Helminths Flashcards
dioecious
have male and female sex organs in separate worms
monoecious
worms have both male and female sex organs
name the three groups of helminths
nematodes, trematodes, cestodes
give a brief description of cestode anatomy (3 parts)
scolex- attaches to intestinal epithelium, may have hooks
proglottid- has testes and ovary
gravid proglottid- further away from scolex, full of eggs to be shed in feces
what is unique about taenia life cycle?
pig or cow can be intermediate host
larva creates cysticercus in animal muscle
human eats contaminated meat and cysticercus attaches to intestinal epithelium
taenia saginata
beef tapeworm
taenia solium
pork tapeworm
how can taenia saginata/solium be prevented?
cook or freeze meat
What differentiates taenia saginata from taenia solium?
taenia solium has an autoinfection route that causes neurocystocercosis
echinococcuus granulosus
canine tapeworm, humans get infected by consuming food or water contaminated by dog feces
hydatid disease is related to which helminth?
echinococcus granulosus (canine tapeworm)
what is a hydatid cyst?
cyst that embeds in muscle, liver or brain and has many larvae inside, must remove cyst in tact but if it breaks the infection will spread
diphyllobothrium latum
fish tapeworm, bothrium=spoon, looks like a spoon; get this from eating contaminated fish (sushi)
Clonorchis sinensis
chinese liver fluke, humans eat contaminated fish
In life cycle of Clonorchis sinensis, the two intermediate hosts are ____ and ____, the infective stage is _____ and infective route is ____
hosts: snails and fish
infective stage: metacercaria in fish
infective route: oral consumption of fish
diphyllobothrium latum clinical presentation
intestinal problems- nausea, vomit, diarrhea
neurological- headache, insomnia
anemia
Clonorchis sinensis clinical presentation
similar to hepatitis
walls of bile ducts thicken
liver enlarges
necrosis of liver tissue
Three major factors of schistosomiasis
method of human waste disposal
presence of snail intermediate host
contact with cercaria-infested water
schistosoma
blood fluke, infection occurs by being in infested , liver and spleen grow large
fasciola hepatica
liver fluke, sheep and cattle are hosts,,
paragonimus westermani
lung fluke, get this from eating improperly cooked crustraceans
enterobius vermicularis
pinworm (nematode), eggs deposited in anus –> scotch tape method
wuchereria bancrofti
causes filariasis; effects lymphatic system, elephantitis
ascaris lumbricoides
large roundworm in humans, fecal oral contamination, gross pic
ancylostoma
hookworm, with teeth, worms suck blood of hosts, cause chronic anemia
necator
hookworm, no teeth, worms suck blood of hosts, cause chronic anemia
trichinella spiralis
get this from eating meat that have encysted muscle; now people just get this from hunting
toxocara canis
worms found in puppies
onchocerca volvulus
river blindness
vector- black fly
dracunculus medinensis
guinea worm
get this by drinking water with copepods, solved by filtering water, worm taken out of body using a stick
loa loa
filarial worm, eye worm, vector- horse fly
What is halzoun?
get this from ingesting raw liver.
Infects pharynx
Causes swelling and obstructs breathing
What is the infective stage for trematodes?
If burrowing in, cercaria is infective stage
If ingested, metacercariae is infective stage
