No 22 - 辽宁医学院

《No 22 - 辽宁医学院》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、No.22Spinalcord(2)Brainstem(1)Ⅱ.InternalStructureIntransversesection,thespinalcordisseentoconsistofthegraymatterandthewhitematter.Thegraymatterofthespinalcordiscentrallylocatedandissurroundedbythewhitematter.Ⅰ)GrayMatterThegraymatterformsabutterfly-shapedcoreofthespin

2、alcord,roughlyintheformofaletterH.Thetransversebarofgraymatterthatconnectsthetwolateralgrayareasisthegraycommissure.Withinthegraycommissureisthenarrow,fluid-filledcentralcanal,whichiscontinuouswiththefourthventricle.Theanteriorandposteriortothegraymatterarerespectivel

3、yanteriorgraycommissureandposteriorgraycommissure.Theanteriorandposteriorgraycommissuresarealsocalledcentralgray.TheverticalbarsofthegrayH,oneithersideofthegraycommissure,areseparatedinto:apairofposteriorhorns(columns),apairofanteriorhorns(columns).Inthethoracicandupp

4、erlumbar(L1-3)regions,thespinalcordalsohasapairoflateralhorns(columns).Thearealocatedbetweentheanteriorandposteriorhornsistheintermediatezone.Thegraymatterofthespinalcordcontainsanenormousnumberofneuronsofvaryingsizeandshape.Rexedlaminastructureofgraymatterofspinalcor

5、d.1.LaminaⅠItisalsocalledmarginallayerorWalderyerlayer.Thenucleusposteromarginalisisinthislamina,formingathinlayerofcellscoveringthetipoftheposteriorhorn.2.LaminaⅡItisalsonamedthesubstantiagelatinosaanteriortomarginalareaandisthecorrelationbetweenthespinalsegments.3.L

6、aminaⅢ4.LaminaⅣInlaminaⅢandⅣ,therearelargercellgroups—nucleusproprius.Theyreceivethenumerousafferentfibersfromposteriorroot.Fibersfromthenucleusproprius,crossesintheanteriorwhitecommisureandcontributetothespinothalamictract.5.LaminaⅤItisequivalenttotheneckofposteriorh

7、orn.Ithasreticularnucleus.6.LaminaⅥItliesthebasepartofposteriorhorn.LaminaⅤandⅥreceivetheafferentfibersofpropersensationfromtheposteriorroots.7.LaminaⅦItoccupiesthegreatpartoftheintermediatezone.1)Thenucleusthoracicus(nucleusdorsalisofClarke)issituatedinthemedialporti

8、onofthebaseofposteriorhorn.ItiswelldefinedinthesegmentsofC8—L3.Theaxonscontributefiberstotheposteriorspinocerebellartractsof