gastric secretions-osmosis Flashcards
what is a food bolus partially digested into
chyme
route of chyme
passes through pyrloci pshincter into duodeum
how is the pancreas connected to the duodenum
pancreatic duct
layers of stomach
mucosa
submucosa
muscularis externa
serosa
what does the mucosa contain
glands with cells which scerete components of gastric juie
what do parietal cells secrete and where are they located
in body of sotmach, secrete hcl
HCL
strong acid which helps break down porteins
chief cells
secre pepsinogen- inactive
how is pepsin created
once pepsinogen is exposed to pepsin
what do g cells secrete
gastrin
where is gatsrin secreted into
blood stream
what does gastrin enhance
hcl, pepsinogen ad contraction of stomach muscles
what does the usbmucosa cintain
connective tissue
blood vessels
nerv
what do the nerves connect to form
submucosal plexus of nerves
role of submuocsal plexus of nerves
regulates gastric secretions and controls blood flow to stomach
externa
contains 3 layers of muscle
peristalsis
when the 3 layers of muscle contract in wave form s
thickness in stomach
increases form orad to caudad to help push food towards pylroic sphincter
which contorls the rate at which the stomach contracst
enteric nervous system
what is composed of the ENS
myenteric and submucosal plexuses
role of parasympathetic on ENS
increases gastric secretion anf motility
sympa
inhibits hastrci secretion and motiltiy
what do mechanoreceptors trigger the release of
gastrin from g cells in stomach
what do mechanoreceptors sense
distnesion ins tomach from food
what do high fat foods stimulate
release of CCK
what is ccK released form
i cells in duodenum
effect of cck
slows contractions to aid digestion
what do s cells secrete
secretin
function of secretin
Increases secretion of bicarbonate-rich fluid from pancreas and hepatic duct cells, decreases gastric acid secretion, trophic effect on pancreatic acinar cells
what do d cells secrete
somatostatin
function of somatostatin
Decreases acid and pepsin secretion, decreases gastrin secretion, decreases pancreatic enzyme secretion, decreases insulin and glucagon secretion
inhibits trophic effects of gastrin, stimulates gastric mucous production
