Development Gastrointestinal System

Question 1

what does the ectoderm form?

Answer 1

the epidermis layer of the skin
the epithelium of the oral and nasal cavities and the nervous system and sense organs

Question 2

what does the mesoderm result in the formation of?

Answer 2

forms muscle and connective tissue, bone and parts of the circulatory, urinary and genital systems

Question 3

what does the endoderm result in the formation of?

Answer 3

forms mucosal epithelium and glands of respiratory and digestive systems

Question 4

what does the thickening of oral epithelium form?

Answer 4

forms the ectodermal dental lamina

Question 5

what results in the formation of the dental bud?

Answer 5

the dental lamina invaginates to form the dental bud

Question 6

the dental bud expands and branches to become what?

Answer 6

it becomes the enamel organ (outer and inner enamel epithelium)

Question 7

what is mesenchyme?

Answer 7

it is an embryonic connective tissue characterised by loosely associated cells and extra cellular matrix

Question 8

where is most mesenchyme derived from?

Answer 8

it is derived from mesoderm

Question 9

where are tooth connective tissues derived from?

Answer 9

they are derived from neural crest cells plus mesoderm

Question 10

what is neuro-mesenchyme?

Answer 10

it is the mesenchyme from tooth connective tissues that are derived from neural crest cells plus mesoderm

Question 11

slide 7,8,9

Question 12

what are both minor and major salivary glands formed from?

Answer 12

from outgrowths of epithelium that push into the underlying mesenchyme

Question 13

where are the gland acini and the ducts formed from?

Answer 13

the branches that push into the underlying mesenchyme - these branches become canalised

Question 14

what does the primitive gut tube start as?

Answer 14

starts as a single tube of endoderm

Question 15

SLIDE 11,12,13

Question 16

what does the dorsal mesentery become?

Answer 16

it becomes: greater omentum, mesoduodenum, mesentery (mesojejunum and mesoileum), mesocolon and mesorectum

Question 17

what does the ventral mesentery become?

Answer 17

it becomes the lesser omentum, coronary and falciform ligaments of the liver

Question 18

caudally, what does the ventral mesentery become?

Answer 18

it becomes the median ligament of the urinary bladder

Question 19

what lines the abdominal cavity?

Answer 19

serous membrane

Question 20

position of spleen to stomach?

Answer 20

caudal

Question 21

14,15,16,17

Question 22

what does liver growth do to the orientation of the simple stomach?

Answer 22

it pushes the cranial end of the stomach to the left side

Question 23

what happens in order for the fundus region to form?

Answer 23

increased growth along the left cranial end of the future greater curvature

Question 24

rumen develops as an expansion of what?

Answer 24

of the fundus

Question 25

the reticulum arises as a…?

Answer 25

as a caudoventral pocket of the developing rumen

Question 26

what does the omasum develop as?

Answer 26

it develops as a bulge along the lesser curvature

Question 27

where does the abomasum develop from?

Answer 27

develops from the rest of the stomach

Question 28

what happens later in the development of the rumen?

Answer 28

the rumen ‘flips’ caudally to be on top of the abomasum and the reticulum is cranial

Question 29

20,21,

Question 30

Where does the pancreas arise from?

Answer 30

it arises from the same portion of the foregut as the liver as two endodermal diverticulum

Question 31

what happens after the migration of ventral pancreas?

Answer 31

two primordia fuse

Question 32

pancreas - how does the islet tissue develop?

Answer 32

the islet tissue develops by budding from the ducts

Question 33

what does the dorsal bud of the pancreas develop into?

Answer 33

they develop into major parts of the pancreas

Question 34

what does the midgut give rise to?

Answer 34

it gives rise to the middle parts of the digestive canal

Question 35

what does the midgut consist of?

Answer 35

duodenum (caudal part)
jejunum
caecum
ascending colon

Question 36

hindgut consists of?

Answer 36

transverse colon (first two thirds)

Question 37

location of midgut?

Answer 37

it hangs from the dorsal body wall by a short mesentery

Question 38

describe the early growth of the intestinal loop?

Answer 38

it is very rapid, causing it to hang in a loop from elongated mesentery