医学英语课件cells.ppt

Whatarealllivingorganismsmadeof CELLS CYTOLOGY Celltheory cellsarethebasicunitofstructureineverylivingthing advancesinmicroscopyoneofthefoundationsofbiologyThetheorysaysthatnewcellsareformedfromotherexistingcells andthatthecellisafundamentalunitofstructure functionandorganizationinalllivingorganisms Whatiscytology Creditfordevelopingcelltheoryisusuallygiventothreescientists 1 Schwanncells SCs 雪旺细胞 Schwanncells SCs 是形成周围神经髓鞘的胶质细胞 1839年德国科学家西奥多 施沃恩最先描述 2 MatthiasJakobSchleiden 马蒂亚斯 许莱登 5April1804 23June1881 wasaGermanbotanistandco founderofthecelltheory alongwithTheodorSchwannandRudolfVirchow Germancellbiologistandphysiologist SchwannstudiedmedicineattheUniversityofBerlinanddiscoveredinthegastricjuicepepsin adigestiveenzymeforprotein Itwasthefirstenzymethatcouldbepresentedfromananimaltissue TheodorSchwann 西奥多 施万 MatthiasJakob马蒂亚斯 雅各布 许莱登1804 1881 MatthiasJakobSchleidenBorninHamburg SchleidenwaseducatedatHeidelberg thenpracticedlawinHamburg butsoondevelopedhisloveforthebotany 植物学 intoafull timepursuit Hein1838 studiedplanttissuesandstatedthatallplantsareaggregatesofindividualcellswhicharefullyindependent Thushemadethefirststatementofcelltheory AGermandoctor pathologist biologistandpolitician knownforhisadvancementofpublichealth Referredtoas thefatherofmodernpathology heisconsideredoneofthefoundersofsocialmedicine Virchowiscreditedwithmultipleimportantdiscoveries Virchow smostwidelyknownscientificcontributionishiscelltheory whichbuiltontheworkofTheodorSchwann Heiscitedasthefirsttorecognizeleukemiacells RudolphVirchow鲁道夫 魏尔肖 1821 1902 UnitOne Cytology Cytologystudiesthestructureoffunctionofcells Celltheory 1 Allknownlivingthingsaremadeupofoneormorecells 2 Alllivingcellsarisefrompre existingcellsbydivision 3 Thecellisthefundamentalunitofstructureandfunctioninalllivingorganisms 4 Theactivityofanorganismdependsonthetotalactivityofindependentcells 5 Energyflow metabolismandbiochemistry occurswithincells 6 Cellscontainhereditaryinformation DNA whichispassedfromcelltocellduringcelldivision 7 Allcellsarebasicallythesameinchemicalcompositioninorganismsofsimilarspecies multicellular multi morethanone many多 多数 prefixtoformn andadj multicultural multimedia multinational multicell multicellular multicellularity multi storeycarpark amoeba n 变形虫 阿米巴 usu usedasprefix amoeb BrE ameb AmE amebiform amebocyte micron micro microorganism microscope microcirculation microfracture microphone microwave microclimate micron macro macrobacterium macrobiosis macrophage ovum n femaleeggcell卵子 ova ovulatev 排卵 ovulatorya 排卵的 ovaryn 卵巢 cytoplasm n theprotoplasmofacellexcludingthenucleus细胞质 胞质 胞浆 cyto 细胞 cyte细胞 cytobiology cytodifferentiation cytogenetics cytolysosome plasma also plasm n 血浆 clearcytoplasm透明细胞质basiccytoplasm细胞质基质 phospholipid n 磷脂 phosphaten 磷酸盐 磷肥 lipid animportantconstituentofmembranes phosphorusn 磷 cholesterol n 胆固醇 chole pref 胆 胆汁 cholecyst胆囊cholebilirubin胆玉红素 直应胆红素 steroide甾族化合物sterone甾酮 固酮steroidogenesis类固醇生成 steroln 甾醇固醇 oligosaccharide n 低聚糖 寡糖 oligo 少 小 缺 低于正常 oligoamniosn 羊水过少 oligodynamic sacchar 糖 sacchariden 糖类polysacchariden 多糖disacchariden 二糖monosacchariden 单糖 chromosome n athreadlikebodyinthecellnucleusthatcarriesthegenesinalinearorder染色体 chromo 色 chromogenica 显色的 chromosomeaberration染色体畸变 chromosomearm number band chromotinn 染色质 Chromosomesalsodeterminethesexofanimals endoplasmicreticulum n 内质网 endo 内 endocardiala 心内 膜 的 endocellulara 细胞内的 endochromen 胞内染色质 extra 外 endocrinea 内分泌的 mitochondria n 线粒体 mito 线 丝 mitosisn 有丝分裂 mitochromen 线色素 mitochondrion aerobic a dependingonfreeoxygenorair需氧生活的 aero n 氧 空气 aerodynamica 空气动力的 aerobicexercise aerospacen 航空航天工业 aerobics aerobicbacteria lysosome n 溶酶体 lys o 溶解 溶化 lysophosphalipidn 溶血磷脂 lysogenesisn 溶源性 engulf v flowoverorcovercompletely吞没 吞噬 engross oneself fully沉浸其中 Thelittleboatwasengulfedbythewaves Heengulfedhimselfintohisstudies uterus n womb子宫 uterectomyn 子宫切除术 uteralgian 子宫痛 uter 子宫 anultrasoundscanoftheuterus osmosis n 渗透作用 osmosev 渗透 osmosologyn 渗透学 osmoticdiarrhea osmoticshock osmoticpressure osmo n 气体 渗透 osmotherapyn 渗透疗法 osmotica 渗透的 filtration n theprocessoffilteringaliquidorgas过滤 滤液 Alldrinkingwatermustbefiltered filter v 过滤filtratev 过滤 筛选 UseasunblockthatfiltersUVAeffectively filtertip phagocytosis n 嗜菌作用 phagocytablea 可被吞噬的 phagocyten 吞噬细胞 phago 吞噬 pinocytosis n 胞饮作用 pinocytea 胞饮细胞 pinosomen 胞饮泡 吸液小体 pino 胞饮 evaporate v loseorcausetoloseliquidbyvaporization 使 蒸发 消失 逐渐 消失 衰减 Thewatersoonevaporatedinthesunshine Hisconfidencehadnowcompletelyevaporated evaporation collide v crashtogetherwithviolentimpact碰撞 冲突 Theshipscollidedinthefog Theinterestsofthetwocountriescollide collision equilibrium n astablesituation平衡 均衡 平静 equidistanta 等距的 equilaterala 等边的 equi equal Anydisturbancetothebody sstateofequilibriumcanproducestress Hesatdowntotryandrecoverhisequilibrium spontaneous a happeningorarisingwithoutapparentexternalcause自发的 本能的 自然的 aspontaneousofferofhelp aspontaneousabortion ataperecordingofspontaneousspeech GeneralIntroduction CellStructure CellularTransportMechanisms CellStructureandCellularTransportMechanism CellMembrane Nucleus CytoplasmandCellOrganelles Diffusion Osmosis FacilitatedDiffusion ActiveTransport Filtration PhagocytosisPinocytosis Cells Alllivingorganismsaremadeofcellsandcellproducts Thissimplestatement calledtheCellTheory wasfirstproposedover150yearsago Youmaythinkofatheoryasaguessorhypothesis andsometimesthisisso Butatheoryisactuallythebestexplanationofalltheavailableevidence AlloftheevidencesciencehasgatheredsofarsupportsthevalidityoftheCellTheory hyper hypotensionhypocritical Cells GeneralIntroduction CellTheory Hypothesis150yearsago validity Cellsarethesmallestlivingsubunitsofamulticellularorganismsuchasahumanbeing Acellisacomplexarrangementofthechemicals isliving andcarriesoutspecificactivities Microorganisms suchasamoebasandbacteria aresinglecellswhichfunctionindependently Humancells however mustworktogether andfunctioninterdependently Homeostasisdependsuponthecontributionsofallofthedifferentkindsofcells sub zerotemperatures subtropicalclimate subway subtitle Independently onone sownInterdependently mutuallyHomeostasis processbywhichthefunctionsandchemistryofacellarekeptstable Cells GeneralIntroduction Cellsarethesmallestlivingsubunits Humancellsvaryinsize shape andfunction Mosthumancellsaresosmalltheycanonlybeseenwiththeaidofamicroscope andaremeasuredinunitscalledmicrons Oneexceptionisthehumanovumoreggcell whichisaboutonemillimeterindiameter justvisibletotheunaidedeye Somenervecells althoughmicroscopicindiameter maybequitelong Thoseinourarmsandlegs forexample areatleasttwofeetlong centimeter厘米decimeter分米 Cells GeneralIntroduction Humancellsvaryinsize shape andfunction microns Cells GeneralIntroduction Humancellsvaryinsize shape andfunction ovumeggcell Withrespecttoshape humancellsvarygreatly Someareroundorspherical othersrectangular stillothersirregular Whitebloodcellsevenchangeshapeastheymove Asfor inrespectof Inviewof leukocyte erythrocyte CellStructureDespitetheirmanydifferences humancellshaveseveralsimilarstructuralfeatures acellmembrane cytoplasmandcellorganelles andanucleus Redbloodcellsareanexceptionsincetheyhavenonucleiwhenmature Thecellmembraneformstheouterboundaryofthecell andsurroundsthecytoplasm organelles andnucleus WBC erythrocytes leucocytes RBC WBC WBC CellMembraneAlsocalledtheplasmamembrane thecellmembraneismadeofphospholipids cholesterol andproteins Thephospholipidspermitlipid solublematerialstoeasilyenterorleavethecellbydiffusionthroughthecellmembrane Cholesterolprovidesgreaterstabilitytothemembrane compoundwithfattyacids 磷脂 Fattysubstancefoundinfatsandoil producedbytheliver Theproteinshaveseveralfunctions someformporesoropeningstopermitpassageofmaterials othersareenzymesthatalsohelpsubstancesenterthecell Stillotherproteins witholigosaccharides 低聚糖 寡糖 ontheiroutersurface areantigens markersthatidentifythecellsofanindividualas self few little sugar oliguriatrigeminalnerve tetracylinepentagon Andyetanothergroupofproteinsservesasreceptorsitesforhormones Manyhormonesbringabouttheirspecificeffectsbyfirstbonding linking toaparticularreceptoronthecellmembrane Thisbondingthentriggers stimulates induces chemicalreactionswithinthecellmembraneortheinteriorofthecell exterior anterior posterior superior inferior ProteinsinCellMembrane Althoughthecellmembraneistheouterboundaryofthecell itshouldalreadybeapparenttoyouthatitisnotastatic motionless orwall likeboundary butratheranactive dynamicone Thecellmembraneisselectivelypermeable thatiscertainsubstancesarepermittedtopassthroughandothersarenot Bychoice impermeable permeate NucleusWiththeexceptionofmatureredbloodcells allhumancellshaveanucleus Thenucleusfloatsinthecytoplasm andisboundedbyadouble layerednuclearmembranewithmanypores walledoff erythrocyte leukocyte drifts Anucleolus 核仁 isasmallspheremadeofDNA RNA andprotein ThenucleoliformatypeofRNAcalledribosomalRNA whichbecomespartofribosomes核糖体 acellorganelle andisinvolvedinproteinsynthesis DNA deoxyribonucleicacid RNA ribonucleicacid Thenucleusisthecontrolcenterofthecellbecauseitcontainsthechromosomes 染色体 The46chromosomesofahumancellareusuallynotvisible theyarelongthreadscalledchromatin 染色质 Whenacelldivides however thechromatincoils twistintoawindingshape extensivelyintovisiblechromosomes ChromosomesaremadeofDNAandprotein RememberfromourearlierdiscussionthattheDNAisthegeneticcodeforthecharacteristicsandactivitiesofthecell AlthoughtheDNAinthenucleusofeachcellcontainsallofthegeneticinformationforallhumantraits onlyasmallnumberofgenesareactuallyactiveinaparticularcell Theseactivegenesarethecodesfortheproteinsnecessaryforthespecificcelltype 这些活性基因为特定细胞类型所必须的蛋白编码 CytoplasmandcellorganellesCytoplasmisawaterysolutionofminerals gases andorganicmoleculesthatisfoundbetweenthecellmembraneandthenucleus Chemicalreactionstakeplacewithinthecytoplasm andthecellorganellesarefoundhere Cellorganellesareintracellularstructures oftenboundedbytheirownmembranes whichhavespecificrolesincellularfunctioning 溶酶体 中心粒 核糖体 Theendoplasmicreticulum ER isanextensivenetworkofmembranoustubulesthatextendfromthenuclearmembranetothecellmembrane RoughER 粗面内质网 hasnumerousribosomesonitssurface whilesmoothER 滑面内质网 hasnoribosomesatall Asanetworkofinterconnectedtunnels theERservesasapassagewayforthetransportofthematerialsnecessaryforcellfunctionwithinthecell TheseincludeproteinssynthesizedbytheribosomesontheroughER andlipidssynthesizedbythesmoothER abundantconsiderablemultitudinous Endoplasmicreticulum synthesize v 合成 synthesisn 合成 syn pref 表示 共 合 之义 synactica 合作的 一起工作的 synthetica 人工的 合成的 synaesthesian 通感 联觉 syndromen 综合症 syndicaten 企业联合 Ribosomes核糖体areverysmallstructuresmadeofproteinandribosomalRNA SomearefoundonthesurfaceofroughER whileothersfloatfreelywithinthecytoplasm Ribosomesarethesiteofproteinsynthesis TheGolgiapparatusisaseriesofflat membranoussacs somewhatlikeastackofsaucers CarbohydratesaresynthesizedwithintheGolgiapparatus andarepackaged alongwithothermaterials forsecretionfromthecell Tosecreteasubstance smallsacsoftheGolgimembranebreakoff decompose andfuse jointogether withthecellmembrane releasingthesubstancetotheexteriorofthecell instrument equipment facilities apileof Aminute roundparticlecomposedofRNAandproteinfoundinthecytoplasmoflivingcellsandactiveinthesynthesisofproteins 核糖体一种微小圆形的由RNA及蛋白质构成的微粒 发现于活细胞的细胞质中 且活跃于蛋白质的合成中 ribosome carbohydrate n 碳水化合物 carbo pref 表示 碳 carbonn 碳 carbonaten 碳酸盐 黑金刚石 carbiden 碳化物 碳化钙 hydra pref 表示 水 hydraten 水化物 hydrationn 水合作用 hydratablea 能水合的 carbohydrate n 碳水化合物 nitraten 硝酸盐 carbonaten 碳酸盐 黑金刚石 acetaten 醋酸盐 sulfaten 硫酸盐 Mitochondria 线粒体 areovalorsphericalorganelleswithinthecytoplasm boundedbyadoublemembrane Theinnermembranehasfoldscalledcristae Withinthemitochondria theaerobic oxygen requiring reactionsofcellrespirationtakeplace Therefore mitochondriaarethesiteofATP andhenceenergy production CellsthatrequirelargeamountsofATP suchasmusclecells havemanymitochondriatomeettheirneedforenergy 嵴 鸡冠突起 Adenosinetriphosphate三磷酸腺甘 Mitochondria likeasoleofaslipper 线粒体 Groundsubstance基质 Amembrane boundorganelleinthecytoplasmofmostcellscontainingvarioushydrolyticenzymesthatfunctioninintracellulardigestion 溶酶体一种被膜包住的小器官 存在于大多数细胞的细胞质中 内含多种水解酶 在细胞内消化中起作用 Lysosomes Lysosomesaresinglemembranestructureswithinthecytoplasmthatcontaindigestiveenzymes Whencertainwhitebloodcellsengulfbacteria thebacteriaaredigestedanddestroyedbytheselysosomalenzymes Worn outcellpartsanddeadcellsarealsodigestedbytheseenzymes whichcontributestotheprocessofinflammationindamagedtissues Lysosomes溶酶体 agingcell celldebris inflammation n 炎症 flamen 火焰 热情vi 燃烧 inflamevt vi 使 发怒 过热 使发炎 itissuffix炎症 Centrioles 中心粒 体 areapairofrod shapedstructuresperpendicular 垂直的 tooneanother Theirfunctionistoorganizethespindlefibersduringcelldivision Oneoftwocylindricalcellularstructuresthatarecomposedofninetripletmicrotubulesandformtheastersduringmitosis 中心体是两个圆柱体细胞组织之一 每个圆柱体由九个三联体微管组成 在有丝分裂中形成星状体 Ciliaandflagella 纤毛和鞭毛 aremobilethread likeprojectionsthroughthecellmembrane Ciliaservethefunctionofsweepingmaterialsacrossthecellsurface Theyareusuallyshorterthanflagella andanindividualcellhasmanyofthem Cellsliningthefallopiantubes 输卵管 forexample haveciliatosweeptheeggcelltowardtheuterus Theonlyhumancellwithaflagellumisthespermcell Theflagellumprovidesmotility ormovement forthespermcell CellularTransportMechanismsLivingcellsconstantlyinteractwiththebloodortissuefluidaroundthem takinginsomesubstancesandsecretingorexcretingothers Thereareseveralmechanismsoftransportthatenablecellstomovematerialsintooroutofthecell diffusion osmosis facilitateddiffusion 易化扩散 activetransport 主动转运 filtration phagocytosis andpinocytosis 胞饮作用 Someofthesetakeplacewithouttheexpenditureofenergybythecells But othersdorequireenergy intheformofATP Eachofthesemechanismsisdescribedbelowandanexampleisincludedtoshowhoweachisimportanttothebody DiffusionDiffusionisthemovementofmoleculesfromanareaofgreaterconcentrationtoanareaoflesserconcentration Diffusionoccursbecausemoleculeshavefreeenergy thatis theyarealwaysinmotion Themovementofmoleculesfromaregionofhigherconcentrationtoaregionoflowerconcentration Themoleculesinasolidmoveveryslowly thoseinaliquidmovefaster andthoseinagasmovefasterstill aswheniceabsorbsheatenergy melts andthenevaporates turnintovapor Asthesugardissolves thesugarmoleculescollide strike withoneanother Thesecollisionsspreadoutthesugarmoleculesuntiltheyareevenly equally dispersedamongthewatermolecules Themoleculesarestillmoving butassomegotothetopothersgotothebottom andsoon Thus anequilibrium steadiness isreached Withinthebody thegasesoxygenandcarbondioxidemovebydiffusion Inthelungs forexample thereisahighconcentrationofoxygeninthealveoli airsacs andalowconcentrationofoxygeninthebloodinthesurroundingpulmonarycapillaries Theoppositeistrueforcarbondioxide alowconcentrationintheairinthealveoliandahighconcentrationinthebloodinthepulmonarycapillaries Thesegasesdiffuseinoppositedirections eachmovingfromwherethereismoretowherethereisless Oxygendiffusesfromtheairtothebloodtobecirculatedthroughoutthebody Carbondioxidediffusesfromthebloodtotheairtobeexhaled breatheout OsmosisOsmosismaybesimplydefinedasthediffusionofwaterthroughaselectivelypermeablemembraneorbarrier Thatis waterwillmovefromanareawithmorewaterpresenttoanareawithlesswater Anotherwaytosaythisisthatwaterwillnaturallytendto inclineto movetoanareawherethereismoredissolvedmaterial suchassaltorsugar Osmosisisthemovementofwater reddots throughasemipermeablemembranetoahigherconcentrationofsolutes溶质 bluedots Watereasilymovesthroughcellmembranesbyosmosis Ifa2 saltsolutionanda6 saltsolutionareseparatedbyamembraneallowingwaterbutnotsalttopassthroughit waterwilldiffusefromthe2 saltsolutiontothe6 saltsolution Theresultisthatthe2 solutionwillbecomemoreconcentratedandthe6 solutionwillbecomemoredilute Inthebody thecellsliningthesmallintestineabsorbwaterfromdigestedfoodbyosmosis Thesecellshavefirstabsorbedsalts havebecomemore salty andwaterfollowssaltintothecells Theprocessofosmosisalsotakesplaceinthekidneys whichreabsorblargeamountsofwatertopreventitslossinurine oliguria FacilitatedDiffusion 易化扩散 Thewordfacilitatemeanstohelporassist Infacilitateddiffusion moleculesmovethroughamembranefromanareaofgreaterconcentrationtoanareaoflesserconcentration buttheyneedsomehelptodothis Inthebody ourcellsmusttakeinglucosetouseforATPproduction Glucose however willnotdiffusethroughmostcellmembranesbyitself evenifthereismoreoutsidethecellthaninside Diffusionofglucoseintomostcellsrequirescarrierenzymes proteinsthatarepartofthecellmembrane Glucosebondsto linksto thecarrierenzymes andbydoingsobecomessolubleinthephospholipidsofthecellmembrane Theglucose carriermoleculediffusesthroughthemembraneandglucoseisreleasedtotheinteriorofthecell ase telomeraseperoxidasetranscriptase ThisprocessdoesnotrequireATPbutdoesrequirecellmembraneproteinswhicharecalledcarrierproteinstocarrythemoleculesacrossthecellmembranefromanareaofhigherconcentrationtoanareaoflowerconcentration ActiveTransport 主动运输 ActivetransportrequirestheenergyofATPtomovemoleculesfromanareaoflesserconcentrationtoanareaofgreaterconcentration Noticethatthisistheoppositeofdiffusion inwhichthefreeenergyofmoleculescausesthemtomovetowheretherearefewerofthem Activetransportisthereforesaidtobemovementagainstaconcentrationgradient Inthebody nervecellsandmusclecellshave sodiumpumps tomovesodiumions Na outofthecells Sodiumionsaremoreabundantoutsidethecells andconstantlydiffuseintothecell theirareaoflesserconcentration Withoutthesodiumpumpstoreturnthemoutside theincomingsodiumionswouldbringabout cause produce trigger anunwantednerveimpulseormusclecontraction NerveandmusclecellsconstantlyproduceATPtokeeptheirsodiumpumpsworkingandpreventspontaneousimpulses contactcontractcontrast Anotherexampleofactivetransportistheabsorptionofglucoseandaminoacidsbythecellsliningthesmallintestine ThecellsuseATPtoabsorbthesenutrientsfromdigestedfood evenwhentheirintracellularconcentrationbecomesgreaterthantheirextracellularconcentration ActiveTransport1 ActiveTransportrequiresthecelltouseenergy usuallyintheformofATP 2 ActiveT