General characteristics: Flashcards
Define parasitology:
Parasitology is the science that deals with organisms that take up their abodes (places) temporarily or permanently, on or within other living organisms.
* organisms that spend all or part of their lives as parasites in or on other organisms
Parasite is applied to (in biology):
a weaker organism that obtains food and shelter from another organism and derives all the benefit from the association
Define parasitism:
an intimate and obligatory relationship between two heterospecific organisms which the parasite, usually the smaller of the two partners, is metabolically dependant on the host
Name different types of parasites:
Ectoparasites
Endoparasites
Extracellular
Intracellular
Permanent
Temporary
Obligate
Facultative
What is an obligatory parasite?
A parasite that is completely dependant on the host during parts or all of its life cycle
What is a facultative parasite:
An organism that does not absolutely depend on the parasite way of life, but is capable of adapting to it if placed in such relationship
What is a permanent parasite?
A parasite that lives all of its life in or on animal (tapeworms, louse)
What is a temporary parasite?
A parasite that lives a part of its life cycle in or on animals, like during feeding of mosquitos, ticks etc.
Name different hosts:
Definitive
Intermediate
Paratenic
Define a definitive host:
Harbors the adult or sexual stage of the parasite (where parasite reaches sexual maturity)
Define intermediate host:
Is temporary, but required by parasite to complete its life cycle. Parasite usually undergoes morphological or physiological change in it.
Parasite does NOT reach sexual maturity.
Define paratenic host:
Harbors the parasite in an arrested state of development. Optional transport host, there is no detectable morpholical changes in the host.
List diagnostic methods in parasitology:
Coprological
Urine, skin
Haematological
Histopathological
Immunological
Molecular biological
How should fresh fecal material be collected?
Directly from the rectum of large animals
Indirectly immediately after defecation in small animals
What are pseudoparasites?
False parasites, organic or anorganic substances similar to the propagation stages of parasites (eggs, cysts, larvae)
What criteria are used in the diagnosis of helminths eggs?
Size
Shape
Structure of shells
Internal structure
Colour
Helminths and arthropoda are part of:
eukaryota
Name interspecies relationships:
Symbiosis - both partners complement each other
Mutualism - both partners benefit each other
Commensalism - one benefits
Parasitism - one benefits, the other is harmed
What is an accidental parasite?
When a parasite attacks an unnatural host and survives (eg rat tapeworm)
What is an erratic parasite?
one that wanders into an organ in which it is not usually found
What is an aberrant host?
a host in which a parasite cannot persist or develop for a longer time
Name different specificities of parasites:
Host: stenotic or eurixic
Topic
Seasonal
Age
Define what is the prevalence?
The proportion of infected individuals showing disease in a group of animals in a certain date.
Define life cycle:
Life cycle describes the ontogenesis, development and reproduction of the parasite
Name transmission mechanisms of parasites:
Horizontal - between individuals of the same generation
Vertical - transplacental or lactogenic
Iatrogenic - by physician or veterinarian
Explain immune responses to parasites:
- Inflammatory - first line of defence
- Mast cells secrete cytokine
- Macrophages and dendritic cells are activated
- They kill phagocytosed parasites
Name common waterborne parasites:
Giardia
Cryptosporidium
Name common parasites found in meat:
Toxoplasma
Trichinella
Taenia
Gnathostoma
What are basic structures of protozoan?
Cell membrane
Cytoplasm organelles: pseudopodium, flagellum, cilia
Nucleus: vesicular and compact
