Introduction to Veterinary Parasitology- Ectoparasites Flashcards
(40 cards)
What is Symbiosis?
Relationships among different living organisms
What is phoresy?
A type of symbiosis that is induced by chance contact with no chemical or physiological dependence (without being a parasite).
What is exploitation?
A type of symbiosis in which the host is harmed by the parasitic organism and is sometimes killed.
This can involve a variety of strategies, including diverting resources, altering host behavior, and even directly exploiting the host’s own defense mechanisms.
What are the 3 types of relationships between organisms? Please describe them
- Commensalism: one organism benefits while the other is not influenced at all. Can be either a facultative or an obligatory association (‘eating at the same table’).
- Mutualism: both organisms benefit from the interaction (‘reciprocal’).
- Parasitism: One member (parasite) lives either on or withing the other (host). May cause harm or death to host, and the parasite is metabolically dependent on the host.
What is an ectoparasite?
A parasite that lives on the surface of the host
What is an endoparasite?
A parasite that lives within the host.
What are the 6 types of hosts?
- Definitive (final)
- Intermediate
- Paratenic (transport)
- Vector
- Reservoir
- Dead-end
don’t insert popcorn, very regular disaster
What is a definitive (final) host?
The host in which the parasite completes a sexual reproduction cycle, as well as the final/ adult stages
What is an intermediate host?
The host in which the parasite undergoes development of immature stages as well as asexual reproduction
What is a paratenic host?
A host in which the parasite survives without further development. It is not essential for the life cycle. (ex. parasites in rodents)
When staying at your parent’s house, you survive & don’t develop further
What is a vector? What are the 2 types?
The host that carries a parasite from one host to another.
2 types:
Biological- develops and multiplies
mechanical- no biological development/ multiplication
What is a reservoir host?
A host with no clinical disease, but serves as a source of infection for others
What is a dead-end host?
A host where a parasite can start a life cycle, but infection/transmission cannot occur
Most parasites are in a ______ of animals, which leads to the __/__ rule.
minority; 80/20 rule (80% of parasites can be found in 20% of hosts)
Are younger animals less or more susceptible to parasitic infections?
more susceptible
What is the selection pressure from drug use?
Pressure that is placed on parasites to evolve to resist drugs and pass the evolved genes to offspring
Parasite burdens are over-dispersed, or ______ _____.
negative binomial
How do you identify every organism?
by using a combination of its genus and species names
Hosts crowded together (stocking density) favors _______
transmission of parasites
An organism that requires only one host to complete its life cycle has what type of life cycle?
Direct life cycle (monoxenous). This includes most nematodes
An organism that needs two or more hosts to complete its life cycle has what type of life cycle?
An indirect life cycle (heteroxenous). This includes many Apicomplexa and some Cystoisospora (second host is not essential = Feculative heteroxenous)
In the worm life cycle, eggs hatch and develop after being released to the environment through feces. The eggs develop into infective L3 larvae in the environment, which is dependent on ______.
Environmental temperature
What is a pre-patent period?
The period between a host becoming infected and the reproductive stages being detected (often in feces)
What is a patent infection?
An infection during the period when the parasite is reproducing in the host
