Physio Exam 3 Lec 2

Front 1

Small intestine structural feats

Back 1

villus-crypt structure for absorption

Front 2

Colon structural feats

Back 2

it has surface epithelial cells with interspersed crypt

Front 3

crypt epithelial cells mainly mediate

Back 3

secretion

Front 4

Endocrine hormones travel to target cells via

Back 4

blood stream

Front 5

Paracrine hormones travel to target cells via

Back 5

interstitial space

Front 6

Open type enteroendocrine cells

Back 6

apical membranes are in contact with the lumen.

Front 7

Closed type enteroendocrine cells (ECC)

Back 7

membranes are not in contact with the lumen
Example enterochromaffin-like cells which secrete histamine

Front 8

Closed type ECC are rich in

Back 8

secretory granules .

Front 9

Target cells of ECC may be located in

Back 9

Other regions of the GI tract (ileal break)
Glandular structures associated with the GI tract (Incretins)
Organs that have no direct role in digestion and secretion (hypothalamus)

Front 10

Nutrients, especially fat, reach the terminal when they are not efficiently absorbed in the proximal small intestine

Enteroendocrine cells in the terminal ileum and colon sense the extra non-absorbed nutrients

Peptide YY (PYY) will be then secreted from the terminal ileum and colon

PYY decreases

Back 10

intestinal motility and inhibits fluid secretion

Front 11

PPY effect is to

Back 11

retain food food for a longer time to allow more efficient digestion and absorption

Front 12

Incretins

Back 12

GI hormones that increase insulin secretion (stimulate beta cells)

Front 13

The two main incretins

Back 13

GIP (gluco-insulinotropic peptide)
GLP-1 (glucagon-like peptide-1

Front 14

Incretin is essential to

Back 14

stimulate secretion of insulin. IV glucose (bypassing gut) does not increase insulin levels as much as when glucose is ingested

Front 15

GI signals to central appetite circuits in the hypothalamus in the midbrain

Back 15

Ghrelin has orexigenic (increases the appetite) effects
Peptide YY (PYY) elicits anorectic effects

Front 16

GI hormones may influence energy homeostasis

Back 16

Regulating hunger and satiety
Affecting food intake
Inflicting taste aversion and nausea in response to the ingestion of harmful substances

Front 17

Secretin source, stimulus, pathway

Back 17

S cells of Duodenum
Increase in Acid
Endocrine, Paracrine

Front 18

Secretin effects

Back 18

-increases pancreatic HCO3 and H2O secretion
-Decreases gastric acid secretion

Front 19

Gastrin source, stimulus, pathway

Back 19

G cells of Antrum
Oligopeptides, neural
endocrine

Front 20

Gastrin effect

Back 20

-stimulates gastric acid secretion
-stimulates histamine secretion
(stimulates beginning of digestion)

Front 21

Cholecystokinin (CCK) source, stimulus, pathway

Back 21

I cells of duodenum
fatt acids, glucose
paracrine, endocrine

Front 22

CCK effects

Back 22

-Inhibits gastric emptying & acid secretion
Stimulates pancreatic enzyme secretion
Induces gallbadder contraction
Inhibits food intake
(slows down stomach)

Front 23

Gluco-insulinotropic peptide (GIP) source, stimulus, pathway

Back 23

K cells of intestine
Fatty acids, glucose
endocrine

Front 24

GIP effect

Back 24

stimulates insulin secretion

Front 25

Proglucagon derived peptides (GLP 1/2) source, stimulus, pathway,

Back 25

L cells of small intestine and colon
Fatty acids, glucose, hydrolyzed proteins (nutrients in distal GI)
Endocrine, Paracrine

Front 26

GLP 1/2 effects

Back 26

Stimulates insulin secretion
Regulates epithelial cells proliferation

Front 27

PPY mediates

Back 27

Ileak break

Front 28

PPY source, stimulus, pathway

Back 28

L cells of intestine
Fatty acids, glucose, hydrolyzed proteins.
Endo, Para

Front 29

PPY effects

Back 29

Inhibits:
Gastric emptying & acid secretion
Pancreatic secretion
Intestinal motility
Food intake

Front 30

Motilin source, Stimulus, Pathway,

Back 30

M cells
Fastin, changes in pH?
Endo, Para

Front 31

Motilin effect

Back 31

Increases contraction of Lower esophageal sphincter (LES)
Increases gastric emptying
Increases Intestinal motility
(rumbling of stomach)

Front 32

Ghrelin source, stimulus, path

Back 32

X/A cells in stomach, proximal intestine
Fasting
Endo

Front 33

Ghrelin effects

Back 33

Stimulates gastric emptying
Increases appetite & food intake
Decreases energy expenditure
Decreases fat metabolism

Front 34

Somatostatin Source, Stimulus, Path

Back 34

D cells
Protein, Fat, Bile
Endo, Para

Front 35

Somatostatin effect

Back 35

Inhibits gastrin release
Increases the absorption of fluid
Decreases the secretion of fluid
Increases smooth muscle contraction
Decreases pancreatic secretion

Front 36

Serotonin (5-hydroxytryptamine) source,Path

Back 36

Enterochromaffin cells
Para

Front 37

Serotonin Stimulus

Back 37

Mechanical stimuli: stroking of mucosa, pressure
Chemical stimuli: Glucose, adenosine, bile acids
Enterotoxins: Cholera toxin or E. coli

Front 38

Serotonin Path

Back 38

Paracrine

Front 39

Serotonin Effects

Back 39

Inhibits Electrolyte and fluid absorption
Increases secretion
Regulates smooth muscle contraction

Front 40

The hormones that facilitate digestion are

Back 40

CCK, Secretin, GIP, Motilin

Front 41

Clinical use of somatostatin (Octreotide)(pro-absorptive)

Back 41

Diarrhea
Gastrinoma/Carcinoid

Front 42

Clinical use of Serotonin (Tegaserod)

Back 42

Irritable Bowel syndrome
Constipation

Front 43

GLP-1 (Exanatide) clinical use

Back 43

Improve insulin sensitivity type 2 diabetes mellitus patients

Front 44

Motilin (Erythromycin) clinical use

Back 44

Gastroparesis