4 Histo of the Stomach and Esophagus

Question 1

What are the layers of the GI tract from the lumen outward

Answer 1

Mucosa —> submucosa —> muscularis/muscalris externa —> serosa/adventitia

Question 2

What are the layers of the mucosa

Answer 2

Lining epithelium, lamina propria, muscularis mucosae

Question 3

What is found in the lamina propria

Answer 3

It is loose, vascularized CT

Lymphatic nodules, lymphocytes, plasma cells, and macrophages

Question 4

What does the muscularis mucosae do

Answer 4

Controls mobility of mucosa as well as squeezes gland contents out

Question 5

What kind of CT is found in the submucosal layer

Answer 5

Dense, irregular CT and glands in esophagus and duodenum

Question 6

What are the layers of the muscularis/muscularis externa? What do they do?

Answer 6

Inner circular layer - constricts the lumen

Outer longitudinal layer - shortens the tube

Question 7

What is between the layers of the muscularis/muscularis externa

Answer 7

Neurovascular plexuses

Question 8

What cell type is mesothelium

Answer 8

Simple squamous

Question 9

What is the serosa/adventitia layer made of

Answer 9

Loose CT and mesothelium

Question 10

What cell type is the mucosa epithelium in the GI

Answer 10

Simple columnar

Question 11

What are the main parasympathetic GI innervations

Answer 11

Vagus until splenic flexure

Pelvic splanchnic after splenic flexure

Question 12

What is the sympathetic innervation of the GI

Answer 12

Greater, lesser, least, and lumbar splanchnic nn

Question 13

What is the innervation found in the submucosa of the GI called

Answer 13

Submucosal plexus of Meissner

Question 14

What is the innervation between the muscularis layers called

Answer 14

Myenteric plexus of Auerbach

Question 15

What in the esophagus determines whether it has serosa or adventitia?

Answer 15

The diaphragm

Above - adventitia and adipose

Below - serosa

Question 16

Where do cardiac esophageal glands reside

Answer 16

In the lamina propria (mucosa)

Question 17

What are the submucosal glands

Answer 17

Consists of small lobules with mucous and serous cell types and are drained by a single duct

Question 18

What are the layers of esophagus

Answer 18

Mucosa, submucosa, muscularis, and adventitia or serosa (adventitia above diaphragm)

Question 19

Where is muscularis mucosa present in the mucosa of the esophagus

Answer 19

In lower segment

Question 20

Increase in pressure of what layer of esophagus causes varices?

Answer 20

Submucosa, this is where the venous plexuses are

Question 21

What kind of muscle is found in the muscularis of the esophagus

Answer 21

Upper third = skeletal muscle
Middle third = blend
Lower third = smooth muscle

Question 22

What cell types meet at the gastroesophageal junction

Answer 22

Stratified squamous —> simple columnar

Question 23

What are the two sphincters of the esophagus

Answer 23

Upper - anatomical and involved in swallowing reflex

Lower - functional and prevents reflux of gastric contents

Question 24

What does GERD stand for? What does it cause?

Answer 24

GastroEsophageal Reflux Disease

Chronic inflammation, ulceration, and dysphagia

Question 25

What can GERD cause in the long term?

Answer 25

Barrett’s esophagus Esophagus epithelium replaced by stomach epithelium

Question 26

What are people with Barrett’s esophagus at high risk for

Answer 26

Stomach cancer

Question 27

What are the regions of the stomach

Answer 27

Cardia - 2-3 cm near esophageal opening Fundus - projects to the left of cardia Body - extensive central region Pyloric antrum - ends at gastroduodenal orifice

Question 28

What are the two stomach regions based on motility

Answer 28

Orad - fundus and upper body that relaxes during swallowing Caudad - lower body and antrum, participates in regulation of gastric emptying

Question 29

What are gastric mucosal folds called

Answer 29

Rugae

Question 30

What protects the epithelium of the stomach

Answer 30

Mucosal barrier

Question 31

What kind of cells are found on the stomach mucosa

Answer 31

Secretory simple columnar

Question 32

What glands are found in the stomach mucosa

Answer 32

Cardiac, gastric and pyloric

Question 33

What type of CT is found in the submucosa of the stomach? What other portion has this

Answer 33

Dense, irregular CT GI

Question 34

What are the muscle layers in the muscularis of the stomach

Answer 34

Oblique, circular, and longitudinal

Question 35

What muscularis layer forms the pyloric sphincter

Answer 35

Circular

Question 36

What do cardiac glands look like

Answer 36

They are single tubes that have coiled ends

Question 37

What do cardiac glands secrete

Answer 37

Mucus

Question 38

Where are the cardiac cells

Answer 38

They extend only a few cm from the gastroesophageal junction

Question 39

What are the regions of the stomach’s glands

Answer 39

Pit (foveolar), neck, and body

Question 40

What cells are found in the pit of glands

Answer 40

Mucous cells

Question 41

What cells are found in the neck of glands

Answer 41

Mucous neck cells, stem cells, and parietal cells

Question 42

What cells are contained in the upper body of glands? Lower?

Answer 42

More parietal cells, chief cells, stem cells Parietal cells, more chief cells, more enteroendocrine cells

Question 43

What is Ménétriers disease

Answer 43

TGF-α induced hyperplasia of surface mucous cells

Question 44

What are the symptoms of Ménétriers disease

Answer 44

Nausea, vomitting, epigastric pain, gastrointestinal bleeding, diarrhea

Question 45

What do parietal cells produce

Answer 45

Hydrochloric acid and intrinsic factor (glycoprotein that binds to B12)

Question 46

What features of parietal cells allow them to function

Answer 46

Abundant mitochondria - for ATP production for ATPase pumps Secretory/intracellular canaliculus - for vesicle production Abundant H/K dependent ATPase

Question 47

Where are chief cells primarily found

Answer 47

Lower 1/3 of gastric gland

Question 48

Where are chief cells not found

Answer 48

Cardiac glands and pyloric antrum

Question 49

What do chief cells contain and secrete

Answer 49

Zymogen granules of pepsinogen

Question 50

What converts pepsinogen to pepsin

Answer 50

Acids

Question 51

What stimulates pepsinogen release

Answer 51

Feeding

Question 52

What do enteroendocrine cells of the stomach

Answer 52

Somatostatin, gastrin, ghrelin

Question 53

What does gastrin do

Answer 53

Produced by G cells in pyloric antrum and stimulates production of HCl by parietal cells

Question 54

What does somatostatin do

Answer 54

Produced by D cells and inhibits gastrin action

Question 55

What does ghrelin do

Answer 55

Produced in gastric fundus Binds to receptor in pituitary and stimulates GH Increases with fasting and triggers hunger

Question 56

How are pyloric glands diffrent than gastric pits

Answer 56

Pits are deeper and extend halfway through mucosa Glands have larger lumen and are highly branched

Question 57

What do pyloric glands produce

Answer 57

Mucus and lysozyme (lyses bacteria)

Question 58

What cells are found in a high number in pyloric glands

Answer 58

Enteroendocrine cells and G cells (gastrin) GALT in lamina propria

Question 59

What is the difference between serosa and adventitia

Answer 59

Serosa is covered by peritoneum and adventitia is retroperitoneal