医学人体寄生虫学 节肢动物二.pptx

ArthropodsII

TeachingpointsClassInsecta:flea,sandfly,louse,bedbug,cockroachClassArachnida:tick,itchmite,folliclemite,chiggermite

OrdersiphonapteraMorethan2000speciesintheworldand450speciesinChinaEcto-parasitesofmammalianandbirdsⅠFleas

SomespecieofClassInsecta

LaterallycompressedWinglessThe3rdpairoflegsadaptedforjumpingPresenceofpygidium:peculiarsensoryorgantodetectaircurrentsSomespecieofClassInsecta

AdultPupaLarva(legless,segmented,3larvalinstars)EggLifecycleoffleaBothsexescantakeblood

MainHarmofflea:DiseasetransmissionMainreasonsforagoodvectorA.Verysensitivetobodytemperature.B.Plaguebacteriarapidlymultiplyandblocktheproventriculus.C.Strongabilityofanti-starvation.

MainHarmofflea:Diseasetransmission1.Plague(black-death)Pathogen:YersiniapestisVectors:Pulexirritans（人蚤）;Xenopsyllacheopis(客蚤)2.Endemictyphus:RickettsiamooseritransmittedbyX.cheopis

proventriculusWhentakesabloodmeal,theplagueorganismrapidlymultipliesandblockstheflea’sproventriculus.Whilethefleasfeedsagain,itisunabletoengorgeandisforcedtoregurgitatebloodandthebacteriafromtheproventriculusintothehost.

Verysmall(1.3-3.5mm)HairybodyWingsheldina“V”abovethebodyWeakflyinginsectsActiveatdawnorduskSomespecieofClassInsectaⅡSandflies

VectorsofLeishmanaeCutaneouslesion(closeup)CutaneousLeishmaniasisVisceralForm(Kala-Azar）

DorsoventrallyflattenedWinglessProtuberanceoftibiaandclawsformgrippingorganBlood-feedingectoparasitesSomespecieofClassInsectaⅢLice

Crablouse:Pubes,eyelashHeadlouse:baseofhairBodylouse:underwear2-4mm1.5-2mmPubiclouse:pubes,eyebrowsoreyelashes

LifecycleoflouseAllstagesandbothsexesfeedsolelyonblood.ObtaindailybloodmealstosurviveInjectsalivaintothewound;meanwhilefeces