Introduction to Parasitology Flashcards
A narrower field of parasitology, concerned primarily with the animal parasites of humans and
their medical importance in human communities
Medical Parasitology
Area of biology concerned with the phenomenon of dependence of one living organism on another
Parasitology
Deals with tropical diseases and other special medical problems of tropical regions
Tropical Medicine
An illness which is indigenous to or endemic in a tropical area
→ May also occur in sporadic or epidemic proportions in areas that are non
tropical
→ Many are parasitic diseases
→ E.g. Malaria that is endemic in the Philippines can be present in western
countries due to global transportation of goods
Tropical DIseases
A pathogen that simultaneously injures and derives sustenance
from a host
Parasite
Organisms may develop unique relationships due to
their habitual and long associations with one another
and this relationship is very important for their survival
Biological Relationships
the living together of unlike organisms.
● → May also involve protection or other advantages to
one or both organisms
Symbiosis
Forms of Symbioses
Commensalism
Mutualism
Parasitism
One organisms benefit from
the relationship without
harming or benefitting the
other. give example.
Commensalism
ex: Entamoeba coli - nourished
and protected from harm in the
intestinal lumen without
harming the host tissue
2 organisms mutually benefit
each other and give example
Mutualism
ex: Termites and flagellates in
their digestive system which
synthesize cellulase for
breakdown of ingested wood
One parasite lives in or
another depending on the
latter for its survival and
usually at the expense of the
host and give example
Parasitism
ex: Entamoeba histolytica derives
nutrition from the human host
and causes amoebic dysentery
Classification of Parasites
According to Habitat
TYPE:
Endoparasites
Ectoparasites
Erratic
Lives Inside the host’s body Presence of such parasites is
called INFECTION
E.g. Trichuris trichiura
Endoparasites
live Outside the host’s body, Presence of such parasites is
called infestation
E.g. lice in scalp
Ectoparasites
Found in an organ which is not its
usual habitat
Note: always know the natural
habitat
E.g. Ascaris lumbricoides which is
normally found in the small
intestine → extraintestinal
migration into the lungs and heart
Erratic
Classification of Parasites
According to Dependance of Host
Obligate
Facultative
Needs a host at some stage of their life cycle to complete their development and to propagate their species. They depend entirely upon their host for existence.
Obligate
Example of Obligate
Tapeworm
May exist in a free-living state or may become parasitic when the need arises.
Facultative
Classification of Parasites
According to mode of living
Accidental/incidintal
Permanent
Temporary
Spurious
Establishes in a host where it does not ordinarily live.
Accidental/incidintal
example: ascaris lumbricoides - found in respiratory system
Remains on or in the body of the host for its entire life
Permanent
example: Gut microflora
Lives on or in the host for only a short period of time.
Temporary
Free-living organism that passes through the digestive tract without infecting the host but may cause injury to the host
Spurious
