Histology of the upper GI tract: Esophagus and stomach

Question 1

3 components of the mucosa

Answer 1

1) lining epithelium with mucosal and submucosal glands and ducts
2) lamina propria that is vacularized loose connective tissue
3) muscularis mucosae

Question 2

where in GI tract is there stratified squamos?

Answer 2

oral cavity, oropharynx, esophagus, anal canal

Question 3

simple columnar epithelium is where?

Answer 3

stomach, SI, LI, rectum

Question 4

Lamina propria of what is relevant site of immune responses (peyer’s patch or GALT)

Answer 4

SI and LI

Question 5

structure and function of muscularis mucosase

Answer 5

thin double layer of SM, for local movement of mucosa

-increases contact area with food, propel and mix food in GI tract

Question 6

what kind of tissue is the submucosa? and has what

Answer 6

dense irregular connective tissue

-BV, nerves, lymphatics branching into mucosa and muscularis layers

Question 7

glands are present in the submucosa of the ___ and ___

Answer 7

esophagus and duodenum

Question 8

mucosa alone can extend into the lumen as? and this does what?

Answer 8

villi, which increase the absorptive capacity of digestive tube

Question 9

adventitia is where

Answer 9

outside the peritoneal cavity, binds to the body wall

Question 10

adventitia made of ___ and contains __

Answer 10

made of loose CT, contains blood vessels and nerves

Question 11

serosa location

Answer 11

within the peritoneal cavity

Question 12

serosa made of __ ___

and contains

Answer 12

loose CT, simple squamos epithelium

contains BV, nerves, adipose tissue

Question 13

in the upper esophagus the muscularis mucosae consits of _____ instead of ___

Answer 13

thin elastic fibers instead of smooth muscle cells

Question 14

the lower esophagus contains ___

Answer 14

smooth muscle fibers

Question 15

at the gastroesophageal junction the mucosa transitions from __ to __

Answer 15

stratified squamos, to simple columnar and glandular secretory mucosa

Question 16

portal-caval anastomoses

Answer 16

increase in portal venous pressure results in dilation of veins

Question 17

esophagus muscularis externa : upper 1/3, middle 1/3, lower 1/3

Answer 17

upper: skeletal muscle
middle: transition, primary SM
lower 1/3: smooth muscle

Question 18

upper esophageal spchinter:

Answer 18

anatomically defined, cricothyroid, initiation of swallowing

Question 19

lower esohpageal spchinter

Answer 19

functionally defined, gastroesophageal sphincter: prevents gastric refulx

Question 20

GERD change in epithelium (barrett’s esophagus)

Answer 20

change in epithelium from stratified sqaumos to simple columnar epithelium
-predisposes to the development of adenocarcinoma of the esophagus
premalignant may be present for 20 years

Question 21

hernias

Answer 21

movement of esophagus through esophageal hiatus of respiratory diaphragm into the thorax (sliding or paraesophageal)

Question 22

function of the somtach

Answer 22

homogenize and chemically process the swallowed semisolid fluid

Question 23

rugae

Answer 23

longitudinal fold of gastric mucosa and submucosa of stomach

Question 24

gastric mucosa consists of what

Answer 24

gastric glands surrounded by lamina propria

Question 25

gastric glands: cardia region

Answer 25

simple tubular and coiled at lower end, lined by mucus-secreting cells

Question 26

gastric glands amount, gastric pit

Answer 26

2-7 glands per gastric pit

Question 27

types of cells in gastric gland

Answer 27

mucous neck cells, parietal cells, stem cells, chief cells, gastroenteroendocrine cells

Question 28

mucous cells (2 classes)

Answer 28

1) surface mucous cells lining the pit 2) mucous neck cells locatied at the opening of the gastric gland into the pit -both cells produce mucins, glycoproteins

Question 29

mucus layer from mucous cells: makeup and function

Answer 29

contains 95% water and 5% mucins, make insoluble gel that attaches to the surface of gastric mucosa = thick protective layer. -can trap thing in it, traps bicarb to help neutralize the acidity of the stomach, makes ph alkaline

Question 30

chief cell location

Answer 30

predominate lower 1/3 of gastric gland, not in cardiac glands, rare in pyloric antrum

Question 31

what stimulaes exocytosis of pepsinogen

Answer 31

feeding after fasting | also acetylcholine

Question 32

the gastric glans of the fundus-body region contain two major cell types

Answer 32

chief cells and parietal cells

Question 33

stimulation and release of HCL from parietal cells

Answer 33

after stimulation, tubulovesicles fuse with the plasma membrane of the intracellular canaliculus carbonic anhydrase and H+/K+ ATPase are localized in the microvilli projecting into the lumen of the intracellular cancaliculus, can relaease HCL

Question 34

autoimmune gastritis

Answer 34

autoantibodies to H+/K+dependent ATPase on parietal cells and intrinsic factor -decreases HCL in gastric juice (achlorhydria) and lack of intrinsic factor--> no B12 absorption and leads to pernicious anemia

Question 35

stimulation of HCL by parietal cells

Answer 35

acteylcholine (directly) and gastrin (from enteroendocrine cells of pyloric antrum) acetylcholine also stimulates release of gastrin

Question 36

H pylori site it resides and causes what

Answer 36

mucus blanket lining in the gastric epithelium especially the pyloric antrum is site where they survive and replicate in the lumen. presence has been associated with acid peptic ulcers and adenocarcinoma of the stomach

Question 37

gastroenteroendocrine cells produce what and location

Answer 37

produces peptide hormones and are despersed throughout the mucosa of the stomach, through the colon

Question 38

peptide hormones produced by gastrointestinal endocrine cells have 3 general functions

Answer 38

1) regulation of water, electrolyte metabolism, and enzyme secretion 2) regulation of GI motility and mucosal growth 3) stimulation of the release of other peptide hormones

Question 39

secretin is released where?

Answer 39

released by cells in duodenal glands of lieberkuhn

Question 40

secretin stimulates what

Answer 40

pancreatic and duod bicarb and fluid release to control gastric acid secretion

Question 41

secretin together with what stimulates what

Answer 41

growth of exocrine pancreas, also with acetylcholine stimulates chief cells to secrete pepsinogen, inhibits gastrin release to reduce HCL secretion in the stomach

Question 42

Gastrin produced by what cells and where

Answer 42

G cells in the pyloric antrum

Question 43

main function of gastrin

Answer 43

to stimulate production of HCL by parietal cells

Question 44

Gastrin can also activate ___ to stimulate __

Answer 44

CCK, gallbladder contraction

Question 45

CCK produced where and stimulates what

Answer 45

in duod, stimulates gallbladder contraction and relaxation of sphincter of Oddi when protein and fat-rich chyme enters duodenum

Question 46

glucose-dependent insulinotropic peptide (GIP) | produced where and stimulates what

Answer 46

produced in duod, stimulates insulin release when glucose is detected in SI

Question 47

motilin released whwer and does what

Answer 47

SI and stimulates GI motility, neural control mech

Question 48

ghrelin porduced where and does what

Answer 48

produced in the stomach fundus, binds receptor present in GH secreting cells of anterior hypophysis and stimulates secretion of growth hormone levels increase during fasting and trigger hunger by acting on hypothalamic feeding centers

Question 49

hypertrophic pyloric stenosis

Answer 49

food cannot get from stomach to duodenum, so infants start puking as soon as they eat, no bile in their vomit

Question 50

what kind of fibers predominate in the lamina propria

Answer 50

reticular and collagen fibers

Question 51

submucosa consists of what tissue

Answer 51

dense irregular CT, collagenous and elastic fibers are abundant