01. Intro to Parasitology Flashcards Preview

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Flashcards in 01. Intro to Parasitology Deck (41)
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1
Q

What kind of parasite is Ascaris lumbricoides?

A

Roundworm/nematode

2
Q

What kind of parasite is Trichuris trichiura? what is its common name?

A

Human whipworm - nematode

3
Q

What kind of parasite is Clonorchis sinensis? What organ does it infect?

A

Liver fluke

4
Q

What is the parasite responsible for Chagas’ disease?

A

Trypanosoma cruzi

5
Q

What parasite causes leishmaniasis?

A

Leishmania

6
Q

What parasite causes african sleeping sickness?

A

Trypanosoma brucei

7
Q

What are common parasites in North America?

A
Pinworms
Giardia
Dog roundworm (dog heartworm)
Toxoplasma (cat feces)
Ticks (lyme disease)
8
Q

Are bacteria or viruses parasites?

A

No, only eukaryotic organisms can be classified as parasites

9
Q

What are the requirements to be a parasite?

A

May be an animal or a plant (eukaryotic)
Not bacterial or viral
Can be unicellular (malaria/toxo) or multicellular (worm/insect)
Can live in or on a host

10
Q

Definition of parasite?

A

eukaryotic organism that acquires some of its basic nutritional requirements through its intimate contact with another living organism.

11
Q

What are unicellular parasites called?

A

Protozoa

12
Q

What are multicellular parasites called?

A

Metazoa

13
Q

Define ectoparasite

A

lives on the external surface of another living organism

ex: head louse, tick, flea

14
Q

Define endoparasite

A

lives within an organism

can be metazoan (Hookworm, tapeworm, roundworm, pinworm) or protozoan (Leishmania, Plasmodium, Trypanosoma, Giardia)

15
Q

Define hemiparasite

A

Parasitic plant that derives some or all of its sustenance from another plant (ex: mistletoe)

16
Q

Define definitive host

A

when the parasite reached sexual maturity in that host (ex: mosquito for malaria, cat for toxo)

17
Q

Define intermediate host

A

parasite always asexual in this host; where the parasite completes a part of its life cycle and undergoes morphological changes and physiological changes (ex: human for malaria, mice for toxo)

18
Q

Define reservoir host

A

alternate host from which the parasite can be transmitted to human or domestic animals. The parasite can still go through its life cycle - important source of infection in epidemiology (ex: rat for toxo)

19
Q

Define accidental host

A

host that accidentally harbours an organism that is not usually parasitic in this host and cannot be transmitted. it is a dead end for the oarasite and can damage the host (ex: human and pork tapeworm Taenia solium, causes cysticercosis (in brain and eye)

20
Q

Define vector

A

plays an active roll in Tmission of parasite, can be definitive or intermediate. transports the parasite from an infected to a non-infected host (ex: female Anopheles mosquito that Tmits malaria

21
Q

Parasitism (process)

A

1) encounter: parasite meets the host
2) entry (may not be the location where damage occurs)
3) spread (this is at proper location, the parasite will propagate here)
4) multiplication
5) Damage: by parasite and or host response
6) outcome: parasite or host wins or coexist

22
Q

what are the main modes of transmission?

A
  • skin, respiratory, gastrointestinal, urogenital

- vector borne, blood transfusion, or organ transplant

23
Q

what is external transmission? is there growth of the pathogen during this step?

A
  • the passive carriage of the pathogen on the body or vector

- no

24
Q

what is internal transmission?

A
  • when the pathogen is carried within the vector
25
Q

what are the two types of internal transmission?

A
  • harbourage transmission: pathogen does not undergo changes within the vector (mechanical vector)
  • biological transmission: pathogen undergoes changes within the vector (biological vector)
26
Q

define infectivity

A

ability of the organism to establish a discrete, focal point of infection

27
Q

define invasiveness

A

ability of organism to spread to adjacent or other tissues

28
Q

penetration of host’s mucous membranes can be ______ or ______

A
  • active

- passive

29
Q

give examples of passive penetration

A
  • skin lesions
  • insect bites
  • wounds
30
Q

once below the mucous membrane, what does a parasite require for spread to deeper tissues?

A
  • production of specific products and/or enzymes that promote spreading
  • circulatory system gives the parasite full access to the body
31
Q

define symbiosis

A

two species of organisms that lived together, with no implication regarding the length or outcome of the association

32
Q

what are the 4 types of symbiosis?

A
  • phoresis
  • commensalism
  • mutualism
  • parasitism
33
Q

which symbioses are considered “loose” associations?

A

phoresis and commensalism

34
Q

which symbiosis are considered “intimate” associations?

A

mutualism and parasitism

35
Q

define phoresis

A
  • to carry
  • an association in which one species provides shelter, support, or transport for another organism of a different species
36
Q

define commensalism

A
  • “at the same table together”
  • one member of the association benefits (one way benefit) while the other is not affected. no harm is exerted in either direction
37
Q

define mutualism

A
  • reciprocal
  • highly inter-dependent association, to the extent that the both species benefit from the association in terms of their growth and survival
  • two way benefit, no harm
38
Q

define parasitism

A
  • intimate relationship between two organisms in which one (the parasite) lives on, off or at the expense of the other (host)
39
Q

define helminth

A

multicellular parasitic worms that include flukes, tapeworms, and roundworms

40
Q

define protozoa

A

unicellular endoparasites that include flagellates, amoebas, malarial organisms

41
Q

define arthropods

A

multicellular ectoparasites that include insects (lice, fleas) and arachnids (ticks, mites) that are carriers (vectors) of diseases