal canal allow?

Passage of developing testis into scrotum

14

What is a mesentery?

Double layer of peritoneum suspending gut tube from abdominal wall

15

Why is a mesentery needed?

Blood and nerve supply
Mobility

16

What is the function of the dorsal mesentery?

Suspends entire gut tube from dorsal (back) body wall

17

What is the function of the ventral mesentery?

Suspends foregut from ventral body wall

18

What do the dorsal and ventral mesenteries do in the foregut?

Divide the cavity into left and right sacs

19

Which sac contributes to the greater sac?

Left sac

20

Where does the lesser sac come to lie?

Posterior to the stomach

21

What is the greater omentum?

Double sheet of peritoneum folded on itself, from dorsal mesentery. Hangs down from greater curvature of stomach over intestines and ascends back up to transverse colon and posterior abdominal wall

22

What is the lesser omentum?

Double layer of peritoneum from liver to lesser curvature of stomach. Free edge conducts portal triad

23

What does the dorsal border of the stomach become?

Greater curvature

24

What are retroperitoneal structures?

Those that were never in peritoneal cavity and never had a mesentery

25

What are secondarily retroperitoneal structures?

Began development invested in peritoneum but with successive growth and development, mesentery is lost through fusion at posterior abdominal wall

26

What does the respiratory diverticulum separate?

Respiratory primordium (ventrally) from oesophagus (dorsally)

27

What are the consequences of abnormal positioning of tracheoesophageal septum?

Tracheo-oesophageal fistulae
Oesophageal atresia

28

What organs are formed in the ventral mesentery?

Liver, biliary system, part of pancreas

29

What organs are formed in the dorsal mesentery?

Pancreas

30

What connects the liver to the anterior abdominal wall?

Falciform ligament

31

Where is the bare area of the liver?

Superior, where liver and diaphragm are connected

32

What happens to the lumen of duodenum in 5th and 6th weeks?

Lumen is obliterated then recanalised by end of embryonic period

33

Give examples of retroperitoneal organs:

Oesophagus, kidneys, rectum

34

Give examples of secondarily retroperitoneal organs:

Ascending and descending colon
Duodenum (except duodenal cap)
Pancreas