Histo of the Esophagus & Stomach

Question 1

What are the four layers of the GI tract?

Answer 1

mucosa

submucosa

muscularis externa

serosa/adventita

Question 2

What are the components of the mucosal layer?

Answer 2

Epithelium

Lamina Propria-contains lymphatics, lymphocytes etc.

muscularis mucosae-controls mobility of mucosa glands (gastric pits)

Question 3

What are the components of submucosal layer?

Answer 3

Dense irregular CT with neurovasculature & lymphatics

Question 4

What are the components of the muscularis externa?

Answer 4

Two layers of smooth muscle -inner and outer layers

Question 5

Contraction of the circular layer does what?

Answer 5

Constricts lumen

Question 6

Contraction of longitudinal layer does what?

Answer 6

shortens the tube

Question 7

What are the components of Serosa/Adventitia?

Answer 7

When suspended by mesentery, adventitia is covered by mesothelium forming serosa

-without mesothelium–>adventitia

Question 8

Where is nonkeratinzed stratified squamous found?

Answer 8

(Protective) Oral cavity pharynx anal canal

Question 9

Where is simple columnar epithelium (secretory)?

Answer 9

Mucosa packed with glands Stomach

Question 10

Where is simple columnar epithelium (Absorptive)?

Answer 10

Mucosa arranged as villi with crypts

Question 11

What is simple columnar epithelium (Absorptive/Protective)?

Answer 11

Mucosa arranged into closely packed glands goblet cells

Question 12

What do the submuscosal plexus of meissner and myenteric plexus of auerbach regulate?

Answer 12

• Peristaltic contractions of muscularis externa and muscularis mucosae
• Secretory activities of the mucosal and submucosal glands

Question 13

Thoracic esophagus has what kind of external layer?

Answer 13

adventita

Question 14

Inferior to the diaphragm has what kind of external layer?

Answer 14

serosa

Question 15

Where are cardiac esophageal glands found?

Answer 15

In the lamina propria of terminal esophagus

Question 16

What does the upper sphincter of the esophagus do?

Answer 16

anatomical, swallowing reflex

Question 17

What does the lower sphincter of the esophagus do?

Answer 17

function, prevents reflux of gastric contents

Question 18

What is Barrett’s esophagus/metaplasia?

Answer 18

Chronic GERD Nonkeratinzed stratified squamous in transition zone–> becomes columnar mucus-secreting

Question 19

What is the gastroesophageal Junction?

Answer 19

Transition from esophagus to stomach

Nonkeratinized stratified squamous–> simple columnar

Question 20

What are the four regions of the stomach?

Answer 20

Cardia

Fundus

Body

Pyloric antrum

Question 21

Orad Area

Answer 21

fundus and upper part of the body relaxes during swallowing

Question 22

Caudad Area

Answer 22

Lower portion of the body & the antrum

Regulation of gastric emptying

Question 23

What makes up a fundic (gastric) gland?

Answer 23

Gastric Pit

Isthmus/Neck

Gastric gland

Question 24

What are hallmarks of chief cells?

Answer 24

• abundant RER & apical secretory (zymogen) granules
• produce gastric lipase
• peipsinogen

Question 25

What are the hallmarks of parietal cells?

Answer 25

• Produce HCL and IF
• Usually round or pryamidal-shaped, round nucleus
• Cytoplasm is intensely eosinophilic due to increase in mitochondria

Question 26

What are enteroendocrine cells?

Answer 26

• Epithelial cells in gastric mucosa with endocrine functions
• Secrete to help with digestive function

Question 27

What is the difference between cardiac and pyloric glands?

Answer 27

cardiac glands are circular and pyloric glands are more tubular