Chapter 28 - G.I. Hormones

Question 1

Where is gastrin produced?

Answer 1

G sells in antrum

Question 2

Target cells of gastrin? Response?

Answer 2

Parietal cells and chief cells; increased HCl, intrinsic factor, pepsinogen secretion

Question 3

Mechanism of action of omeprazole?

Answer 3

Blocks H/K ATPase of parietal cell

Question 4

Where is somatostatin produced?

Answer 4

D cells in antrum

Question 5

Secretion of somatostatin is simulated by what?

Answer 5

By acid in duodenum

Question 6

Target cells of somatostatin? Response?

Answer 6

Many - the great inhibitor; inhibits gastrin, HCl release, inhibits release of insulin, glucagon, secretin, GIP, motilin, neurotensin, enteroglucagon; decreases pancreatic and biliary output

Question 7

What is octreotide? What is it used for?

Answer 7

Somatostatin analog, can be used to decrease pancreatic fistula output

Question 8

Gastric inhibitory peptide is made where?

Answer 8

K cells in duodenum

Question 9

Secretion of GIP stimulated by what?

Answer 9

Amino acids, glucose, long chain fatty acids, decreased pH

Question 10

Target cells of GIP? Response?

Answer 10

Parietal cells of stomach and data cells the pancreas, decreased HCL secretion and pepsin, increase insulin release

Question 11

CCK is produced where?

Answer 11

Produced by I cells of duodenum and jejunum

Question 12

Secretion of CCK stimulated by what?

Answer 12

Secretion stimulated by amino acids, fatty acid chains

Question 13

Response of CCK?

Answer 13

Gallbladder contraction, relaxation of sphincter Oddi, increased pancreatic enzyme secretion, some increase in intestinal motility

Question 14

Secretin is produced where?

Answer 14

S cells of duodenum

Question 15

Secretion of secretin is stimulated by what? Inhibited by what?

Answer 15

Stimulated by fat, bile, pH less than 4; inhibited by pH greater than four, gastrin

Question 16

Response to secretin?

Answer 16

Increased pancreatic HCO3-, increased bile flow, inhibit gastrin release (this is reversed in patients with gastrinoma), inhibit HCl release

Question 17

High pancreatic duct output shows what electrolyte response?

Answer 17

Increased HCO3-, decreased CL-

Question 18

Slow pancreatic duct output shows what electrolyte response?

Answer 18

Increased CL, decreased HCO3-; carbonic anhydrase in duct exchanges HCO3- for CL

Question 19

Where is vasoactive intestinal peptide produced?

Answer 19

Produced by cells in gut and pancreas

Question 20

Secretion of VIP stimulated by what?

Answer 20

Fat, acetylcholine

Question 21

Response to VIP?

Answer 21

Increased intestinal secretion and motility, inhibits gastrin release

Question 22

Insulin is produced where?

Answer 22

Beta cells of pancreas

Question 23

Secretion of insulin stimulated by what? Inhibited by what?

Answer 23

Stimulated by glucose, glucagon’s, CCK; inhibited by somatostatin, pancreatostatin

Question 24

Response to insulin?

Answer 24

Cellular glucose uptake; promotes protein synthesis

Question 25

Where is glucagon produced?

Answer 25

Alpha cells of pancreas, also from alpha cells stomach, intestines

Question 26

Secretion of glucagon stimulated by what? Inhibited by what?

Answer 26

Stimulated by decreased glucose, increased amino acids, acetylcholine, gastrin releasing peptide; inhibited by increased glucose, increased insulin, somatostatin

Question 27

Response to glucagon?

Answer 27

Glycogenolysis, gluconeogenesis, lipolysis, ketogenesis, decreased gastric acid secretion, decreased pancreatic secretions, decreased intestinal motility, decreased stomach motility, increased LES pressure, decreased MMCs

Question 28

Pancreatic polypeptide produced where?

Answer 28

Islet cells in pancreas

Question 29

Secretion of pancreatic polypeptide stimulated by what?

Answer 29

Food, vagal stimulation, other GI hormones

Question 30

Response to pancreatic polypeptide?

Answer 30

Decreased pancreatic and gallbladder secretion

Question 31

Motilin is produced where?

Answer 31

Intestinal cells of gut

Question 32

Secretion of motilin stimulated by what? Inhibited by what?

Answer 32

Stimulated by duodenal acid, food, vagal input, gastrin releasing peptide; inhibited by somatostatin, secretin, pancreatic polypeptide, duodenal fat

Question 33

Bombesin is otherwise known as what? Response?

Answer 33

Gastrin releasing peptide; increased intestinal motor activity, increased pancreatic enzyme secretion, increased gastric acid secretion

Question 34

Where is peptide YY produced?

Answer 34

Terminal ileum following fatty meal

Question 35

Response to peptide YY?

Answer 35

Inhibits acid secretion and stomach contraction; inhibits gallbladder contraction and pancreatic secretion

Question 36

Anorexia is mediated by what?

Answer 36

Hypothalamus

Question 37

What is the recovery time for small bowel? Stomach? Large bowel?

Answer 37

Small bowel – 24 hours, stomach – 48 hours, large bowel - 3-5 days