SR 34 - GI Hormones and Physiology

Question 1

What do these cells produce? Gastric parietal cells

Answer 1

HCl

Intrinsic factor

Question 2

What do these cells produce? Chief cells

Answer 2

Pepsinogen

Question 3

What do these cells produce? G cells

Answer 3

Gastrin

Found in the antrum

Question 4

What do these cells produce? Mucous neck cells

Answer 4

Bicarbonate mucus

Question 5

Name the receptors on the parietal cell that stimulates hCl release

Answer 5

Histamine
Acetylcholine
Gastrin

Question 6

Where is most of hte bile acids absorbed?

Answer 6

Terminal ileum

Question 7

Where is intrinsic factor + B12 absorbed?

Answer 7

Terminal ileum

Question 8

How may times is the entire bile acid pool circulated during a typical meal?

Answer 8

Twice

Question 9

What are timulators of gallbladder emptying?

Answer 9

CCK

Vagal inuput

Question 10

What are the inhibitors of gallbladder emptying?

Answer 10

Somatostatin
Sympathteitcs (you cannot flee and ingest food at the same time)
VIP

Question 11

What stimulates the release of CCK?

Answer 11

Fat, protein, amino acids, HCl, antral stretch

Question 12

What inhibits the release of CCK?

Answer 12

Trypsin

Chymotrypsin

Question 13

What are CCKs actions?

Answer 13

Empties gallbladder
Opens ampulla of vater
Slows gastric emptying
Stimulates pancreatic acinar cell growth and release of exocrine products

Question 14

What is the source of CCK?

Answer 14

Duodenal mucosal cells

Question 15

What is the source of secretin?

Answer 15

Duodenal cells (argyrophilic S cells)

Question 16

What stimulates secretin release?

Answer 16

pH

Question 17

What inhibits release of secretin?

Answer 17

High pH in the duodenum

Question 18

What are the actions of secretin?

Answer 18

Release pancreatic bicarb/enzymes/H2O
Release bile/bicarbonate
Decreases lower esophageal sphincter tone
Decrease release of gastric acid

Question 19

What is the source of gastrin?

Answer 19

Gastric antrum G-cells

Question 20

What stimulates gastrin release?

Answer 20

Stomach peptides/amino acids
Vagal input
Calcium

Question 21

What inhibits gastrin release?

Answer 21

pH

Question 22

What are the actions of gastrin?

Answer 22

Release of HCl from parietal cells

Trophic effect on mucosa of the stomach and small intestine

Question 23

What is the source of somatostatin?

Answer 23

Pancreatic D cells

Question 24

What stimulates the release of somatostatin?

Answer 24

Food

Question 25

What are the actions of somatostatin?

Answer 25

Globally inhibits GI function

Question 26

What is the purpose of hte colon?

Answer 26

Reabsoprtion of H2O and storage of stool

Question 27

What is the main small bowel nutritional source?

Answer 27

Glutamine

Question 28

What is the main nutritional souce of the colon?

Answer 28

Butyrate (short-chain fatty acid)

Question 29

Where is calcium absorbed?

Answer 29

Duodenum actively | Jejunum passively

Question 30

Where is iron absorbed?

Answer 30

Duodenum

Question 31

What hormone primarily controls gallbladder contraction?

Answer 31

CCK

Question 32

What are hte main constituents of bile?

Answer 32

Water, phospholipids, bile acids, cholesterol, bilirubin

Question 33

How do opiates affect the bowel?

Answer 33

They stimulate sodium absoprtion and inhibit secretion in the ileum as well as decreasing GI motility by incoordinated peristalsis

Question 34

Which electrolytes does the colon actively absorb?

Answer 34

Na, Cl

Question 35

Which electrolyte does the colon actively secrete?

Answer 35

HCO3 (which is why diarrhea causes normal anion gap acidosis)

Question 36

Which electrolyte does the colon passively secrete?

Answer 36

K+

Question 37

What is hte gastrocolic reflex?

Answer 37

Increased secretory and motor functions of the stomach result n increased colonic motility

Question 38

What is the blood supply to the liver?

Answer 38

75% from portal vein (products of digestion) | 25% from hepatic artery (rich in O2)

Question 39

What are Peyer patches?

Answer 39

Nodules of lymphoid tissue with B/T cells in the small intestine that selectively sample lumenal antigens found in the terminal ileum.