寄生虫学英文课件：experimental lecture of cestode.ppt

Section 3 Cestode Spirometra mansoni Taenia solium and Taenia saginata Hymenolepis nana and Hymenolepis diminuta Echinococcus granulosus Eggs Egg of tapeworm Shape: spherical Size: 30~45μm Color: brown Shell: thin outer membrane , often lost Contents: radially striated embryonic membrane; a fully developed embryo or oncosphere with 3 pairs of hooks. Egg of Hymenolepis nana Shape: oval Size: 30~50μm Color: transparent Shell: thin Contents: an oncosphere surrounded with a thin shell, On the embryophore two poles, from which 4-8 polar filaments spread out between the two membranes Egg of H. diminuta Compare with egg of H. nana : spheroid yellowish larger thick eggshell absence of filaments arising from the papilla on the embryo. Adults Adult of T.solium and T. saginata 3 segments: immature proglottid, mature proglottid and gravid proglottid Larvae Cysticercus of T. solium an oval, milky white and semi-transparent bladder, with an invaginated scolix or holdfast and filled with liquid. * * Aims and demands Mastery of: Morphological characters of eggs Differences of scolex and gravid proglottid between T. solium and T. saginata Morphological character of hydatid cyst Knowing : morphological characters of all adults cysticercus of tapeworm plerocercoid and procercoid Eggs are indistinguishable among taeniids T. saginata T.solium Each tapeworm has a small, rounded scolex at the anterior end, and proglottids can be distinguished at the posterior, wider end. Adult of Hymenolepis nana