VisionBioGuru视觉生物大师

VisionBioGuru视觉生物大师第1页/共24页第2页/共24页TheConjunctiva

linestheinsideoftheeyelidsandcoversthesclera(whitepartoftheeye).Itiscomposedofrarestratifiedcolumnarepithelium.第3页/共24页TheSclera

TheCorneaWindowoftheeyeHelpsfocusenteringlightraysComposedofconnectivetissuew/thinlayerofepitheliumHasmanynervefibersthatenterthemarginandradiatetowardthecenter–associatewithmanypainreceptorsw/lowthresholdColdreceptorsabundantWhiteportionoftheeyeMakesup5/6ofposterioroutertunicOpaqueb/cofhowthecollagenandelasticfibersarearranged.ProtectstheeyeAttachmentforextrinsicmuscles第4页/共24页TheOpticNerveTheChoroidCoatLocatedinthebackoftheeyeAttachedtotheretinaTransmitsimagesfromtheretinatothebrainFlipsthepicturesPartofthemiddletunicPosterior5/6oftheglobeoftheeyeHasbloodvesselsthatnourishsurroundingpartsContainsmelanocytesMelaninfrommelanocytesabsorbexcesslightandkeeptheinsidepartoftheeyedark第5页/共24页TheCiliaryBodyTheIrisThickestpartofthemiddletunicExtendstothefrontfromthechoroidcoatFormsinternalringaroundtheeyeContainfoldscalledciliaryprocesses2groupsofmusclefibers–ciliarymusclesControlshowmuchlightenterstheeyeThindiaphragmcomposedofconnectivetissue&thinconnectivetissueItisthecoloredportionoftheeyeExtendsfromthefrontoftheperipheryintheciliarybodytothemiddleofthecorneaandthelensDividestheanteriorcavity(cornea&iris)intoanteriorchamber(irisandvitreoushumor)第6页/共24页ThePupilTheLens

ThecircularopeninginthecenteroftheirisBlackspotinthecenteroftheirisControlshowmuchlightenterstheretinaItsdiametersisusually3-7mmTransparentHeldinpositionbyfiberscalledsuspensoryligaments(zonularfibers)fromtheciliaryprocessesLacksbloodvesselsLocatedbehindtheirisandthepupilComposedofspecialepithelialcells第7页/共24页VitreousHumorAqueousHumorFrontofirisandpupilWateryfluidcreatedbyepitheliumoninnersurfaceofciliarybodySeparatedintoanteriorandposteriorchambersMaintainseyepressureNourishesfrontpartoftheeyeJelly-likefluidFillsthecentralcoreoftheeyeHelpsmaintainsphericalshapetotheeyethiswithcollagenousfibersformthevitreousbody第8页/共24页TheMaculaLuteaTheFoveaCentralis

YellowishspotintheretinaThecentralfocusingspotResponsibleforseeingdetails(reading)andcolorvisionAdepressioninthemaculaluteaIntheregionoftheretinathatproducesthesharpestvisionHasnorods–onlycones第9页/共24页TheOpticDiskLacksreceptors,oftencalledtheblindspotThenervefibersfromtheretinaandbecamepartoftheopticnerve.AcentralarteryandveinpassthroughhereThesevesselswithvesselsinthechoroidcoatsupplybloodtothecellsoftheinnertunicJelly-likefluidFillsthecentralcoreoftheeyeHelpsmaintainsphericalshapetotheeyethiswithcollagenousfibersformthevitreousbody第10页/共24页TheRetinaComplexstructureLayersof(epithelium,nervefibers,&membranes)ContainsphotoreceptorscalledrodsandconesContinuouswiththeopticnerveandextendstothefrontastheinnerliningoftheeyeball6retinalcellgroups:rods,cones,bipolarneurons,ganglioncells,videdirectpathforimpulsestothereceptorstotheopticnerve&brainTheretinacontainstwotypesofphotoreceptors,rodsandcones.Therodsaremorenumerous,some120million,andaremoresensitivethanthecones.However,theyarenotsensitivetocolor.The6to7millionconesprovidetheeye'scolorsensitivityandtheyaremuchmoreconcentratedinthecentralyellowspotknownasthemacula.Inthecenterofthatregionisthe"foveacentralis",a0.3mmdiameterrod-freeareawithverythin,denselypackedcones.第11页/共24页Thereceptorsintheretina第12页/共24页Pigmentepitheliumthepigmentedcelllayerjustoutsidetheneurosensoryretinanourishesretinalvisualcellsfirmlyattachedtotheunderlyingchoroidandoverlyingretinalvisualcells.第13页/共24页RodsConesResponsibleforblackandwhitevisionTherodsaremorenumerousandmoresensitivethantheconestheyareabsentinthefoveacentralisResponsibleforcolorvisionDenselypackedinthefoveacentralis第14页/共24页HorizontalcellsBipolarcellsHorizontalcellsintegrateandregulatetheinputfromrodsandcones.Theyarealsoresponsibleforallowingeyestoadjusttoseewellunderbothbrightanddimlightconditions.Bipolarcellsexistbetweenrodsandconesandganglioncells.Theytransmitsignalsfromtherodsandconestotheganglioncells.第15页/共24页AmacrinecellGanglioncellAGanglioncellisatypeofneuronlocatedneartheinnersurfaceoftheretinaItreceivesvisualinformationfromrodsandconesviatwointermediateneurontypes:bipolarcellsandamacrinecells.Ittransmitsvisualinfotothalamus,hypothalamusandmidbrain.Amacrinecellsareinterneuronsintheretina.Theyareresponsiblefor70%ofinputtoretinalganglioncells.Theylackaxons–buthavemanydendrites第16页/共24页DirectionofImpulsePhotonsmovethroughthe6layersofcellsandstriketherodsandconesTheyprocessthelightinformationThisinfoisintegratedbythehorizontalcellsThe