ExerciseⅡ Observation of Cestodes
Experimental objective
1.Master the use and maintenance of microscope.
2.Master the morphological features（adult and egg）of different genius of medical Cestodes include Taenia solium（pork tapeworm），Taenia saginata（beef tapeworm），Spirometra mansoni.
Experimental Principles
To observe the morphological features（adult and egg）of different genius of medical Cestodes by the optical microscope.
Laboratory equipment
1.Optical microscope.
2.Human parasitology teaching specimen.
Experiment methods and contents
Methods：find the parasites at low magnification，and then observe them with high magnification（if necessary）.（Figure 1，2）
1.Adult worm
Pay attention to body shape，body length，scolex and strobila.
The adult worm：the scolex-Small and globular，with 4 suckers，Rostellum and hooks.
Scolex of Taenia solium（4 suckers，Rostellum and hooks）.
2.Egg
Eggs of T.solium are indistinguishable from those of T.saginata.The outer egg-covering is radially striated and covers the oncosphere.The proglottid may rupture either in the host's intestine or after it leaves the host.The egg is broadly ovoid 31×43 micrometers with or without a shell.
It has a very thick embryo membrane，brownish yellow，with radial stripes，containing six hook larvae，which we called oncosphere.
1.Adult worm
Pay attention to body shape，body length，scolex and strobila.
Figure 1 Taenia solium（pork tapeworm）
（Corresponding book color chart NO.30，31，32，33）(https://www.daowen.com)
（Corresponding book color chart NO.34）
The adult worm：the scolex-Large quadrate，with 4 suckers，Rostellum and hooks are absent.
Scolex of Taenia saginata（4 suckers，without Rostellum and hooks）.
Gravid proglottids of Taenia solium：More Uterine branches than Taenia solium.（Figure 3，4）
Gravid proglottids of Taenia saginata（Also full filled with eggs）.
2.Egg
The same with T.solium.
3.Attentions
（1）The stroblia can be loosely subdivided into 3 regions：immature，mature，and gravid proglottids.
（2）Each proglottid contains a set of reproductive organs of both sexes.
（3）Reproductive organs in immature proglottids are visible but nonfunctional，while those of mature proglottids are fully functional.
（4）Gravid proglottids are filled with eggs.
（5）Uterine branches（7-12 in T.solium，15-20 in T.saginata）.
Figure 3 Ancylostoma duodenale
（a）Armed scolex of Taenia solium（left）and unarmed scolex of T.saginata（right）.（b）Gravid proglottids of Taenia solium（left）and T.saginata（right）.
Figure 4 Spirometra mansoni（frog tapeworm）
（Corresponding book color chart NO.35）
Egg is broadly ovoid，about 65μm×45μm，with a thick，light brown shell.
It has an operculum at one end and often a small knob at the other（At high magnification）.