眼科学-眼的解剖.ppt

眼睑eyelidsTheeyelidsprotecttheeyesfromtheenvironment,injuryandlight.?Theyalsomaintainasmoothcornealsurfacebyspreadingtearsevenlyovertheeye.?Thelidsarecomposedofanouterlayerofskin,amiddlelayerofmuscleandtissuethatgivesthemform,andaninnerlayerofmoistconjunctivaltissue.Severalmusclesworktogethertocontrolthe?actionsofthelids.?Locatedinthemiddlelayeroftheeyelidistheorbicularisoculi,acircularmusclethatclosesthelids.?Thelevatormuscleisattachedinsidetheupperlidandelevatesit.?AsmoothmusclecalledMuellersgivesthelidstoneandhelpsmaintainelasticity.Tinyoil-producingmeibomianglandslinetheinneredgeofthelids.?Theseglandsproduceoilthatlubricatestheeye.?Rowsoflashesprotecttheeyesfromtheelementsanddebris.?Notonlydotheeyelidsprovideprotectionandmoisture,theydisplayexpressionandemotionsthatareanimportantpartofourindividuality.结膜一层薄而透明的粘膜，富含血管。覆盖于眼睑后面和眼球的前面。按其所在部位可分为三部：即睑结膜、球结膜和二者的结合部即结膜穹窿。Conjunctiva???Theconjunctivaisthethin,transparenttissuethatcoverstheoutersurfaceoftheeye.?Itbeginsattheouteredgeofthecornea,coveringthevisiblepartofthesclera,andliningtheinsideoftheeyelids.??Itisnourishedbytinybloodvesselsthatarenearlyinvisibletothenakedeye.??Theconjunctivaalsosecretesoilsandmucousthatmoistenandlubricatetheeye.Theconjunctivalepitheliumcontainsgobletcell—unicelluarmucousglands2.葡萄膜巩膜途径(10~20%)Uveoscleraloutlow经葡萄膜小梁、睫状肌间隙流入睫状体和脉络膜上腔，经巩膜、涡静脉旁间隙流出。非压力依赖性。前房与睫状肌间隙间无屏障——房水流入无阻力。脉络膜、睫状突血管通透性高——蛋白质浓度高。新型降眼压药前列腺素衍生物可使睫状肌间隙增宽。3.少量房水被虹膜表面的隐窝所吸收(5%)非压力依赖性4.还有很少量经玻璃体、视网膜排出。（二）晶状体（lens）是一个双凸透镜状的富于弹性的透明体。位于虹膜、瞳孔之后，玻璃体之前，借晶体悬韧带与睫状体联系。晶体后表面的凸度大于前表面，是重要的屈光间质之一。后表面中央叫后极，前表面中央叫前极，显露于瞳孔中央。前后两面交界处叫赤道。成人晶体直径约9～10mm,厚约4～5mm前屈率半径10mm，后曲率半径6mmLensThecrystallinelensislocatedjustbehindtheiris.?Itspurposeistofocuslightontothere