Cysticercoid Larvae and Hymenolepiasis Quiz

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Questions and Answers

What is the definitive host of H. diminuta?

Humans or rodents

What is the intermediate host of H. diminuta?

Arthropods

How is H. diminuta transmitted to humans?

By eating contaminated food such as cereals, grains, and grain-based foods.

What happens when eggs of H. diminuta are ingested by an arthropod intermediate host?

They release onchospheres and develop into cysticercoid larvae. Signup and view all the answers

Describe the autoinfection process of H. diminuta.

Eggs release their onchospheres that penetrate the intestinal villi and continue the life cycle without exiting the body. Signup and view all the answers

What do adults of H. diminuta produce and release?

Gravid proglottids and eggs Signup and view all the answers

Describe the morphology of H. diminuta eggs.

Round or slightly oval with a striated thick outer membrane and a thin inner membrane. Oncospheres have six hooks. Signup and view all the answers

What is the difference between the oncospheres of H. diminuta and H. nana?

H. diminuta oncospheres have six hooks and a smooth or slightly granular space between the two membranes, while H. nana oncospheres have six hooks and polar filaments filling the space between the oncosphere and outer shell. Signup and view all the answers

How can both H. diminuta and H. nana eggs be detected?

Both eggs can be detected in stool specimens. Signup and view all the answers

What is the difference in the scolex morphology between H. nana and H. diminuta?

H. nana scolex has four suckers and a rostellum with hooks, while H. diminuta scolex has four suckers but no hooks. Signup and view all the answers

Explain the life cycle of H. diminuta.

The intermediate hosts, such as insects, ingest the eggs. Larvae develop in the intermediate host and then are ingested by rodents. Rodents are then eaten by insects, completing the life cycle. Signup and view all the answers

What are the symptoms of hymenolepiasis?

Most often asymptomatic. Heavy infections with H. nana can cause weakness, headaches, anorexia, abdominal pain, and diarrhea. Signup and view all the answers