Normal Structure and Function of the Upper GI Tract

Question 1

epithelium lining esophagus

Answer 1

non-keratinizing stratified squamous epithelium

Question 2

what parts of the GI tract are lined with non-keratinizing stratified squamous epithelium and which parts are lined with simple columnar?

Answer 2

non-keratinizing stratified squamous epithelium: esophagus and anal canal (to protect against abrasion)
simple columnar: stomach, small intestine, large intestine (to secrete, absorb, protect)

Question 3

function of muscularis mucosae

Answer 3

thin layer of smooth muscle fibers whose contracting move and fold the mucosa to facilitate digestion and absorption

Question 4

which tunic contains mucus-secreting glands and in which parts of the GI tract?

Answer 4

submucosa of esophagus and duodenum

Question 5

function of Meissner’s plexus

Answer 5

muscularis mucosae movement, blood flow, and mucosal gland secretion

Question 6

what part of the stomach produces gastrin?

Answer 6

antrum (G cells)

Question 7

what part of the stomach produces acid?

Answer 7

body and fundus

Question 8

what cells secrete histamine, and in response to what?

Answer 8

ECL cells; in response to vagus nerve to increase acid secretion

Question 9

HCl and intrinsic factor are secreted by what cells?

Answer 9

parietal cells

Question 10

zymogen secretory granules containing proenzymes (for pepsin, lipase) are in what cells?

Answer 10

chief cells

Question 11

what do parietal cells secrete?

Answer 11

HCl and intrinsic factor

Question 12

what do chief cells secrete?

Answer 12

pepsin, lipase