Digestive System 2

Question 1

At gastroesophageal junction epithelium changes from ____ ____ to simple ___

Answer 1

At gastroesophageal junction epithelium changes from stratified squamous to simple columnar

Question 2

the esophagus is a tubular structure that stems from ____ to stomach

Answer 2

oropharynx

Question 3

near the stomach, the esophagus has ____ ____ glands in ____ ___ (mucous layer)

Answer 3

near the stomach, has esophageal cardiac glands in lamina propria (mucuos)

Question 4

The esophagus has ___ ___ glands in the lamina propria and ___ ___ glands in the submucosa.

Answer 4

esophageal cardiac glands in the lamina propria and esophageal MUCOUS glands in the submucosa.

Question 5

Any organ that is located below the diaphragm is covered with ____. Any organ covered above the diaphragm, is covered with _____

Answer 5

Any organ that is located below the diaphragm is covered with serosa. Any organ covered ABOVE the diaphragm, is covered with adventitia.

Question 6

How do you tell apart the upper and lower part of the esophagus

Answer 6

upper: skeletal muscle, ahs adventitia lower: has esophageal cardiac glands, only smooth muscle, covered with serosa.

Question 8

label

Answer 8

E= esophagus (SS non keratinized)

GP= gastric pits

SM= smooth muscle

CG = cardiac gland

C= cardiac portion of stomach

Question 9

When not distended, mucosa and submucosa have longitudinal folds called ____. Function?

Answer 9

Rugae. to incrase the surface area for absorption and secretion.

Question 10

Label

Answer 10

SM= SUBMUCOSA. Made with loose CT (aereolar) and dense irregular fibrous CT with blood vessels.

ME = muscularis externa.

M = mucosa. filled with glands that penetrate through the lamina propria.

S = serosa.

Question 11

Glands that secrete HCl and pepsin are mainly found inthe ___ and ___ regions of the stomach. Glands of the __ and ___ producive mainly mucous.

Answer 11

. Cells that secrete HCl and pepsin are restricted mainly to the body and fundus regions. Glands of the cardia and pylorus produce primarily mucus.

Question 12

the muscularis externa of the stomach as ___ layers of muscle. What are they?

Answer 12

3 layers. MIDDLE Circular layer, outer longitudinal, and INNER oblique layer. allows for thorough mixing of the stomach contents.

Question 13

the 4 regions of a gland in the stomach fundus region

Answer 13

1) pit
2) isthmus
3) neck
4) base

Question 14

T/F: in the cardiac and pyloric regions, there is more “pit space” than glands space in the mucosa. What do the glands produce in these regions of the stomach?

Answer 14

TRUE: pits are 2/3 and glands are 1/3 of mucosa. glands produce mucous and lysozymes.

Question 15

What is this?

Answer 15

cardiac portion of the stomach. Note that the gastric pits take up more space than the glands in the lamina propria.

Question 16

T/f: in body and fundus, pits take up less space than glands in the mucosa layer. What do these glands secrete? what shape are the glands?

Answer 16

TRUE. there are more glands than pit depth in the body and fundus. glands secrete gastric juice. specific cells secrete dif molecules (parietal cells = Hcl, chief cells = lipases and zymogens, etc).

Glands are simple branched tubular that consist of an isthmus, neck and base.

Question 17

5 typs of cells of the glands found in the fundic poriton of the stomach

Answer 17

1) stem cells. divide by mitosis to replace all cell types. found in upper neck and isthmus.
2) mucous neck cells. low columnar with basal nucleus. found in the neck region
3) parietal cells. more abundant in the upper parts of the gland. Produce Hcl and Intrinsic factor, a glycoprotein required for the absorption of vitmain B12
4) cheif cells; found at the base of the galnd. produce pepsinogen.
5) enteroendocrine cells; release hormones. Ex/ G cells = gastrin, increases HCl secretion. D cells= somatostatin, inhibits activity of other cells.

Question 18

how does pepsinogen get activated?

Answer 18

gets activated to pepsin by Hcl that was produced by the parietal cells.

Question 19

What is this? label

Answer 19

MN= mucous neck cells. don’t pick up stain because they are mucous

P = parietal cells .looks like boobs, and are more abundant on the top

MM = muscularis mucosae ( most bottom layer of the mucous layer)

C = chief cells. hard to distinguish from mucous neck cells but if you notice that that the MM layer is near by, you know they are chief cells because cheif cells are found more basally in the mucous layer.

Question 20

3 types of enteroendocrine cells.

Answer 20

3 Types of Enteroendocrine cells that we will cover:

1) EC Cells: produces serotonin and substance P. Increases motility/ mechanically help with digestion.
2) G Cells: Gastrin release. Increases the activity of HCl/ secretion of HCl, especially in the presence of food.
3) D Cells: produces somatostasin. Inhibits the activity of the other cells.

Question 21

which connective tissue comprises the submucosa of the stomach

Answer 21

1) loose CT (areolar)
2) dense irregular CT

Question 22

is the stomach lined with serosa or adventitia?

Answer 22

serosa.

Question 24

3 stomach functions

Answer 24

1) mix ingested food with gastric juiec
2) store food
3) begin protein digestion by pepsin.

Question 25

Outline the cells activated with an empty stomach and what hormones are released

Answer 25

Empty stomach = low pH –> D cells release somatostatin, which inhibits the activity of other cells such as G cells to stop the secretion of Hcl. there is nothing to digest.

Question 26

outline the cells activity and hormones invovled with the stomach is full

Answer 26

Full stomach = pH increases

1) d cells are inactived
2) G cells release gastrin, which facilitates Hcl secretion. also causes chief cells to release increased amounts of pepsiongen.
3) EC cells release serotonin and substance P, which results in the increased gastric motility

Question 27

2 ways that surface area is increased in the small intestine

Answer 27

1) plicae circularis- folds in the mucosa and submucosa
2) intestinal villi. folds in the epithelium and lamina propria

(also 3) the length of the small intestine.

Question 28

the intestinal glands are located in the ___ of ____. What is the conformation/strcuture of these glands?

Answer 28

CRYPTS of LIEBERKUHN. Simple tubular glands.

Question 29

the microvilli of small intestine are located on the luminal surface of __- cells.

Answer 29

EPITHELIAL CELLS.

Question 30

What cells are located at the “top” portions of the villi? What cell types are located at the bottom portions of the crypts in a small intestine? Outline their function.

Answer 30

top: 1) goblet cells- secrete mucin
2) absorptive cells (enterocytes)- columnar epithelial cells with microvilli. Absorb nutrients and secretes further peptidases.

Bottom:

1) stem cells (above paneth cells), divide by mitosis to give rise to other intestinal cells
2) paneth cells; found at the BOTTOM of the crypts of lieberkuhn. Contain granules of lysozymes which may stain reddish. Serves a DEFENSIVE FUNCTIOn by digestibe bacterial cell walls

Question 31

what cell is this?

Answer 31

Paneth cells at the bottoms of the intestinal crypts (of lieberkuhn).

Question 32

T/F Enteroendocrine cells are also found in the small intestine

Answer 32

true. but they do not have G cells in the small intestine because HCl is not needed in the small intestine. They still release many hormones that regulate motility and secretion.

Question 33

What is GALT? Where is it found? what is it comprised of?

Answer 33

found in the lamina propria and submucosa of the intestinal lining. Includes plasma cells, macrophages and lymphocytes.

Question 34

What is the muscularis mucosa of the gut comprsied of?

Answer 34

made of inner circular and outer longitudinal layers of SMOOTH MUSCLE. part of the mucousa layer.

Question 35

What is a characteristic gland of the duodenum? What layer is this gland found in? Function?

Answer 35

the duodenum has BRUNNERS glands in the submucosa. produces alkaline substance to neutralize the acidity of chyme from the stomach.

Question 36

what is a characteristic tissue in the ileum? what layer of the wall is it found in?

Answer 36

the ileum has PEYERS PATCHES made of GALT tissue.

Question 37

What is this? Label

Answer 37

This is most likely the duodenum. There are glands in the submucosa that are characteristic of brunners glands

D= ducts

MM= muscularis mucosae

DG= duodenal glands in the submucousa (brunner glands)

Question 38

the muscularis externa has inner circular and outer longitudinal layers of smooth muscle in the long intestine. what lies between these two layers?

Answer 38

AUERBACHS plexus. clouds of autonomic ganglia. O