Hoorcollege Lever

Download Hoorcollege Lever

Post on 29-Jan-2016

266 views

Category:

Documents

2 download

Embed Size (px)

DESCRIPTION

Hoorcollege over de lever

TRANSCRIPT

  • Liver/LAMIDe lever: Topografie en functierechter bovenbuik zeer groot en belangrijk orgaan galsynthese en -secretie excretie van bilirubine eiwitsynthese albumine stollingsfactoren gluconeogenese deaminatie van aminozuren detoxificatiefunctie (alcohol, ) opslag triglyceriden, glycogeen, vitamines

  • Liver/LAMILeverDe leverfuncties:

    ~ complexe interacties tussen:

    vasculatuur- a. hepatica propria- v. portae hepatis- sinusoden- centrale venen

    - hepatocyten

    - galdraineersystemen- galcanaliculi- intrahepatische galductuli

  • Liver/LAMIHet leverkapsel (van Glisson)Kapsel van ongeordend dens bindweefsel.

    Omgeeft de hele lever, behalve ter hoogte van de hilus, waar het als een bindweefselschede rond de vaten en de galwegen de lever binnendringt.

  • Liver/LAMILever: de levervasculatuurAfferent- Arteria hepatica propria: zuurstofrijk bloed, uit de aorta (via truncus coeliacus)

    - Vena portae hepatis: zuurstofarm bloeduit tractus digestivus en de milt

    Efferent- Centrale vene hepatische vene v. cava inferior

  • Liver/LAMIFrom NetterCiba collection III/3De lever

    ??

  • Liver/LAMITerminale tak van de arteria hepaticaTerminale tak van de vena portaeSinusodenTerminale hepatische venule (centrale vene van de lobule)De lever: de levervasculatuur

  • Liver/LAMILIVERBileHepatic arteryPortal veinGITHepatic veinsLiver is the blood-processing glandular intermediary between you and your GIT that determines blood quality in two ways METABOLIC by Hepatocytes PROTECTIVE by Kupffer cells (MFs)

  • Liver/LAMIHEPATIC PARENCHYMA working tissuePlate of hepatocytesSINUSOIDPlate of hepatocytesEndothelial cellsSpaceSINUSOIDKupffer cellblood

  • Liver/LAMICVCVCVPTPTPTPTPTPTPTPTPTPTPTPTportale tractus (PT); centrale vene (CV)Lever: hepatocyt-heterogeniteit(Klassiek) LobulusconceptversusAcinusconceptversus Portaal lobulusconceptPT

  • Liver/LAMI

  • Liver/LAMIBLOOD & BILE FLOWS IN THE LIVERCENTRAL VEINSUBLOBULAR VEIN INFERIOR VENA CAVACentrifugal flow of bile within plates of hepatocytes in canaliculiBile ductulePortal venuleHepatic arterioleCentripetal blood flow in sinusoids6543217HEPATIC VEIN

  • Liver/LAMI

  • Liver/LAMIMicroscopic anatomy of the liver. The portal tract carries branches of the portal vein, hepatic artery, and bile duct system. The portal vein gives rise to branching septal veins, which penetrate the hepatocellular parenchyma at regular intervals. Blood from the septal veins enters directly into the parenchymal sinusoids between hepatocytes. The hepatic artery gives off capillaries that supply the bile duct system; these capillaries usually dump into the portal vein but may deposit blood directly into sinusoids. Arterioles also occasionally convey blood directly to the sinusoids. The bile duct system gives off bile ductules, which traverse the mesenchyme of the portal tract to penetrate the parenchyma; at that point, they become hemicircular, abutting hepatocytes (not shown) to form the canals of Hering. Bile traveling through the bile canalicular system between hepatocytes enters into the biliary tree through these canals of Hering. Blood from the portal vein and hepatic artery travels through the sinusoids of the parenchyma toward the terminal hepatic vein, leaving the liver by this route. On the basis of blood flow, three zones can be defined, zone 1 being the closest to the blood supply and zone 3 being the farthest. Pathologists refer to the regions of the parenchyma as "periportal, midzonal, and centrilobular," the last term owing to the historical concept that the terminal hepatic vein was at the center of a "lobule."

  • Liver/LAMICELL TYPES & ARRANGEMENT OF LIVERMicrovilliHepatocytes in platesBile canaliculusSPACE OF DISSEFenestrated Endothelial cellsSINUSOIDKupffer cellSTELLATE CELLHEPATOCYTE ENDOTHELIAL CELL KUPFFER CELL STELLATE CELL

  • Liver/LAMICELL TYPES & ARRANGEMENT OF LIVERMicrovilliHepatocytes in platesTight junctionsBile canaliculusSPACE OF DISSEFenestrated Endothelial cellsSINUSOIDKupffer cellReticular fiberSTELLATE CELLHepatocytes work on plasma, not blood cells, and need time to act. The space of Disse & the fenestrations provide a backwater for the microvillated hepatocytes to work

  • Liver/LAMI LM gepolariseerde veelvlakkige metabool actieve cellen: sinusodaal oppervlak intercellulair oppervlak canaliculair oppervlak grote, ronde, centrale celkern (vaak binucleair) vaak polyplod heterochromatine-rijk duidelijke nucleolus bleek (glycogeen) en granulair eosinofiel (mitochondrin) cytoplasma

    Lever: de hepatocyten

  • Liver/LAMI EM groot en actief perinucleair Golgi-apparaat rijk aan RER, GER en vesikels veel vrije ribosomen, glycogeen, en lysosomen talrijke mitochondrin vetdruppelsLever: de hepatocyten

  • Liver/LAMILever: de hepatocytDrie belangrijke oppervlakken:Hepatocyt - galcanaliculusHepatocyt - bloedvatHepatocyt - hepatocyt

  • Liver/LAMISinusodaal oppervlak

    70% v/h totale hepatocytenoppervlakuitwisseling van stoffen tussen de sinusoden en de hepatocytenEM onregelmatige korte microvilli coated pits (endocytose) perisinusodale ruimte van Disse tussen het sinusodale oppervlak v/d hepatocyt & endotheelcel in de wand v/d sinus collageneuze reticulinenetwerkLever: de hepatocyt

  • Liver/LAMISinusodaal oppervlak

    EM onregelmatige korte microvilli (pijlpunten)coated pits (endocytose) perisinusodale ruimte van Disse (groene pijl) tussen het sinusodale oppervlak v/d hepatocyt (H) & endotheelcel in de wand v/d sinus (S) collageneus reticulinenetwerk fenestraties v/h capillair (gebogen pijlen)Lever: de hepatocyt

  • Liver/LAMI15% v/h totale hepatocytenoppervlakvia dit oppervlak komt de gal uit de hepatocyt in de canaliculi terecht EM: galcanaliculusbuisje, gevormd door ondiepe groeven op het oppervlak van aangrenzende hepatocytensluitlijstenhet lumen is gevuld met onregelmatige microvillicelmembraan rijk aan alkalische fosfatase en adenosinetrifosfaatpericanaliculaire actinefilamenten (hepatocyt) Lever: de hepatocytCanaliculair oppervlak

  • Liver/LAMIPitt cells

    Rare cells Natural killer cells Function: Important barrier in tumor defense Role in clearance of hepatotropic viruses ? Role in tissue rejection after liver transplantation ?

  • Liver/LAMIHepatic stellate cells (ITO)

    Function:

    Vitamin A storageFibrogenesis Resting state: production of collagen III, IV Activated cell: collagen I, III, IV, VI, fibronectinProduction of cytokins e.g. EGFRegulation of blood flow in sinusoids

  • Liver/LAMIKupffer cellsDescribed by Kupffer in 1876 2 % of the non-parenchymal cells Zone 1 > zone 3 Origin ? Circulating monocytes Function: Phagocytic activity Bactericidal capacity Clearing of viruses Clearing of endotoxins

  • Liver/LAMI

  • Liver/LAMISinusoidal endothelial cells

    Flat epithelium Fenestrae Filtration function

  • Liver/LAMIKupffer cell deals with gut endotoxins & other bad stuffCELL TYPES & ARRANGEMENT OF LIVERMicrovilliTight junctionsBile canaliculusHepatocytes in platesSPACE OF DISSE has ECM materials, but no distinct basal laminaFenestrated Endothelial cellsSINUSOIDReticular fiberSTELLATE CELL makes collagen fibrils & ECM materials

  • Liver/LAMIHEPATOCYTEGOLGILysosomeGERGolgi complexMicrovilliTight junctionBile canaliculusMitochondrionSmooth ERGlycogenPEROXISOMESpace of Disse

  • Liver/LAMI

  • Liver/LAMIZONES IN LIVER PARENCHYMA IPortal vein branchCentral vein}Peri-portal zone}Peri-venous/ peri-central zoneLobule

  • Liver/LAMIZONES IN LIVER PARENCHYMA II Alternative termsPortal vein branchCentral vein}Peri-portal zone ZONE 1}Centrilobular/ peri-central zone ZONE 3LobuleZONE 2}

  • Liver/LAMILiver: Function

    Exocrine glandThe provision of bile acids and alkaline fluid for the digestion and absorption of fats and for the neutralisation of gastric acid in the intestineThe degradation and conjugation of waste products of metabolism of metabolismThe detoxification of poisonous substancesThe excretion of waste metabolites and detoxified substances in bile substances in bile Endocrine gland

  • Liver/LAMIBile

    250 600 ml/day Stored in the gallbladder ( 50 ml)Derived fromThe hepatocytes 75 % of the bile volume Mix of inorganic and organic substances, e.g. lipids, bile acids, lecithin and cholesterolContainsalbumin IgA mucosal immunitybile pigments, namely bilirubintoxic metabolitesThe duct cells

  • Liver/LAMIBile

    The duct cells25 % of the bile volumeWatery, alkaline fluid, rich in bicarbonateTo provide the appropriate pH for the process of micelle formationNeutralises the stomach acid of the intestinal chyme

  • Liver/LAMIBile acids

    Consist of Primary : cholic acid, chenodeoxycholic acid Secundary: deoxycholic acid, lithocholic acidDerivatives of cholesterolEssential for the formation of micelles in bile, which functions as a transport mechanisme for cholesterolEssential for the effective digestion and absorption of dietary fats

  • Liver/LAMI

    Bilirubin

    Conjugated ( 99 %) (glucuronic acid,glucuronosyl transferase)Bilirubin monoglucuronides (20 %)Bilirubin diglucuronides (80 %)Water-soluble Excretion into bile

    Unconjugated ( 1 %)HydrophobicRemains in circulation

  • Liver/LAMIFunction

    Metabolic functions Carbohydrate metabolism Fat metabolism Protein metabolism Storage of vitamins Storage of iron Blood coagulation Immu