1. all cestodes have
    an intermediate host and are hermaphroditic
  2. tapeworms have different names in the intermediate host; the purpose of an intermediate host is to
    form the scolex (head) to hold on

    thus, when the intermediate host is consumed by definitive host, the scolex is developed and ready for permanent implantation
  3. tapeworm in dog/intermediate host
    • dog: Taenia pisiformis
    • rabbit: Cysticercus pisiformis¬†

    dog eats the rabbit obtaining the C. pisiformis which will molt and become T. pisiformis
  4. swine cestode
    Macracanthorhynchus hirudinaceus
  5. "thorny headed" worm
    Macracanthorhynchus hirudinaceus

    • red in appearance
    • embryo surrounded by several membranes
    • contains hooks at one end
  6. may, dung, and water beetles are intermediate hosts of this cestode aquired by pigs while rooting
    Macracanthorhynchus hirudinaceus
  7. most common cestode in man
    Taenia multiceps
  8. most deadly/pathogenic cestodes
    • Echinococcus granulosus
    • Echinococcus multiocularis
  9. most common cestode shared by human&animal because the intermediate host is the flea; most common in children
    Dipylidium caninum
  10. hydatid cyst
    • Echinococcus granulosus in human
    • larval parasite migrates through the liver and lungs
    • treatment is possible;surgery preferred
  11. more serious form of Echinococcus because no treatment and surgery is more dangerous
    Echinococcus multiocularis
  12. line of proglottids
  13. cestodes feed on
    glycoproteins in the intestines
  14. aqautic tapes
    • dog: Diphyllobothrium
    • cat: Spirometra
  15. order of true tapeworms
  16. scolex of Taenia&Dipylidium
    • four radial cups (suckers)
    • rostellum which may or may not be retractable
    • has hooks
  17. scolex of Anaplocehala&Monezia
    • four raid cups (suckers)
    • small to no rostellum
    • no vestigial hooks
  18. scolex of Diphyllobothrium&Spirometra
    • weak cups
    • no rostellum
    • no hooks
  19. rostellum
    at apex of scolex, dome shaped projection that may retract into the scolex
  20. all nutrients are absorbed through
    the skin on the flat surface of strobila
  21. Eucestode strobila have marginal pores:
    • Taenia: one on the margin
    • Mesocestoides: one in center
    • Dipylidium: two, one on each margin

    • eggs pass out of the pores until the gravid proglottid is discharged or damaged in the intestinal tract
    • once proglottid is discharged, oncospheres (eggs) leave through the pores to be consumed by intermediate host or entire proglottid consumed
  22. Diphyllobothrium uterine pores:
    one but discharge their eggs in the intestines
  23. which cestodes come out in segments/ribbons?
    • segments: Eucestodes (Cyclophyllidae)
    • ribbons: Diphyllobothridae
  24. terrestrial eucestodes
    • taenia
    • dipylidium
  25. structure of cestode eggs
    • egg capsule: externally to protect embryo
    • embryophore: serves as waste disposal area as well as port for nutrition and protection
    • oncosphere: the vermiform embryo itself
  26. metacestode
    stages of larval development
  27. tapes and their larva named according to # of bladder and scolex
    Cysticercus: one bladder, one scolex

    all belong to genus Taenia
  28. why is Echinococcus difficult to get rid of?
    have as many as 3 scolex holding on

    may have to deworm several times
  29. tapeworm of horse

    cysticercoid larvae in intermediate host: mite (Oribatei)
  30. most common tapeworm
    Dipylidium caninum (dog)

    cysticercoid larvae in intermediate host: flea (Ctenocephalides spp) biting lice (Trichodectes canis) sucking lice (Linognathus setosus)
  31. larvae of Mesocestoides
  32. larvae of Taenia
  33. Eucestode metacestodes utilize only one intermediate host, aquatic tapes have how many?

    • crustacean (snail, clam)
    • aquatic (fish) or amphibian (frog)
  34. most common tape
    • Dipylidium caninum
    • flea/lice common intermediate host

    characteristics: rostellum with hooks, mature proglottids have 2 sets of sex organs with dual openings
  35. dipylidium caninum lifecycle
    • oncospheres emerge from proglottids once passed
    • eggs ingested by flea/lice within which eggs hatch and migrate to body cavity
    • tapeworm develops into cysticercoid stage with maturation of scolex (1-2 days)
    • flea/lice ingested by definitive host (dog) where cysticercoid molts in the intestines
    • while in the intestines, mature tape develops (2-3 wks) liberating thousands of eggs
  36. lifecycle of taenia
    all indirect.

    • eggs laid in contaminated soil
    • eggs consumed by intermediate vertebrate host
    • egg hatches in intermediate host and attaches hexacanth embryos which are 1st stage larvae
    • embryos move to organs (do not stay in just intestinal tract like dipylidium) and develop scolices
    • in the organ (liver) embryo differentiates to 2nd stage
    • definitive host now eats intermediate host
    • scolices attach to intestinal wall where maturing begins
  37. definitive intermediate host of dipylidium

    rabbit eats egg passed on ground. eggs hatch inside rabbit and inhabit their liver. dogs eat rabbit...
  38. Hydatid cyst
    metacestodal stage of Echinococcus granulosus in man

    eggs ingested, go to circulation and lodge in liver and lungs, develop into metacestodes with multiple scolices
  39. how does man get Cystic Hydatid Disease?
    dog eats herbivore and picks up the hydatid cyst by eating the liver. dog passes eggs and man accidentally consumes them through a kiss or handling contaminated soil. parasite leaves egg and goes to liver to become metacestode in man causing serosis/fatty metamorphosis of the liver
  40. Alveolar Hydatid Disease
    • Echinococcus multiocularis in man
    • contracted by handling dog/cats which eat rodents or by eating fruits or veggies grown in soil contaminated by faces of infected fox, coyote, dogs. seen most commonly in the lungs.
  41. ruminant tapeworms
    • Monezia expansa
    • Monezia benedini

    symptoms: emaciation, abdominal&thoracic congestion, visceral enlargements
  42. lifecycle of moniezia expansa
    • eggs passed in feces
    • eggs ingested by grain mite
    • hexacanth matures to cysticercoid
    • grain mite ingested by host
    • cysticercoid matures in intestines
    • adult worms in intestines reproduce..
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