W05_06 parasitology - helminths Flashcards
how to classify helminths?
flat worms + round worm
how to classify flat worms?
trematodes (flukes; nonsegmented) + cestodes (tapeworms; segmented)
how to classify round worms?
nematodes (filarial or non-filarial)
what are the segments of flatworms called?
proglottids
what’s the difference between direct and indirect life cycles of helminths?
direct: 1 host. Indirect: >1 host
what’s the definitive host for helminths?
the host where the parasite reaches sexual maturity
what’s the intermediate host for helminths?
species in which the larval, juvenile, or non-sexual stages develop
how does ascaris cause issues in the host?
mechanical obstruction.
how does the host harm the helminths?
cytokines, leukocytes, Th2 response for intestinal worms, eosinophils degranulate onto IgE-coated worms
which Ig subclass do you expect to see with worm infections?
IgE
what is a hydatid cyst?
a cyst due to echinococcus tapeworm
how is hydatid cyst diagnosed?
radiology
why do you want to avoid spilling hydatid cysts?
they contain many baby echinococcus tapeworms. If you spill it, they will grow elsewhere
what’s neurocysticercosis?
brain disease caused by pork tapeworm taenia solium
what’s the diagnostic method for cysticercosis?
gold standard is biopsy, but we can use antibodies, PCR, or radiology
