Digestive System Summary Notes Flashcards
main functions of the digestive system?
motility digestion (duodenum) secretion absorption (jejumen) excretion (exertion)
what is motility?
smooth muscle contractions that are involuntary (from esophagus to rectum)
what is digestion and were does it occur?
occurs in duodenum
chemical hydrolysis of polymers to monomers
what is secretion?
release of various digestive juices in the lumen of the GI
what is absorption and where does it occur?
nutrients moving from the GI lumen to blood vessels
occurs in jejumen
what is excretion?
minor components which are indigestible
what are the functions of the stomach?
production of HCl
synthesis of intrinsic factor
production of pepsinogen which turns into pepsin when in contact with stomach acid
does absorption happen in the stomach?
little to none
where does chemical digestion of starch start?
in the mouth
components of small intestine?
duodenum
jejunum
ileum
what does the duodenum do?
receives digestive juices from accessory glands (liver, pancreas, gallbladder)
what does the small intestine do?
release internal signals to regulate organs in close proximity
what does the pancreas do?
neutralize HCl
release various enzyme’s
what does bile do?
emulsifies fat
where does bile come from?
bilirubin from hemoglobin
what does the gallbladder do?
concentrates bile and removes water out of bile
what local hormones are produced by the duodenum?
GIP (gastric inhibitory peptide)
CCK (cholecystokinin)
what does GIP do?
slows down rate of gastric emptying
travels through blood vessels
what does CCK do?
stimulates pancreas, liver, gallbladder
travels through blood vessels
segments of large intestine (colon)?
ascending colon transverse colon descending colon sigmoid colon (leads to rectum) rectum
what does the large intestine do?
reabsorbs remaining water through osmosis by absorbing Na
