消化腺（全英文）PPT课件

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1、DigestiveSystemDigestiveGlandsComponentsdigestiveglandsfoundinthewallofdigestivetractaccessorydigestiveglands:salivaryglands/pancreas/liverGeneralstructure*Parenchyma(functionalportionofanorgan,asdistinguishedfromthesupportingtissue):acini/glandcellsduct*Stroma(unfunctionalportionofanorgan):capsu

2、le,CTinside.Salivaryglands*Parotid*SubmandibularG.*SublingualG.Threetypesofacini*serous*mucous*seromucousFunction:*moisteningfood*carbohydratedigestion*SecreteIgAPancreaspositionedretroperitoneallyontheposteriorwalloftheabdominalcavityatthelevelofthesecondandthirdlumbarvertebrae.nodistinctcapsule

3、,butiscoveredbyathinlayerofLCTbothanexocrine&endocrinegland.*exocrinepart:producespancreaticjuice*endocrinepart:producehormonesComponentsoftheexocrinepancreasconsistsofserousglandsacinifilledwithacidophiliczymogengranulesintercalatedductextendsintothecentreoftheacini,whichislinedbycentroacinarcel

4、lsductsystem:intercalatedducts(lowcolumnarorcuboidalepith.)Interlobularducts(columnarepith.)Mainpancreaticducts(tallcolumanrepth.)majorduodenalpapillaFunctionofpancreaticjuice:*Trypsin,chymotrypsin&carboxypeptidasehydrolyseproteins;*ribonuclease&deoxyribonucleasesplitnucleicacids;*amylasehydrolys

5、esstarch&glycogen*lipasehydrolysestriglyceridesintofattyacidsandmonoglycerides*cholesterolesterasebreaksdowncholesterolestersintocholesterolandafattyacid.ComponentsoftheEndocrine*IslandsofLangerhansscatteredthroughouttheexocrinepancreas.*Vascularization(manyfenestratedcap.)ismoreextensivethanthat

6、oftheexocrineacini.*ThreedifferenttypespresentA-cells(20%):glucagonproducerB-cells(75%):insulinproducerD-cells(5%):somatostatinproducerLiver*largestgland(~2%ofbodyweightinadult).*receivesbothvenous&arterialbloodthroughtheportalV.(~75%)&hepaticA(~25%),respectively.*CTofcapsuleextendedintotheparenc

7、hyma,forming“classical”liverloblules(basicstructureunits).*functionsasanexocrinegland(secretingbile).Structuresofliverlobules*six-sidedprismwithacentralV.atitscentre*delimitedbyinterlobularCT*portaltriadsinthecornerofl