[7] Histology of the GI Tract, and Glands

Question 1

Entrance to the GI System

Answer 1

Oral Cavity

Question 2

Which lingual papillae have no taste buds?

Answer 2

Filiform

Question 3

Which lingual papillae are the most abundant?

Answer 3

Filiform

Question 4

Where are Von Ebner glands found?

Answer 4

Circumvallate Papillae

Question 5

Function: Von Ebner Glands

Answer 5

Lubrication

Question 6

4 Main Layers

Answer 6

1. Mucosa
2. Submucosa
3. Muscularis Externa
4. Adventitia/Serosa

Question 7

[Esophagus Layers]

Describe: Mucosa

Answer 7

Stratified squamous, thinly keratinized epithelium

Question 8

[Esophagus Layers]

Describe: Submucosa

Answer 8

• With blood vessels, lymphatic vessels and nerves (Meissner’s plexus)
• Contain numerous esophageal glands proper for lubrication of food

Question 9

[Esophagus Layers]

Describe: Muscularis Externa

Answer 9

Upper 1/3: Purely striated
Middle 1/3: Mixed
Lower 1/3: Purely smooth muscle

Question 10

[Stomach Layers]

Epithelium changes from what to what?

Answer 10

Stratified Squamous -> Simple Columnar

Question 11

[Stomach Layers]

In what layer are glands only found?

Answer 11

Mucosa

Question 12

[Stomach Layers]

Where do glands pour their secretions?

Answer 12

Depressions in rugae called gastric pits / foveolae

Question 13

What produces Pepsinogen?

Answer 13

Chief Cells

Question 14

What cells produces HCl acid?

Answer 14

Parietal Cells

Question 15

What are the most numerous glands of the gastric mucosa?

Answer 15

Chief Cells

Question 16

What are the most conspicuous glands of the gastric mucosa?

Answer 16

Parietal Cells

Question 17

Function: Gastric Intrinsic Factor

Answer 17

Vitamin B12

Question 18

Types of Enteroendocrine Cells and Function

Answer 18

1. G Cell: Gastrin (+ HCl Production)
2. EC Cell: Serotonin
3. D Cell: Somatostatin
4. A Cell: Enteroglucagon
5. ECL Cell: Histamine

Question 19

3 Layers of Stomach Muscularis

Answer 19

1. Circular: Complete
2. Oblique: Incomplete
3. Longitudinal: Incomplete

Question 20

How are parietal/chief cells replaced?

Answer 20

Mitosis / Stem Cells

Question 21

Define: Mucosal Restitution

Answer 21

Undamaged cells from bottom of gastric pits migrate to denuded basal lamina

Question 22

Surface Modifications of the Small Intestine

Answer 22

1. Plicae Circularis/Valves of Kerckring
2. Villi
3. Microvilli
4. Crypts of Lieberkuhn
5. Absorptive Cell

Question 23

Glands found in the Intestine

Answer 23

1. Goblet Cells

2. APUD Cells

Question 24

Function: Paneth Cell

Answer 24

Create lysozymes and IgA (Immunologic)

Exclusive to small intestine

Question 25

Muscularis Mucosae is composed of?

Answer 25

Smooth Muscle Cells

Question 26

[Brunner’s Glands]

Location
Function

Answer 26

L: Duodenum
F: Secrete alkaline mucus and EGF

Question 27

Explain Peyer’s Patches role in neglected typhoid fever

Answer 27

They can hypertrophy and outgrow their blood sources causing necrosis

Question 28

[Cecum and Colon]
Describe:

1. Mucosa
2. Plicae Circularis
3. Crypts
4. Paneth Cells
5. Goblet Cells

Answer 28

1. Smooth Mucosa
2. ( - ) Plicae Circularis
3. Numerous Crypts
4. ( - ) Paneth Cells
5. More Goblet Cells

Question 29

[Anus]

Epithelium changes from what to what?

Answer 29

From columnar -> stratified squamous epithelium

Question 30

Differentiate minor and major salivary glands via opening

Answer 30

Minor: Open directly to mucosa via short ducts
Major: Open to the oral cavity via branching ducts

Question 31

Pathway of Pancreatic Duct System

Answer 31

Acinus -> Intercalated Duct -> Intralobular Duct -> Interlobular Duct -> Pancreatic Duct

Question 32

What is the main pancreatic duct?

What is the accessory duct?

Answer 32

Main: Wirsung
Accessory: Santorini

Question 33

Where are exocrine glands located?

What about endocrine glands?

Answer 33

Exocrine: Apical
Endocrine: Basal (Close to blood)

Question 34

[T/F]

There are striated ducts in the pancreatic duct system.

Answer 34

F