Histo of Esophagus and Stomach

Question 1

Main 4 layers of the GI tract tissue from lumen to superficial?

Answer 1

Mucosa
Submucosa
Muscularis externa
Adventitia or Serosa

Question 2

Which main layer of the GI tract tissue varies the most over the course of the organs?

Answer 2

Mucosa

Question 3

Mucosa has 3 layers, from lumen to more superficial?

Answer 3

Lining epithelium - VARIES
Lamina propria
Muscularis mucosae

Question 4

In the lamina propria layer of the Mucosa, what will you find?

Answer 4

Loose CT that is well vascularized and contains lymphatic nodules and WBCs

Question 5

Does the muscularis mucosae layer of the Mucosa control food movement?

Answer 5

NO - controls mobility and infoldings of mucosa

Question 6

Describe the Submucosal layer in the GI tract

Answer 6

Dense irregular CT with neurovasculature and lymphatics and sometimes glands

Question 7

In what regions of the GI tract does the Submucosal layer have glands?

Answer 7

Esophagus and the Duodenum

Question 8

How many layers does the Muscularis Externa have?

Answer 8

2

Question 9

What are the layers of the Muscularis Externa?

Answer 9

Inner circular layer

Outer longitudinal layer

Question 10

Function of the inner circular layer of the Muscularis Externa?

Answer 10

Constrict lumen

Question 11

Function of the outer longitudinal layer of the Muscularis Externa?

Answer 11

Shorten tube

Question 12

What resides between the inner circular layer and the outer longitudinal layer of the Muscularis Externa?

Answer 12

Neurovascular plexuses

Question 13

Mesothelium

Answer 13

Simple squamous epithelium

Question 14

When the Adventitia is covered with Mesothelium

Answer 14

Serosa

Question 15

Areas without Mesothelium

Answer 15

Adventitia

Question 16

Areas without mesothelium… are they intraperitoneal or retroperitoneal?

Answer 16

Retroperitonal (adventitia)

Question 17

What are the main mucosal types along the GI tract?

Answer 17

Non-keratinized stratified squamous OR

Simple Columnar epithelium

Question 18

Where will you find Non-keratinized stratified squamous and what is its job?

Answer 18

Oral cavity, pharynx, anal canal

Job = PROTECTION

Question 19

Where will you find Simple columnar epithelium?

Answer 19

Stomach
Small intestines
Large intestines

Question 20

In the stomach, describe the mucosa there

Answer 20

Simple columnar epithelium packed with glands

Job = SECRETION

Question 21

In the small intestines, describe the mucosa there

Answer 21

Simple columnar epithelium arranged as villi with crypts, may or may not have glands
Job = ABSORPTION

Question 22

In the large intestines, describe the mucosa there

Answer 22

Simple columnar epithelium packed with glands and goblet cells
Job = ABSORPTION AND PROTECTION

Question 23

What are the 2 plexuses that innervate the GI tract?

Answer 23

Submucosal plexus of Meissner

Myenteric plexus of Auerbach

Question 24

Which plexus is in between the inner circular layer and the outer longitudinal layer of the Muscularis Externa?

Answer 24

Myenteric plexus of Auerbach

Question 25

What does the neurovascular plexuses control?

Answer 25

``` Peristaltic contractions (move food) down muscularis externa AND Secretory activities of the mucosal and submucosal glands ```

Question 26

Preganglionic axons of the parasymp. ___ motility

Answer 26

INCREASE

Question 27

Postganglionic axons of the symp. _____ motility

Answer 27

DECREASE

Question 28

What type of epithelium does the Mucosal layer of the esophagus contain?

Answer 28

Nonkeratinized stratified squamous

Question 29

The submucosal layer of the esophagus contains what?

Answer 29

Collagen, elastic fibers, blood vessels and venous plexuses

Question 30

Increased pressure can cause dilation of submucosal venous sinuses in the esophagus

Answer 30

Esophageal varices

Question 31

What type of glands may be seen in the esophagus?

Answer 31

Cardiac esophageal glands in lamina propria and submucosal glands

Question 32

Describe the muscularis externa layers in the upper third of the esophagus?

Answer 32

Skeletal muscle

Question 33

Describe the muscularis externa layers in the middle third of the esophagus?

Answer 33

Smooth and skeletal muscle

Question 34

Describe the muscularis externa layers in the lower third of the esophagus?

Answer 34

Smooth muscle

Question 35

GERD

Answer 35

Reflux of gastric contents, causes chronic inflammation and difficulty swallowing

Question 36

If GERD is chronic, what can occur?

Answer 36

Nonkeratinized stratified squamous will transition to columnar mucus-secreting/glandular = Barrett's esophagus

Question 37

Place where the nonkeratinized stratified squamous transitions to simple columnar

Answer 37

Gastroesophageal junction - very sharp transition

Question 38

Rugae

Answer 38

Longitudinal folds of gastric mucosa that expand during eating - covered with gastric pits

Question 39

Gastric glands produce mucosal barrier for protection and reach lumen via?

Answer 39

Gastric pits on Rugae

Question 40

What type of epithelium is present in the mucosal layer of the stomach?

Answer 40

Simple columnar

Question 41

What type of glands does the lamina propria contain in the stomach?

Answer 41

Cardiac, gastric and pyloric

Question 42

What facilitates release from gastric glands?

Answer 42

Muscularis Mucosae

Question 43

What are the layers in the Muscularis Externa in the stomach?

Answer 43

Oblique Circular Longitudinal

Question 44

What layer in the Muscularis Externa thickens to form the pyloric sphincter?

Answer 44

Circular

Question 45

Does the stomach have adventitia or serosa?

Answer 45

Serosa!

Question 46

What are the parts of a gastric gland?

Answer 46

Gastric pit Neck/isthmus Gastric gland

Question 47

Where in the mucosal layer do the gastric glands begin?

Answer 47

Muscularis mucosae

Question 48

What are the cell types found on the gastric glands?

Answer 48

Surface mucous cells Mucous neck cells Chief cells Parietal cells

Question 49

What do mucous cells of the gastric gland release?

Answer 49

Mucin to neutralize acid environment

Question 50

Where are surface mucous cells found?

Answer 50

Line lumen and gastric pits

Question 51

Where are mucous neck cells found?

Answer 51

In gastric gland neck

Question 52

Where are chief cells found?

Answer 52

Inferior 1/3 part of gastric glands

Question 53

How do chief cells stain in gastric glands?

Answer 53

Abundant granules, basal nuclei and basophilic cytoplasm

Question 54

What do chief cells in gastric glands release?

Answer 54

Pepsinogen - converted to pepsin Gastric lipase = protein digestion

Question 55

Where are parietal cells found?

Answer 55

Upper segment and neck of gastric glands

Question 56

How do parietal cells stain in gastric glands?

Answer 56

Large cells, central round nuclei and cytoplasm stains eosinophilic

Question 57

What do parietal cells in gastric glands produce?

Answer 57

HCL and intrinsic factor

Question 58

Gastric ulcers

Answer 58

Erosive lesions in mucosa that extend deeper - painful

Question 59

What are some causes of gastric ulcers?

Answer 59

Bacterial infection NSAIDS Overproduction of enzymes or underproduction of mucous/bicarbonate

Question 60

Cells that are scattered in gastric mucosa that release hormones essential for digestive function

Answer 60

Enteroendocrine cells