PID BLOCK 3- parasit Flashcards
Phoresis
Association where 2 organisms merely traveling together
Mutualism
both organisms are benefited
Commensalism
one partner is benefited and the other is unaffected
Parasitism
One partner is benefited, the other is harmed
Host
the partner who is harmed in parasitism
Parasite
the partner who is benefited in parasitism
Definitive host
harbors adult (sexual) stage of a parasite
Intermediate host
harbors larval (asexual) stage of a parasite
Paratenic host
harbors a parasite that does not undergo required development
a transfer host
Reservoir
an animal host that serves to maintain the parasites life cycle in nature
Incidental host
unusual host, unnecessary for the maintenance of the parasite in nature
Obligate parasite
totally dependent upon its host
Temporary parasite
parasitic for limited periods, for feeding or repro
Facultative parasite
not normally parasitic but can survive for a limited period when they accidently find themselves within another organism
Ectoparasite
- lives on host
- causes infestations
Ex: lice
Endoparasite
- lives in host
- causes infections
Protozoa
multiply in definitive host
- single celled, nucleated
Locomotion by pseudopodia, flagella, cilia
6 types of parasites
- Nematodes
- Cestodes
- Trematodes
- Insects
- Arachnids
- Protozoa
Nematodes
Roundworms
-round, cylindrical
- complete alimentary canal
- celom, body cavity
- sexes usually separate
Cestodes
Tapeworms
- flat, no colem (body cavity)
- no alimentary canal
- hermaphroditic
- Scolex (head) with 4 suckers or bothria
- Strobila (body) w head, neck, and proglottids (segments)
- parasitic with indirect life cycle
Vector
object or organism that transmits parasite from host to host
Biological or Mechanical
Mechanical Vector
transmits parasite unchanged from host to host
Biological vector
parasite multiplies or develops
Helminths
adult worms dont multiply in definitive host
Worms die over time unless host is re-exposed, metazoans
Severity proportional to worm load
Ex: Nematode, cestode, trematode
