Development of abdominal wall, peritoneum, peritoneal cavity and foregut

Question 1

How is the anterior abdominal wall formed?

Answer 1

Lateral folding of the embryo

edges meet each other in midline

Question 2

How is the posterior abdominal wall formed?

Answer 2

Lateral folding of embryo

lengthening of trilaminar disc

Question 3

How is the primitive gut tube formed?

Answer 3

Lateral folding of embryo

Cranio-caudal folding of embryo

Question 4

How does lateral folding of the embryo form the promitive gut tube?

Answer 4

Pinches off portion of yolk sac

Question 5

How does cranio-caudal folding of the embryo form the primitive gut tube?

Answer 5

Elongates the primitive gut tube

Question 6

What type of embryonic tissue is the primitive gut tube made up of?

Answer 6

Endoderm

Question 7

What are the different parts of the primitive gut tube? How are they arraged?

Answer 7

Foregut at cranial end

Midgut

Hindgut at caudal end

Question 8

What is the primitive gut tube located in in the embryo?

Answer 8

Intraembryonic coelom

Question 9

What does the intraembryonic coelom develop into?

Answer 9

Thoracic cavity

Abdomino-pelvic cavities

Question 10

How is the intraembryonic coelom separated into thoracic and abdomino-pelvic cavities?

Answer 10

Septum transversum divides it into two

Question 11

What does the septum transversum develop into?

Answer 11

Diaphragm

Question 12

What do the somatic and splanchnic mesoderm lining the intra-embryonic coelom develop into?

Answer 12

Pericardium

Pleura

Peritoneum

Question 13

What does the somatic mesoderm lining the intra-embryonic coelom develop into?

Answer 13

Parietal pericaridum

Parietal pleura

Parietal peritoneum

Question 14

What does the splachnic mesoderm lining the intra-embryonic coelom around the primitive gut tube develop into?

Answer 14

Visceral pericardium

Visceral pleura

Visceral peritoneum

Question 15

What are the types of mesenteries in the embryo?

Answer 15

Dorsal mesentery

Ventral mesentery

Question 16

What does the dorsal mesentery attach to?

Answer 16

Posterior abdominal wall

Entire length of primitive gut tube

Question 17

How does the dorsal mesentery develop?

Answer 17

Primitive gut tube

pulls down on splanchnic mesoderm that wraps around it

Question 18

What does the ventral mesentery attach to?

Answer 18

Anterior abdominal wall

Foregut part of primitive gut tube

Question 19

What are the different parts of the peritoneal cavity in the foregut?

Answer 19

Right sac

Left sac

Question 20

What are the different parts of the peritoneal cavity in the midgut and hindgut?

Answer 20

Left sac

Question 21

Why does the forget have a right sac and left sac whereas the midgut and hindgut have only a left sac?

Answer 21

Because the foregut has a dorsal and ventral mesentery
divide the peritoneal cavity into two

But the midgut and hindgut only have a dorsal mesentery
entire peritoneal cavity is continuous

Question 22

What does the dorsal mesentery develop into?

Answer 22

Greater omentum

Question 23

What does the ventral mesentery develop into?

Answer 23

Lesser omentum

Falciform ligament

Question 24

What does the left sac of the peritoneal cavity develop into?

Answer 24

Greater sac

Question 25

What does the right sac of the peritonal cavity develop into?

Answer 25

Lesser sac

Question 26

Where does the dorsal mesentery move as it develops into the greater omentum?

Answer 26

Moves anteriorly around stomach

Question 27

Where does the right sac move to as it develops into the lesser sac?

Answer 27

Moves posteriorly to stomach

Question 28

Where does the ventral mesentery move as it develops into the lesser omentum?

Answer 28

Moves posteriorly around stomach

Question 29

What causes the right sac, dorsal and ventral mesenteries to move as they develop?

Answer 29

By rotation of the stomach By growth of the liver

Question 30

How does the stomach rotate in the embryo?

Answer 30

Rotates clockwise along its long axis

Question 31

What does the foregut develop into?

Answer 31

``` Oesophagus Stomach Liver, gall bladder Pancreas Duodenum - proximal to bile duct ```

Question 32

What is the blood supply of the foregut?

Answer 32

Coeliac trunk

Question 33

Where does the coeliac trunk arise?

Answer 33

Abdominal aorta | anteriorly

Question 34

What does the foregut extend from and to?

Answer 34

From the lung bud | to the liver bud

Question 35

What is the lung bud?

Answer 35

A pouch that forms off the anterior wall of the foregut

Question 36

What happens to the relationshop between the lung bud and the foregut?

Answer 36

They are completely separated

Question 37

How is the lung bud completely separated from the foregut?

Answer 37

Tracheo-oesophageal septum grows between the two

Question 38

What does the liver develop within?

Answer 38

Ventral mesentery

Question 39

What does the liver develop from?

Answer 39

Liver bud from foregut Septum transversum

Question 40

How does the ventral mesentry develop into the lesser omentum?

Answer 40

As the liver grows within the ventral mesentery the remainder of the ventral mesentery that connects the liver to the stomach forms the lesser omentum

Question 41

How does the ventral mesentery develop into the falciform ligament?

Answer 41

As the liver grows within the ventral mesentery the remainder of the ventral mesentery that connects the liver to the anterior abdominal wall forms the falciform ligament

Question 42

Hows does the duodenum develop?

Answer 42

Rotation of stomach pushes it to the right Rotation of stomach and growth of liver pushes it posteriorly

Question 43

What does the pancreas develop from?

Answer 43

Dorsal pancreatic bud off the foregut Ventral pancreatic bud off the foregut

Question 44

What does the dorsal pancreatc bud develop into?

Answer 44

Superior head Neck Body Tail

Question 45

What does the ventral pancreatic bud develop into?

Answer 45

Inferior head

Question 46

How does the inferior head of the pancreas join with the rest of the developing pancreas?

Answer 46

By rotation of the stomach

Question 47

What are the exceptions to the blood supply of the foregut? Why?

Answer 47

Duodenum Pancreas head because develop at junction between foregut and midgut

Question 48

What is the blood supply of the duodenum and pancreas head?

Answer 48

Coeliac trunk Superior mesenteric artery

Question 49

Where does the superior mesenteric artery arise from?

Answer 49

Abdominal aorta

Question 50

What is the bare area of the liver?

Answer 50

Part of the liver that is not covered by peritoneum

Question 51

Why does the liver have a bare area?

Answer 51

Because part of it developed from the septum transversum | and remains in contact with the diaphragm