28 Gastrointestinal hormones

Question 1

Gastrin - source?

Answer 1

G-cells in antrum of stomach

Question 2

Gastrin - stimulated by?

Answer 2

Amino acids
Vagal input (acetylcholine)
Calcium
ETOH
Antral distention
pH > 3.0

Question 3

Gastrin - inhibited by?

Answer 3

pH <3.0
Somatostatin
Secretin
CCK

Question 4

Gastrin - target cells?

Answer 4

Parietal cells

Chief cells

Question 5

Gastrin - effect?

Answer 5

Increased HCL
Increased intrinsic factor
Increased pepsinogen secretion

Question 6

Omeprazole - MOA

Answer 6

Blocks H/K ATPase of parietal cells

Causes decreased H+ release

Question 7

Somatostatin - source?

Answer 7

D cells in antrum of stomach

Question 8

Somatostatin - Stimulation?

Answer 8

Acid in duodenum

Question 9

Somatostatin - Target?

Answer 9

Everything - the great inhibitor

Question 10

Somatostatin - response?

Answer 10

Inhibits gastrin release
Inhibits HCl release
Inhibits release of insulin glucagon, secretin and motilin
Increases pancreatic and biliary output

Question 11

CKK - source?

Answer 11

I cells of duodenum

Question 12

CKK - stimulation?

Answer 12

AA and Fatty acid chains

Question 13

CKK - effect?

Answer 13

Gallbladder contraction
Relaxation of sphincter of Oddi
Increased pancreatic enzyme secretion

Question 14

Secretin - source?

Answer 14

S cells of duodenum

Question 15

Secretin - stimulation?

Answer 15

Fat, bile, pH <4.0

Question 16

Secretin - inhibition?

Answer 16

pH >4.0, gastrin

Question 17

Secretin - response?

Answer 17

Increased pancreatic HCO3 release
Inhibits gastrin release
Inhibits HCl release

Question 18

How does the gastrin-response to Secretin change in a gastrinoma?

Answer 18

Secretin causes increased gastrin release (normal is inhibition)

Question 19

What is the composition of pancreatic duct output when there is high volume?

Answer 19

Increased HCO3

Decreased Cl

Question 20

What is the composition of pancreatic duct output when there is low (slow) volume?

Answer 20

Increased Cl

Decreased HCO3

Question 21

Why does the rate of pancreatic duct outflow effect the Cl and HCO3 concentrations?

Answer 21

Carbonic anhydrase in the duct exchanges HCO3 for Cl; therefore, the longer it is in the ducts (i.e. the slower it is moving) the more chloride you have switched out.

Question 22

Vasoactive intestinal peptide - source?

Answer 22

Cells in gut and pancreas

Question 23

Vasoactive intestinal peptide - stimulation?

Answer 23

Fat

Acetylcholine

Question 24

Vasoactive intestinal peptide - response?

Answer 24

Increased intestinal secretion (water, electrolytes)

Increased motility

Question 25

Glucagon - source?

Answer 25

Alpha cells of pancreas

Question 26

Glucagon - stimulation?

Answer 26

Decreased glucose Increased AA Acetylcholine

Question 27

Glucagon - inhibition?

Answer 27

Increased glucose Increased insulin Somatostatin

Question 28

Glucagon - response?

Answer 28

``` Increased glycogenolysis Increased gluconeogenesis Increased lipolysis Increased ketogenesis Decreased gastric acid secretion ```

Question 29

Insulin - source?

Answer 29

Beta cells of pancreas

Question 30

Insulin - stimulation?

Answer 30

Glucose Glucagon CCK

Question 31

Insulin - inhibition?

Answer 31

Somatostatin

Question 32

Insulin - response?

Answer 32

Increased cellular glucose uptake | Promotes protein synthesis

Question 33

Pancreatic polypeptide - source?

Answer 33

Islet cells in pancreas

Question 34

Pancreatic polypeptide - stimulation?

Answer 34

Food Vagal stimulation Other GI hormones

Question 35

Pancreatic polypeptide - response?

Answer 35

Decreased pancreatic and gallbladder secretion

Question 36

Motilin - source?

Answer 36

Intestinal cells of gut

Question 37

Motilin - stimulation?

Answer 37

Duodenal acid Food Vagus input

Question 38

Motilin - inhibition?

Answer 38

Somatostatin Secretin Pancreatic polypeptide Duodenal fat

Question 39

Motilin - response?

Answer 39

Increased intestinal motility (small bowel - phase III peristalsis)

Question 40

Erythromycin - action on motility?

Answer 40

Acts on motilin receptors | Increases intestinal motility

Question 41

Bombesin (gastrin-releasing peptide) - response?

Answer 41

Increased intestinal motor activity Increased pancreatic enzyme secretion Increased gastric acid secretion

Question 42

Peptide YY - source

Answer 42

Terminal ilium

Question 43

Peptide YY - stimulation

Answer 43

Fatty meal

Question 44

Peptide YY - response?

Answer 44

Inhibits acid secretion and stomach contraction | Inhibits gallbladder contraction and pancreatic secretions

Question 45

In what order, and in what time period, does the bowel recovery after surgery?

Answer 45

Small bowel - 24hrs Stomach - 48hrs Large bowel - 3-5 days