Lecture 12_NPB_101

Lecture 12_NPB_101 - Lecture12 OnlineHandouts: Lec12Notes...

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Unformatted text preview: Lecture12 OnlineHandouts: Lec12Notes Review VisualSystem Announcements: None Reading(Required): Ch6(pg.221227) Taste&Smell VisualSystem AutonomicNervous System Reading(Recommended): Ch7(pg.234240) REV:OnandOffGanglionCells Na+channel openindark NTrelease indark NTclosesNa+ channel Photoreceptor BipolarCell + GanglionCell REV:OnandOffGanglionCells LIGHT Na+channel openindark NTrelease indark Photoreceptor Na+channel closedinlight NoNTrelease inlight NTclosesNa+ channel + + Depolarizing (On)BipolarCell Hyperpolarizing (Off)BipolarCell NTopensNa+ channel + OnGanglionCell OffGanglionCell ReSnalConvergence Asmanyas100 photoreceptorsmay convergeontoa bipolarcell ~108receptors Severalbipolars convergeontoasingle ganglioncell ~106ganglioncells Fig.621,pg.199 ProperSesofRodVisionandCone Vision Table63,pg.203 RecepSveFieldsofGanglionCells RecepSveFieldsofGanglionCells TherecepSvefieldofaganglioncellisacircleof photoreceptorsinthereSna. Aganglioncellmaydepolarizeorhyperpolarize dependingonwherelightisshoneintherecepSvefield. Wecanclassifythemaccordinghowtheyrespondto lightshinedwithinthecentercircleoftherecepSvefield Oncenter,offsurround Offcenter,onsurround WhenanimageisprojecteduponthereSna,itis analyzedbymany,manyganglioncells(bothOnand Offcenter) What'sthePoint? Wearepresentedsignificantlycomplexvisual sSmuli,madeupofcontrasSnglighttodark edges;inotherwords,thecontoursofan object ByanalyzingtheinputfromOncenterandOff centerganglia,thevisualcortexdetects contours,borders,andedges ContrastDetecSon Thebrainanalyzes inputfromMANY ganglioncellsthat respondtothe image. + + + + + VisualSystemAnatomy Fig.629,pg.206 TheVisualCortexAnalyzes CharacterisScsoftheImage CorScalcellsareorganizedtoprocess informaSonabout Lines OrientaSon Color Binocularprocessing Itdoesnotformapictureinthebrain,perse. VisualPercepSonisaProductof OrganizaSonofSensaSons WeperceiveparScular imagesbasedonseveralclues thatareprovidedtothe brain. Thebrainusesthesecluesto determinewhatissignaland whatisnoise Itignoresthenoiseandpays afenSontothesignal SignalversusNoise? TheAutonomicNervousSystem PNS:EfferentDivision CommunicaSonlinkbywhichCNScontrols acSviSesofmusclesandglands TwodivisionsofPNS Autonomicnervoussystem(ANS) InvoluntarybranchofPNS Innervatescardiacmuscle,smoothmuscle,mostexocrine glands,someendocrineglands,andadiposeSssue SomaScnervoussystem Subjecttovoluntarycontrol Innervatesskeletalmuscle ANS Autonomicnervepathway ExtendsfromCNStoaninnervatedorgan Twoneuronchain Preganglionicfiber(synapseswithcellbodyofsecond neuron) Postganglionicfiber(innervateseffectororgan) Fig.71,pg.234 ANS Twosubdivisions SympatheSc nervoussystem ParasympatheSc nervoussystem Sympathetic Parasympathetic Nervous System Nervous System Fibers originate in Fibers originate from thoracic and lumbar cranial and sacral areas regions of spinal cord of CNS Most preganglionic fibers are short Long postganglionic fibers Preganglionic fibers release acetylcholine (Ach) Most postganglionic fibers release noradrenaline (norepinephrine) Preganglionic fibers are longer Very short postganglionic fibers Preganglionic fibers release acetylcholine (Ach) Postganglionic fibers release acetylcholine AutonomicEfferentNeuronOrganizaSon Fig.72,pg.235 StructuresInnervated bySympatheHcand ParasympatheHc NervousSystems Fig.73,pg.237 ANS Mostvisceralorgansinnervatedbyboth sympatheScandparasympatheScfibers Ingeneralproduceoppositeeffectsina parScularorgan DualinnervaSonoforgansbybothbranches ofANSallowsprecisecontroloverorgan's acSvity SNS PNS ANS SympatheScsystemdominatesinemergency orstressful("fightorflight")situaSons Promotesresponsesthatpreparebodyfor strenuousphysicalacSvity ParasympatheScsystemdominatesinquiet, relaxed("restanddigest")situaSons PromotesbodymaintenanceacSviSessuchas digesSon ANS ExcepSonstogeneralruleofdualreciprocal innervaSonbythetwobranchesofautonomic nervoussystem MostarteriolesandveinsreceiveonlysympatheSc nervefibers(arteriesandcapillariesarenot innervated) MostsweatglandsareinnervatedonlybysympatheSc nerves SalivaryglandsareinnervatedbybothANSdivisions butacSvityisnotantagonisScbothsSmulate salivarysecreSon EffectsofANSonVariousOrgans ...
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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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