Test 2 into to cestodes Flashcards
Define: Cysticercus
Infective form of the tapeworm. After the egg hatches it becomes a cysticercus
Define: Cysticercoid
Larval form of the tapeworm. Similar to Cysticercus but with a scolex filling the cyst.
Define Strobila
Body of the tapeworm containing many proglottids.
Define Proglottid
Contains male and female gonads. Fill with eggs
Define Bothria
Shallow sucking grooves
Define Bothridia
Four leaflike flexible structures
Define acetabula
Four hemispherical muscular cups
Define rostella
head of the worm. crown. may contain hooks
Define scolex
head of the worm. has suckers and sometimes hooklets for attachment.
Where are the sexually immature proglottids found?
closest to the scolex
What does gravid mean?
filled with eggs.
How many hosts does a tapeworm require to live?
More than one (except H. nana)
In the definitive host, where do the adults reside?
In the GI tract
Describe the life cycle of the typical tapeworm.
adults live the the GI tract. after about 3 months they mature and start producing eggs. Gravid proglottids or even eggs themselves are passed in the feces. the eggs are eaten by an intermediate host where they develop into cysticerci. This is the infectious stage. at this stage they migrate to the intermediate hosts muscle cells. the animal is eaten and the cysticerci migrate to the GI tract where they mature.
how do tapeworms get nutrients?
absorb nutrients through the proglottids.
What is the scientific name for the beef tapeworm?
Taenia saginata
how long do T. saginata eggs remain infectious? What do they infect?
about 159 days. Infect cows, sometime llamas
How long can a tapeworm live for? how long can they get?
25 years. 4-10 meters
how many proglottids will be on a T. saginatas body?
1000-2000
Describe the proglottids.
Gravid proglottids are longer than they are wide (20X5 mm). uterus contains 15 or more side branches.
How do the tapeworm eggs get out?
Entire gravid proglottids are passed through the anus.
Describe the eggs of T. saginata.
Eggs contain a fully developed embryo. Embryo has three pairs of hooklets. Eggs have a thick, radially striated, brown shell.
Describe what happens when a cow eats a T. saginata egg.
The larva are released from the egg in the small intestine. The larva penetrates the intestinal wall and get into the blood stream. The blood carries the larva to striated muscle where it becomes a bladder worm or cysticercus. Stays in muscle for up to three years waiting to be eaten. The scolex is held in the cyst like structure (balloon with a finger pushing it in)
What are the clinical manifestations of a tapeworm infection?
Symptoms are usually asyptomatic. Some people might experience epigastric fullness or epigastric pain. Proglottids are passed through the anus and may be found in stools, bedding, or clothing.
What is the drug of choice for tapeworm treatment?
Praziquantel.
How do you prevent getting a tapeworm infection?
Cook meat at 56 degrees C for at least 5 mins or freeze it for 5 days at -10 degrees C. Dont defecate out in field where cattle are grazing to keep it from infecting cows. Inspect meat.
What is the scientific name for the pork tapeworm?
Taenia solium
What can T. solium eggs infect?
Humans or pigs
Describe the life cycle of T. solium.
Same as T. saginata
What is the difference between the human and pig cycles?
Human cycle is when the human is the intermediate host. Pig cycle is where the pig is the intermediate host.
How does a human play the intermediate host role?
BY eating eggs. By retro infection (eggs go backwards by perilstalsis) or by eating eggs (fecal oral contact).
What is the pathology associated with a T. solium infection where the person ingests eggs?
cysticercus migrates through the body. can become lodged in muscle, eye, or the brain. Inflammation happens when the parasite dies.
How many uterine branches are in a proglottid of T. solium?
less than 14. use this to differentiate from T. saginata
