大學(xué)英語(yǔ)digestive-system備課講稿

DigestivesystemThefunctionofthedigestivesystemistopreparefoodforintakebybodycells.Nutrientsmustbebrokendownbymechanicalandchemicalmeansintomoleculesthataresmallenoughtobeabsorbedintothecirculation.Withincells,thenutrientsareusedforenergyandforrebuildingvitalcellcomponents.Digestiontakesplaceinthedigestivetract.Mouth,oralcavityOr/o:oralcavity,oraladministrationorallanguagestomat/o:stomatitis,stomatoscopysaliva:isthewaterysubstanceproducedinthemouths.Itisproducedinandsecretedfromthesalivaryglands.Humansalivaiscomposedmostlyofwater(99.5%),butalsoincludeselectrolytes,mucus,antibacterialcompounds,andvariousenzymes.Theenzymesinthesalivabreakdownsomeofthestarchandfatinthefoodatthemolecularlevelsalivaryamylase

ToothDent/i:

Dentist:amedicalprofessionalwhospecializesinthecareofteethDentalgia:toothache

odont/o:Oligodontia:theconditionofnaturallyhavingfewerthantheregularnumberofteeth,itisalsocalledhypodontiaPeriodontitis:referstoanumberofinflammatorydiseasesaffectingthetissuesthatsurroundandsupporttheteethtongue

Lingu/oLinguisticSublingualtablet:Usuallyasmall,flattabletintendedtobeinsertedbeneaththetongue,wheretheactiveingredientisabsorbeddirectlythroughtheoralmucosaandintoblood;suchatabletdissolvesverypromptly.Nitroglyerinsublingualtablet:atypeofvasodilator.Itrelaxesbloodvessels,increasingthebloodandoxygensupplytoyourheart.Thismedicineisusedtorelievechestpaincausedbyangina.esophagusesophagusisamusculartubewhosecontractionscanpropelfoodtothestomach.

eso-=inside,inward

phag/o=swallow

esogastritis:Inflammationofthemucousmembraneofthestomach

phagocyte:cellsthatprotectthebodybyingestingharmfulforeignparticles,bacteriaanddeadordyingcells

StomachThethreebasic/mainfunctionsofthestomacharetokillanybacteriaingested,breakdownthefoodintosmallerpiecestocreatealargersurfaceareaforeasierdigestion,andtoholdfoodandreleaseitataconstantrate.ThestomachisahighlyacidicenvironmentduetohydrochloricacidproductionandsecretionwhichproducesapHrangeusuallybetween1and2.Combinedwithdigestiveenzymes,suchanenvironmentisabletobreakdownlargemoleculestosmalleronessothattheycaneventuallybeabsorbedfromthesmallintestine.AzymogencalledpepsinogenissecretedandturnsintopepsinunderlowpHconditionsandisanecessityinproteindigestion

gastr/o:stomachgastritisgastroscopygastralgiagastrectomygastrelcosisPept/i,peps/i:digestion

pepsin:anenzymeinthestomachandwhichdegradesfoodproteinsintopeptidespepticulcer:dyspepsia:hardordifficultdigestion

Smallandlargeintestine

Thesmallintestineisthemajorsitefordigestionandabsorptionofnutrients.Theupperpart,theduodenum,isthemostactiveindigestion.Secretionsfromtheliverandpancreasareusedfordigestionintheduodenum.Thepancreassecretesdigestiveenzymesandstomachacidneutralizingbicarbonate.Protease(enzymessecretedfromthepancreas)continuethebreakdownofproteinintosmallpeptidefragmentsandsomeaminoacids.Theliverproducesbile,whichisstoredinthegallbladderbeforeenteringthebileductintotheduodenum.Bileemulsifiesfats,makingthemsusceptibletoenzymaticbreakdown.Bilecontainscholesterol,phospholipids,bilirubin,andamixofsalts.Thelargeintestineismadeupbythecolon,cecum,appendix,andrectum.Materialinthelargeintestineismostlyindigestibleresidueandliquid.

enter/o:

dysentery

entericcoatedtablet:Anoraldosageforminwhichatabletiscoatedwithamaterialtopreventorminimizedissolutioninthestomachbutallowdissolutioninthesmallintestine.Thistypeofformulationeitherprotectsthestomachfromapotentiallyirritatingdrug(e.g.,aspirin)orprotectsthedrug(e.g.,erythromycin)frompartialdegradationintheacidicenvironmentofthestomach.

rect/o:rectum

rectaladministration:suchasbysuppository,itisinsertedintotherectumwhereitdissolvesandisabsorbedintobloodcirculation.

hepat/o:liver

hepatatrophia:Atrophyoftheliverhepatoma:livercancer

bile:

bil/i:

bilirubin:theyellowbreakdownproductofnormalhemecatabolism.Hemeisformedfromhemoglobin,aprincipalcomponentofredbloodcells.Bilirubinisexcretedinbile,anditslevelsareelevatedincertaindiseases.injaundice,whichiscausedbyhyperbilirubinemia,theskin,mucusmembraneandwhitesoftheeyesarestainedandturnyellow

chol/e:

cholecalciferol:VitaminD3,whichcanpromotetheabsorptionofcalcium.

melancholy:Temperamenttheory:Thetheorythatholdsthattherearefourbasictemperaments,i.e