托福经典加试

托福听力经典加试：神经元细胞(四道题)

重要：biology讲glialcell。以往人们对神经传导的讨论仅限于neuron

（神经元），也叫nervecell。神经传导通过electricalcommunication

从一个结点传到另一个结点，神经元被认为起主要作用，glialcell讨

论的很少，始终被忽视，被看作helpthegrowthofneurons(出题)，

起帮助作用。后来偶然发觉大脑中glialcell比neuron的数目多许多，

glialcell引起了科学家的重视，开头讨论它毕竟起什么作用（此处出

题，问glialcell怎么引起科学家留意的）。后来有一重大突破，发觉

glialcell传导信号不是用的electricalsignal，而是用chemical

conductor（一说chemicalcommunication）（此处出题）。传统观点始终

误以为glialcell也像nervecell一样用电信号。后来谈到glialcell

可能的作用：使人更intelligent。对glialcell的熟悉目前非常有限，

但相关讨论已经开头流行，是大家毕业之后可选的讨论课题（此处出题）

r,

scientistsaccidentallydiscoverthatglial’samountismuchmore

lattractpeople’e

ltoneuron,

gton,gtog,astglialwasthought

tosupportnervecell.

Glialcells(神经胶质细胞)andNeurons（神经细胞）

Glialcells,commonlycalledneurogliaorsimplyglia,are

non-neuronalcellsthatprovidesupportandnutrition,maintain

homeostasis,formmyelin,andparticipateinsignaltransmission

umanbrain,gliaareestimatedto

outnumberneuronsbyabout10to1.[1]

Glialcellsprovidesupportandprotectionforneurons,theother

ethusknown

asthe“glue“胶水rmainfunctions

ofglialcellsaretosurroundneuronsandholdtheminplace固

定,tosupplynutrientsandoxygentoneurons供给,toinsulateone

neuronfromanother隔开,andtodestroypathogensandremovedead

neurons破坏病菌，转移死N.

Gliawasdiscoveredin1856bythepathologistRudolfVirchowin

hisarchfora”connectivetissue”inthebrain大脑的连接组

织.Thehumanbraincontainsabouttentimesmoreglialcellsthan

neurons.[1]Followingitsdiscoveryinthelate19thcentury,this

factunderwentsignificantmediadistortion,emergingasthefamous

mythclaimingthat“weareusingonly10%ofourbrain“.Therole

ofglialcellsasmanagersofcommunicationsinthesynap突触

gap,thusmodifyinglearningpace,hasbeendiscoveredonlyvery

recently

Inadditiontoneurons,thenervoussystemispopulatedwithanother

categoryofcells,ellsareapproximately10

timesmoreplentifulthanneurons,butsincetheyareapproximately

one-tenththesize,theytakeupequalsize,gliaisaGreekterm

meaningglue,rearchesoriginallybelievedthatglialcells

rvedastheputtythatheldtheneuronstogether,recentrearch

indicatesthatthecellsprovideveryimportantcontributions.

aneuronisthefunctioningunitofthenervoussystem,specialized

toreceive,integrate,andtransmitinformation,theflowof

informationmovesinthefollowingdirection.