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1、复习题？1.试述保虫宿主与转续宿主的区别。2.寄生虫为什么能在有免疫力的人体中生存而不被排除？寄生虫病的传播途径包括污染或含有寄生虫的感染期的土壤水食物节肢动物传播媒介√√√√寄生虫感染阶段是指寄生虫的：感染人体阶段感染保虫宿主阶段感染中间宿主阶段感染中间宿主阶段感染昆虫媒介阶段√人体寄生虫病的传染源包括：仅有病人和带虫者医学节肢动物所有野生动物病人、带虫者、感染的动物√关于蛲虫，下列哪项是错误的：1.生活史简单2.感染率儿童高于成人，城市高于农村3.生活史属间接型4.带虫者和病人是唯一的传染源5.感染方式主要是人群中的间接接触和肛门 －手－口直接感染√AscarisLumbri
2、coidesP162AscarisLumbricoidesAscarislumbricoides,commonsaying“roundwormofman”,isthelargestoftheintestinalnematodesparasitizinghumans.Itisthemostcommonwormfoundinhuman.Itisworldwideindistributionandmostprevalentthroughoutthetropics,sub-tropicsandmoreprevalentinthecountrysidethaninthecity似蚓蛔线虫（蛔
3、虫）Ascarislumbricoides♀♂一、形态成虫活体20~35cm15~31cm活体AdultwormofA.lumbricoides蛔虫唇瓣扫描电镜图“品”受精卵未受精卵脱蛋白质膜受精卵虫卵蛋白质膜卵壳卵细胞新月形间隙卵黄颗粒成虫（小肠）卵随粪入土潮湿、荫蔽、O2充足21-30。C感染期卵经口误食、孵出幼虫、体内移行二生活史录像录像侵入肠粘膜的小V、小L右心门静脉肝肺肺泡（蜕皮2次）咽支气管气管食管胃小肠（蜕皮1次）蛔虫幼虫的体内移行：1.Siteofinhabitation:smallintestine2.Infetivestage:embryonatedeggs3.
4、Routeofinfection:bymouth4.Nointermediateandreservoirhosts5.Lifespanoftheadult:about1year生活史的特点：III.PathogenesisTherearetwophasesinascariasis:1.Theblood-lungmigrationphaseofthelarvae:Duringthemigrationthroughthelungs,thelarvaemaycauseapneumonia.Thesymptomsofthepneumoniaarelowfever,cough,blood-t
5、ingedsputum,asthma.Largenumbersofwormsmaygiverisetoallergicsymptoms.Eosionophiliaisgenerallypresent.TheseclinicalmanifestationisalsocalledLoeffler’ssyndrome.2.Theintestinalphaseoftheadults.Thepresenceofafewadultwormsinthelumenofthesmallintestineusuallyproducesnosymptoms,butmaygiverisetovagueab
6、dominalpainsorintermittentcolic,especiallyinchildren.Aheavywormburdencanresultinmalnutrition.Moreseriousmanifestationshavebeenobserved.Wanderingadultsmayblocktheappendicallumenorthecommonbileductandevenperforatetheintestinalwall.Thuscomplicationsofascariasis,suchasintestinalobstruction,appendi
7、citis,biliaryascariasis,perforationoftheintestine,cholecystitis,pancreatitisandperitonitis,etc.,mayoccur,inwhichbiliaryascariasisisthemostcommoncomplication.录像致病（pathogenesis)录 像1、幼虫致病2、成虫致病蛔虫性哮喘并发症掠夺营养引起变态反应哮喘,荨麻疹并发症(国内报告8468例)胆道蛔虫症455
