PARA LEC Flashcards
is the area of biology concerned
with the phenomenon of dependence of one
living organism on another
Parasitology
is concerned primarily with parasites of humans
and their medical significance, as well as their
importance in human communities
Medical Parasitology
is a branch of medicine that deals
with tropical diseases and other special medical
problems of tropical regions
Tropical
Medicine
is an illness, which is indigenous to or endemic
in a tropical area but may also occur in sporadic
or epidemic proportions in areas that are not
tropical
tropical disease
is the
living together of unlike organisms. It may also
involve protection or other advantages to one
or both organisms
Symbiosis
is a symbiotic
relationship in which two species live together
and one species benefits from the relationship
without harming or benefiting the other
Commensalism
is a symbiosis in which two organisms mutually
benefit from each other like termites and the
flagellates in their digestive system, which
synthesize cellulase to aid in the breakdown
of ingested wood
Mutualism
is a symbiotic
relationship where one organism, the parasite,
lives in or on another, depending on the latter
for its survival and usually at the expense of the
host.
Parasitism
A parasite
living inside the body of a host is known as an
endoparasite
a parasite living outside
the body of a host
ectoparasite.
The
presence of an endoparasite in a host is called an
infection
the presence of an ectoparasite
on a host is called an
infestation.
A parasite is
considered _________________ when it is found in an organ
which is not its usual habitat.
erratic
Most parasites
are _____________________ in that they need a host
at some stage of their life cycle to complete
their development and to propagate their
species.
obligate parasites
A __________________ may exist in a free-living
state or may become parasitic when the need arises
facultative parasite
A parasite, which establishes itself in a host where it does not ordinarily live, is called
an _______________________
accidental or incidental parasite
A _______________________ remains on or in the body of the host
for its entire life, while a _____________________ lives
on the host only for a short period of time
permanent parasite, temporary parasite
A ________________________ is a free-living organism that
passes through the digestive tract without
infecting the hos
spurious parasite
A _______________________ is one in
which the parasite attains sexual maturity
definitive or final host
An _______________ harbors
the asexual or larval stage of the parasite
intermediate host
A ___________________ is one in which the
parasite does not develop further to later stages
paratenic host
_________________ are responsible for transmitting the
parasite from one host to another.
Vectors
A ______________ transmits the parasite only after the
latter has completed its development within
the host
biologic
vector
A ______________________, only transports the parasite.
mechanical or phoretic vector
A ___________ harbors a particular pathogen without
manifesting any signs and symptoms.
carrier
________________ is the process of inoculating an infective agent
Exposure
_____________________ connotes the establishment of
the infective agent in the host
infection
The __________________ is the period between
infection and evidence of symptoms.
incubation period
is the period between
infection or acquisition of the parasite and
evidence or demonstration of infection
biologic incubation period
results when an infected
individual becomes his own direct source of
infection
Autoinfection
is the use of anthelminthic
drugs in an individual or a public health
program
Deworming
refers to the number
(usually expressed as a percentage) of previously
positive subjects found to be egg negative
on examination of a stool or urine sample
using a standard procedure at a set time after
deworming
Cure rate
is the
percentage fall in egg counts after deworming
based on examination of a stool or urine sample
using a standard procedure at a set time after
the treatment.
Egg reduction rate (ERR)
are provided with a nucleus or nuclei, cytoplasm,
an outer limiting membrane, and cellular
elaborations called organelles
protozoan parasites
Many of these protozoa require a ____________________ for feeding, locomotion,
osmoregulation, and reproduction
wet environment
infective stage of a protozoa, also is relatively resistant to environmental changes
cysts
vegetative state of a protozoa
trophozoites
Helminths causing infections in man belong to three groups
annelids, nematodes, and flatworms.
are also known as
roundworms because they are elongated and
cylindrical in shape, with bilateral symmetry
nematodes
parasites that have a complete digestive tract
and a muscular pharynx that is characteristically
triradiate. They are provided with separate
sexes, although some may be parthenogenetic
nematodes
are dorso-ventrally flattened with
bilateral symmetry
Cestodes
cestodes have an
anterior structure called the _________________, which is
the main organ of attachment of the worm to
the definitive host.
scolex
Adult trematodes
are equipped with an oral sucker, and a
ventral sucker called an acetabulum
acetabulum
A third sucker in trematodes are called a ___________________ is observed only among the heterophyids
genital sucker or gonotyl
composed of
bilaterally symmetrical organisms with
segmented and jointed appendages. The
body is covered with a chitinous exoskeleton
Arthropods
Entamoeba histolytica is currently classified within the subphylum ______________, superclass
__________________, class _____________, order ______________,
family ______________, and genus ________________.
Sarcodina, Rhizopoda, Lobosea, Amoebida, Entamoebidae, Entamoeba
E. histolytica trophozoites adhere
to the colonic mucosa through a ______________________
galactose inhibitable adherence lectin (Gal lectin)
the amebae kill mucosal cells by activation of their _____________, leading to their apoptotic death
engulfment
caspase-3
presents as gradual
onset of abdominal pain and diarrhea with or
without blood and mucus in the stools
Amebic colitis
It clinically presents as
a mass-like lesion with abdominal pain and
a history of dysentery. It can be mistaken for
carcinoma
Ameboma
is the most
common extra-intestinal form of amebiasis.
Amebic liver abscess (ALA)
a minimum of __________ stool specimens
collected on different days should be examined.
three
The standard method of parasitologic
diagnosis is ________________________ of the
trophozoites and cysts in stool specimens.
microscopic detection
For detection of trophozoites, ________________
specimens should be examined within _________________ from defecation
fresh stool, 30 minutes
____________________ is the drug of choice
for the treatment of invasive amebiasis
Metronidazole
is the drug of choice for asymptomatic
cyst passers
Diloxanide furoate
______________ are the major reservoirs of
infection with E. histolytica
Humans
is morphologically
similar to E. histolytica, but their DNA and
ribosomal RNA are different.
Entamoeba dispar
The appearance of _________________ is relatively
similar to that of E. histolytica apart from its
smaller size
E. hartmanni
