系统解剖学英文版教学课件：Visual organ

SensorysystemAsensorysystemisapartofthenervoussystemresponsibleforprocessingsensoryinformation.Asensorysystemconsistsofsensoryreceptors,neuralpathways,andpartsofthebraininvolvedinsensoryperception.Commonlyrecognizedsensorysystemsarethoseforvision,hearing,somaticsensation(touch),tasteandolfaction(smell).SensoryOrgans:

SensoryreceptorsAccessoryorgansSensoryreceptorsconverttheenergyofthestimulus(light,heat,sound,smell)intonerveimpulsesandsendthesetothecentralnervoussystem.

Typesofsensoryreceptors(basedontheregionthatsensoryreceptorsarelocated):Exteroceptors(skin,themucousofthenasalandoralcavities,thevisualandauditoryorgans)Proprioceptors(muscles,tendonsjointsandligaments)Enteroceptors(thewallofviscera,theheartandbloodvessels)VisualOrgan(Theeye)Intheorbitandembeddedbythefattissue.Separateditfromthefattissuebyfascialsheath.I.Location:II.Generalshapeoftheeyeball

SphericalDiameter:2.5cmOpticaxis(redline)Visualaxis(blueline)Equator(yellowdashline)III.StructuresoftheeyeballFibroustunic

(theoutermostlayer)①CorneaTheanteriorandtransparentpartItismadealmostentirelyofproteinandcontainsnobloodvessels.Asaresult,cornealtransplantstendtobeverysuccessful;littlechancefortheimmunesystemtoreacttotheforeigntissue.I)Thewalloftheeyeball②Scleratheposteriorpart,whiteandopaqueFormsabout80%ofthesurface.Function:toprotecttheinternaleyestructuresandtogiveshapetotheeye.Themusclesthatmovetheeyeinsertontothesclera.(3)ScleralvenoussinusThisisnarrowtubeencirclingtheedgeofthecornea.Itdrainsfluidfromthespacebehindthecornea.2.Vasculartunic(1)Choroid(middlelayer,justinsidethefibroustunic).Containsarichsupplyofbloodvesselstoadjacentlayers.Containscellsthatproducelargeamountsofthepigmentmelanin.(2)Ciliarybody(Anteriortothechoroid)CiliaryprocessesCiliarymuscleCiliaryzonule(suspensoryligaments)Functionsoftheciliarybodyproducesaqueoushumor.TheaqueoushumorisdrainedbythescleralvenoussinusCiliarymuscleregulatestheshapeofthelensforfocusingoraccommodation.Function:Regulatetheamountoflightenteringtheeyebychangingthesizeofthepupil(theholeinthemiddleoftheiris).Inbrightlight,thesphinctermuscleoftheiriscontractandthepupilconstricts;thislimitstheamountoflightenteringtheeye.Indimlight,theradialmuscleoftheiriscontractsandthepupildilates;morelightenterstheeye.(3)Iris(anteriortotheciliarybodyandthelens)Thevertebrateretinaisalight-sensitivetissueliningtheinnersurfaceoftheeye.

Theopticsoftheeyecreateanimageofthevisualworldontheretina,whichservesmuchthesamefunctionasthefilminacamera.Lightstrikingtheretinainitiatesacascadeofchemicalandelectricaleventsthatultimatelytriggernerveimpulseswhicharesenttovariousvisualcentersofthebrainthroughthefibersoftheopticnerve.3.Nervoustunic(retina)Theretinaisalayeredstructurewithseverallayersofneuronsinterconnectedbysynapses.Theonlyneuronsthataredirectlysensitivetolightarethephotoreceptorcells(therodsandcones).Rodsfunctionmainlyindimlightandprovideblack-and-whitevision,whileconessupportdaytimevisionandtheperceptionofcolor.3.Nervoustunic(retina)istheserratedanteriorboundaryoftheretinalocatedsome8mmfromthelimbus.Attheoraserrata,theretinaisfirmlyadherenttothechoroid,whichisthereasonwhyaretinaldetachmentendshere.OraSerrata

isanobscurationofthevisualfield.istheplaceinthevisualfieldthatcorrespondstothelackoflight-detectingphotoreceptorcellsontheopticdiscoftheretinawheretheopticnervepassesthroughit.Is35mmtothenasalofMaculaluteaSincetherearenocellstodetectlightontheopticdisc,apartofthefieldofvisionisnotperceived.1.Blindspot(scotoma)Specialstructuresoftheretinaisanoval-shapedhighlypigmentedyellowspotnearthecenteroftheretinaofthehumaneye.hasadiameterofaround5

mmandisoftenhistologicallydefinedashavingtwoormorelayersofganglioncells.Nearitscenteristhefovea,asmallpitthatcontainsthelargestconcentrationofconecellsintheeyeandisresponsibleforcentral,highresolutionvision.2.Maculalutea

1.ChambersofeyesAnteriorchamberPosteriorchamberIridocornealangleScleralvenoussinusII.Contentsoftheeyeballisaclear,gelatinousfluidsimilartoplasma,butcontaininglow-proteinconcentrations.issecretedfromtheciliaryepithelium,astructuresupportingthelens.islocatedintheanteriorandposteriorchambersoftheeye,thespacebetweenthelensandthecornea.2.TheaqueoushumorProductionanddrainageissecretedbytheciliarybody.Drainageout:FromciliaryprocessPosteriorchamberpupilAnteriorchamberIridiocornealangleScleralvenoussinus2.TheaqueoushumorMaintainstheintraocularpressureandinflatestheglobeoftheeye.Providesnutrition(e.g.aminoacidsandglucose)fortheavascularoculartissues;posteriorcornea,trabecularmeshwork,lens,andanteriorvitreous.Immuneresponsetodefendagainstpathogens.Providesinflationforexpansionofthecorneaandthusincreasedprotectionagainstdust,wind,pollengrains.forrefractiveindex.Functions2.Theaqueoushumoratransparent,biconvexstructureintheeyethat,alongwiththecornea,helpstorefract

lighttobefocusedontheretina.BetweenirisandvitreousbodyElasticmembrane(lenscapsule)-near/farvisionNobloodvessels3.Lens

Cataractsareopacitiesofthelens.Whilesomearesmallanddonotrequireanytreatment,othersmaybelargeenoughtoblocklightandobstructvision.Cataractsusuallydevelopastheaginglensbecomesmoreandmoreopaque,butcataractscanalsoformcongenitallyorafterinjurytothelens.

Diabetesisalsoariskfactorforcataract.3.Lens(disorder)isthetransparent,colourless,gelatinousmassthatfillsthespacebetweenthelensoftheeyeandtheretinaliningthebackoftheeye.nobloodvessels,and98-99%ofitsvolumeiswater

VitreouscapsuleSupportretina4.ThevitreousbodyRetinodialysisaseparationortearintheretinainitsanteriorpart,intheareaoftheoraserrata,justbehindtheciliarybody.Myopia(Nearsightedness)aconditionoftheeyewherethelightthatcomesindoesnotdirectlyfocusontheretinabutinfrontofit.Thiscausestheimagethatoneseeswhenlookingatadistantobjecttobeoutoffocusbutinfocuswhenlookingatacloseobject.axisbulbistoolongDisorderofretina3.Hyperopia（Farsightedness）adefectofvisioncausedbyanimperfectionintheeye

(oftenwhentheeyeballistooshortorthelenscannotbecomeroundenough),causingdifficultyfocusingonnearobjects,andinextremecasescausingasufferertobeunabletofocusonobjectsatanydistance.Asanobjectmovestowardtheeye,theeyemustincreaseitsopticalpowertokeeptheimageinfocusontheretina.Ifthepowerofthecorneaandlensisinsufficient,asinhyperopia,theimagewillappearblurred.axisbulbistooshortDisorderofretina31AccessoryorgansoftheeyeUpperandlowereyelidsMedialandlateralanglesPalpebralfissureLacrimalpalpillaLacrimalpunctum1.Eyelids1.Skin(Eyelashes)2.Subcutanousareolartissue(Ciliaryglands(Zeisgland)3.Orbicularisoculi4.Tarsus(Tarsalglands)5.ConjunctivaLayersoftheeyelidsEyelidbump(Stye)aninfectionofthesebaceous

glandsofZeisatthebaseoftheeyelasheschalazioniscausedbyinflammationofablockedTarsalglandsusuallyontheuppereyelid.DisordersofEyelids2.Theconjunctivalinestheinsideoftheeyelidsandcoversthesclera.Athinandtransparentmucousmembrane.Theconjunctivaistypicallydividedintothreeparts:PartAreaPalpebralortarsalconjunctivalinestheeyelidsBulbarorocularconjunctivacoverstheeyeball,overthesclera.ThisregionoftheconjunctivaistightlyboundtotheunderlyingsclerabyTenon'scapsuleandmoveswiththeeyeballmovements.FornixconjunctivaFormsthejunctionbetweenthebulbarandpalpebralconjunctivas.Itislooseandflexible,allowin