Block_1_The_nervous_system_Rev_2011.ppt

bch4040aspectsofneuroscience lecturer profdtsangoffice rm516b bmsbemail davidtsang cuhk edu hkcontact msjannylee rm132 sctel 26096359 1 block1structureandfunctionofthenervoussystem 2 2 outline whydowestudythebrain functionsofthenervoussystem ns nssindifferentanimalsnsanddevelopmentcanwe advance brainfunctionfurther componentsofthensandtheirfunctions centralnervoussystem cns peripheralnervoussystem pns autonomicnervoussystem ans methodsforstudyingbrainstructureandfunctionlocalizationandlateralizationoffunctionsinthecnsdifferencesbetweenmaleandfemalebrains autism 3 3 4 4 arecommonbeliefstrue bulging foreheadasignoflongevity 頭大 聰明 maybesufferingfromhydrocephalus 腦水腫 brainsizeisgenerallyrelatedtolifeexpectance godoflongevity whydowestudythebrain weighs 1 300 1 500gutilizes 1 5totaloxygen 1 4bloodflowsthro itcomplexityanddiversity containsmanycelltypes madeupofabout100billionneurons organizedintoexquisitelycomplexcircuits respondingtoexperience drugs disease andinjury themostcomplexlivingstructureontheuniverse societyforneuroscience makesuswhoweare individuality 5 functionsofthenervoussystem organizeanddirectbehavior speech reflex monitortheoutsideworldwitheyes ears learningandmemory survival improvement thinkingandpersonality generateideascareandupkeepingofbodyviaautonomicnervoussystem ans stimulatedevelopmentandmaturationofbodycontrolofbehavior dysfunctioncausesdepression schizophrenia etc 6 6 7 7 figure9 1 evolutionofthenervoussystem evolutionofthenervoussystem complex simple forebrain size evolutionofthebrain reptilian paleomammalian neomammalian 8 largeportiondevotedtohigherfunctions reasoning cognition inhuman braindevelopmentandfunction 9 embryonicdevelopmentofns 10 nsdevelopsveryearlyinlife 11 schematicflowchartofhumanbraindevelopment ref http en wikipedia org wiki neural development 12 schematicflowchartofhumanspinalcorddevelopment 13 monitoringbraindevelopment 14 15 15 brainisalmostfullydevelopedat2yrsofage 16 17 18 measurementofbodylengthandweightareincludedtogaugeinfantdevelopment timelineofchilddevelopment 1 19 19 mos timelineofchilddevelopment 2 20 20 growthanddevelopmentiscloselyrelatedtothedevelopmentofthebrain mos canweelevateourbrainfunctionfurther 21 humanbraincannotgetsmarter humanbrain scapacitydependsonspeedyinterlinksamongdifferentpartsofbrain brainpowerrequiresdisproportionate energyconsumptionphysicallyimpossibleforhumanstoprovideextraamountsofenergyandoxygenhumanintelligencefacestightconstraintsedbullmore deptofpsychiatryatcambridge 22 23 memory abilitytostore retain andsubsequentlyretrieveinformationthreetypes sensory short termandlongtermrelationship 24 25 26 activeingredients flavonoids kaempferol quercetin isorhamnetinterpenoids ginkgolides 銀杏內酯 a b cbilobalide 白果內酯 treatments cerebraldisorders alzheimer sdisease neuroprotectantinhypoxia ischemiavasculardiseasesa smartdrug enhancememory ginkgobilobaleaves白果葉 ginkgobilobaleaves 白果葉 resultsconflicting ginkgoextractmayhave3effects improvesbloodflow microcirculation protectsagainstoxidativecelldamageblocksmanyoftheeffectsofplatelet activatingfactor plateletaggregation bloodclotting cardiovascular renal respiratoryandcentralnervoussystemdisorders 27 28 29 componentofplasmamembranehighconcentrationsinretinaandbrain braincontains 60 lipids myelin mostarephospholipidsnordaforomega 3fattyacids 1 2fattyfishserving wk foundinhuman sbutnotincow smilkbabyformulaehavedhaandepaadded epaanddhaandbrain cholineandmemory cholinenotsynthesizedinbraincholine acetylcoa acetylcholineevidenceneuropathological cholinergictransmitterinalzheimerpsychopharmacological anti cholinergicdrugs e g scopolamine short termmemory clinical tacrine cholinesteraseinhibitor lecithinimprovesmemoryinalzheimerpatientssourceseggyolk lecithin meatandlegumes lowinfruits vegetablesrda 0 4 0 9mg day 30 memoryandthebrain mechanismsofmemoryarenotcompletelyunderstoodbrainareas hippocampus amygdala striatum etcarethoughttobeinvolvedinspecifictypesofmemoryforexample thehippocampusisbelievedtobeinvolvedinspatiallearninganddeclarativelearning informationthatisexplicitlystoredandretrieved whiletheamygdalaisthoughttobeinvolvedinemotionalmemorymemory andlearning notsolelydependentonspecificbrainregions 31 32 exerciseyourbrain whatkindoftableisedible componentsofthens 33 33 34 nervoussystem divisions centralnervoussystem 中樞神經系統 cns consistsofbrainandspinalcord brainthro cranialnerves spinalcordandthepnsregulatesvirtuallyallhumanactivity function centralcontrolofbodyfunctionsperipheralnervoussystem 周邊神經系統 pns containsmainlysensoryandmotornervefibersfunction relaysensory e g fromreceptors sensoryfiber heat pain tothebrain motor e g frommotorcortextomuscles movementoflimbs mechanic andothermessagesautonomicnervoussystem 自主神經系統 ans sympathetic 交感神經系統 andparasympathetic 副交感神經系統 nsactivated controlledbycentersinthehypothalamus brainstemandspinalcordfunction controlssmoothmuscle glandsecretion sweatgland bloodvessel e g dilation contraction andvisceramovements 34 partofthepns structuresandfunctionsofthecns 35 36 36 centralnervoussystem cns consistsofbrainspinalcordbrainandspinalcordcontinuouswitheachother 37 brain controlcenterofcnsandbody responsibleforbehaviorandotherbodyactivitieslocatedinthehead protectedbybonyskull advantage closetoprimarysensoryapparatusofvision hearing balance senseoftaste andolfaction advantage extremelycomplex braincontains 100billionneurons eachlinkedtothousandsofneurons suggestingwhat 37 bonyskullencasesthebrain3toughmeningesseparatetheskullandthebrain 38 38 skullduramater firmlyattachedtoskull arachnoidlayerpiamater innermostlayerfirmlyattachedtobrain containsmanybloodvessels skullandmeninges brain divisionofthebrain thebrainisdividedinto2hemispheres 39 brain cerebrum largestpartofthebraincoveredwithalayerofgraymatter cerebralcortex separatedinto2distinctbutsymmetricalhemispheres l r eachdividedinto4lobes frontal parietal temporalandoccipital hemisphereslinkedbythecorpuscallosum transfersinformationbtwthe2hemispherestocoordinatelocalizedfunctionsleftcontrolstherightside viceversacerebraldominance speechareaislocatedintheleftwhileareasthatgovernspatialperceptionsresideintheright 40 40 41 lateralizationoffunctionsinhumancerebralhemispheres 41 42 brainoverview 42 thelobesarenamedafterthebonesoftheskullthatsurroundthem 43 functionsofdifferentcerebralareas 44 phrenologists 腦理學家 attemptedtolocalizebrainfunctiononthebasisofbumpsandridgesontheskull thelobesofthecerebralhemispheres planning decisionmakingspeech sensory auditory vision lobesofthecerebralhemispheres 45 46 46 front speech taste coordinatesmovements planning reasoning concentrate pain musclemovements hearing vision left electricalstimulationtolocalizefunctions 47 47 leftside 48 48 localizationofsensoryfunction lefthemisphere moreimportantfunction occupy largerarea 49 49 50 50 interpretssensoryinformation 51 51 conclusion manybrainareasareinvolvedinexecutingafunction 52 localizationoffunction advantageordisadvantage specialization dedicatedneuralcircuits integrationoffunction complexity subdivisionoffunction efficiency shortaxons fastertransmissionofimpulse fewerionpumps utilizelessenergy extraspaceforotherfunctions complexitydisadvantage injury damage severelossoffunction 52 53 53 brainpartsassociatedwithdisorders thoughsomefunctionsaremainlylocalizedincertainbrainareas theyrequiretheparticipationofotherareas formingpathways circuits 54 message structuresunderthecortexandtheirfunctions basalgangliaamygdaladiencephalon 55 56 spinalcord 57 locationofsomeinternalstructures caudatenucleusandamygdala basalganglion consistsof5largesubcorticalnuclei caudatenucleus putamen globuspallidus subthalamicnucleusandsubstantianigra2sets mirroredinlandrhemisphereslocation belowthecerebralcortexandabovethethalamus caudatenucleus putamenandglobuspallidusinfrontandsubthalamicnucleusandsubstantianigraatcaudalendinterconnectedwiththecerebralcortex thalamusandbrainstem reticularformation functions motorcontrol voluntarymovementsandestablishingpostures cognition emotionsandlearning 58 caudatenucleus onewithineachhemisphereac shapestructurewithawiderheadatthefront taperingtoabodyandatailfunction controlvoluntarymovementandimportantinlearningandmemoryhighlyinnervatedbydopamineneurons degeneration parkinson sdisease 59 59 amygdala latinforalmond 2setslocation deepwithinthemedialtemporallobesfunctions emotione g good bad feelingsad scared orsilly orgladsenseofsmellandpheromone processingmodulatememoryconsolidation primaryrolesintheformationandstoragememoriesassociatedwithemotionalevents 60 60 bottomview 61 diencephalon thalamushypothalamus 62 63 63 relativelocationsofsomeinternalorgans 64 thalamus 2sets oneineachhemispherelocation betweenthebrainstemandthecerebrumfunction atranslator inputsfrombasalgangliaandcerebellumareprocessedintoaformreadableandrelaysthemtoappropriatepartsofthecerebralcortex motoroutputsprocessandrelaysensoryinformation auditory somatic visceral gustatoryandvisual tocerebralcortexregulatessleep wakefulnessandconsciousnessdamage permanentcomathalamicsyndrome strokes burningorachingsensationononehalfofabody contralateralhemianaesthesia hypothalamus locatedbelowthalamus justabovebrainstem aboutthesizeofanalmondlinksthenstotheendocrinesystemviathepituitarygland synthesizesandsecreteshypothalamic releasing inhibitinghormones inturncontrolssecretionofpituitaryhormonescontrolsbodytemperature hunger thirst fatigue anger andcircadiancycles responsibleforactivitiesoftheansresponsiveto leptin ghrelin angiotensin insulin pituitaryhormones cytokines plasmaconcentrationsofglucoseandosmolarity etc 65 65 otherstructures cerebellumaseparatestructureattachedtothebottomofthebrain tuckedunderneaththecerebralhemispheresfunction maintainsposture balanceandcoordinationofmovementbrainstemconnectstherestofthebraintothespinalcord composedof midbrain ponsandmedullaoblongatanerveconnectionsofthemotorandsensorysystemsfromthemainpartofthebraintotherestofthebodypassthroughitinchargeoffunctionsneedstostayalive breathing respirationrate digestingfood gastrointestinalactivity andcirculatingblood heartrate 66 67 movementcontrol rolesofbasalgangliaandcerebellum bothbasalgangliaandcerebellummodifymovementconstantlymotorcortexsendsinformationtoboth andbothstructuressendinformationrightbacktocortexviathethalamus adjustmentoutputsofthecerebellumareexcitatory whilethebasalgangliaareinhibitorythebalancebetweenthese2systemsallowsforsmooth coordinatedmovement andadisturbanceineithersystemwillshowupasmovementdisorders spinalcord 45cmlonginmenand 42cmlonginwomen5regions 8cervicalsegments12thoracicsegments5lumbarsegments5sacralsegments1coccygealsegmentfunctions integrationoflow levelfunctions e g jerkreflex monitoredatalltimesbyhighercenters 68 68 spinalcord 69 69 whitemattercontainsmyelinatednervefibersgraymattercontainsmainlycellbodyanddendritesdh dorsalhorn vh ventralhorn cc centralcanal motor sensory spinalcord function general transmissionofsignalsbetweenbrainandrestofthebodybutalsocontainsneuralcircuitsthatcanindependentlycontrol integrationoflow levelfunctions e g jerkreflex others a asaconduitformotorinformation whichtravelsdownthespinalcord b asaconduitforsensoryinformation whichtravelsupthespinalcord c serveasacenterforcoordinatingcertainreflexesinjury paraplegia quadriplegiaorfullbodyparalysisbelowthesiteofinjurytothespinalcord 70 peripheralnervoussystem pns nsoutsidethecns consistsofthenervesandganglia massofneuronalcellbodies mainfunction connectthecnstothelimbsandorgansunlikecns pnsisnakeddivisions sensory somaticnervoussystem 軀體神经系統 consistsof12pairsofcranialnervesand31pairsofspinalnervesreliesinformationbetweencnsandext environmentautonomicnervoussystem ans 自主神經系統 sympathetic 交感神經系統 parasympathetic 副交感神經系統 enteric 71 autonomicnervoussystem 自主神經系統 ans 72 72 ans consistsofsensoryandmotorneuronsthatrunbetweencns esp hypothalamusandmedullaoblongata andvariousinternalorgans heart lungs viscera andexocrineandendocrineglands responsibleformonitoringconditionsintheinternalenvironmentandbringingaboutappropriatechanges regulatesheartrate digestion respirationrate salivation perspiration pupildiameter dischargeofurine sexualarousal etcwithmajorfunctionaim maintaininghomeostasismaincomponents parasympatheticnervoussystemsympatheticnervoussystem 73 73 74 sacral lumbar thoracic cervical ans functionsofsympatheticandparasympatheticnss sympathetic functionsinactionsrequiringaquickresponse dealingwithresponsetostressanddanger metabolicrate elevatingbloodpressure breathingrate andbloodflowtothemusclesparasympatheticfunctionsinactionsthatdonotrequireanimmediateresponseandactiveduringrest sleeping anddigestingfood loweringmetabolicrate slowingactivity synthesizingglycogen andrestoringbloodpressureandrestingheartbeattheyarecomplementaryinnatureratherthanantagonistic sympatheticastheacceleratorandtheparasympatheticasthebrake 75 neurotransmittersinans attheeffectororgans sympatheticneuronsreleasenoradrenalin na toactonnoradrenergicreceptors withtheexceptionofthesweatglands acetylcholine ach andtheadrenalmedulla adrenalin parasympatheticsystem ganglionicneuronsuseachtostimulatemuscarinicreceptors 76 relationbetweencns ssnsandans 77 methodsforstudyingbrainfunction 78 studiesofbrainfunction animalandcellularstudiesargument equivalenttohuman old static morphological histologicalpost traumaticandpathologicalobservationsproblem cause result recent neuroimaging computerizedtomography ctscan positronemissiontomography pet magneticresonanceimaging mri 79 79 whatisneuroimaging arelativelynewdisciplinewithinmedicine neuroscienceandpsychologytechniquesdirectly indirectlyimagethestructure functionandpharmacologyofthebraintwobroadcategories structuralandfunctionalstructuralimaging structureofthebrainandthediagnosisofgrossintracranialdisease suchastumor andinjury example ct pet mri functionalimaging diagnosemetabolicdiseasesandlesionsonafinerscale suchasalzheimer sdisease andalsoforneurologicalandcognitivepsychologyresearch e g enablestheprocessingofinformationbycentersinthebraintobevisualizeddirectly areaofthebraintoincreasemetabolismand lightup onthescan example pet mri 80 80 computedtomography principle employingtomography usingdigitalgeometryprocessinggeneratea3 dimageoftheinsideofanobjectfromalargeseriesoftwo dimensionalx rayimagestakenaroundasingleaxisofrotationapplication diagnosisofalargenumberofdifferentdiseases inthehead examples bleeding braininjuryandskullfractures stroke tumors etcadvantage disadvantage picturescanbeobtainedinminutes butresultsarestatic 81 amultislicectscanner 82 83 83 ctscan continuousrotationofsourceanddetector x rayslicedataisgeneratedusinganx raysourcethatrotatesaroundtheobject x raysensorsarepositionedontheoppositesideofthecirclefromthex raysource 84 84 positronemissiontomography pet principle measuresemissionsfrom labeledmetabolicallyactivechemicalsinjectedintothebloodstreamdifferentcompoundscanshowbloodflowandoxygenandglucosemetabolisminthetissuesoftheworkingbrain reflecttheamountofbrainactivityinthevariousregionsofthebraindiagnosis braintumors strokes andneuron damagingdiseases alzheimer sdisease identifylocationandactivityofspecificbraintransmitterreceptorsandsynaptic vesiculartransporters 85 85 apetfacility 86 87 87 sensorsinthepetscannerdetecttheradioactivityasthecompoundaccumulatesinvariousregionsofthebrain emissiondataarecomputer processedtoproduce2 or3 dimensionalimagesofthedistributionofthechemicalsthroughoutthebrain pet labeled compound 88 88 petimageofthehumanbrainshowingenergy labeled 13c glucose consumption areasofhighenergymetabolism lowactivity 89 89 magneticresonanceimaging mri anoninvasivemethodtotakepicturesofthebodywithoutinvolvingradiationorisotopesprinciple usespowerfulmagnetsandradiowaves signalsfromthemagneticfieldbounceoffbodyandaresenttoacomputertogenerate2 3 dimagesofbrainstructuresprovidesadetailedphysicalappearance watercontent andsubtlederangementsofstructureofthebrain suchasinflammationorbleeding butnotmetabolismnosignificantsideeffectsreported 90 90 91 functionalmagneticresonanceimaging fmri 功能性磁振造影 principle oxyhemoglobinanddeoxyhemoglobinbehavedifferentlyunderamagneticfieldrelativeconcentrationofoxyhemoglobinanddeoxyhemoglobinchangesinlocalcerebralbloodinthebrainassociatedwithneuralimagesgeneratedreflectsbrainstructuresareactivated andhow duringperformanceofdifferenttasksprovidesbothstructuralandfunctionalinformationhighresolution 2 3mm 92 93 93 donald sct petandmriexaminationresults 94 radiologistsaid youhavenothingrightinyourleftandnothingleftinyourright donaldwasveryhappyandsaid thankgod unlikech i mnotempty headed aretheredifferencesbetweenmaleandfemalebrains 95 95 scientificandpublicinterest explaindifferencesinthewaythatmenandwomenbehavedifferently evidence toypreferencesinhumanandmonkeyproblemsolvingabilityeffectofbraininjuryexogenoustestosterone 96 97 97 boys girls toyvehicles constructionaltoys andmechanicaltoys girls boys dolls enactingsocialandemotionalthemes toypreferences 98 98 problem solvingtasks 99 99 100 100 101 101 102 102 effectsoftestosteroneonperformancesinmaleandfemalebrains men women sheandhebrainsdifferences brainweight men 100gheavierbraincellnumbers men4 morecellularconnections womenmoredendriticconnectionscorpuscallosumsize womanlarger transferdatabetweenr lhemispherefaster languagecenterlocation menoftenjustinthedominanthemisphere usuallytheleftside womenonboththehypothalamusthehippocampus siteofshort termmemory areasinvolvedinmemoryhormone estrogen 103 103 104 104 absolutebrainsizemaynotbethebestmeasureofintelligence brainweight male female differencesinthecorpuscallosum corpuscallosum majorpathwaythatconnectstherightandleftcerebralhemispheressomeclaims thecorpuscallosumisbiggerandmoredevelopedinwomenthaninmenusingmri someresearchershavefoundnodifferencesinthesizeofthecorpuscallosuminmenandwomen 105 105 differencesinthehypothalamus cleardifferences preopticareainvolvesinmatingbehaviormen 2 2x womenandcontains2xmorecells onlyapparentafter4yearsold suprachiasmaticnucleusinvolvesincircadianrhythmsandreproductioncyclesdifference shapelikesasp