physiology of the GI tract

Question 1

what makes up the upper GI tract?

Answer 1

oral cavity 
salivary glands 
pharynx 
oesophagus 
stomach 
pancreas
liver 
gall bladder

Question 2

what makes up the lower GI tract?

Answer 2

small and large intestine

Question 3

what are the major sites of absorption?

Answer 3

stomach
small intestine
large intestine

Question 4

what is absorbed in the stomach?

Answer 4

alcohol and water

Question 5

what is absorbed in the small intestine?

Answer 5

minerals 
glucose 
amino acids 
fats 
vitamins 
water 
alcohol 
bile salts

Question 6

what is absorbed in the large intestine?

Answer 6

sodium
potassium
some fatty acids, gases and water

Question 7

what is the function of the oral cavity?

Answer 7

mastication

mixes food with saliva

Question 8

what are the names of the three pairs of salivary glands?

Answer 8

parotid
submandibular
sublingual

Question 9

what cells are present in the salivary glands and what do they secrete?

Answer 9

mucus cells secrete mucus
serous cells secrete thin fluid rich in amylase
mixed acinus has both

Question 10

what is the function of saliva?

Answer 10

moisten 
begin starch and fat digestion 
cleanse teeth 
inhibit bacteria 
bind food into bolus

Question 11

what is the pharynx and what is its function?

Answer 11

air filled cavity
transports food from the mouth to the stomach
constrictor muscles in pharynx move bolus into oesophagus

Question 12

what is the function of the stomach?

Answer 12

stores food 
minimizes ingestion of bacteria 
reduces food to chyme 
regulates the rate that contents empty into the small intestine 
secretes intrinsic factor

Question 13

what cells line the gastric glands?

Answer 13

goblet 
stem cells 
parietal cells 
chief 
enteroendocrine

Question 14

what do goblet cells secrete in the gastric glands?

Answer 14

mucus

Question 15

what is the function of parietal cells in the gastric glands?

Answer 15

secrete HCl acid and intrinsic factor

Question 16

what is the function of chief cells in the gastric glands?

Answer 16

secrete pepsinogen

and chymosin and lipase in infancy

Question 17

what is the function of enteroendocrine cells in the gastric glands?

Answer 17

G cells secrete gastrin
D cells secrete somatostatin
enterochromaffin- like cells secrete histamine

Question 18

what are the main components of gastric juice?

Answer 18

hydrochloric acid
mucus
enzymes: pepsinogens, gastric lipase
intrinsic factor

Question 19

what stimulates gastric acid production?

Answer 19

cephalic phase and gastric phase

gastrin, acetylcholine and histamine

Question 20

what inhibits gastric acid production?

Answer 20

intestinal phase

somatostatin

Question 21

what is the function of gastric acid?

Answer 21

activates pepsin and lingual lipase
denatures proteins
breaks up connective tissues and plant cell walls
converts ingested ferric ions to ferrous ions
destroys ingested bacteria and pathogens

Question 22

what enzymes does the pancreas produce?

Answer 22

trypsin 
chymotrypsin 
carboxypeptidase 
pancreatic amylase 
lipases

Question 23

what is the hepatopancreatic ampulla?

Answer 23

where the common bile duct and pancreatic duct meet

Question 24

what is the function of the liver?

Answer 24

sythesises and stores bile

Question 25

what is the function of bile salts?

Answer 25

emulsifies dietary lipids, rendering them accessible to pancreatic lipases facilitates the absorption of fat-soluble vitamins

Question 26

what are the three sections of the small intestine?

Answer 26

duodenum jejunum ileum

Question 27

what are peyer patches in the small intestine?

Answer 27

populations of lymphocytes

Question 28

what cells are present in intestinal crypts?

Answer 28

absorptive cells goblet cells rapidly dividing cells paneth cells

Question 29

what is secreted by the small intestine?

Answer 29

mucus water hormones

Question 30

what are scretagogues?

Answer 30

hormones controlling secretions

Question 31

how is gastric acid produced?

Answer 31

H+ and HCO3- produced from CO2 and H20 by carbonic anhydrase H+ secreted into stomach lumen by a H+/K+ ATPase HC03- exchanged for Cl- Cl- pumped out and joins with H+ forming HCl

Question 32

where is gastrin produced?

Answer 32

in the antrum of the stomach by epithelial endocrine cells

Question 33

what is the stimulus for gastrin release?

Answer 33

amino acids and peptides in stomach

Question 34

what effect does gastrin have in the stomach?

Answer 34

stimulates HCl secretion

Question 35

where is cholecystokinin produced?

Answer 35

in the small intestine by intestinal endocrine cells

Question 36

what is the stimulus for cholecystokinin release?

Answer 36

amino acids, peptides and fatty acids in the small intestine

Question 37

what effect does cholecystokinin have in the stomach?

Answer 37

inhibits acid secretion

Question 38

where is secretin produced?

Answer 38

in the small intestine by intestinal endocrine cells

Question 39

what is the stimulus for secretin release?

Answer 39

acid in the small intestine

Question 40

what effect does secretin have in the stomach and pancreas?

Answer 40

inhibits acid secretion in the stomach | stimulates bicarbonate secretion in the pancreas

Question 41

where is GIP produced?

Answer 41

in the small intestine by intestinal endocrine cells

Question 42

what is the stimulus for GIP release?

Answer 42

glucose and fat in the small intestine

Question 43

what is the effect of GIP in the pancreas?

Answer 43

stimulates beta cells to secrete insulin