Visceral fluke - Paragonimus westermani Flashcards
(34 cards)
AKA
Oriental lung fluke
Tegument is densely covered with ___________
scale-like spines
Oral vs ventral suckers
similar size
Two ___________ testes are situated _______
irregularly lobed
posteriorly
_________ is _____ to the ___ testis and is connected via oviduct to the uterus
lobed ovary
anterior
right
a ______ that lies _____ to the left ____
tightly coiled rosette
anterior
testis
Eggs are ____ and have a rather ___________
ovoid
flattened operculum
Vitelline follicles are ______ and _______, lying parallel to caeca
extensive
extend bilaterally
Ventral sucker is located:
medially between the ovary & uterus
Adults live in
the lungs where cross fertilization occurs
____ containing _____ are coughed up and expelled with sputum
Eggs
zygotes
Other eggs may get trapped in:
the surrounding lung tissue and produce bronchial abscesses
some eggs may be _____ with ____, passed through the _____ and expelled with ____
swallowed
sputum
digestive system
feces
Once eggs reach water, embryos require ____ in water before ______.
> 2 wk
miracidium’s development is complete
Miracidium must encounter & enter a snail host within ____
24 hours
Inside the snail, ____ and _____ generations are produced in the ______, which in turn develop many _____
sporocyst
2 redial
digestive gland
cercariae
Cercariae have
spined and knoblike tails, and emerge from the snail after 3 months of initial infection.
Their tail is useless for swimming
After emergence, they ____ over rocks until they encounter suitable crustaceans ________.
crawl
freshwater crabs, crayfish
Using their _______, they penetrate the crustacean’s exoskeleton and encyst in the crustaceans, where they develop into _______
sharply pointed stylet
metacercariae
How humans get infected:
Eating undercooked crustaceans
worms excyst in the:
duodenum & remain there for few days before entering the coelom
Later they penetrate ___________, and enter _______ and develop to sexual maturity in 2-3 months
the diaphragm and pleura
bronchioles of the lungs
wandering juveniles may become lodged in:
other organs
brain, heart and skin, producing ectopic lesions
disease caused by paragonimus infection:
Paragonimiasis