GI Hormones

Question 1

decrease gastric emptying

Answer 1

Cholecystokinin

Question 1

secreted by I cells (duodenum, jejunum)

Answer 1

Cholecystokinin

Question 1

this hormone secretion is inhibited when stomach pH < 1.5

Answer 1

gastrin

Question 1

this hormone secretion is inhibited by vagal stimulation

Answer 1

somatostatin

Question 1

pepsin secretion is upregulated by these 2 factors:

Answer 1

vagal stimulation, local acid

Question 3

this hormone secretion is inhibited by adrenergic input

Answer 3

VIP

Question 4

decrease insulin and glucagon release

Answer 4

Somatostatin

Question 4

what is a VIPoma?

Answer 4

non-α, non-β islet cell pancreatic tumor that secretes VIP -> copious watery diarrhea -> Hypokalemia -> Achlorhydria WDHA syndrome

Question 5

gastric acid secretion

upregulated by these 3 factors:

downregulated by these 4 factors:

Answer 5

up: Histamine***, ACh, Gastrin (via ECL cells -> histamine)
down: somatostatin, GIP, prostaglandin (misoprostol), secretin

Question 6

secreted by Parasympathetic ganglia in sphincters, gallbladder, small intestine

Answer 6

VIP

Question 8

increase gastric motility

Answer 8

Gastrin

Question 9

decrease pepsinogen secretion

Answer 9

Somatostatin

Question 11

increase smooth muscle relaxation, including lower esophageal sphincter (LES)

Answer 11

NO

Loss of NO secretion is implicated in increased LES tone of achalasia.

Question 12

secreted by Small intestine

Answer 12

motilin

Question 12

this hormone secretion is stimulated during fasting states

Answer 12

motilin

Question 13

decrease gall bladder contraction

Answer 13

Somatostatin

Question 14

increase relaxation of intestinal smooth muscle and sphincters

Answer 14

VIP

Question 16

sphincter of Oddi relaxation

Answer 16

Cholecystokinin

Question 17

decrease gastric H+ secretion

Answer 17

GIP, secretin, somatostatin

Question 18

increase gallbladder contraction

Answer 18

Cholecystokinin

Question 19

increase intestinal water and electrolyte secretion

Answer 19

VIP

Question 20

Produces migrating motor complexes (MMCs)

Answer 20

Motilin

Question 21

secreted by D cells (pancreatic islets, GI mucosa)

Answer 21

Somatostatin

Question 23

decrease pancreatic and small intestine fluid secretion

Answer 23

Somatostatin

Question 24

this hormone secretion is stimulated by stomach distention, alkalinization, a.a., peptides, vagal stimulation

Answer 24

gastrin

Question 25

this hormone secretion is stimulated by FA + a.a.

Answer 25

cholecystokinin

Question 26

secreted by S cells (duodenum)

Answer 26

Secretin

Question 27

increase bile secretion

Answer 27

secretin

Question 28

increase pancreatic HCO3– secretion

Answer 28

secretin HCO3 neutralizes gastric acid in duodenum, allowing pancreatic enzymes to function.

Question 29

this hormone secretion is stimulated by H+

Answer 29

secretin, somatostatin

Question 30

increase insulin release

Answer 30

GIP

Question 31

this hormone secretion is stimulated by distention and vagal stimulation

Answer 31

VIP

Question 32

secreted by K cells (duodenum, jejunum)

Answer 32

Glucose-dependent insulinotropic peptide

Question 33

increase gastric H+ secretion

Answer 33

Gastrin

Question 35

secreted by G cells (antrum of stomach)

Answer 35

Gastrin

Question 36

increase pancreatic secretion

Answer 36

Cholecystokinin

Question 37

HCO3 secretion is upregulated by these 2 factors:

Answer 37

pancreatic and biliary secretion with secretin

Question 38

motilin receptor agonist

Answer 38

erythromycin

Question 39

this hormone secretion is stimulated by FA, a.a., oral glucose

Answer 39

GIP

Question 40

increase growth of gastric mucosa

Answer 40

Gastrin

Question 41

this hormone secretion is stimulated by H+, fatty acids in lumen of duodenum

Answer 41

secretin

Question 42

potent stimulators of gastrin secretion

Answer 42

chronic PPI use (rebound acid secretion) phenylalanine tryptophan

Question 43

Zollinger-Ellison Syndrome of parietal cells of G cells acid secretion secretin injection

Answer 43

**# of parietal cells - increased** because they are **stimulated by gastrin** to produce gastric acid + IF **# of G cells - decreased** due to negative feedback from all the gastrin that is being produced by the tumor **acid secretion - increased**; refractory to medical therapy **secretin injection --\>increase gastrin secretion** (paradoxical since secretin normally decreases it!!)