Pancreas and Liver Flashcards
Rebecca
overall what is the exocrine function of the pancreas and liver
accessory organ for intestines provides excretions (digestive enzymes, HCO3)directly into intestine lumen
overall what is the endocrine function of the pancreas and liver
regulate blood borne energy substrate avaliable (after absorption) via hormones - glucose , fatty acids
what are the exocrine and endocrine functions of the pancreas
digestive pro-enxymes are secreted via the pancreatic duct into the 2nd part of the duodenum
where is the pancreas located
retroperitoneal except its tail, lies behind the lining of the abdomnial cavity, difficult to acces and is close to major blood vessels
what does the main pancreatic duct combine with
the common bile duct from the liver and gall bladder which then combine together and both enter the duodenum
where does the portal vein form in relation to the pancreas
behind the neck of the pancreas at L1
pancreatic blood supply
mainly via splenic artery from coeliac trunk
pancreatic-duodenal (superior and inferior and anterior and posterior) arteries from SMA or coeliac trunk
main exocrine functions of the pancreas
primary - neutralise acid (coming just from stomach)
deliever enzymes for macronutrient digestion in duodenum
what are acinar cells
main secretory cells in the pancreas, clusters connected by intercalated ducts
what else is in the intercalated ducts in the pancreas other than acinar cells
lining cells add ions and secretions after the acinar cells
what regulates exocrine release in the pancreas during the cephalic phase
vagus nerve stimulates secretions by releasing ACh and VIP
25% of secretions
what regulates exocrine release in the pancreas during the gastric phase
medicated by vagovagal relfexes (10%)
what regulates exocrine release in the pancreas during the intestinal phase
hormonally by secretin and CCK (65%)
when are zymogen granules secreted
in response to CCK and VIP
what are zymogen granules
house inactive and active digestive enzymes
how are zymogen granules secreted
exocytosed (regulated hormonally and neurally) from acinar cells into luminal space
where do ion and serous fluid secretion occur
acinar and intercalated duct cells
how do the acinar cells release ions
basolateral CCK and ACh binding stimulates CL transport (facilitates paracellular Na)
how do intercalated ductal cells secrete ions
secretin and ACh bind in ductal cells , activated cystic fibrosis transmembrane regulators
what alters ionic concentration
flow rate of secretions
increased flow rate - HCO3 increases , Cl decreases
where is the liver located
lies across upper abdomen under diaphragm, surronded by peritoneum except from bare area (may be palpable )
what is Glisson’s capusle
surronds the liver, CT layer with extensions into the organ between lobules
what is the liver’s supply of nutrients from the stomach and gut
hepatic portal vein
what does the hepatic artery supply
hepatocytes with oxygen
how is bile drained in the liver
via canaliculi that lie between the hepatocytes into bile ductules and eventually into bile ducts
where is th venous drainage in the liver
by hepatic veins that enter via IVC
liver and surronding anatomy
has right and left lobes separated by falciform ligament
quadrate lobe next to gall bladder
caudate lobe next to IVC (posterior)
bare area is diaphragmatic surface of liver
what are the functions of the liver
- synthesis and secretion of bile
- storage of glucose, glycogen, proteins, vitamins and fat
- detoxification of metabolic waste
- synthesis of blood clotting and anticoagulant factors (fibrinogen and prothrombin)
what are the components of bile
bile acids, electrolytesm cholesterolm phospholipds and bilirubin
how are bile pigments (mainly bilirubin) dervived
breakdown product of haemoglobin (kupffer cells)
what are bile agents responsible for
the detergent and emulsifying effect of bile on fats , increase absorption of fats by the small intestine
what do hepatocytes do
secrete bile into the canaliculi across the series of bile ducts until form common hepatic duct
what way is bile flow
bile flow from hepatocytes is in the opposite direction of blood from hepatic artery and portal vein
where does the bile travel to
goes from common bile duct into the duodenum or into the gall bladder
what does the sphincter of Oddi control
the path of the bile
- contracted the bile mainly goes to gallbladder
- relaxed mainly goes to duodenum
what is the sphincter relaxtion regulated by
primarily by CCK
what do bile acids do
emulsify lipids
what does the gall bladder do
stores and distributes bile - in concentrated form, less is needed to have the same effect
how does the gall bladder release bile
contracts to expel bile in response to CCK
what does vagal stimulation do to the gall bladder
causes weak gall bladder contraction
what inhibits bile acid secretion in gall bladder
somatostatin and noradrenaline
what are the non-biliary liver functions
metabolism of CHO , protein and fat - glycogen
detoxification - removal of ammonia, ethanol, drug biotransformation
immune system function - removal of intestinal bacteria from portal blood so none in systemic circulation
