Histology of Esophagus, Stomach, SI, LI

Question 1

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

Answer 1

mucosa
submucosa
muscularis externa
serosa/adventitia

Question 2

What does the mucosal layer consist of?

Answer 2

• lining epithelium
• lamina propria
• muscularis mucosae

Question 3

What is in the lamina propria?

Answer 3

lymphatic nodules, lymphocytes, plasma cells, macrophagaes

Question 4

What is the fxn of the muscularis mucosae?

Answer 4

controls mobility of mucosa and glands

Question 5

What is in the submucosal layer?

Answer 5

• dense irregular CT

- glands present in esophagus and duodenum

Question 6

What is the difference between adventitia and serosa?

Answer 6

Serosa: adventitia covered by mesothelium and suspended by mesentery/peritoneal fold

Adventitia: without mesothelial covering

Question 7

What kind of epithelium is protective?

Answer 7

nonkeratinized stratified sqamous

Question 8

Where would you find nonkeratinized stratified squamous epithelium?

Answer 8

oral cavity
pharynx
anal canal

Question 9

What epithelium is secretory?

Answer 9

simple coumnar packed with glands

Question 10

Where would you find simple columnar epithelium?

Answer 10

stomach

Question 11

What epithelium is absorptive?

Answer 11

simple columnar with villi that contain crypts

–>glands in SI

Question 12

What type of epithelium is absorptive and protective?

Answer 12

simple columnar arranged in closely packed glands with extensive goblet cells

Question 13

Where is protective/absorptive epithelium found?

Answer 13

LI

Question 14

Where is absorptive epithelium found?

Answer 14

SI

Question 15

Does the esophagus have serosa or adventitia?

Answer 15

Both

thoracic= adventitia
inferior to diaphragm= serosa

Question 16

Where are cardiac esophageal glands?

Answer 16

lamina propria of terminal esophagus

Question 17

What cell types make up submucosal glands in the esophagus?

Answer 17

mucous and serous drained by single duct

Question 18

Increased pressure in submucosal venous plexus of esophagus can cause __________-

Answer 18

esophageal varices

Question 19

What type of muscle is the upper third esophagus?

Answer 19

skeletal

Question 20

What type of muscle is middle third esophagus?

Answer 20

skeletal and smooth

Question 21

What type of muscle is lower third esophagus?

Answer 21

smooth

Question 22

Describe Barrett’s esophagus/metaplasia

Answer 22

d/t chronic GERD:

nonkeratinized stratified squamous becomes columnar mucus-secreting epithelium in TRANSITION ZONE

Question 23

How to identify stomach from esophagus

Answer 23

Transition from nonker strat sqamous to simple columnar with lots of glands and pits

Question 24

What protects the mucosal surface of the stomach?

Answer 24

gastric mucosal barrier

Question 25

What is stomach rugae (mucosal folds) sovered by?

Answer 25

gastric pits

Question 26

Does the stomach have adventitia or serosa?

Answer 26

serosa

Question 27

What cells make up the gastric glands?

Answer 27

``` surface mucous mucous neck parietal (IF, HCl) chief (pepsinogen, lipase) G cell (gastrin) ```

Question 28

What cell is in the inferior regions of gastric glands, has abundant RER and secretory granules?

Answer 28

chief cells

Question 29

What cells is near neck of gastric gland, large, one or two central nuclei and intensely eosinophilic (pink)?

Answer 29

parietal cell

Question 30

What is the difference between cardiac and pyloric glands in histo?

Answer 30

cardiac are tubular and coiled-->appear circular in oblique sections pyloric are mainly branched

Question 31

Where are plicae circulares visible?

Answer 31

jejunum, not really in ileum

Question 32

What are villi covered with?

Answer 32

simple columbar with enterocytes and goblet cells

Question 33

Where are lacteals?

Answer 33

lymph in the middle of villi in SI

Question 34

What are intestinal glands lined with ?

Answer 34

simple columnar epithelium

Question 35

What cells are in intestinal gland epithelium?

Answer 35

Enteroendocrine Paneth M (microfold) Intestinal stem cells

Question 36

What cell secretes gastrin, secretin, GIP, motilin and CCK to help control gut motility?

Answer 36

enteroendocrine cell

Question 37

What is a pyramidal-shaped cell at the base of intestinal glands?

Answer 37

paneth cell

Question 38

What is the function of paneth cells?

Answer 38

innate immunity, secretes antimicrobial substances to regulate normal bacterial flora

Question 39

What reside in a niche at the crypt base, near Paneth cells?

Answer 39

intestinal stem cells -->diff into goblet, enterocyte, and enteroendocrine cells

Question 40

What are locaed in ilea mucosa overlying peyer patches?

Answer 40

M cells -->transport particles and microorganisms (gram -)

Question 41

What is the fxn of M cells?

Answer 41

internalize gram - bacteria and transfer to immune cells -->fxn as Antigen-transporting cells

Question 42

How do you differentiate duodenum from pylorus?

Answer 42

abundant Brunner's glands in submucosa, deep to muscularis mucosae, lots of deep villi

Question 43

What are the fxn of Brunner;s glands in submucosa of duodenum?

Answer 43

neutralize acidic chyme

Question 44

Are there submucosal glands in jejunum?

Answer 44

NO

Question 45

Where are long finger-like villi with lacteals located?

Answer 45

jejunum

Question 46

Where are peyer's patches located?

Answer 46

ileum -->circles under short villi (c/t jejunum)

Question 47

Hallmarks of LI

Answer 47

- simple columnar epithelium with intestinal glands - goblet cells - NO intestinal villi

Question 48

Does the SI and LI have adventitia or serosa?

Answer 48

Serosa

Question 49

Describe anal transitional zone (AZT)

Answer 49

simple columnar epithelium-->stratified squamous epithelium middle 1/3