Platyhelminthes Flashcards
The classes that make up the Platyhelminthes are
Turbellaria (planarians
Trematoda (flukes)
Cestoda (tapeworms)
Turbellaria are also known as
planarians
Trematoda are also known as
flukes
Cestoda are also known as
tapeworms
A genus within Turbellaria is
Dugesia
Two genuses within the Trematoda are
Fasciola and Schistosoma
A genus within the Cestoda is
Taenia
Platyhelminthes have how many germ layers
three
Platyhelminthes have no coelom which makes them
acoelomates
Platyhelminthes have cephalization which means that
they have an obvious “head” end
Platyhelminthes have a digestive tract.
incomplete
Platyhelminthes are characterized by their
flattened bodies
How do planarians feed?
by everting their ventral pharynx
What structure allows planarians to move?
cilia on their ventral side
planarians have the amazing ability to
regenerate
flukes and tapeworms are both
endoparasites
tapeworms have no
mouth or gut
The scolex of tapeworms is made up of
hooks and suckers
the Strobila of tapeworms is made up of
proglottids
The strobila of tapeworms can be
immature, mature or gravid
The two types of hosts for tapeworms are
definative (human)
intermediate (pig or dog)
In the definitive host,
sexual reproduction occurs
In the intermediate host,
asexual reproduction occurs through various larval stages
The flukes definitive host is
in the liver of a sheep
The intermediate host for a fluke is
a snail
Dioecious means
each individual has male or female reproductive organs but not both
monoecious means
each individual has male and female reproductive organs
How can you tell if you’re looking at a midsection cross section of a Planaria?
it shows the pharynx
How do Taenia pisiformis gravid proglottids differ from mature ones?
gravid proglottids have eggs
Why does the meracercarial cyst stage of the fasciola hepatica occur on vegetation?
Because the vegetation is consumed by sheep which become the definitive hosts of the flukes.
Which stage of the Fasciola hepatica is shown?
What happens to this after it leaves the intestines of a sheep?
the egg
it enters water where it undergoes embryological development before the next stage hatches out
Which stage of the Fasciola hepatica life cycle is pictured here?
What occurs during this stage?
Miracidium, also known as the free-swimming stage
In this stage, the miracidium seeks a fresh-water snail, burrows into it’s tissue and loses its cilia before moving on to the next stage.
Where does the sporocyst stage of the Fasciola hepatica’s life cycle occur?
What occurs during this stage?
This occurs within the snail or intermediate host.
As the sporocyst grows, it asexually reproduces the next stage within itself.
Which stage if the Fasciola hepatica life cycle is shown here?
What occurs during this stage?
Redia
The Redia leaves the sporocyst and lives within the liver of the snail. As it grows it asexually reproduces the next stage in itself.
Pictured is which stage of the Fasciola hepatica life cycle?
What occurs during this stage?
Cercaria, which is another free-swimming stage
During this stage, the Cercaria leaves the snail and seeks out to find a particular plant. Once found, it settles on the plant’s surface and looses it’s tail, becoming the next stage of the life cycle.
Pictured is which stage of the Fasciola hepatica life cycle?
What occurs during this stage?
Metacercaria
This stage remains on the plant until it is consumed by humans
Pictured is which stage of the Fasciola hepatica life cycle?
Where does this take place?
Pictured is an adult sheep liver fluke.
This stage lives in the bile ducts of a sheep liver where it sexually produces eggs that pass into the intestine.
Pictured is?
Name the numbered structures.
Dugesia
- Eye
- Digestive system
- Transverse muscle layer
- longitudinal muscle layer
- excretory system
- flame cell
- pharynx
- nerve cord
- brain
- ovary
- testes
Name the numbered structures.
- parenchyma
- gastrodermis
- lumen of pharynx
- epidermis
- diverticula of intestinal cavity
- dorsoventral muscles
- circular muscles
- nerve cord
- pharyngeal cavity
- ciliated epidermis
- pharynx
- longitudinal muscles
What genus of which class is pictured?
Name the numbered structures.
Dugesia of Turbellaria (planarians)
- eyespot
- auricle
- gastrovascular cavity
- pharynx
- mouth
- diverticulum of intestinal cavity
Name the numbered structures.
- epidermis
- testis
- cilia
- pharyngeal cavity
- dorsoventral muscles
- gastrodermis = endoderm
- pharynx
Name the numbered structures
- epidermis
- intestinal cavity
- mesenchyme
- dorsoventral muscles
- endoderm
Pictured is
Name the numbered structures.
The scolex of Taenia pisiformis
- hooks
- rostellum
- suckers
Pictured is?
Name the numbered structures.
the immature proglottids of Taenia pisiformis
- early ovary
- early testes
- excretory canal
- immature vagina and ductus deferens
Pictured is?
Name the numbered structures (1,2,4,5).
the mature proglottid of Taenia pisiformis
- uterus
- ovary
- excretory canal
- testes
Pictured is
Name the numbered structures.
the gravid proglottids of Taenia pisiformis
- zygotes in branched uterus
- genital pore
