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29 Cards in this Set
- Front
- Back
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main characteristics of flatworms
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food borne parasites
intestin of defin host bilat symetry, acoelomate, mostly hermaphroditic |
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describe parts of tapeworm
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head - scolex - no mouth(unlike flukes)
body strobia - no dig system(unlike flukes) suckers - bothria rostellum(crown of spines) neck proglottids - male & female organs per ++ genital pore in each tegument - surface active trnsport |
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Describe reproductive systems of tapeworms
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male - testes - vas def - cirrus
female - ovary - oviduct - ootype - uterus (vitellaria present for egg) Genital pore in each proglottid on venteral or lateral margin |
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What is a chain of proglottids called
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Strobila, thus adult worms are strobilate
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Describe Tegument
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non cellular homogenous layer with hairlike projections called microtrichs. Absorb nutrients and may resist digestion. Beneath this, parenchymal cells in which organs are situated. longitudinal nerve trunks and excretory canals present.
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what is a dg feature of Cestodes present in parenchyma
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calcareous corpuscles
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diagnosis of tapeworm is made by
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eggs or proglottids in feces
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Describe family taeniidaee features (Cyclophyllidea)
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scolex with 4 suckers/ no hooks/ no rostellum
GP on lateral margin Eggs lack operculum but have hexacanth embroyo when passed. |
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five species of adult tapeworm Cyclophyllidea
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T sagnata - beef tapeworm
T solium pork tapeworm Hymenolepsis nana H diminuta Dipylidiuim cnainum |
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Describe Pseudophyllidea
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scolex with two grooves(bothria - not suckers)
GP on midventral surface Eggs - operculum and are unembryonated with passed. |
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Name genus/species in Pseudophyllidea
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Diphyllobothrium latum - fish tapeworm
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talk taenia saginata, T solium
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WW (beef growing/pork)
Human only def host 4-6 m long/1K-2K proglottds |
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How are cows/pigs infected w Taenia
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ingest vegetation contaminated with eggs or gravid proglottids
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Describe Taenia in intestine/mm of animal host
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oncospheres hatch and invade intestinal wall, migrate to striated mm, where become cysticerci. Cysti can survive several years.
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How are humans infected with Taenia
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eating raw or undercooked infected meat.
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Describe cysticer in human intestine
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dev over 2 mos into adult tapeworm. attach to SI with scolex and reside in SI.. Adults produce proglottids which mature, become gravid, detach and migrate to anus or are passed.
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What happens after proglottids released in stool from Taenia
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Eggs(hexacanth = oncosphere, with hooks) released after passed. Eggs hatch in bovine intestine, releasing hexacanth embroyo.
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Describe hexacanth embroyo in cow/pig
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penetrates wall of intestine, enters blood or lymph to go to CT of mM where dev into cysticercus. has invaginated scolex
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How to DX Taenia
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eggs in feces or on perianal skin.
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TX for Taenia
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Prazi or Niclosamide once
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Describe T Solium scolex
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Rostellum with hooks
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Diff betw T sag and sol proglottid
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T solium has smaller number uterine branches - diagnostic. square shape,
also note, only one worm/person |
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specific locations for two Taenia species
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both ww but Saginata esp in E Africa(Ethiopia) and T solium in Mex, CA SA, China, Indonesia, Tanzania
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Can cattle become infected with adult T saginata
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no, only human. Humans cannot harbor the metacestode as eggs will only hatch in cows. Adults only in humans for solium as well.
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What is neurocysticercosis and disease it produces
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infection with cysticercosis of solium and produces epilepsy ww - leading cause of.
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time for juvenile to adult stage in Taenia
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in SI over 3 months time
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Can person be infected with cysticercus of T solium and if so how
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yes, from ingestion of egg of worm in own feces or other human feces infected. WASH hands.
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what regions/comnditions show cysticercosis of T solium
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1 incidence of T solium inf high
2 pigs roam freely within human habtat 3 improper disposal human feces |
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What is cause of seizures in children in LA
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neurocysticercosis
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