Chapter 28: GI Hormones Flashcards Preview

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Flashcards in Chapter 28: GI Hormones Deck (43)
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1
Q

Produced by G cells in stomach antrum

A

Gastrin

2
Q

What stimulates secretion of gastrin?

A

Amino acids, vagal input (acetylcholine), calcium ETOH, antral distention, pH > 3.0

3
Q

What inhibits secretion of gastrin?

A

Inhibited by pH

4
Q

Gastrin target cells

A

Parietal cells and chief cells

5
Q

Gastrin elicited response

A

Increased HCl, intrinsic factor, and pepsinogen secretion

6
Q

Blocks H/K ATPase of parietal cell (final pathway for H+ release)

A

Omeprazole

7
Q

Mainly produced by D cells in stomach antrum

A

Somatostatin

8
Q

What stimulates secretion of somatostatin?

A

Secretion stimulated by acid in duodenum

9
Q

Somatostatin target cells

A

Many, is the great inhibitor

10
Q

Somatostatin elicited response

A

Inhibits gastrin and HCl release, inhibits release of insulin, glucagon, secretin, and motion; decreased pancreatic and biliary output

11
Q

Can be used to decreased pancreatic fistula output

A

Octreotide (somatostain analogue)

12
Q

Produced by I cells of duodenum

A

CCK

13
Q

What stimulates secretion of CCK?

A

Amino acids and fatty acid chains

14
Q

CCK elicited response

A

Gallbladder contraction, relaxation of sphincter of Oddi, increased pancreatic enzyme secreiton

15
Q

Produced by S cells of duodenum

A

Secretin

16
Q

What stimulates secretin secretion?

A

Stimulated by fat, bill, pH

17
Q

What inhibits secretin secretion?

A

Inhibited by pH > 4.0, gastrin

18
Q

Secretin elicited response

A

Increased pancreatic HCO3- release, inhibits gastrin release (this is reversed in patients with gastrinoma), and inhibits HCl release

  • High pancreatic duct output: increased HCO3-, decreased Cl-
  • Slow pancreatic duct output: increased Cl-, decreased HCO3- (carbonic anhydrase in duct exchanges HCO3- for Cl-)
19
Q

Produced by cells in gut and pancreas

A

Vasoactive intestinal peptide

20
Q

What stimulates secretion of vasoactive intestinal peptide?

A

Secretion stimulated by fat, acetylcholine

21
Q

Vasoactive intestinal peptide elicited response

A

Increased intestinal secretion (water and electrolytes) and motlity

22
Q

Mainly released by alpha cells of pancreas

A

Glucagon

23
Q

What stimulates secretion of glucagon?

A

Decreased glucose, increased amino acids, acetylcholine

24
Q

What inhibits secretion of glucagon?

A

Inhibited by increased glucose, increased insulin, somatostatin

25
Q

Glucagon elicited response

A

Glycogenolysis, gluconeogensis, lipolysis, ketogenesis, decreased gastric acid secretion, decreased gastrointestinal motility, relaxes sphincter of Oddi

26
Q

Released by beta cells of the pancreas

A

Insulin

27
Q

What stimulated secretion of insulin?

A

Glucose, glucagons, CCK

28
Q

What inhibits secretion of insulin?

A

Somatostatin

29
Q

Insulin elicited response

A

Cellular glucose uptake, promotes protein synthesis

30
Q

Secreted by islet cells in pancreas

A

Pancreatic polypeptide

31
Q

What stimulates secretion of pancreatic polypeptide?

A

Food, vagal stimulation, other GI hormones

32
Q

Pancreatic polypeptide elicited response

A

Decreased pancreatic and gallbladder secretion

33
Q

Released by intestinal cells of gut

A

Motilin

34
Q

What stimulates release of Motilin?

A

Duodenal acid, food, vagus input

35
Q

What inhibits release of motion?

A

Somatostatin, secretin, pancreatic polypeptide, duodenal fat

36
Q

Motilin elicited response

A

Increased intestinal motility (small bowel; phase III peristalsis) -> erythromycin acts on this receptor

37
Q

Where does erythromycin act to increase peristalsis?

A

Motilin receptor

38
Q

Increase intestinal motor activity, increase pancreatic enzyme secretion, increase gastric acid secretion

A

Bombesin (gastrin-releasing peptide)

39
Q

Released from terminal ileum following a fatty meal -> inhibits acid secretion and stomach contraction; inhibits gallbladder contraction and pancreatic secretion

A

Peptide YY

40
Q

What mediates anorexia?

A

Hypothalamus

41
Q

Small bowel recovery

A

48 hours

42
Q

Stomach recovery

A

48 hours

43
Q

Large bowel recovery

A

3-5 days