Histo Esophagus & Stomach

Question 1

What are the 4 layers of the GI tract from lumen to superficial

Answer 1

Mucosa
Submucosa
Muscularis externa
Serosa/Adventitia

Question 2

How do you know which organs have advantitia vs serosa?

Answer 2

Serosa - Intraperitoneal organs
Adventitia - Retroperitoneal

SAD PUCKER - Retroperitoneal organs
Supra renal glands
Aorta/Vena Cava
Dudodenum (2,3,4)
Pancreas
Ureters
Ascending/Descending Colon
Kidneys
Esophagus
Rectum

Question 3

What are the Three layers of the Mucosa?

Answer 3

Epithelium
Lamina Propria
Muscularis Mucosa (thin muscle layer)

Question 4

What tissue is the Lamina Propria composed of and what structures does it contain?

Answer 4

Loose Connective Tissue

Blood Vessels
Lymph nodules

Question 5

What does the Muscularis Mucosa do?

Answer 5

Controls mucosal glands and movement of mucosa

Question 6

What tissue is the submucosa composed of and what structures does it contain?

Answer 6

Submucosa is composed of dense irregular connective tissue

Contains neurovasculature
Lymphatics

Contains glands in the Esophagus and Duodenum

Question 7

In which organs will you find glands in the Submucosa?

Answer 7

Esophagus and duodenum

Question 8

What is the structural difference between the Serosa and Adventitia?

Answer 8

Serosa has an adventitia with a mesothelium layer on top

Adventitia is alone in retroperitoneal organs (no mesothelium)

Question 9

What type of cell is typically epithelial in the GI tract?

Answer 9

Simple columnar

Question 10

Does the esophagus have adventitia or serosa?

Answer 10

Esophagus has both

Thoracic esophagus has adventitia

Abdominal esophagus (below diaphragm) has serosa

Question 11

What are the two glands found in the esophagus?

Answer 11

Cardiac esophageal Glands - Found in the Lamina Propria (mucosa) of the terminal esophagus (near cardiac of the stomach)

Submucosal Glands - Small lobules with mucous and serous cell types drained by a single duct

Question 12

Muscularis Mucosa is only present in some of the esophagus, where?

Answer 12

Lower segments

Question 13

What cell type makes up most of the epithelium of the esophagus?

Answer 13

Non-keratinized stratified squamous

Question 14

How does the muscularis vary by segments of teh esophagus?

Answer 14

Upper third = striated muscle
Middle third = striated and smooth muscle
Lower third = smooth muscle

Question 15

How does the epithelium transition from the Esophagus to the stomach?

Answer 15

Stratified Squamous –> simple columnar

Gastric epithelium is glandular with pits and glands

Question 16

In chronic GERD (Barrett’s esophagus) what happens to the Esophageal epithelium?

Answer 16

Changes from Stratified squamous to columnar mucus-secreting/glandular cells

Question 17

What are the layers of muscle in the muscularis of the stomach?

Answer 17

Oblique, Circular, Longitudinal

Question 18

What are the names of the glands of the stomach, where are they found?

Answer 18

Cardiac glands, Gastric glands, Pyloric glands

(Gastric Glands = Fundus glands)

Named according to location in the stomach

Located in the Lamina Propria

Question 19

Describe the Gastric Glands

Answer 19

Aka Fundic Glands

Simple branched tubular glands

Extend from bottom of gastric pits to muscularis

Have 3 parts:

• Isthmus (between gastric pit and gland below) - site of stem cell niche
• Neck - Narrow and long segment
• Fundus - Shorter and wider segment; base

FOUND ANYWHERE IN THE STOMACH PYLORIC AND CARDIAC GLANDS ARE ABSENT

Question 20

How to recognize mucous neck cell?

Answer 20

Mucous does not absorb stain, cells appear white/clearer

Question 21

What types are cells are found in the neck of the Gastric Gland?

Answer 21

Mucous neck cells
Enteroendocrine cells (G cells - secrete gastrin)
Parietal cells (secrete acid)

Question 22

What types of cells are found in the Fundus of the Gastric glands?

Answer 22

Enteroendocrine cells (G cells - secrete gastrin into blood)
Chief cells (secrete pepsinogen, for protein digestion)
Some parietal cells (acid secretion)

Question 23

What cells are found in the Isthmus of the Gastric Gland?

Answer 23

Dividing stem cells

Question 24

How do Chief cells appear on a slide?

Answer 24

Stained darkly red due to presence of zymogen (pepsinogen) granules.

Question 25

What is special about the structure of parietal cells?

Answer 25

They have intracellular canaliculi

-invaginations of apical surface continuous with gastric lumen (increases surface area)

Question 26

What are the two types of Enteroendocrine Cells?

Answer 26

Open Cells - Have a thin cytoplasmic extension that reaches the gland lumen. Have villi and chemoreceptors that signal hormone secretion into the blood stream

Closed - Have no direct contact with the glandular lumen, found in basement membrane, secrete homrones into blood

Question 27

Where is gastrin produced and what does it do?

Answer 27

Gastrin is produced in G cells of the pyloric antrum of the stomach

It signals HCl secretion from the Parietal cells

Question 28

Where is somatostatin produced and what does it do?

Answer 28

Produced in D cells

Inhibits the action of Gastrin (blocks promotion fo acid secretion from Parietal cells)

Question 29

Where is ghrelin produced and what does it do?

Answer 29

Ghrelin is produced in the Gastric Fundus

It signals the pituitary and causes secretion of Growth Hormone

Also triggers hunger sensation

Question 30

Describe cardiac glands

Answer 30

Glands are tubular coils and are also somewhat branched

Opening is continuous with gastric pits

Lined with mucous-secreting cells (similar to esophagus)

HALLMARK: Glands appear circular and oblique in sections

Question 31

Describe Pyloric glands

Answer 31

Branched, coiled, tubular glands found between fundus and pylorus

Large gastric pits that occupy half of the mucosa

Gut-Associated Lymphoid Tissue (GALT) can be seen in lamina propria