Micro 2 - Midterm Flashcards
What are the factors that influence the distribution of parasitic diseases?
Rapid Travel
Immigration
Increased # of immunocompromised patients
What is the definition of Infection?
Invasion and multiplication of a pathogenic parasite in the body with accompanying rxn by the host
Define Infestation
Parasitic organisms or arthropods that live on the surface of a host without multiplication.
Any damage of a host tissues or organs that leads to malfunction of an organ caused by a parasite is describing…
Disease
What is a Vector
Any arthropod or other living organism that transport a pathogenic microorganism from an infected to a non-infected host
What is the difference between a final/definitive host and an intermediate host?
Final = parasite passes sexual reproduction phase Intermediate = passes larval stage or asexual reproduction phase
T or F
Vector is usually a intermediate host
True
What is the exception to the vector being an intermediate host rule
Plasmodium Infection
Anophele Mosquitos carrying plasmodium - malaria mosquito is the final or definitive host & humans = intermediate
The animal that harbour a species of parasite & can serve as a source of parasitic infection is known as..
Reservoir Host
What type of antibodies are formed when parasites elicit an immune response?
IgM, IgG, and IgA
What are the factors effecting immune response to parasitic infections?
Rapid rate of reproduction
Large Size
Slime Layer & Capsule
Complex Life Cycles
Masking of surface antigens
Byproducts prevent production of antibodies, macrophages & lymphocytes
High production of IgE antibody (helminth worm)
Induced T-cell delayed hypersensitivity response
Concomitant - resistance to re-infection from an antibody
Long co-evolution with host = evolved adaptation
What does concomitant mean?
Parasitic larval form can be distorted by host antibodies and the presence of antibodies provides resistance to re-infection by new larvae.
T or F
A protozoa is a unicellular eukaryotic microorganism
True
What is the name for the worm like organisms?
Helminths-metazoa
Describe a protozoa
Unicellular, animal-like microbe usually having some form of motility
What are the classifications of medically important protozoa
Style of movement
Mode of reproduction
Stages in the life cycle
T or F
Most amebas are free living and very infectious
False
Usually not infectious
T or F
Amebas are major loco motors with pseudopodia
True!
Some species have flagella during reproductive states
How do Amebas reproduce?
Binary Fission (asexual)
T or F
The cyst is the active form & the trophozoite is the inactive form
False!
Opposite is true
Cyst = inactive
Trophozoite = active
Sarcodina aka
Ameba
T or F
Flagellata reproduce both sexually and asexually
True
What is the active form of a Flagellata? Inactive
Active = Trophozoite Inactive = Cyst
All of the following are Flagellatas except: Trypanosoma Balantidium Coli Giardia Trichomonas Leishmania
Balantidium Coli
What is another name for Ciliophora?
Ciliata
What is the function of the cilia?
Movement
Attachment
Feeding
T or F
Ciliata reproduce sexually
False!
Asexual Transverse Fission
Give an example of Ciliata discussed in class
Balantidium Coli
T or F
The entire group of Sporozoa are parasites
True
How do Sporozoa reproduce?
By well developed asexual and sexual stages
Do most Sporozoa form Trophozoites or Cysts?
Cysts
What are the two main methods of transmission of Sporozoa?
Ingestion of the infective stage of protozoa
By arthropod vector
Where are Sarcodina (ameba) most commonly found in the human body?
Lower GI tract
What stage of the life cycle of a Sarcodina is infective to humans?
Some form a non-feeding, non-motile cyst stage
What is the metabolizing stage of the Ameba?
Trophozoite
T or F
In the active feeding stage of a Trophozoite they are sensitive to the environmental change
True
T or F
The cyst form of Ameba cannot survive for periods outside the body
False!
Can!
What makes the cyst form of the Ameba resistant to environmental changes
It is surrounded by mineral wall, mostly calcium
How many nuclei can the cyst form have depending on species?
1-8
When can a cyst form a trophozoite from its nuclei? During what stage?
Excyst Stage
What conditions will stimulate excitation of a cyst in the Gi tract?
Alkaline pH
T or F
Each nucleus of a cyst Ameba will produce 2 trophozoites
False!
One for One
How does the Trophozoite become a cyst as it moves along the GI
Trophozoite moves along with a bowel movement, the environment becomes drier and the trophozoites start to undergo encystation
T or F
Cyst formation can survive active dysentery
False!
Cannot because the feces are so rapidly flushed from body.
What does Entamoeba Histolytica cause in humans?
Amebic dysentery
Describe the different forms of Entamoeba Histolytica
Large motile trophozoite
Small non-motile cyst that contains 4 nuclei
What form of the Entamoeba will be destroyed in the mouth?
Trophozoite
Cysts will not be destroyed
Where do the trophozoites attach themselves in the human body?
The mucous of cecum and large intestines with pseudopods. They will mature and reproduce here.