CESTODES GENERALITIES Flashcards
Cestodes Taxonomy
Phylum Platyhelminthes
Class Cestoda
Common Name of Cestodes
Tapeworms
Cestode: Type of Parasite
Monoecious / Hermaphroditic
Cestode General Appearance
Flat, Tape / Ribbon-like appearance and Segmented
Habitat of Tapeworms
Small Intestine
Tegument:
Give its functions
Glycoalyx
Proximal
Distal
Glycoalyx:
- Carbohydrate-rich - for protection
- Microthrices - for absorption
Proximal - Muscles of tegument
Distal - Has mitochondria
Eggs of Cyclophyllidea
Embryonated
Non-operculated
D. latus egg
Operculated
Unembryonated
Function of Scolex
Attachment organ / Holdfast organ (Attach to the small intestine)
2 Types of Scolex
Acetabulate & Bothriate
4 Cup-like suckers
(2 in front, 2 at the back)
Aid in attachment
Found in true tapeworms
Acetabulate
Slit-like groove or depression
Spoon, spatulate,
almond-shaped
Bothriate
How many bothriate does D. latus have?
2, hence DIBOTHriocephalus
Crown of scolex
Protruding structure where hooks are attached
Rostellum
Has hooks / hooklets
Armed Rostellum
No hooks
Unarmed Rostellum
T/F:
Not all tapeworms have rostellum
T
Region of growth and where proglottids arise
Neck
Tapeworm segments / Chain of Segments
Proglottids
Process of formation of proglottids
Strobilization
Strobila
1 segment
Most proximal
Still developing
No reproductive structures
Immature Proglottid
What are the reproductive structures seen in Mature Proglottid?
1) Uterus
2) Ovaries
3) Testes
4) Vitellaria
5) Vas deferens
Well-developed reproductive structures
Mature Proglottid
Most distal from neck
Filled with eggs
Testes & ovaries sometimes not seen
Gravid / Ripe Proglottid
Detachment of gravid
segment from the body
Apolysis
For egg shell production
Vitellaria
Located in the medial surface of the proglottids
Opening for eggs to exit from the gravid segment
Uterine Pores
Site where male and female organs meet
Genital Pores
Describe the Digestive System of Cestodes
N/A
T/F
Cestodes do not have Digestive & Circulatory System
T
Describe the strobila of the False Tapeworm
Anapolytic: Proglottids unable to detach
Describe the strobila of the True Tapeworm
Apolytic: Proglottids able to attach
Cestodes obtain nutrient via absorption and diffusion through their ________
Tegument
Describe the Vitellaria of Order Pseudophyllidea
Diffused with many follicles
Dispersed, not compact
Found ventrally
Describe the Vitellaria of Order Cyclophyllidea
Compact and separate
Describe the uterine pore of False & True Tapeworms
True: N/A
False: Present in median Ventral Surface
T/F
All reproductive organs still present in the gravid proglottid of false tapeworm.
F; True Tapeworm
Ova of False Tapeworms
Oval
Operculated
Unembryonated
Ova of True Tapeworms
Spherical
Nonoperculated
Eggs Embryonated
Larval Stages of False Tapeworms
Coracidium -> Procercoid (sparganum) -> Plerocercoid
Larval Stages of True Tapeworms
Depends per species
Cysticercus
Cysticercoid
Hydatid cyst
T/F
The coracidium is motile and ciliated.
T
Oncosphere of D. caninum and Taenia spp.
Hexacanth embryo (6 hooklets)
False Tapeworm
Inner Envelope
Embryophore
Outer Envelope
Inner Envelope: Surround oncosphere
Embryophore: Ciliated and surrounds the inner envelope
Outer Envelope: Surrounds ciliated embryophore
D. caninum:
Embryophore
Shell
Embryophore: Not ciliated
Shell: Outermost
Taenia spp.
Embryophore
Shell
Both striated
Pseudophyllidea:
Infective stage to humans and causes what?
Plerocercoid (found in fishes) causes Sparganosis
Larval invasion, multi-organ infection
Sparganum
What is located on distal
part of procercoid?
Cercomer
