消化腺（全英文）课件

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

2、a(unfunctionalportionofanorgan):capsule,CTinside.Salivaryglands*Parotid*SubmandibularG.*SublingualG.Threetypesofacini*serous*mucous*seromucousFunction:*moisteningfood*carbohydratedigestion*SecreteIgAPancreaspositionedretroperitoneallyontheposteriorwalloftheabd

3、ominalcavityatthelevelofthesecondandthirdlumbarvertebrae.nodistinctcapsule,butiscoveredbyathinlayerofLCTbothanexocrine&endocrinegland.*exocrinepart:producespancreaticjuice*endocrinepart:producehormonesComponentsoftheexocrinepancreasconsistsofserousglandsacinif

4、illedwithacidophiliczymogengranulesintercalatedductextendsintothecentreoftheacini,whichislinedbycentroacinarcellsductsystem:intercalatedducts(lowcolumnarorcuboidalepith.)Interlobularducts(columnarepith.)Mainpancreaticducts(tallcolumanrepth.)majorduodenalpapill

5、aFunctionofpancreaticjuice:*Trypsin,chymotrypsin&carboxypeptidasehydrolyseproteins;*ribonuclease&deoxyribonucleasesplitnucleicacids;*amylasehydrolysesstarch&glycogen*lipasehydrolysestriglyceridesintofattyacidsandmonoglycerides*cholesterolesterasebreaksdownchol

6、esterolestersintocholesterolandafattyacid.ComponentsoftheEndocrine*IslandsofLangerhansscatteredthroughouttheexocrinepancreas.*Vascularization(manyfenestratedcap.)ismoreextensivethanthatoftheexocrineacini.*ThreedifferenttypespresentA-cells(20%):glucagonproducer

7、B-cells(75%):insulinproducerD-cells(5%):somatostatinproducerLiver*largestgland(~2%ofbodyweightinadult).*receivesbothvenous&arterialbloodthroughtheportalV.(~75%)&hepaticA(~25%),respectively.*CTofcapsuleextendedintotheparenchyma,forming“classical”liverloblules(b

8、asicstructureunits).*functionsasanexocrinegland(secretingbile).Structuresofliverlobules*six-sidedprismwithacentralV.atitscentre*delimitedbyinterlobularCT*portaltriadsinthecornerofl