bile + biliary system Flashcards
how much bile on average is secreted daily ?
250-1100 ml/day
describe the route of bile secretion :
polygonal cells in liver, canaliculi , ductal system , hepatic duct
how does vagus control effect bile secretion :
stimulation cause 2-4 fold increase in secretion
bilateral vagotomy stops feeding-induced stimulation of bile flow
splanchnic nerve stimulation causes vasoconstriction + decreased bile flow
how does vasoactive intestinal polypeptide (VIP) control bile secretion ?
inhibits net fluid + electrolyte absorption in gallbladder
blockage of neural VIP increases fluid absorption in gallbladder
what effect does serotonin have on bile secretion ?
inhibits net fluid + electrolyte reabsorption
what effect does secretin have on bile secretion ?
stimulates bile flow without increasing bile salt secretion
what effect does CCK have on gall bladder
release of CCK causes gall bladder to contract
bile duct is pushed into bile duct then into pancreatic duct
how does bile end up in the small intestine ?
it enters the pancreatic duct which enters the small intestine via the sphincter of Oddi
is the secretion of bile active ?
yes
it is independent of liver sinusoidal blood pressure
how do bile salts leave the small intestine ?
reabsorbed by different parts of small intestine
passively diffuse into circulation + reenter liver
what is the enterohepatic circulation ?
refers to the recycling of bile acids secreted by the liver
what is maintenance of enterohepatic circulation dependent on ?
intestinal function
passive uptake of bile acids
active uptake of bile acids
what are 4 possible causes of gallstones ?
- too much absorption of water from bile
- too much absorption of bile acids from bile
- too much cholesterol in bile
- inflammation of epithelium
what are some problems associated with gallstones ?
- decreased lipase activity
- decreased vitamin k uptake
- jaundice
