The study of parasites
- Lives at the expense of its host
- gains nourishment from its host
- lives in/on another organism
What is symbiosis?
The relationship between 2 different species
When one benefits while the other is unaffected it is known as ____________.
Both organisms benefit is known as ____________
When one organism benefits at the expense of another it is known as ___________
What is an ectoparasite?
A parasite that lives on the outside of the host, such as in the hair or on the skin.
Known as an infestation
examples: Scavvies, lice, and mites
What is an endoparasite?
A parasite that lives within the body of the host.
Known for infection
This type of parasite can live independently of a host, known as the "free-living" stage, and becomes parasitic if ingested or enters through a wound.
A parasite that is unable to survive outside a host is known as _____________
An obligate parasite
What is a pseudoparasite?
An artifact mistaken for a parasite
ex. pollen or hair
What is a definitive host?
Harbors the adult and/or sexual stage
AKA final host
What is an intermediate host?
Harbors the larval or asexual stage of a parasite
What is an accidental/incidental host?
A parasite establishes itself in a host other than its natural host.
Normally the parasite lives in or on host other than humans
AKA "dead-end" host is no longer transmitted
This is a living carrier that transmits a parasite
What is a reservoir?
A continuous source of infection
-An animal or area that harbors the infective parasite
An infected individual showing no signs of clinical manifestation but has the potential to infect others is known as being a ___________
What is the greatest vehicle for most of transmission of parasites?
Parasitic life cycle:
During this stage the parasite is capable of invading a definitive host
Parasitic life cycles:
During this stage a parasite can be identified by examining appropriate specimen from an infected host
What is the difference between parasitic infection and parasitic disease?
Parasitic infection: infected host suffers very little damage and typically has no symptoms
Parasitic disease: host suffers pathologic changes and has various symptoms
What are some common symptoms of parasites? (9)
- abdominal pain and cramping
- bowel obstruction
- enlarged organs
- skin lesions
What is the pathogenesis of a parasite dependent on?
- Number of parasites
- Size of parasite
- Tissue tropism
- Specific mechanisms of tissue damage
- Location and migration patterns
- Patients immune system
What is a mechanical effect due to a parasite?
Obstruction of vessels or hollow viscera
True or False:
Parasites can invade or destroy host cells
True or False:
Parasites can cause an inflammatory reaction on their own or due to their byproducts
True or False:
Parasites compete for nutrient but do not cause vitamin deficiency
False- Parasites can cause vitamin deficiency which can in turn cause anemia
What is a physical barrier against parasites?
What is a chemical barrier against parasites?
Proper hand washing
What is natural resistance to parasite?
Genetic factors that may influence resistance