【正文】 ans are just beginning to differentiate. Mature proglotids Mature proglottids of Taenia sp. each proglottid measures about 4 mm in length Mature proglottid genital ans Gravid proglottid: only the uterus exists in the segment Differences between Pseudophylidea and Cyclophylidea ______________________________________________________ Diferentiating Pseudophylidea Cyclophylidea Feature ______________________________________________ Scolex two grooves four suckers (bothrium) Pseudophyllidea Cyclophyllidea Uterus curved ducts sacklike with a pore uterus pore is absent Differences between Pseudophylidea and Cyclophylidea Egg operculum without operculum an egg cell oncosphere and some (larva) yolk cells Metacestode The developing stages in the intermediate host are called metacestode. such as: sparganum ( plerocercoid) cysticercus (bladder worm) hydatid cyst procercoid Clinical aspects Damage caused by adult: The majority of cases are symptomless. In some patients may be intestinal disfort, vomiting or diarrhea. Appendicitis and intestinal obstruction may occur in some patients. Damage caused by larvae: The larval stages of tapeworms may produce serious diseases. Such as: hydatid disease Cysticercosis Sparganosis Summarized Life cycle of tapeworm Adult egg hexacanth embryo (oncosphere) Metacestodes (larval stages) (1 or 2 intermediate hosts) 10 1P at ri ck M an so n ( 1 8 4 4 – 1 9 2 2 )Spirometra mansoni and sparganosis Adult tapeworm Scolex Neck Immature segments Mature segments Gravid segments *Hermaphroditic Morphology of the adult worm Scolex: 1 to 2 mm long, with 2 sucking grooves. Mature segment Male genital system: Testis, vas efferens, vas deferens, seminal vesicle, Cirrus. Female genital System: Ovary, oviduct, Ootype, uterus (with an opening) vagina yolk gland. * Gravid segment is similar to mature segment Egg 52 to 76чm by 31 to 44чm, elliptic, brownish with an operculum (eyelidlike), one egg cell and some yolk cells inside. Sparganum The secondstage larva is called sparganum. It is elongated and tapelike, milky white in color, and unsegmented. Question 1 Which kinds of hosts may human serve as in the life cycle of Spirometra mansoni ? Why/why not? A first intermediate host B second intermediate host C final host D transport host Question 2 How many intermediate hosts are there in the life cycle of Spiromrtra mansoni ? What are they? Life cycle First intermediate host ( copepod ) The first intermediate host (copepod ) and development of the larva ? egg (in water) ? Coracidium (larva) ? eaten by ? copepod ? and develop ? to ? procercoid (larva) The second intermediate host ? Procercoid (in copepod) ? eaten by ? tadepole ? and ? develop ? to ? sparganum ? (in Frog) 2nd intermediate host (frogs and sometimes snakes ) Transport host: Amphibians, reptiles, and mammals. Adult Egg hatch in water Coracidium ( intestine of final host) ingested by copepod 1st intermediate host swallowed by tadpole Sparganum (in frog’s mucles) procercoid amphibians, reptiles, and mammals as 2nd intermediate host or transport host by pasting or eating sparganosis Sparganosis Life cycle Adult Egg Coracidium