GI 4

Question 1

digestive processes do not start until all food enters the GI tract
true
false

Answer 1

false

Question 2

is the activation of parietal cells by gastrin to secrete gastric acid indirect or direct

Answer 2

direct

Question 3

what does gastric acid from parietal cells do (2)

Answer 3

activates pepsin by cleaving pepsinogen
kills bacteria

Question 4

what do chief cells secrete

Answer 4

pepsinogen

Question 5

what does gastric acid do to pepsinogen

Answer 5

cleaves it to make pepsin

Question 6

what are the 5 gastric acid functions

Answer 6

stimulates release of pepsinogen and cleaves it to make pepsin
denatures proteins
kills bacteria
inactivates amylase in saliva
stimulates D cells to release somatostatin

Question 7

what do D cells release

Answer 7

somatostatin

Question 8

OH combined with CO2 makes

Answer 8

HCO3-

Question 9

how does H+ get across apical membrane

Answer 9

actively transported continuously

Question 10

what are the 2 systems of acid secretion

Answer 10

primary: water spontaneously dissociating into H and OH

secondary: carbonic anhydrase making CO2 and H2O into H2CO3 and then creating free hydrogen

Question 11

what cells do acid secretion (primary and secondary) processes occur in

Answer 11

parietal cells

Question 12

what joins with hydrogen in the lumen of the stomach to make hydrochloric acid

Answer 12

cl-

Question 13

where are all the apical transporters stored before stimuli

Answer 13

in vesicles

Question 14

what stimuli causes exocytosis in parietal cells and insertion of apical transporters (3)

Answer 14

gastrin
histamine
ACh

Question 15

what stimuli removes transporters from apical membrane of parietal cells

Answer 15

somatostatin secreted by D cells

Question 16

cephalic phase stimuli is what kind of reflex

Answer 16

long reflex

Question 17

what ensures that there’s not too much acid released

Answer 17

D cells that release somatostatin

Question 18

gastric phase stimuli is what kind of reflex

Answer 18

short reflex

Question 19

Gastric acid is released from:
G cells
D Cells
Chief Cells
Parietal cells

Answer 19

parietal cells -> they have a proton pump

Question 20

what secrets secretin

Answer 20

S cells in small intestine

Question 21

what secrets CCK

Answer 21

I cells of duodenum and jejunum

Question 22

what are chief cells stimulated by

Answer 22

acid secretion via short reflexes

Question 23

what cleaves proteins into smaller peptides in the lumen

Answer 23

pepsin

Question 24

what releases an intrinsic factor that can bind to vitamin B12 so it can be absorbed

Answer 24

parietal cells

Question 25

how does vitamin B12 get into the lumen

Answer 25

by being bound to an intrinsic factor to be recognized by a transporter

Question 26

what inhibits pepsinogen release by inhibiting chief cells

Answer 26

D cell-somatostatin

Question 27

is the autonomic vagal input sympathetic or parasympathetic

Answer 27

parasympathetic

Question 28

what is secreted from mucous cells (2)

Answer 28

mucus HCO3-

Question 29

what is mucus secretion stimulated by (2)

Answer 29

parasympathetic input irritation

Question 30

what is HCO3- secretion stimulated by (2)

Answer 30

parasympathetic inout H+

Question 31

what is a peptic ulcer

Answer 31

a sore or break in the lining of the stomach or duodenum

Question 32

what are peptic ulcers caused by

Answer 32

excessive acid production

Question 33

whats a major cause of peptic ulcers

Answer 33

helicobacter pylori

Question 34

what is the helicobacter pylori attracted to on stomach wall

Answer 34

low ph

Question 35

why is motility regulated

Answer 35

ensure proper digestion and absorption

Question 36

when does the intestinal phase begin

Answer 36

when home enters the small intestine

Question 37

what kind of contractions during intestinal phase

Answer 37

segmental and peristaltic

Question 38

what promotes motility? (3)

Answer 38

parasympathetic innervation gastrin cholecystokinin

Question 39

what do villi increase surface area for

Answer 39

absorption of mucus

Question 40

whats do crypts in the intestinal phase do

Answer 40

secrete hormone and fluid secretory cells

Question 41

where do fats enter in the intestinal phase

Answer 41

lacteals of lymphatics

Question 42

what do goblet cells secrete

Answer 42

mucus