ANPS 1200 (E4, L2)

What are the 3 main functions of stomach?

storage, mechanical digestion (churning), chemical digestion

What does stomach convert food to?

chyme

What are rugae

folds that allow stomach expansion

What controls emptying of the stomach into the SI?

pyloric sphincter

What layer is unique in the stomach msucularis?

oblique layer (3 layers total)

Which gastric cells secrete mucous and bicarbonate?

mucous cells

Which gastric cells secrete HCI and intrinsic factor?

Parietal cells

why is intrinsic factor important?

required for vitamin B12 absorption

which gastric cells secrete pepsinogen?

chief cells

what activates pepsinogen →pepsin?

HCI

which gastric cells secrete gastrin?

G cells (enteroendocrine)

What does gastrin do?

increase acid secretion and motility

What are 3 things that protect the stomach lining?

-Mucus + bicarbonate

-tight jxn

-rapid cell turnover

what happens if the mucosal barrier breaks down?

ulcers

most common cause of gastric ulcers?

H. pylori

what triggers the cephalic phase?

sight, smell, thought of food

what nerve is involved in the cephallic phase?

vagus nerve

what triggers the gastric phase?

food in stomach (stretch+peptides)

what happens in the intestinal phase?

slows gastric emptying

what type of chyme slows gastric emptying the most?

fatty, acidic chyme

what is the main digestive function of the liver?

produces bile

what does bile do?

emulsifies fats

what vessel brings nutrient rich blood to the liver?

portal vein

what vessel brings oxgyen to the liver?

hepatic artery

functional unit of liver?

lobule

what cells perform liver functions?

hepatocytes

where is bile stored?

gallbladder

what hormone causes gallbladder contraction?

CCK

what condition involves hardened bile deposits?

gallstones

what does the exocrine pancreas secrete?

digestive enzymes + bicarbonate

what do proteases digest?

proteins

what does amylase digest?

carbohydrates

what does lipase digest

fats

why are pancreatic enzymes released inactive?

prevent self-digestion

what enzyme activates trypsinogen?

enteropeptidase

what is the role of bicarbonate from pancreas?

neutralizes acidic chyme

what stimulates CCK release?

fats and proteins

what does CCK do?

↑enzymes

↑bile

relax sphincter

what stimulates secretin release?

acidic chyme

what does secretin do?

↑bicarbonate secretion

where does most digestion occur?

small intestine

what are 3 things mix in the small intestine?

bile, pancreatic enzymes, bicarbonate

what is the main role of stomach vs small intestine?

stomach=breakdown

small intestine=digestion+absorption