Digestion CAccessory StructuresPancreasSlide 4Slide 5Pancreas FunctionPancreatic Secretory StructuresPancreatic & Accessory DuctHepatopancreatic ampullaPancreas HistologyLobulateAcinar CellsEndocrineLiverSlide 15Liver Digestive FunctionMetabolic RegulationHematological FunctionBile synthesis & secretionSlide 20Slide 21Liver AnatomyRight & Left LobesSlide 24Caudate & Quadrate lobesSlide 26Blood SupplyLiver HistologyCentral VeinHepatocyte functional unitSinusoidsSlide 32Slide 33Liver Fluid MovementSlide 35Bile CanaliculiSlide 37Hepatic TriadHepatic TriadGall BladderSlide 41Bile DrainageSlide 43Slide 44GallstonesSlide 46Slide 47Clinical ApplicationLeading CausesLiver CirrhosisDigestion CChapter 22Accessory Structures•Last week we talked about–Teeth–Tongue–Salivary glands•Today we will cover–Pancreas–Gall bladder–LiverPancreas•Assists in chemical digestion–Enzyme secretion•Assists in neutralizing acid chyme•~15 cm long•Secretes into duodenum•Exocrine (99%) & Endocrine gland (1%)•Structure–Head•Broad portion residing w/in loop of duodenum–Body•Elongated portion inferior to stomach –Tail•Blunt end adjacent to spleenPancreasPancreasPancreas Function•Produce pancreatic juice•Sodium bicarbonate–Neutralizes acid chyme•Enzymes–Pancreatic Amylase- Carbohydrates–Pancreatic lipases- lipids–Trypsin & chymotrypsin- proteinsPancreatic Secretory Structures•Secretion enter duodenum via ducts•2 ducts–Pancreatic duct•Main delivery duct•Joins common bile duct from liver•Duodenal (aka Hepatopancreatic) ampulla–Accessory duct•Smaller, superior ductPancreatic & Accessory DuctHepatopancreatic ampullaPancreas Histology•Lobulated gland•Glandular epithelial cells•99% exocrine–Acinar cells- secrete digestive enzymes•1% endocrine- hormones–Islets of Langerhans–Beta cells (60%)- Insulin–Alpha Cells (25%)- Glucagon–Delta Cells (15%)- SomatostatinLobulateAcinar CellsEndocrineLiver•Hepat= liver•Largest abdominal organ (~3 lbs)•Aids in digestive function•Lobed structure•Highly vascularizedLiverLiver Digestive Function•Metabolic regulation•Hematological Function•Bile synthesis & secretionMetabolic Regulation•Regulates carbohydrate, lipid, & protein•All blood leaving digestive tract travels directly to liver–Hepatic portal vein–Hepatocytes- liver cells•Monitor & adjust blood nutrients•Remove & store excess nutrients•Detoxify bloodHematological Function•Regulates blood composition–Kupffer cells- phagocytic cells•Remove old or damaged blood cells, cellular debris & pathogens•Heavy metals•Produce blood proteinsBile synthesis & secretion•Breakdown product of hemoglobin pigment (RBC)•Functions–Neutralize acid chyme–Emulsify lipids•Breaks lipids into smaller lipid units •Products stored in Gall BladderLiver Anatomy•4 Lobes•Large right & left lobes•Small caudate & quadrate lobesRight & Left LobesRight & Left LobesCaudate & Quadrate lobesCaudate & Quadrate lobesBlood Supply•High rate of profusion•25% of total cardiac output•2 blood sources•Hepatic artery–Blood supply from heart to liver–Oxygen rich•Hepatic portal vein –Blood from the intestines to liver–Nutrient rich, oxygen poor–Liver processes incoming blood from GI tractLiver Histology•Hepatocytes- liver cells•Arranged into columns around large central vein•Hexagonal shaped cell grouping–“spokes on a wheel”•Lobule–Functional unit of liver–Hexagonal arrangement –100,000 lobules/ liverCentral VeinHepatocyte functional unitSinusoids•Extensions of blood vessels between columns of hepatocytes•Carries blood to be processed past hepatocytes•Site of Kupffers cells•Extend between the cells inside the lobulesLiver Fluid Movement•Blood enters via–Hepatic portal vein (GI tract)–Hepatic artery (heart)•Both vessels branch into smaller vessels to supply each liver lobule–Blood enters lobules at periphery–Travels down sinusoids passing hepatocytes•Processed blood drains into central vein•All central veins unite to form hepatic vein–Delivers processed blood to the heartBile Canaliculi•Narrow intercellular channels draining Bile produced by hepatocytes•Bile flows away from central vein toward lobule perifery•Collected by bile ductHepatic Triad •“portal triad”•Arrangement of vessels at lobule periphery•Branch of–Hepatic portal vein–Hepatic artery–Bile ductHepatic Triad•Hepatic Artery•Bile DuctGall BladderBile Drainage•Right hepatic ducts–Collects bile from ducts on right side of liver•Left hepatic ducts–Collects bile from bile ducts on left side of liver•Common hepatic duct –Union of rt & lt hepatic ducts•Cystic duct–Duct from gall bladder•Common bile duct–Union of cystic duct & common hepatic duct–Drains into duodenum–Hepatopancreatic ampullaeBile DrainageGallstones•Bile contains water, cholesterol, fats, bile salts, proteins, bilirubin (waste)•Bile with high concentrations of cholesterol, bile salts, or bilirubin can harden into gallstones–Cholesterol stones- yellow green (80%)–Pigment stones- bilirubinGallstonesClinical Application•Liver Cirrhosis•Scarring of liver•Formation of fibrous scar tissue associated with destruction of normal liver architecture•Only 30% of patients survive 5+ yrs past diagnosis•Most common reason for liver transplantsLeading Causes•2001 7th leading cause of death•Alcoholism–~50% of all Cirrhosis•Hepatitis C–1/70 persons –30% will develop cirrhosisLiver