青光眼发病机制,治疗方式.doc

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1、AqueousproductionAqueoushumourisproducedfromplasmabytheciliaryepitheliumoftheciliarybodyparsplicata,usingacombinationofactiveandpassivesecretion（既有主动分泌也有被动运输）.Ahigh-proteinfiltratepassesoutoffenestratedcapillaries(ultrafiltration)intothestromaoftheciliaryprocesses,fromwhichactivetransp

2、ortofsolutes（溶质）occursacrossthedual-layeredciliaryepithelium.Theosmoticgradienttherebyestablishedfacilitatesthepassiveflowofwaterintotheposteriorchamber.Secretionissubjecttotheinfluenceofthesympatheticnervoussystem,withopposingactionsmediatedbybeta-2receptors(increasedsecretion)andalph

3、a-2receptors(decreasedsecretion)（互相拮抗调节）.Enzymaticactionisalsocritical–carbonicanhydrase（碳酸酐酶）isamongthoseplayingakeyrole.[1]Thetrabecularmeshwork（小梁网）(trabeculum)isasieve-like（筛状）structureattheangleoftheanteriorchamber(AC)throughwhich90%ofaqueoushumourleavestheeye.Ithasthreecomponents

4、.Theuvealmeshwork（葡萄网）istheinnermostportion,consistingofcord-like（索状）endothelialcell-coveredstrandsarisingfromtheiris（虹膜）andciliarybodystroma.Theintertrabecular（小梁）spacesarerelativelylargeandofferlittleresistancetothepassageofaqueous.Thecorneoscleralmeshworkliesexternaltotheuvealmeshwo

5、rktoformthethickestportionofthetrabeculum.Itiscomposedoflayersofconnectivetissuestrandswithoverlyingendothelial-likecells.Theintertrabecularspacesaresmallerthanthoseoftheuvealmeshwork,conferringgreaterresistancetoflow.Thejuxtacanalicular(cribriform)meshworkistheouterpartofthetrabeculum

6、,andlinksthecorneoscleralmeshworkwiththeendotheliumoftheinnerwallofthecanalofSchlemm.Itconsistsofcellsembeddedinadenseextracellularmatrixwithnarrowintercellularspaces,andoffersthemajorproportionofnormalresistancetoaqueousoutflow.TheSchlemmcanalisacircumferentialchannelwithintheperilimb

7、alsclera.Theinnerwallislinedbyirregularspindle-shapedendothelialcellscontaininginfoldings(giantvacuoles)thatarethoughttoconveyaqueousviatheformationoftranscellularpores.Theouterwallislinedbysmoothflatcellsandcontainstheopeningsofcollectorchannels,whichleavethecanalatobliqueanglesandc