NervousSystem

張曉麗6202

zhangxiaoli@INTRODUCTIONCentralnervoussystem

Peripheralnervoussystem

Brain

Spinalcord

Ganglia

Nerve

Graymatter(cortex)

Whitematter(medulla)

nucleusGraymatter

Whitematter

Cerebrospinalganglia

AutonomicgangliaCerebrospinal

nerve

Autonomicnerve

Brainand

SpinalCord

Ganglia1.Cerebral

Cortex

Typesofneurons

（multipolarneurons）

Pyramidal

Cell

Granular

Cell

Fusiform

Cell

Pyramidal

CellS,

M

and

L,PyramidalcytonApicalprincipaldendrite:thick,branches

toformsynapseswithneuronsaroundBasal

dendrites:(dendritic

spine)originatefromcytonforhorizontalrunningdendritestoformsyn.withneuronsaroundAxon:

oppositetoprincipaldendrite

short

:withincortex

(small,intermediateN.)Long(medium,large,majorprojectiveN.)

association

fiber:toentercortexofthesameoroppsitesideprojection

fiber:todescendintobrainstemand

spinal

cordtoformsynapsewithmotorneuron

大腦皮質錐體細胞(Golgi染色)Fusiform

Cellsmallinnumber,variousinsize,spindle-likecytonDendriteapical

dendrite:superfacialbasal

dendrite:Axon:

originatefromtrunk

ofbasaldendrite

GolgiⅠtype

:Large,deepincortex,longaxon,entermedulla

association

fiber

projection

fiber

Granular

Cells

Mostinnumber,smallcytonstellate

cellhorizontal

cellbasket

cellNeurogliaformcellascending

axonic

cell/Martinotti

cell(interneuron)

①StellateCell

MostinnumberAxon:Mostshort,terminateatpyramidalorfusiformcellSomelong,ascendtocorticalsurface,contactwithapicaldendriteofpyramidalcellorhorizontalcelltoformsynapses

②HorizontalCell

Bothaxonanddendritesparalleltocorticalsurfacetocontactwithapicaldendritesofpyramidalcellsandfusiform

cells

Dendrite:

fewspinesAxon:

Brancheshorizontallyextending,tosurroundthecytonandoriginationalpartofpyramidalcellsprincipaldendritetoformsyn.③Basketcell④NeurogliaformCellDendrite:short,densebranchestoformdendriticplexusAxon:short,axonplexusAxonanddendriticplexusinterwindedtogetherM:MartinotticellN:neuroglioformcellP:pyramidalcellF:fusiformcellB:basketcellS:stellatecellH:horizontalcell⑤AscendingAxonicCellorMartinottiCellSmallmultipolarneuronAxon:

Verticallyascendingtocorticalsurface,Dendrites:shortandsmall,branches,AfewspinesFunctionofGranularCells:Interneurons:

formingcomplicatedmirocircuitincerebralcortexProcessingtheinformationreceptedandtransmittootherneuronlikepyramidalcellandfusiformcelletc.InhibitoryExcitatoryLaminationof

cerebralcortex

大腦皮質分層結構ML分子層EGL外顆粒層EPL外錐體細胞層IGL內顆粒層IPL內錐體細胞層PML多形細胞層A銀染法示神經元形態B尼氏染色示6層結構C髓鞘染色示神經纖維的分布In

Neocortex(6layers)MolecularlayerExternalgranularlayerExternalpyramidallayerInternalgranularlayerInternalpyramidallayerPolymorphiclayer

In

archicortex(3layers)

hippocampalformation（hippocampus

anddentategyrus)

molecularlayer

pyramidallayer

Polymorphiclayer

MolecularLayerNeuron:smallandfewHorizontalcellsandstellatecells,NfparalleltothesurfaceofcortexExternalGranularLayerStellatecellsandfewsmallpyramidalcellsExternalPyramidalLayerThicker,manymediumandsmallpyramidalcellsandstellatecellsInternalGranularLayer:Densecells,moststellatecellsInternalPyramidalLayer:Majormediumandlargepyramidalcells.Betzcell(120×80)inprecentralmotorarea,apicaldendritesprotrudetomolecularlayer,axondescendingtobrainstemandspinalcordPolymorphicLayer:Majorfusiformcells,alsopyramidalcellsandgranularcellsThe6-layerstructureofthecerebralcortexvariesindifferentregionsofthebrain.Forexample,the4thlayer(IGL)ofprecentralgyrus(motorcortex)isnotobvious,butthe5thlayer(IPL)iswelldeveloped4thlayerofvisualcortexiswelldeveloped,cellsin5thlayeraresmall.HippocampusDentategyrus

Hippocampalformation

海馬結構SulciandGyriofInferiorSurface

molecularlayerpyramidallayerPolymorphiclayerLaminationofcerebralcortexNeuronalconnectionofcerebralcortexafferentfibers

---------intrinsicneurons(granularcellsin1-4layers)---principal

neurons(pyramidaland

fusiform

cells----efferent

fibers:（3、5、6layers)----efferentfibers-----othercorticalareas----association

fibers

(5-6layers)---efferentfibers----

noncortical

regions----projection

fibersimpulseM:MartinotticellN:neuroglioformcellP:pyramidalcellF:fusiformcellB:basketcellS:stellatecellH:horizontalcell2.CerebellarCortexhemisphereVermis小腦蚓

FlocculonodularlobeCerebellarfolia小腦葉片(convolutions腦回)

vermisAnteriorlobePosteriorlobeFlocculo-nodularlobeNeuronsandlaminationofcerebellarcortex

Neurons:

stellatecellbasketcell

Purkijecellgranularcell

Golgicell

Granularcell:

excitatoryneuron

(glutamicacid谷氨酸)stellate

cell,basket

cell,Golgicell:

inhibitoryneuron

(γ-aminobutyricacid,GABAγ氨基丁酸)

LaminationofCerebellar

CortexMolecular

Layer

PurkinjeCell

Layer

Granular

LayerlaminationofcerebellarcortexNeuronsofcerebellar

cortex--------

MolecularLayer

Stellate

Cell:small,

multi-process,short

axon,superfacial

zoneBasket

Cell:

large,

deeplayer,long

axon,verticaltolongaxisofcerebellfolia,paralleltosurfaceofcerebellacortexbasket-likebranchestosurroundthePCstoformsynapses

Neuronsandlaminationofcerebellar

cortex--------Purkinjecelllayer

Purkinje/piriform

celllarge,pear-shaped,2-3principal

dendritesalotofbranches,fan-likeprotrudetotheML

long

axon:

leavegraymatterto

enterwhitematter/medulla,terminatesatcerebellar

nuclei

Purkinjecell

NeuronsandLaminationofCerebellar

Cortex----GranularLayer

Granular

Cell

4-5shortdendritesaxon---molecularlayerTshapedbranchesiscalledparallelfiberonePL

canformSyn.with400

PCs0.2-0.3

millionsynapses/perPCGolgi

Cell

(Large

Stellate

Cell)Dendrite：alotofbranches,enterMLtoformSyn.Withaxonof

granularcells

(parallelfibers)

Axon:shortanddensebranchesinGL,formSyn.Withdendritesof

granularcells

NeuronalConnectionofCerebellar

Cortex

Afferentfibers：

Climbing

Fiber

Mossy

FiberA′drenalinergic

FiberEfferentfibers:AxonsofPurkinjeCells(theonlyefferentneuron)小腦皮質神經元與傳入纖維的關系

Neuronalconnectionofcerebellarcortex

climbingfibersFrominferiorolivarynucleus(下橄欖核)inmedullaoblongata延髓)----synapseswithdendritesofPC

＞300

synapseswith1PC

Toexcit

one

PCstrongly小腦皮質神經元與傳入纖維的關系

Neuronalconnectionofcerebellarcortex

mossyfibers

fromspinalcordandnucleiofbrainstem)----mossyending

----synapseswithdendritesofmanygranularcells,axonsorproximaldendritesof

Golgicells(cerebellar

glomerulus)

excitingmanyPCsPerMFcandistributedin2ormorecerebellarfolia,canexcite800+GC,oneGCcancontactwith400+PC,PerMFcanexciteab×104PC小腦皮質神經元與傳入纖維的關系Inconclusion,bothclimbingfiberandmossyfibercantransmitinformationfromoutsideofthecerebellaintoit,andbothofthemactonPC.ClimbingfibercanexciteonePCdirectlyandverystronglyMossyfiberexciteab×104PCthroughparallelfiberofGranularCellindirectly

NeuronalConnectionofCerebellar

Cortex

adrenalinergicfibersfromnucleusceruleus

(藍斑核)ofbrainstem----synapseswithdendritesofPCs

Function:toinhibitePCs小腦皮質神經元與傳入纖維的關系

3.SpinalCordAnteriormedianfissurePosteriormedian

sulcusCentralcanal

(e′pendymalepithelium)Graymatter

anteriorhornlateralhornposteriorhornWhitematter

SpinalCordAnteriormedianfissurePosteriormediansulcusCentralcanal(ependymalepithelium)Graymatter

anteriorhornlateralhornposteriorhornWhitematter

Spinalcord1.Anteriorhorn2.Posteriorhorn3.WhitematterSpinalcord

Anteriorhorn

ɑmotorneuron

(large,25μ,thickaxon)---controlextrafusalmusclefibers/skeletal,causingcontractionofmuscle.

γmotorneuron

(small,15-25μ,thinaxon)---controlintrafusalmusclefibers,

regulatingmusculartonus(a﹑cetyl′choline

乙酰膽堿,﹑choli′nergicneuron)

Ranshaw

cell:synapseswithɑtoinhibit

ɑneuron

(glycine

甘氨酸)

SpinalCordreciprocalinnervation交互支配extensormuscle伸肌Flexormuscle屈肌Renshaw’scell

SpinalCord

(↑ɑmotorneuron★γ

motorneuron

)

→→★

SpinalCordLateral

Horn:mediumandsmallvisceralneuronpreganglionicneuronsofsympatheticsystem----itsaxonterminatesatsympathetic

gangliapreganglionicfiber(acetylcholine,cholinergicneuron)Spinalcord

Posterior

Hornmediumandsmallintermediate/associationtoacceptimpulsefromdorsalrootfiberaxonascendigntobrainstem,cerebellum,thalamustoformnervefiberbundlesTract/bundle

cells

threekindsoftracts:ascending,descending,

fasciculus

proprius固有束SpinalCordWhite

matterMyelinatednervefibersAscendingtractsFasciculus

gracilis（薄束）Fasciculus

cuneatus

（楔束）

Posteriorspinocerebellartract（脊髓小腦后束）Anteriorspinocerebellartract（脊髓小腦前束）Spinothalamic

tract（脊髓丘腦束）Spinalcord

Descendingtracts

Lateralcorticospinaltract（皮質脊髓側束）Anteriorcorticospinal

tract（皮質脊髓前束）Rubrospinaltract（紅核脊髓束）Vestibulospinaltract（前庭脊髓束）Reticulospinaltract（網狀脊髓束）Mediallongitudinalfasciculus

（內側縱束）Tectospinaltract（頂蓋脊髓束）Fasciculus

proprius

（固有束）Spinalcord4.gangliacerebrospinalgangliaautonomicganglia

sympatheticgangliaparasympatheticganglia

CerebrospinalGangliaSensorygangliaCapsuleGanglioncellpseudounipolarneuroncentralprocessperipheralprocessSatellitecellMyelinated

nervefibers

Cerebrospinalganglia

Ganglioncell

Myelinat