Establishment of the Digestive System Flashcards

1
Q

The first indication in the formation of the digestive tract is initiated by the establishment of the ____

A

endodermal layer of the blastocyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The mesoderm splits into somatic and splanchnic layers where the splanchnic layer become closely associated with the endoderm as the _____

A

splanchnopleure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The intraembryonic tube, lined by endoderm and covered by splanchnic mesoderm

A

Primitive Gut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Gives rise to the epithelial lining of the digestive tract

A

ENDODERM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Forms connective tissue and smooth muscle components of the digestive tract wall

A

SPLANCHNIC MESODERM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  • The cranial portion lying beneath the head
  • The first part of the primitive gut to be definitely incorporated into the embryo
A

foregut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

*foregut

Ends blindly, but has communication with the undifferentiated part of the gut called ____

A

anterior intestinal portal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

*foregut

Closed cranially by the ____ which is lined by endoderm on the inside and covered by ectoderm on the outside.

A

oro-pharyngeal membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

*foregut

An ectodermal depression at the location of the oro- pharyngeal membrane, the ____, later develops into the oral cavity.

A

stomodaeum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  • A connecting portion between the foregut and the hindgut
  • Opens into the yolk sac
  • The last to acquire its floor through the lateral body folds
A

Midgut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  • Formed in similar manner as the foregut beneath the caudal portion of the embryo.
  • The posterior intestinal portal is its communication with the rest of the gut.
A

Hindgut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

*hindgut

Also blind, being closed by the _____, similarly lined by endoderm and covered by ectoderm.

A

cloacal membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

*hindgut

A depression at the site of the cloacal membrane, the _____, develops into the anus and the opening of the uro-genital system.

A

proctodaeum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  • Extends from the developing pharynx, where it opens dorsal to the larynx, to the spindle-shaped primordium of the stomach.
  • Its principal morphogenic development is elongation.
A

Esophagus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

*Species differentiation

Coated by skeletal muscle throughout its
length (____),
to the diaphragm (____),
to the mid-thorax (____),
or not at all (____).

A

dog, ruminants

pig

cat, horse, human

avian

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Develops as a spindle-shaped dilation of the more caudal portion of the foregut, becoming evident during the third week of gestation in the pig.

A

Stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q
  • The ____ develops as an expansion of the fundus, and a caudoventral pocket of the developing rumen forms the ____.
  • The _____ develops as a bulge along the lesser curvature.

The rest of the stomach becomes _____.

A

rumen

reticulum

omasum

abomasum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The liver and the pancreas both develop from ____ and ____ that originate from the most caudal region of the foregut.

A

dorsal and a ventral endodermal buds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

the liver and a minor portion of the pancreas

A

ventral bud-

20
Q

the major portion of the pancreas

A

dorsal bud-

21
Q

The hepatogenic part of the ventral endodermal bud develops into a ____ and ____

A

larger cranial and a smaller caudal portion.

22
Q

develops into the gall bladder and cystic
duct.

A

caudal or cystic portion (pars cystica)

23
Q

develops into the liver tissue and the remaining bile ducts.

A

cranial or hepatic portion (pars
hepatica)

24
Q

The relatively large endodermal cells
differentiate into ____ and become arranged in column or plates with intervening _____.

A

hepatocytes (Pars hepatica)

sinusoids

25
Q

Initially, the liver develops a left and a right lobe , but subsequent outgrowths from the right
lobe form the ____ and ____ . This, in turn, is followed by species-specific division of the lobes.

A

quadrate and caudate lobes

26
Q

*SPECIES DIFFERENCES

the liver remains more or less horizontally attached to the diaphragm in the midline

A

Carnivores and pig-

27
Q

*SPECIES DIFFERENCES

the intestinal system displaces the liver by 45° to the right

A

Horse-

28
Q

*SPECIES DIFFERENCES

the stomach system pushes the liver 90° to the right.

A

Ruminants-

29
Q

Develops from dorsal and ventral endodermal buds off the caudal end of the foregut.

A

pancreas

30
Q

One diverticulum arises ventrally as a bud of the hepatic diverticulum; it forms the ____ and ____ of the pancreas.

A

pancreatic duct and right lobe

31
Q

The other diverticulum arises dorsally from the duodenum (minor duodenal papilla) and forms the ____ and ____

A

accessory pancreatic duct and the left
lobe of the pancreas.

32
Q

*SPECIES DIFFERENCES

Accessory pancreatic duct is later obliterated in

A

cat and small ruminants.

33
Q

*SPECIES DIFFERENCES

Pancreatic duct is later obliterated in

A

ox and pig.

34
Q

*Pancreas

At the termination of the smallest branch, cluster of cells form the secretory ____ (exocrine portion)

A

pancreatic acini

35
Q

Scattered between the acini are group of cells, the ____ (endocrine portion).

A

islet of Langerhans

36
Q

The haematopoietic liver occupies most of the abdominal cavity, the growing intestinal loop is displaced out of the abdominal cavity into the extra-embryonic coelom.

A

PHYSIOLOGICAL UMBILICAL HERNIATION

37
Q

*Intestines

The cranial limb which becomes the ____ returns to the abdomen first

A

ascending duodenum

38
Q

The mass of the ____ fills much of the ventral abdomen and the _____ lies on the right side of the abdomen

A

coiled jejunum

distal jejunum

39
Q

During the process of passing in and out of the intestine in the abdominal cavity, accompanying rotational mvts occur
along its dorsal mesenteric attachment, thus the twisted part of the mesentery that attached the intestine to the dorsal body wall is called the _____

A

root of the mesentery

40
Q

The intestinal loop rotates _____ around a dorso-ventral axis with the cranial mesenteric artery located in the axis.

A

clockwise

41
Q

*Intestines

The first phase of rotation, which occurs
when the intestinal loop forms the hernia, accounts for ___.

A

180°

42
Q

*Intestines

Later, during the reduction of the hernia,
an additional rotation augments the rotation to about ___.

A

270°

43
Q

*Intestines

At the return of the intestinal loop to the abdominal cavity the final species- specific positioning of the intestines occurs; a process that includes yet more rotation bringing the total to about ___.

A

360°

44
Q

*SPECIES DIFFERENCES

In ____—the secondary loop coils
into inverted pyramid

A

pig

45
Q

*SPECIES DIFFERENCES

-spiral colon is rope-like

A

Ruminant

46
Q

*SPECIES DIFFERENCES

In ____—the secondary loop bends on itself; also the cecum enlarges so that the proximal colon is incorporated within the cecum.

A

horse