Cestodes

• CESTODES


  also known as Tapeworms
• They are long, flat, ribbon-like tapeworms
• They have both sexes or hermaphroditic
• Cestodes have NO digestive tract.
• What are the 3 parts of a Tapeworm?

  
  

  • Head
  • Neck
  • Body
• Head is also known as scolex.
• Scolex (head)


  it is the anchoring organ that attaches to the intestinal mucosa
• Scolex (head)


  have 1 or more hooks/suckers for attachment.
• Neck


  it is the unsegmented region w/ regenerative capacity
• Neck


  it is behind the head. it is the growing region.
• Strobila


  Body is also known as?
• Strobila (body)


  it is the segmented part. Consist of long chains of proglottids
• Reproductive


  each segment consist of what organ?
• If treatment doesn't eliminate the neck and scolex, the entire worm may regenerate.
• 2 important order in Class Cestoda

  • Order Pseudophillidea
  • Order Cyclophillidea
• Order Pseudophillidea


  • scolex is unarmed
  • scolex is spatulate
  • w/ dorsal and ventral groove
  • belongs to Superfamily Bothriocephaloidea
• Order Cyclophillidea


  • scolex w/ 4 suckers
  • w/ centrally placed apical rostellum
  • scolex is quadrate
  • armed w/ hooks
  • belongs to Superfamily Taeniodea
• Order Pseudophillidea


  • eggs are operculated
  • larvae have cilia
• Order Cyclophillidea


  • don't have operculated eggs
  • don't have cilia in larvae
• Operculated means...

  eggs w/ lids, openings
• Gravid proglottids are located in the distal portion of scolex.
• Proglottids may be described as?

  • Craspedote
  • Acraspedote
  • Apolytic
  • Anapolytic
• Proglottids


  • it is the segments of the tapeworm
  • consists male and female reproductive organ
• Craspedote


  posterior border of proglottids overlaps and the anterior border of adjoining proglottid
• Acraspedote


  posterior and anterior border of proglottids do not overlap
• Apolytic


  premature detachment of proglottids that follows the release of eggs.
• Anapolytic


  proglottids are not shed from the strobila and eggs are released in other ways
• Cyclophillidean eggs are released from the uterus by apolysis.
• Apolysis


  it is the detachment of tapeworm from proglottid
• What are the 2 Larval Stage?

  • Solid Type
  • Cystic Type
• 2 types under the Solid type

  • Procercoid
  • Plerocercoid/Sparganum Larva
• 2 types under Cystic Type

  • Cysticercoid
  • Cysticercus
• Procercoid


  this larva is relatively globular w/ the scolex invaginated into the body of larva
• Plerocercoid/Sparganum larva


  this larva is elongated w/ head free or invaginated only to the neck.
• Cysticercoid


  this larva is provided w/ a slightly develop bladder anteriorly
• Cysticercus


  head is invaginated into the proximal portion of the bladder.
• Procercoid


  ellipsoid in shape w/ penetration glands at one end and a cercomer at the other end
• Plerocercoid


  long and undifferentiated except for scolex which now has its adult form
• Cysticercoid


  solid-bodied larvae
• Cysticercus


  bladder larva