GI 2

Question 1

What structures of the stomach are anterior?

Answer 1

the cardia, fundus, body

Question 2

What structures of the stomach are posterior

Answer 2

antrum (pyloric region), pyloric sphincer

Question 3

What are the functional regions of the stomach

Answer 3

proximal (reservoir), distal (pump, grinder)

Question 4

Structures that support the unique functions of the stomach

Answer 4

rugae and the oblique layer

Question 5

What is the luminal secretion of the LES and the cardia

Answer 5

mucus and bicarb

Question 6

What is the purposes of the LES and the cardia motility

Answer 6

Prevention of reflux, entry of food, regulation of belching (burping)

Question 7

What do the fundus and the body of the stomach secrete?

Answer 7

H+, intrinsic factor, mucus, HCO3-, pepsinogens, lipases

Question 8

What is the motility of the fundus and the body?

Answer 8

reservoir, tonic force during emptying

Question 9

What do the antrum and the pylorus secrete?

Answer 9

mucus and HCO3-

Question 10

What is the motility of the antrum and pylorus?

Answer 10

mixing, grinding, sieving, regulation of emptying

Question 11

What are the different gastric secretions?

Answer 11

gastrin secretion, acid secretion, paracrine secretion, enzyme secretion (PAGE)

Question 12

Acid is secreted by…

Answer 12

parietal cells in gastric glands

Question 13

What is important about the tubulovesicular membrane (on a parietal cell)

Answer 13

it expresses H+,K+ pumps

Question 14

What happens in parietal cell activation?

Answer 14

once the tubulovesicular membrane is activated, it will merge with the intracellular canaliculus (the fusion create a larger openning in the cell in which the H+/K+ pumps are found due to the fusion and it allows the cell to pump protons out-> the creation the HCl)

Question 15

Acid secretion is stimulated by…

Answer 15

gastrin, ACh, histamine

Question 16

Acid secretion is inhibited by…

Answer 16

prostaglandin E2 and somatostatin

Question 17

What is motility?

Answer 17

the ability of the muscles of the digestive tract to contract

Question 18

Would injecting VIP or ACh into the LES be an effective way to alleviate heart burn? Why?

Answer 18

By injecting ACh; ACh is a smooth muscle contractor, VIP is a smooth muscle relaxer= GERD is caused by relaxation, so to treat a symptom you would want to treat heartburn with ACh to increase smooth muscle motility

Question 19

HCl secretions increase when ___ binds to its receptor by increasing intracellular calcium levels

Answer 19

ACh, or gastrin (Gq-R)

Question 20

What is on the apical side of the parietal cell (in terms of pumps, channels)

Answer 20

H+/K+ pump, Cl- channel

Question 21

What happens to the blood pH after a meal?

Answer 21

the blood pH rises; because you are adding bicarb into the blood in order to secrete HCl-, this is referred to so the alkaline tide

Question 22

G cells are located…; and this tells us what about its secretions?

Answer 22

deep in the pits; they secrete gastrin into the blood (endocrine)

Question 23

Gastrin secretions are triggered by…

Answer 23

vagus nerve stimulation (through GRP); amino acids

Question 24

Gastrin secretions are inhibited by

Answer 24

acid, somatostatin

Question 25

What is the function of gastrin?

Answer 25

acts on parietal and ECL cells to stimulate acid release and stimulate mucosa growth in stomach, small and large intestine

Question 26

What are the 3 major paracrine secretions?

Answer 26

histamine, intrinsic factor, and somatostatin

Question 27

Histamine is secreted by...

Answer 27

ECL cells

Question 28

Histamine is stimulated by

Answer 28

gastrin and ACh

Question 29

Intrinsic factor is produced by...

Answer 29

parietal cells

Question 30

Somatostatin is secreted by

Answer 30

D cells

Question 31

Why is somatostatin important?

Answer 31

it is the primary feedback signal

Question 32

What are the two major enzymes secreted?

Answer 32

pepsin and gastric lipase

Question 33

pepsin is secreted by...

Answer 33

chief cells (as pepsinogen)

Question 34

pepsin is activated by...

Answer 34

acid or pepsin

Question 35

gastric lipase

Answer 35

breaks down lipids; cosecreted with pepsin

Question 36

receptive relaxation

Answer 36

relaxation of stomach muscles as food moves through the esophagus and enters stomach (getting ready for the food before it makes contact)

Question 37

adaptive relaxation

Answer 37

relaxation of stomach muscles when filled (food makes stomach relax)

Question 38

storage occurs where

Answer 38

in the proximal portion

Question 39

mixing/ peristalsis occurs where

Answer 39

in the distal portion of the stomach

Question 40

The stomach wall is not specialized for..., but it is specialized for... (how so)

Answer 40

not specialized for absorption, is specialized for protection (thick, alkaline mucus, tight junctions between epithelial cells, rapid replacement by GI stem cells)

Question 41

What is a gastric ulcer?

Answer 41

destruction of the lining of the gastric mucosa

Question 42

Taking what can provide relief for patients with stomach ulcers (to help with excess acid secretion)

Answer 42

Antacid

Question 43

What can treat ulcer patients that have H. pylori

Answer 43

antibiotics (Warren and Marshall's study)

Question 44

What is cAMP's effect on acid secretion?

Answer 44

cAMP increases acid secretion