Absite Review Gi Hormones

Front 1

which three G.I. hormones are produced by the stomach?

Back 1

Gastrin, somatostatin, and ghrelin

Front 2

in which part of the stomach is gastrin produced?

Back 2

Antrum

Front 3

is gastrin also produced anywhere other than the Antrum?

Back 3

yes the pancreas

Front 4

what four things stimulate the G cells of the antrum to produce gastrin?

Back 4

Vagus nerve(acetylcholine), alkali gastric content, calcium, and ethanol

Front 5

wwhat does gastrin then do?

Back 5

Gastrin acts on the parietal and chief cells, to promote HCl, intrinsic factor, and pepsinogen release

Front 6

which pathway is used by gastrin upon binding to parietal cells?

Back 6

PIP-DAG pathway, leading to increased intracellular calcium, which activates protein kinase C

Front 7

which pathway is used by histamine upon binding to parietal cells?

Back 7

c AMP pathway

Front 8

which four conditions will give an increase in gastrin levels, as well as an increase in gastric acidity?

Back 8

Gastronoma, G cell hyperplasia, retained Antrum, and renal failure

Front 9

which four conditions will give an increase in gastrin levels but normal gastric acidity?

Back 9

Post-vagotomy, chronic gastritis, pernicious anemia, and medical acid suppression

Front 10

where are most gastrinomas located?

Back 10

head of the pancreas

Front 11

what is the effect of secretin on gastrin levels?

Back 11

secretin decreases gastrin levels

Front 12

what levels of gastrin are diagnostic of gastronoma?

Back 12

Gastrin levels greater than 1000, or greater than 200 after a secretin stimulation test

Front 13

what is the single best test for localizing a gastrinoma?

Back 13

Somatostatin receptor scintigraphy

Front 14

what are the symptoms of gastrinomas?

Back 14

ulcers and diarrhea. the diarrhea here is due to lipases broken down by the increased acidity

Front 15

what is the association between gastrin and calcitonin?

Back 15

Gastrin triggers calcitonin release in medullary thyroid cancer

Front 16

what are the side effects of vagotomy?

Back 16

Decreased receptive relaxation, causing increased liquid emptying, as well as decrease solid emptying. Symptoms therefore most commonly include diarrhea but also dumping syndrome

Front 17

how effective is dietary changes in control of the dumping syndrome post vagotomy?

Back 17

very effective

Front 18

what procedure increases emptying of solids?

Back 18

pyloroplasty

Front 19

what is the role of ghrelin?

Back 19

increases appetite

Front 20

which three G.I. hormones are produced by the duodenum?

Back 20

gastric inhibitory peptide GIP, CCK, and secretin

Front 21

which cells produce GIP?

Back 21

K cells

Front 22

what does GIP do?

Back 22

decrease gastrin release, decreased insulin release

Front 23

which cells produce CCK?

Back 23

I cells

Front 24

what does CCK do?

Back 24

increased gallbladder contraction, relax sphinter of Oddi, increase pancreatic enzyme secretion

Front 25

which cells produce secretin?

Back 25

S-cells

Front 26

what does secretin do?

Back 26

Increase pancreatic bicarb release

Front 27

which for G.I. hormones are produced by the small bowel?

Back 27

moyilin, bombesin ( gastrin releasing peptide), peptide YY, and enteroglucagon

Front 28

what does motilin do?

Back 28

stimulate the migrating motor complex (MMC)

Front 29

what are the four phases of the MMC?

Back 29

phase 1 through four, quiescence, acceleration, peristalsis, deceleration

Front 30

what is the length of each MMC cycle?

Back 30

90 min.

Front 31

which part of the G.I. tract does the MMC span?

Back 31

stomach to terminal ileum

Front 32

what does bombesin do?

Back 32

bombesin, aka gastric release peptide, increases gastrin secretion, motility, and enzyme secretions

Front 33

in which part of the small bowel is peptide YY made?

Back 33

Terminal ileum

Front 34

what does peptide YY do?

Back 34

opposite effect of GRP, decreases gastrin secretion, motility and enzyme secretions

Front 35

which cells produce enteroglucagon?

Back 35

L-cells of the small bowel

Front 36

what does into enteroglucagon do?

Back 36

increase insulin release in response to luminal glucose and fat

Front 37

what is the effect enteroglucagon after small bowel resection?

Back 37

causes small bowel mucosal hypertrophy

Front 38

which four hormones are made by the pancreas?

Back 38

insulin, glucagon, vasoactive intestinal peptide VIP, and pancreatic polypeptide

Front 39

which cells produce insulin?

Back 39

Beta cells

Front 40

what is the most common islet cell tumor of the pancreas?

Back 40

Insulinoma

Front 41

what are the symptoms of insulinomas? (aka Whipple's triad)

Back 41

hypoglycemia, symptoms of hypoglycemia, and relief of symptoms after correction of hypoglycemia

Front 42

where in the pancreas are insulinomas most commonly located?

Back 42

they occur evenly throughout the pancreas

Front 43

are insulinomas benign or malignant?

Back 43

most are benign

Front 44

what is the insulin to glucose ratio in insulinomas?

Back 44

Greater than 0.4

Front 45

which cells produce glucagon?

Back 45

A cells

Front 46

what are the symptoms of glucagonomas?

Back 46

Symptoms similar to diabetes mellitus, but also dermatitis (necrolytic migratory erythema)

Front 47

how is the diagnosis of glucagonomas made?

Back 47

fasting glucagon level

Front 48

in which part of the pancreas are glucagonomas is most commonly located?

Back 48

distal pancreas

Front 49

what does vasoactive intestinal peptide do?

Back 49

Increases intestinal secretions

Front 50

are VIPomas confined to the pancreas?

Back 50

No, they can occur extra pancreatically, like in the thorax

Front 51

what are the symptoms of VIPomas (aka Verner-Morrison syndrome)?

Back 51

watery diarrhea

Front 52

what does pancreatic polypeptide do?

Back 52

Decreases intestinal secretions

Front 53

what is bile mainly made of?

Back 53

mostly bile salts, but also lecithin and cholesterol

Front 54

how is bile concentrated in the gallbladder?

Back 54

Active reabsorption of sodium, chloride, and therefore water which follows

Front 55

what is the approximate quantity of the body's pile pool?

Back 55

5g

Front 56

approximately how much bile do we lose daily?

Back 56

0.5g or 10% of the total bile pool

Front 57

How often is the bile pool recirculated?

Back 57

every 4 hours

Front 58

What are the primary bile acids?

Back 58

Cholic acid and Chenodeoxycholic acid.