胃肠肝胆消化系统课件

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1、1VIIGISECRETIONS2ExocrineoftheGItractCompositionFunctionDigestfoodDilutethefoodintoiso-osmoticfluidProvideafavorablepHforthedigestiveenzymesProvidemucusforlubricationandprotectionofthealimentarytractRegulationSaliva1.5l/dpH6.8-7.0Ingest2l/dwaterGastricse

2、cretion2l/d,pH1.5-3Bile0.5l/dpH7.8-8.0Pancreaticjuice1.5ml/dpH8.0-8.4Intestinalsecretion1.5l/dpH7.8-8.0Smallintestineabsorbs8.5l/dColonabsorbs0.4-1l/d0.1l/dwaterexcreted3VII.1Salivarysecretion4Salivarygland5SecretionSaliva:water,ions,mucus,enzymesAcinarC

3、ells:腺泡细胞6FunctionsofSalivarySecretion1.Moistenfood2.Beginchemicaldigestion(amylase,淀粉酶)3.Adjustappetite4.Bacteriostaticaction（抑菌作用)(bacteriolysin,溶菌素)7ControlofsalivarysecretionSecretionratedependsentirelyonneuralcontrolbothparasympathetic(Ach,Mreceptor

4、)(watersecretion)andsympathetic(NA,βreceptor)(enzyme)leadtoincreasedsecretionFearSleepTiredDehydrationNauseaSecretionVasodilationCellcontractionMetabolismPNS(IP3)SNS(cAMP)8VII.2Gastricsecretion9TemporarystoreofingestedmaterialDissolvefoodparticlesandinit

5、iatedigestiveprocessControldeliveryofcontentstosmallintestineSterilizeingestedmaterialProduceintrinsicfactor(VitaminB12absorption)FunctionsofStomach10OesophagusLowerOesophagealSphincterFundusBodyAntrumDuodenumPylorusFunctionalAnatomyofStomachFundusBodyAn

6、trumStorageStorageMucusHClPepsinogenIntrinsicfactorMixing/GrindingGastrin11Gastricglandcells1.Oxynticgland(泌酸腺）ParietalcellChiefcellMucousneckcell2.PyloricglandMucuscell3.CardiacglandMucuscell4.Endocrinecells(G,D,ECL)ECL:enterochromaffin-likecell(肠嗜铬样细胞）

7、12Compositionandfunctionofgastricsecretions1.HClconvertspepsinogentopepsinforchemicaldigestionprovidesoptimalpHenvironmentforpepsindestroyssomebacteriastimulatesthesmallintestinalmucosatoreleasesecretinandCCKpromotestheabsorptionofCa2+andFe2+insmallintes

8、tine13Compositionandfunctionofgastricsecretions2.Pepsinogen(precursorofpepsin)digestionofproteins3.Mucusformsaprotectivebarrier:Mucus-bicarbonatebarrier4.IntrinsicfactorcombineswithvitaminB12tomakeitabsorbable14HClsecretio