Phylum Nematodes Flashcards
Nematoda aka
roundworms
where do nematodes live
50%-ocean
25%-soil and freshwater
10%-on or in plants
15%-inside animals
Nematodes are pseudocoelomate which means what
they have a false body cavity (coelom)
mesodermal organs and gut reside in what
psuedocoel
What is pseudocoelom derived from
blasocoel
how does blastocoel become pseudocoel
splits down the middle
how are nematodes simpler than platyhelminthes
longitudinal muscles- no circular
no osmoregulary cells are present
Are nematodes dioecious or monoecious?
almost all are dioecious
what type of sexual production does not occur in nematoeds
asexual
How are nematodes more evolutionarily advanced due to psudocoelom
longitudinal muscles are more effective because now have a hydrostatic skeleton
space for organs
can circulate material internally
have a complete digestive tract
what diffuses across the body wall of nematodes
ammonia
respiratory system in nematodes
none. diffusion
circulatory system in nematodes
none. simple movement in body cavity
what are medically important parasitic nematodesd
Ascaris sp which are internal roundworms
how many eggs can ascaris lay a day
200,000
How long can juvenil ascaris remain viable on soil or plants
months or years
need shade moisture and oxygen
Ascaris lifecycle in humans
eggs ingested> eggs hatch in digestive system>larva burrow through intestinal wall into veins or lymph vessels and are carried to the lungs> larva enter lung>larva coughed up and swallowed>mature in intestines and hang out
T. canis and T. cati
Toxocara which is common worm for cats and dogs
explain toxocara for prego mama with it
infect embryo in uterus thus puppies are born with worms
What is visceral larva migrans (toxocara)
Toxocara cannot live in human so they wander in internal organs
what nematode parasite is called American Killer
Necator americannus which is a hookworm
Necator americaus causes what
anemia because it occurs as adults feed on blood after attaching to intestinal lining
Necator life cycle
similar to ascaris (larvae pass from bloodstream to lungs to digestive system)
eggs hatch in moist soil and juvenile worms penetrate bare feet
Trichinosis how is it similar to ascaris and different
similar- intestinal parasite as an adult
differ- bloodstream carried larvae to muscle instead of gut
what is most common nematode parasite in human population of the US
pinworm
Where do female pinworms go?
live in large intestine migrate to perianal region to lay eggs (BOOTY BUTT EGGS)
Filarial Worms what does it cause and what is scientific name
Dirofilaria sp
heartworm in dogs
How are filarial worms transmitted
mosquito
What is drancunculus (guinea worm) and what is life cycle
nematode parasite
lives under skin of human host
shed larvae directly from an open sore into the water
infected by drinking contaminated water
what is intermediate host for dracunculus
water flea (cyclops)
Definitive host def
the adult sexually producing form of a parasite lives in
Which nematode parasite has the simplest life cycle
pinworm
which parasite req a mosquito to complete life cycle
dirofilarial
