liver Flashcards
bile: describe the production, concentration, main constituents, functions and clearance of bile, and explain the role of the enterohepatic circulation
3 functions of bile
cholesterol homeostasis, absorption and digestion, toxin excretion
what is in bile
cholesterol, bile salts, bilirubin and drug metabolites, water, other solutes
how does bile aid in emulsification
reduces surface tension of fats, helping formation of micelles
why is bile yellow/green
pigments like bilirubin and bilverdin
when is bile released
constantly synthesised, stored in gall bladder, released when CCK stimulated contraction
what does the gall bladder do
stores, acidifies (by absorbing HCO3-) and concentrates bile (by reabsorbing ions to create osmotic gradient)
with bile emulfsification, where do hydrophilic and hydrophobic domain face
hydrophilic domain faces inwards to micelle, hydrophobic domain faces outwards
what produces bile
hepatocytes (60%), cholangiocytes (40%)
primary secretion of bile in hepatocytes
bile acids, lipids, inorganic ions
secondary modification of bile in cholangiocytes
alteration of pH, water moves in, reabsorption of sugars and acids, secretion of HCO3- and Cl-, IgA exocytosed
what two primary bile acids (salts) are synthesised in liver
cholic acid, chenodeoxycholic acid
what secondary bile acid does gut bacteria produce from cholic acid
deoxycholic acid
what secondary bile acid does gut bacteria produce from chenodeoxycholic acid
lithocholic acid
define enterohepatic circulation
way substances can cycle between gut and liver by continous reabsorption in gut, carriage in portal blood to liver, and hepatocyte secretion into bile canaliculi, to be secreted in bile via common bile duct
example of enterohepatic circulation as beneficial
recycling of bile salts
