硕士医学英语感觉器官和皮肤.ppt

MedicalTerminology（9）TheSenseOrgansandSkin感觉器官与皮肤刘帅研究生英语教研室（综合楼110）,TheSensorySystem:,Thesensorysystemisournetworkfordetectingstimulifromtheinternalandexternalenvironments.Itisneededtomaintainhomeostasis,provideuswithpleasure,andprotectusfromharm.Pain,forexample,isanimportantwarningsignoftissuedamage.Theenergygeneratedinthevariousreceptorsofthesensorysystemmustbetransmittedtothecentralnervoussystemforinterpretation.Thegeneralsensesarewidelydistributedthroughoutthebody.Thesesensesincludepain;touch,thetactilesense;pressure;temperature;andproprioception(本体感觉),theawarenessofbodyposition.,Thespecialsensesarelocalizedwithincomplexsenseorgans.Theseincludethechemicalsensesofgustation(taste)andolfaction(smell),locatedinthemouthandnose,respectively;thesensesofhearingandequilibrium,locatedintheear;andthesenseofvision,locatedintheeye.,SuffixesPertainingtotheSenses,TheEar:,Theearhasthereceptorsforbothhearingandequilibrium.Forstudypurposes,itmaybedividedintothreeparts:theouter,middle,andinnerear.Theouterearconsistsoftheprojectingpinna(auricle,耳廓)andtheexternalauditorycanal(meatus,道).Thiscanalendsatthetympanicmembraneoreardrum(鼓膜，鼓室),whichtransmitssoundwavestothemiddleear.Glandsintheexternalcanalproduceawaxymaterial,cerumen(耳垢),whichprotectstheearandhelpstopreventinfection.,Spanningthemiddleearcavityarethreeossicles(smallbones,小骨),eachnamedforitsshape:themalleus(锤骨),incus(砧骨),andstapes(镫骨).Soundwavestravelingovertheossiclesaretransmittedfromthefootplate(镫骨底)ofthestapestotheinnerear.Theeustachiantube(咽鼓管)connectsthemiddleearwiththenasopharynxandservestoequalizepressurebetweentheouterandmiddleear.Theinnerear,becauseofitscomplexshape,isdescribedasalabyrinth(迷宫).Itconsistsofanouterbonyframeworkcontainingasimilarlyshapedmembranouschannel.Theentirelabyrinthisfilledwithfluid.,Thecochlea(耳蜗),shapedliketheshellofasnail,hasthespecializedorganofCorti(柯替氏器,螺旋器)concernedwithhearing.Cellsinthisreceptororganrespondtosoundwavestravelingthroughthefluid-filledductsofthecochlea.Soundwavesenterthecochleafromthebaseofthestapesthroughanopeningcalledtheovalwindow(前庭窗)andleavethroughanotheropeningcalledtheroundwindow(蜗窗).Thesenseofequilibriumislocalizedinthevestibularapparatus(前庭器).Thisstructureconsistsofthechamberlikevestibuleandthreeprojectingsemicircularcanals.,Specialcellswithinthevestibularapparatusrespondtomovement.Nerveimpulsesaretransmittedfromtheeartothebrainbywayofthevestibulocochlearnerve(前庭蜗神经),theeighthcranialnerve(颅神经),alsocalledtheacousticorauditorynerve.Thecochlearbranchofthisnervetransmitsimpulsesforhearingfromthecochlea;thevestibularbranchtransmitsimpulsesconcernedwithequilibriumfromthevestibularapparatus.,RootsPertainingtotheEarandHearing,RootsPertainingtotheEarandHearing,TheEyeandtheVersion:,Thewalloftheeyeiscomposedofthreelayers.Theoutermostisatoughprotectivelayer,thesclera(巩膜),commonlycalledthewhiteoftheeye.Thislayerextendsoverthefrontoftheeyeasthetransparentcornea(角膜).Themiddlelayerisavascularlayer,theuvea(葡萄膜),whichconsistsofthechoroid(脉络膜),theciliarybody(睫状体),andtheiris(虹膜).Theiris,bywhichweassignthecoloroftheeye,isamuscularringthatcontrolsthesizeofthepupil,thusregulatingtheamountoflightthatenterstheeye.Theciliarybodycontainsamusclethatcontrolstheshapeofthelenstoallowfornearandfarvision,aprocessknownasaccommodation(视觉调节).,Theretina(视网膜)istheinnermostlayerandtheactualvisualreceptor.Itconsistsofspecializedcells,rods(柱细胞)andcones(锥细胞),whichrespondtolight.Therodsfunctionindimlight,havelowvisualacuity,anddonotrespondtocolor.Theconesareactiveinbrightlight,havehighvisualacuity,andrespondtocolor.Propervisionrequirestherefraction(bending)oflightraysastheypassthroughthestructuresoftheeyetofocusonaspecificpointontheretina.Theenergygeneratedwithintherodsandconesistransmittedtothebrainbywayoftheopticnerve(secondcranialnerve).,Wheretheopticnerveconnectstotheretina,therearenorodsorcones.Thispoint,atwhichthereisnovisualperception,iscalledtheopticdisk(视神经乳头，视盘),orblindspot.Intheretina,neartheopticnerve,isthefovea(中央凹),atinydepressionthathasahighconcentrationofconecellsandisthepointofgreatestvisualacuity(sharpness).Thefoveaissurroundedbyayellowishspotcalledthemacula(角膜斑翳).,Theeyeisprotectedbyitspositionwithinabonysocketororbit.Itisalsoprotectedbytheeyelids(眼睑),eyebrows,eyelashes,andtears.Thelacrimal(tear)glandsconstantlybathetheeyeswithalubricatingfluidthatdrainsintothenose.Thereisalsoaprotectiveconjunctiva(结膜),athinmembranethatlinestheeyelidsandcoverstheanteriorportionoftheeye.Theeyeballisfilledwithajellylikevitreousbody(玻璃体).Sixmusclesattachedtotheoutsideofeacheyecoordinateeyemovementstoachieveconvergence,thatis,coordinatedmovementoftheeyessothattheybotharefixedonthesamepoint.,RootsforExternalEyeStructure,RootsfortheEyeandVersion,RootsfortheEyeandVersion,RootsfortheEyeandVersion,SuffixesfortheEyeandVersion,ClinicalAspectsofHearing：HearingLoss,Hearingimpairmentmayresultfromdisease,injury,ordevelopmentalproblemsthataffecttheearitselforanynervouspathwaysconcernedwiththesenseofhearing.Sensorineuralhearingloss(感觉神经性失聪)resultsfromdamagetotheeighthcranialnerveortocentralauditorypathways.Heredity,toxins,exposuretoloudnoises,andtheagingprocessarepossiblecausesforthistypeofhearingloss.Itmayrangefrominabilitytohearcertainfrequenciesofsoundtoacompletelossofhearing(deafness).Peoplewithextremehearinglossthatoriginatesintheinnerearmaybenefitfromacochlearimplant(耳蜗埋植).,Thisprosthesisstimulatesthecochlearnervedirectly,bypassingthereceptorcellsoftheinnerear,andmayallowtherecipienttohearmediumtoloudsounds.Conductivehearingloss(传导性耳聋)resultsfromblockageinsoundtransmissiontotheinnerear.Causesincludeobstruction,severeinfection,orfixationofthemiddleearossicles.Oftentheconditionsthatcauseconductivehearinglosscanbetreatedsuccessfully.,Otitis:,Otitisisanyinflammationoftheear.Otitismediareferstoaninfectionthatleadstotheaccumulationoffluidinthemiddleearcavity.OnecauseismalfunctionorobstructionoftheEustachiantube,suchasbyallergy,enlargedadenoids,injury,orcongenitalabnormalities.Anothercauseisinfectionthatspreadstothemiddleear,mostcommonlyfromtheupperrespiratorytract.Continuedinfectionmayleadtoaccumulationofpusandperforation(鼓膜穿孔)oftheeardrum.Otitismediausuallyaffectschildrenunder5yearsofageandmayresultin,hearingloss.Ifuntreated,theinfectionmayspreadtootherregionsoftheearandhead.Treatmentiswithantibiotics.Atubealsomaybeplacedinthetympanicmembranetoventilatethemiddleearcavity,aprocedurecalledamyringotomy.Otitisexterna(外耳炎)isinflammationoftheexter