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73 Cards in this Set

  • Front
  • Back
what is the phylum that Cestodes are in
Name 4 basic facts about the class cestoda
Adults parasitize small intestines of vertebrates
larva parasitize invertebrates or vertebrates
Both sexes are in the same individual tape
some require several hosts to complete lifecycle
what is the chain of a cestode called?
What is the reproductive unit called?
chain is strobila
unit is segements or proglottids
What is another term for the head of a cestode? what is the dome projection located on the head called?
a scolex(head)
The rostellum(on the head)
what is located on the scolex?
four cups/suckers for attachement and locomotion
What is the first larva stage called and what does it consist of?
It is called a cysticercus. It consists of a head, neck and bladder
A head(scolex)and a bladder (secretion recepticle)
a cysticercus that has already begun to elongate and segment while in the intermediate host
cosits of a single bladder containing many scolices each having the potential of developng into a mature tapeworm
a cyst with manay scolices which is either uniocular or multiocular
what is a Hydatid cyst and what parasite is it linked to?
E.granulosus. It is a single chambered uniocular cyst with a thick laminated outer layer surrounded by a host-derived fibrous tissue capsule
What is an Alveolar cyst and what parasite is it linked to?
E.multiocularis. multiocular cyst composed of multiple thin walled vesicles not surounded by a capsule. Since it is uncapsulated, it is free ro prgressivly expand into surrounding host tissues through its growth. resembles a highlt invasive and proliferative malignant neoplasm
how does the larval stage develop in the definative host and which segmanet is the pregnant segment?
when the larva develop in the definitive host, the bladder gets digested away and the scolex begins to bud segments
each segment is more mature then the one before it
The most mature segment is know as the gravid proglottid (pregnant) and it is this segment that is filled with eggs
the entire cestode parasite is serviced by one common what? (morphologically)
Osmoregulatory system
Nervous system Muscoskeletal system- moving in a cocoordinated effort with common muscle fibers found in each segment
Digestive system- there are no digestive organs, instead nutrients are absorbed through the skin of the parasite
Definitive hsot of Taenia pisiformis?
Dogs and other canids
Intermediate host for Taenia pisiformis
rabbits and rodents
waht is the feline version of taenia pisiformis
taenia taeniaformis
how big can t.pisiformis adults be?
200+ cm in length
What are the segments and scolex like on t.pisiformis worm
segments are reclamgular in shape with branched uterus filled with eggs and one genital pore
segments have a sluggish movement
scolex has 4 suckers and a nonretractible rostellum with many rows of large hooks
Taenia ova
Eggs are individually found, starburst in appearence, small and round in sixe with developing haxacanth embryo and thick shell (can be surrounded by a yolk cell)
taenia life cycle
a rabbit ingests the eggs
the egg hatches in the small intestine and the larval tape burrows through the intestinal wall and travels to the liver
the cysicercus develops in the liver in 2-4 weeks
When the dog eats the rabbit and ingests the cysticercus the scolex attaches to the small intestinal wall and the worm begins to bud prglottids
Gravid prglottids, containing eggs, detach from the end of the worm and pass out in the feces
definitive and intermediate host for Diplylidium caninum dog, cat humans, fox fles and lice
how big can a d.canininum adult be?
up to 50 cm long
what are the scolex and segments like in a d.caninum adult
segments are cucumber seed shaped and oval with characteristically tapered ends
2 genital pores exist on either side of the segments and segments are activly motile
Scolex has 4 suckers and a retractible rostellum armed with several circles of thorn-like hooks
D.caninum ova
egg capsule which is very large in size and can contain 5-30 eggs inside
D.caninum life cycle
Very similar to taenia except the flea in the intermediate host and the dogs ingests the flea while biting at himself to scratch
D.caninum segments can be seen in the stool in about 3-4 weeks
It is critical to treat the animal for fleas while treating for this tape or it will return
Generic name
What does it treat?
Trade name
All tapes
Generic name
what does it treat?
Trade name
All tapes
Generic name
Praziquantel/febantel/pyrantel pamoate
Trade name
drontal plus
All tapes
Generic name
What does it treat?
Trade name
All tapes
Generic name
What does it treat?
Trade name
Taenia only
Generic name
what is it used for?
Trade name
Used to treat human tapes
Tape worm prevention
Find out the source of the problem
Prevent pets from ingesting the intermediate host
Treat for fleas
Echinococcus granulosus
size, # of segments, physical appearence
2-6 mm long
3-5 segments
gravid segment contains 5000 eggs
gravid segment is 1/2 body length
4 suckers
nonretractable rostelum w/2 rows of 32 hooks
definitive host
intermediate host Dogs(wolves and coyotes) Sheep (horse pigs mooses and other wild ungulates)
Ecchinococcus multilocularis
Size, # of segments and general physical appearence
1.2-3.7 mm long
3-5 segments
gravid segment contains 500 eggs
gravid segment is 1/2 body length
genital pore(anterior to midline)
4 suckers
nonretractable rostellum w/ 2 rows of 28 hooks
definitive host
Intermediate host Fox and coyote (cats dogs pigs) Rodents (people)
waht is the zoonotic status of E.granulosus and E.multilocularis
E.granulosus is a zoonotic parasite
E.multiocularis is an extremly zoonotic parasite
What is the metacestode stage of E.granulosus?
it is a hydatid cyst. It contains thousands of tiny protiscolices. these cysts often mesure severl centimeters
they are single chambered, unilocular, hydatid cysts
think laminated outer layer surrounded by a host derived fibrous tissue capsule
what is the metacestode stage of E.multilocularis?
contains thousands of tiny protoscolices. these cysts often mesure several cm.
multichamered, multilocular hydatid cyst
composed of multiple thin walled vesicles not surrounded by a capsule
therefore, uncapsulated. it is free to progressivly expand into surrounding host tissue through growth
resembles a highly invasive and prliferative malignant neoplasm
What is the life cycle like of E.granulosus and E.multilocularis
Adults live in the small intestine and produce eggs
The intermediate host ingests ova which hatch and migrate to the lungs then liver and form a cyst, 5+ months
the DH ingests the IMH. This will then free the cysts in the IMH and realease thousand of scolices into the DH body.
They will pass through the stomach into the small intestine where the scolices will attach and grow into adults.
They will begin to produce eggs about 28-49 days later and they will be passed into the feces and the cycle starts over
Ova of echinococcus
Both E.multilocularis and E.granulosus are very hard to tell from each other and the taenis egg.
Ova are immediatly infectiv when they are passed into the enviroment
they can remain infective in the enviroment for several months
How does echinococcus affect the definitive and Intermediate hosts?
For both echinococcus species the definitive hst does not uaually get sick from the parasite.
Intermediate hosts that have a short life span will also not get sick from the cyst stage of the parasite because it takes a long time for it to develop
Intermediate hosts with a long life span can become very sick from this parasite
Hos can one diagnosis Echinococcus through a fecal test?
the proglottids are too small to see in a fecal
The eggs are too similar to Taenia to make a thourough diagnosis
therefore, Echionococcus should be suspected in dogs or cats if they have taenia like eggs but there are NO visible segments in the fecal
what tests other than a fecal are availible to diagnose echinococcus?
There is an ELISA test availible
there is another technique but it is very dangerous.
One can make and animal purge using Arecoline hydrobromine, and filter the contents to examine for any parasites. Because this parasite is so zoonotic, it is very dangerous to use this technique
What are the most common drugs used to treat echinococcus?
Praziquantel which is found in Droncit, drontal and rontal plus.
What is AHD and how does it affect humans?
AHD is caused by a tumor like or cyst like tapeworm larvae growing in the body. AHD usually involves the liver, but can spread to other organs of the body. Because the cysts are slow-growing, infection with AHD may not produce any symptoms for many years.
what are the symptoms of AHD in humans?
Pain or discomfort in the upper abdominal region, weakness and weight loss may occur as a result of the growing cysts. Symptoms may mimic those of liver cancer and cirrhosis of the liver
What is the treatment for AHD in humans?
Surgery is the most common form of treatment for AHD in humans although removal of the parasite mass is not always 100% effective. After the surgery, chemotheraputic medication may be necessary to keep the cyst from growing back
AHD in people
In people cysts do not contain scolices and are condidered sterile
Symptoms can occur from 10-15 years after the oringonal infection
w/out surgery there is a 94% mortality rate
W surgery there is a 10-14 % mortality rate
Facsciola hepatica
sheep liver fluke
basick body type and shape of fasciola hepatica
1-5 cm by 8-13 cm
body is flat and oval shape with a cephalic cone containing the oral sucker
Fasciola hepatica
Definitive host and intermediate host
D host-sheep, cattle, people
I host-snails
Name the life stages of fasciola hepatica
Basic info about miracidium life cycle
ciliated larva inside egg
miracidium pushes out and swims for a suitable host
dies in 24 hours if it doesn't find one
bores into snail and looses ciliates covering
forma a sporocyst in the gonad or digestive gland
Basic info about sporocyst stage
contains germinal cells
each cell become a germinal ball
each germinal ball develops into a redia
Bacis info about redia stage
Grow until wall burts and then go into the tissue of snail
each germinal ball of 2nf generaton redia develops into a 3rd type of larva, the cercaria
Basic info about the cercaria stage
tadpole like larva that swim
has certain adult organs
leaves the redia through birth pore
goes out of snails tissues into water
lands on aquatic plant
encysts on plant, looses tail becomes a metacercaria
basic info about the metacercaria stage
this is the INFECTIVE stage
when ingested the metacercarial cyst is digested in the host ofs small intestine and becomes a marita
basic info about marita and adult stage
young flukes penetrate the wall of intestine
go into the liver
enter bile ducts
mature into adult fluke
What is acute fascioloasis?
common in sheep and cattle not humans
occurs when a large number(10,000) metacercaria are ingested at once
causes death with that many in the liver
liver capsule may rupture
if fewer are ingested(more common) then a fever and eosinophilia are seen
What is chronic fascioliasis?
common in all host even in humans
this is rarely fatal but of economic importance
In man can cause fever, mild jaundice, anemia and pain under right ribs
Becuase these flukes are not used to having man as a host, they may get lost and end up in the lungs where they become encysted
What is Black disease?
It is very fatal
it is a secondary infection due to bacterium Chlostridium oedematiens proliferating in necrotic lesion produced by the young larvae migrating in the liver
the marita cause tracts which become infected with chlostridium bacteria
how is Fasciola diagnosed?
Diagnosed through prsence of eggs in feces. Ova are very heavy
ELISA testing may be used for humans
How is fasciola treated?
Drug therapy
Albendazole; valbazen
Clurslon; curatrem
Praziquantel(off label)
sheep liver fluke
fasciola hepatica
chinese liver fluke
clonorchis sinensis
lancet liver fluke
cicrocoeliun dendriticum
human lung fluke
paragonimus westermani
salmon fever fluke
nanophyetus salmincola
blood flukes
schistosoma mansoni
farm animnal coccidia
bile duct gall bladder fluke of cats
platynosomum fastosum