L11_NPB_101

L11_NPB_101 - Lecture11 OnlineHandouts: Lec11Notes Review...

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Unformatted text preview: Lecture11 OnlineHandouts: Lec11Notes Review Announcements: Auditorysystem VesVbularsystem Ourrecordsindicated everyonehasbeenaddedto theclassbyToday(4/13) Ifproblem,seeDebbie AbboEPoarch 188Briggs,or [email protected] VisualSystem LastDaytoAddTuesday4/15 Reading(Recommended): Ch6(pg.190208) REV:EarAuditory&VesVbular aircellsrespondsimilarly H inbothsensorysystems: tereociliabendingtoward S thekinocilium: DepolarizaVon tereociliabendingaway S fromthekinocilium: HyperpolarizaVon Fig.630,pg.210&638,pg.219 TheVisualSystem VisibleLight Fig.613,pg.194 EyeOpVcs Convexstructuresofeyeproduceconvergence ofdiverginglightraysthatreacheye Fig.614,pg.194 Eye Twostructuresmostimportantineye's refracVveabilityare Cornea Contributesmostextensivelytoeye'stotalrefracVve ability RefracVveabilityremainsconstantbecausecurvature neverchanges Lens RefracVveabilitycanbeadjustedbychangingcurvature asneededfornearorfarvision AccommodaVon(Focus) Changeinstrengthandshapeoflens AccomplishedbyacVonofciliarymuscleandsuspensoryligaments AgerelatedreducVoninaccommodaVonability Fig.619,pg.197 ThePupil(Amountoflight) Fig.611,pg.193 TheEye Fig.69,pg.192 ReVna ReceptorcontainingporVonoftheeye actuallyanextensionoftheCNS NeuralporVonofreVnaconsistsofthreelayersof excitablecells Outermostlayercontainingrodsandcones Middlelayerofbipolarcells Innerlayerofganglioncells AxonsofganglioncellsjointoformopVcnerve PointonreVnaatwhichopVcnerveleavesistheopVcdisc Regionocencalledtheblindspotbecausenoimagecanbe detectedherebecauseoflackofrodsandcones TheReVna Vitreous Humor Fig.621,pg.199 Photoreceptors Rodandconecells Rods=lowlight&grayscale Cones=colorvision Outersegment DetectslightsVmulus Consistofthreeparts Innersegment Containsmetabolic machineryofcell SynapVcterminal Transmitssignalgeneratedin photoreceptoronlight sVmulaVontonextcellsin visualpathway Fig.624,pg.201 Photopigments UndergochemicalalteraVonswhenacVvatedbylight Consistsoftwocomponents Opsin Proteinthatisintegralpartofdiscmembrane ReVnene DerivaVveofvitaminA Lightabsorbingpartofphotopigment Fourdifferentphotopigments Rodpigment Providevisiononlyinshadesofgray Rhodopsin Absorbsallvisiblewavelengths Conepigments RespondselecVvelytovariouswavelengthsoflight Makecolorvisionpossible Redcones Greencones Bluecones PhototransducVon(DARK) Fig.625,pg.202 PhotoreceptorsReleaseGlutamate ontoBipolarCellsintheDark Thereceptorreleasesglutamateontoa bipolarcellintheDARK. SomebipolarcellsarehyperpolarizedbyNT NTclosescaVonchannel SomebipolarcellsaredepolarizedbyNT NTopenscaVonchannel NTRelease DARKNESS Fig.624,pg.201 PhototransducVon(LIGHT) Fig.625,pg.202 PhotoreceptorsDecreaseGlutamateRelease ontoBipolarCellsintheLight So,inthelight: Receptorshyperpolarizeandreduceglutamate NTrelease Somebipolarsdepolarize "OnBipolars" DBC(depolarizingbipolarcells) Somebipolarshyperpolarize "OffBipolars" HBC(hyperpolarizingbipolarcells) Fig.624,pg.201 LIGHT ConesSensiVvetoDifferentWavelengths Wavelength of light (nm) Eachconeexpressesa photopigmentwitha uniqueabsorbance spectrum Blue(Short) Green(Medium) Red(Long) Visible spectrum Blue cone Green cone Red cone Fig.626,pg.204 Color perceived GanglionCellsAreSimilarlyClassified "OnGanglion"cells depolarizeinthe light "OffGanglion"cells hyperpolarizein thelight Fig.621,pg.199 ...
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This note was uploaded on 04/17/2008 for the course NPB 101 taught by Professor Fuller,charles/goldberg,jack during the Spring '08 term at UC Davis.

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