GI

Question 1

gastric parietal cells make

Answer 1

HCl, intrinsic factor

Question 2

chief cells make

Answer 2

pepsinogen

Question 3

g cells make

Answer 3

gastrin, they are found in the antrum

Question 4

mucous neck cells make

Answer 4

bicarbonate mucus

Question 5

what is pepsin

Answer 5

proteolytic enzyme that hydrolyzes peptide bonds

Question 6

what is intrinsic factor

Answer 6

protein secreted by the parietal cells that combines with vit B12 and enables absorption in the terminal ileum

Question 7

name 3 receptors on the parietal cell that stimulate HCL release

Answer 7

HAG: histamine, acetylcholine, gastrin

Question 8

what is the enterohepatic circulation

Answer 8

circulation of bile acids from the liver to the gut and back to the liver via the portal vein

Question 9

where are most of the bile acids absorbed

Answer 9

terminal ileum

Question 10

how many times is the entire vile acid pool circulated during a typical meal

Answer 10

twice

Question 11

what are the stimulators of gallbladder emptying

Answer 11

CCK, vagal input

Question 12

what are the inhibitors of gallbladder emptying

Answer 12

somatostatin, sympathtics (it’s impossible to flee and digest at the same time), vasoactive intestinal polypeptide (VIP)

Question 13

what is the source of CCK

Answer 13

duodenal mucosal cells

Question 14

what stimulates CCK release

Answer 14

fat, protein, AAs, HCl

Question 15

what inhibits CCK release

Answer 15

trypsin and chymotrypsin

Question 16

what are the actions of CCK

Answer 16

empties gallbladder, opens ampulla of vater, flows gastric emptying, stimulates pancreatic acinar cell growth and release of exocrine products

Question 17

what is the source of secretin

Answer 17

duodenal cells (specifically the argyrophilic S cells)

Question 18

what stimulates secretin release

Answer 18

pH <4.5, fat in the duodenum

Question 19

what inhibits secretin release

Answer 19

high pH in the duodenum

Question 20

what are the actions of secretin

Answer 20

releases pancreatic bicarb/enzymes/h2o, releases bile/bicarb, decreases lower esophageal sphincter tone, decreases release of gastric acid

Question 21

what is the source of gastrin

Answer 21

gastric antrum G cells

Question 22

what stimulates its release

Answer 22

stomach peptides/AAs, vagal input, Ca

Question 23

what inhibits gastrin release

Answer 23

pH <3.0, somatostatin

Question 24

what are the actions of gastrin

Answer 24

release of HCl from parietal cells, trophic effect on mucosa of the stomach and small intestine

Question 25

what is the source of somatostatin

Answer 25

pancreatic D cells

Question 26

what stimulates somatostatin release

Answer 26

food

Question 27

what are the actions of somatostatin

Answer 27

globally inhibits GI fxn

Question 28

what is the purpose of the colon

Answer 28

reabsorption of h2o and storage of food

Question 29

what is the main small bowel nutritional source

Answer 29

glutamine

Question 30

what is the main nutritional source of the colon

Answer 30

butyrate (short-chain FA)

Question 31

where is Ca absorbed

Answer 31

duodenum actively, jejunum passively

Question 32

where is Fe absorbed

Answer 32

duodenum

Question 33

where is vit B12 absorbed

Answer 33

terminal ileum

Question 34

which hormone primarily controls gallbladder contraction

Answer 34

CCK

Question 35

what supplement does a patient need after removal of the terminal ileum or stomach

Answer 35

vit B12

Question 36

name the main constituents of bile

Answer 36

water, phospholipids (lecithins), bile acids, cholesterol, and bilirubin

Question 37

what are most gallstones made of

Answer 37

cholesterol

Question 38

how do opiates affect the bowel

Answer 38

by stimulating Na absorption and inhibiting secretion in the ileum as well as decreasing GI motility by incoordinates peristalsis (therefore, place patients on stool softeners when dispensing pain meds)

Question 39

which type of muscle fibers, smooth or striated, does the esophagus contain

Answer 39

both: upper third - striated muscle, middle third - mixed, lower third - smooth, primarily under vagal control

Question 40

which electrolytes does the colon actively absorb

Answer 40

Na, Cl

Question 41

which electrolyte does the colon actively secrete

Answer 41

K

Question 42

what is the gastroclonic reflex

Answer 42

increased secretory and motor functions of the stomach result in increased colonic motility

Question 43

what is the blood supply to the liver

Answer 43

75% from the portal vein, rich in products of digestion, 25% from the hepatic artery, rich in O2 (but each provide 50% of oxygen)

Question 44

what are the peyer patches

Answer 44

nodules of lymphoid tissue with B and T lymphocytes in the small intestine that selectively sample lumenal antigens found in the terminal ileum