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Flashcards in Parasitology Deck (25)
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1

Define parasite

A smaller organism that lives on or in and at the expense of a larger organism (host).

2

What is the phylum and class of "roundworms"?

Phylum nemathelminths
Class Nematoda

3

What is the phylum and class of "tapeworms"?

Phylum platyhelminthes
Class Cestoda

4

What is the phylum and class of "flukes"?

Phylum platyhelminthes
Class trematoda

5

Nematodes:
*Free-living or parasitic?
*Shape/conformation?
*Ailmentary canal present?
*Separate sexes or hemaphroditic?

*Both free-living and parasitic
*Elongate/cylindrical
*Ailmentary canal present
*Separate sexes

6

Cestodes:
*Shape/conformation?
*Alimentary canal present?
*Separate sexes or hermatphroditic?

*Flat body
*No alimentary canal
*Hermaphroditic

7

What is a scolex and who has one?

Scolex is the "holdfast organ" in cestodes. It's the head

8

What is a strobila and who has it?

Strobila is the body with proglottids found in cestodes

9

What is a proglottid and who has it?

Egg packets found in cestodes

10

Trematodes:
*Shape/conformation?
*Separate sexes or hermaphroditic?

*Dorso-ventrally flattened - Leaf-like
*separate sexes

11

Common name for diptera.

Flies

12

Common name for siphonaptera

Fleas

13

Common name for Phthiraptera

Lice

14

What are the physical characteristics of insects?

Adults have 3 pairs of legs
3 body segments: head, thorax and abdomen
Antenna present

15

What are the physical characteristics of adult arachnids (acari)?

4 pairs of legs
2 body segments: cephalo-thorax and abdomen
No antennae, but palps

16

How many pairs of legs are found in nymph acari? Larvae acari?

4 pairs in nymphs
3 pairs in larvae

17

How are protozoa classified?

Classified based on their mode of locomotion.

18

What are the ways in which protozoa accomplish locomotion?

Pseudopodia
Flagella
Gliding movements
Cilia

19

Define Definitive Host.

Harbors adult (sexual) stage of the parasite

20

Define Intermediate Host

Harbors larval (asexual) stage of the parasite

21

Define Incidental Host

An unusual host, unnecessary for the maintenance of the parasite in nature.

22

In what ways can parasites cause mechanical tissue damage?

Blockage of internal organs
Pressure atrophy
Migration through tissues

23

Give examples of toxic parasite products

Destructive enzymes
Endotoxins
Toxic secretions (tick paralysis)

24

Define premunition

A type of acquired immunity in which the host is able to prevent superinfection by keeping parasite numbers in check without eliminating the infection (i.e. marlia, toxoplasmosis)

25

Define concomitant immunity

A type of acquired immunity in which the parasite elicits a protection against reinfection, but the parasite itself remains in the host, unaffected by the immune response (i.e. schistosomiasis).