EXAM 1* Flashcards
(121 cards)
1
Q
Vector
A
An organism that transmits a pathogen; carries the parasite to the subsequent step(s)
2
Q
Phoresis Definition and Example
A
Traveling together; an organism carries another without dependence
EX: Bacteria on the legs of flies
3
Q
Mutualism Definition and Example
A
Both organisms beneift, usually obligatory (+/+)
EX: Blood sucking leeches cannot digest blood without certain bacteria in their intestine
4
Q
Commensalism Definition and Example
A
One organism benefits while the other is neither helped nor harmed (+/o)
EX: A bird making a nest in a tree
5
Q
Parasitism Definition and Example
A
Harms the host, or lives at the expense of the host (+/-)
EX: Fleas living on a dog
6
Q
Platyhelminth
A
Flat Worm: cestode and trematodes
7
Q
Nematode
A
Round Worm, complete digestive system, dioecious
8
Q
Trematode
A
Platyhelminth, fluke, leaflike. Dingenean and monogenean
9
Q
Dioecious
A
Separate sexes; separate male and female reproductive parts on different organisms
10
Q
Monoecious
A
The organism itself has both female and male reproductive parts
11
Q
Oviparous
A
Produces offspring in the form of eggs that are hatched OUTSIDE of the parent
12
Q
Ovoviviparous
A
Produces offspring in the form of eggs that are hatched INSIDE of the parent
13
Q
Cestode
A
Tape worm, indirect life cycle, proglottids, monoecious
14
Q
Ectoparasite
A
Involves arthropods that feed off host for a blood meal; live on the surface of host
(not all ectoparasites are anthropods that feed on blood; but most)
15
Q
Endoparasite
A
A parasite that resides within the host
16
Q
Protozoan
A
Single celled organism that can be free-living or parasitic
17
Q
Trophozoite
A
Motile feeding form of a protozoan
18
Q
Cysts
A
Stage in a parasitic life cycle that has a protective membrane or thickened wall that allows them to survive outside of a host
19
Q
Oocyst definition and who creates them?
A
A cyst-like structure that contains a zygote (fusion of two gametes, initial stage of an organism)
Formed by apicomplexans
20
Q
Apicomplexan
A
A phylum under protozoa that encompasses organisms that have cellular machinery allowing them to enter a host cell and replicate. produce oocysts
21
Q
Anterior
A
Front
22
Q
Posterior
A
Back
23
Q
Indirect Life Cycle
A
Involves more than one host for its life cycle
24
Q
Digenean Trematode
A
A trematode thatt has a complex life cycle with a snail as its first intermediate host
25
Direct Life Cycle
Does not contain any intermediate hosts
26
Definitive Host
The host in which the parasite reaches sexual maturity
27
Intermediate Host
Required host where the parasite develops but does not reach sexual maturity
28
Paratenic Host
No development takes place in this host and is not infectious to this host; gets the parasite to where it needs to go. (Small fish, big fish example)
29
Reservoir Host
An animal that harbors an infection that can be transmitted to humans; parasite does not undergo any development in this host
30
Aberrant Host
A host in which a parasite cannot complete its life cycle, leads to dead-end infections
31
Facultative Parasite
Can live as a free-living organism or become parasites depending on environmental conditions
32
Obligatory Parasite
An organism that can’t reproduce without a host. Many have free living stages in environment but exist as a cyst
33
Giardia form:
Helminths form:
Cysts; eggs
34
Wucheria spp. Taxonomy? Causes what disease?
Nematode
Causes blockages in the lymphatic system: lymphatic filariasis
35
Incidental/accidental host
Parasitism of a host different than normal; the parasite does not survive but can cause disease
36
Permanent Parasite
Spend entire life in a host
37
Intermittent Parasite
Feed on host, then leave (ex: mosquito)
38
Parasite vs Predator
Parasites keep the host alive and utilize them. Predators kill prey
39
Parasitoid
An organism that lives in or on a host and eventually kills it; usually insects, wasps or flies
40
Protelean Parasites
Insects in which only the immature stages are parasitic and the adults are free living
41
Host Specificity
Infects only a specific host (ie: just humans vs ANY carnivorous mammal)
42
Eimeria spp. Taxonomy? Characteristic? How does one get Infected?
COCCIDIA
Highly host specific.
Infections via ingestion of oocysts and leads to coccidiosis
43
Hyperparasitism and Example
Parasites being a host for another parasite
Ex: tapeworm juvenile in a flea
44
What are the three broad groups of Helminths, what are their common names?
Trematode, Fluke
Cestode, Tapeworm
Nematode, Roundworm
45
What are the two broad groups belonging to the phylum, Platyhelminths?
Cestode
Trematode
46
Digenean vs Monogenean Trematodes
Digenean: Indirect/complex life cycle, has a snail as the first intermediate host
Monogenean: Direct life cycle
47
What are two broad groups of arthropods?
Arachnids
Insects
48
Of the ectoparasites discussed IN THIS COURSE, what group do they belong to?
Arthropods
49
What groups belong to sarcomastigophora? What are their common names?
Sarcodina (Amoeba),
Mastigophora (Flagellates)
50
What group do apicomplexans fall under? What fall under apicomplexans?
Apicomplexans fall under protozoa. Under apicomplexans are coccidia
51
What are three organism examples of coccidia? And what is true about them?
Toxoplasma, Eimeria, Cryptosporidia
They live in the GI tract, many form oocysts
52
Morphology and characteristics of cestodes
Long and flat, contain proglottids (segmented). Monoecious, and have indirect life cycles
53
Morphology and characteristics of trematodes
Flat, leaf-like. Diginean or monogenean
54
Morphology and characteristics of nematodes
Complete digestive system, can be round or long but UNSEGMENTED, dioecious
55
Give an example of an apicomplexan that doesn’t belong to coccidia
Plasmodium spp (forms oocysts)
56
Apicomplexans morphology
Have an apical complex used for host cell invasion and are nonmotile
57
In what circumstances is an oviparous or ovoviviparous parasite more advantageous?
Ovi: favorable in stable environments
Ovivi: favorable in unstable environments
58
Briefly identify and describe the three modes of locomotion in Protozoans
Pseudopodia - “feet” like extensions of cytoplasm
Flagella - long, fewer in number
Cilia - short, more numerous
59
Identify the two main types of reproduction in protozoans
Asexual and sexual (look at other flashcards for examples)
60
Identify and describe types of asexual reproduction in protozoans
Binary fission or budding: one turns into two
Merogony: one turns into many (quickly increase population)
Sporogony: sporozoite formation (infectious stage)
61
Identify and describe types of sexual reproduction in protozoans
Gametogony: producing gametes
Conjugation: nuclei uniting
Syngamy: production of whole cell gametes
62
Exists only as a trophozoite. What’s common about them?
Trichomonas vaginalis
Trypanosoma
BOTH FLAGELLATES (under protozoans)
63
Only exists as cysts
Toxoplasma gondii
64
What’s the purpose of an environmental cyst?
Protects parasite in harsh conditions, allowing survival and transmission to next host
65
Blood fluke
Schistosoma; a parasitic Trematode that lives in the bloodstream of its host
66
Tegument
The outer protective covering in platyhelminths (Trematode, Cestode), aids in nutrient absorption
Does not include nematodes because they have a complete digestive system
67
Cuticle
Outer protective layer in nematodes
68
Strobila and Proglottids
Strobila is the body portion of a Cestode, and is comprised of individual segments called proglottids
69
Holdfast Organs
Structures used by parasites to attach to their host. eg: suckers, spines
70
Scolex
The headlock structure of a Cestode, equipped with suckers or hooks for attachment
71
Buccal Cavity
The mouth opening of some parasites used for feeding or attachment
72
Bursa
A specialized structure in male nematodes for mating (not all males have it)
73
How do amoeba move and eat? What do they form?
Uses pseudopodia, phagocytosis. They form cysts
74
Vector Borne Life Cycle
Transmitted via arthropod vectors
75
What are some examples of vectors borne diseases? What vector do they include?
Trypanosoma brucei - tsetse fly
Leishmania spp - Sandfly
76
In Taenia solium, under what circumstances would the human serve as an intermediate vs a definitive host
IH: ingest eggs, they develop into larval cysts that develop in tissues (possibly in the brain). This condition is called cysticercosis
DH: ingest undercooked or raw pork that contains larval cysts. They develop into adults and produce eggs that are passed in feces.
77
Tapeworm lifecycle; in which host do larval tapeworms occur?
Eggs - Larval stages- Larval cysts - adult larval cysts - lay eggs
Larval stages falls between the eggs and the larval cysts. This occurs in the intermediate host
78
Larval tapeworms vs adult tapeworms
CESTODES
Larval tapeworms are small and focus on transmission in tissues
Adult tapeworms are long and elongated. They focus on reproduction in the definitive host’s intestine
79
Helminth vs Protozoan Structures
Helminths - large, multicellular
Protozoans - small, unicellular
80
Under what circumstances would the shape of the esophagus be relevant to identifying the organism?
When identifying if it is a nematode or not. Nematodes have complete digestive systems and therefore a more complex esophagus
81
What are three organism examples of flagellates? Where do they fall taxonomically?
Leishmania, Giardia, Trypanosoma
Under Protozoa
82
What factors contribute to high rates of parasitism in certain populations?
Poverty, lack of sanitation, malnutrition, high population density, climate conditions favorable to vectors
83
In what ways is parasitism underreported in the US
Misdiagnosis, stigma, lack of routine screening
84
What is a common misconception about parasitism in the US
We are not free of parasitic infections, make struggle with them, this is primarily from pinworms
85
Why are we optimistic about controlling NTDs
Drug donations, technology advances, improvements in medical access
86
Lymphatic filariasis
Wucheria, Brugia
87
River Blindness
Onchocerca
88
Guinea worm
Dracunculus
89
Schistisomiasis
Schistosoma
90
Taeniasis
Taenia
91
Echinococcosis
Echinococcus
92
Whipworm
Trichuris
93
How have news stories and public health campaigns had an impact on parasitic diseases?
Media coverage have increased public awareness. Improved sanitation and sales of anti parasitic drugs
94
What are some major challenges in fighting NTDs?
Climate change, drug resistance, travel and movement of humans and pets
95
How does proper sanitation impact parasite life cycles?
Proper sewage can break fecal oral transmission in soil transmitted helminths like ascaris
96
How does water filtration impact parasitic transmission?
In the instance of Guinea worm, infection depends on copepods in drinking water. Filtering prevents infectione
97
How can controlling parasitism negatively impact the ecosystem?
It alters biodiversity and impacts natural selection. Reduction of hosts have unknown effects on ecosystems
98
What’s the biggest challenge in eradicating Guinea Worm
Dogs acting as animal reservoirs has complicated the efforts. Dogs need to drink filtered water too but now they're passing it to humans
99
What challenges are specific to Guinea worm and the associated countries
Political unrest in Mali
Outbreaks in Chad and Ethiopia
100
Briefly describe the lifecycle for Guinea worm. Who is the IH and DH
Humans drink unfiltered water that contains copepods. Copepods die and release larvae. Fertilized female migrates to skin and discharges the larvae into water. Larvae are consumed by copepods
IH: Copepod
DH: Human
101
Briefly describe the lifecycle for schistosomiasis. Who is the IH and DH
Eggs are secreted in urine and feces. In water, eggs hatch and penetrate snails. They are release from snails and they penetrate human skin in the water. They mature in the liver and migrate to the balder and intestines where they are released.
IH: Snail
DH: Human
102
How does the life cycle of Onchocerca impact control efforts?
They rely on blackfly vectors. Vector control and treatment are key to elimination
103
What are the control efforts for Guinea worm, schistosomiasis and onchocerciasis
Guinea worm: safe drinking water and education
Schistosomiasis: mass drug administration
Onchocerciasis: distribution of ivermectin, an anti parasitic drug
104
What are key clinical signs of schistosomiasis?
Hematuria, bladder damage
105
What are key clinical signs of lymphatic filariasis?
Lymphedema
106
What are the key clinical signs of onchocerciasis? What’s the common name?
River Blindness
Severe itching and blindness
107
How to identify a parasite’s endosymbiont in hyperparasitism? Provide two examples
The endosymbiont is typically the smaller one. Ex: plasmodium in a mosquito OR wolbachia in worms
108
Key clinical signs of malaria
Fever, chills, anemia
109
Apicomplexan reproduction
Merogony: asexual multiplication in a host
Gamogony: formation of gametes and sexual reproduction
Sporogony: produces sporozoites for infection (infective stage)
110
Accidental host example. How does this affect the host.
Humans are usually the definitive host. They ingest cysts that grow into adults and eggs are passed in feces.
However, they can also be the intermediate host in that they ingest eggs. The eggs develop into cysts and develop in tissues causing cysticercosis
111
Provide examples of insects
Mosquitos, fleas, lice
112
Provide examples of arachnids
Mites
Ticks
Spiders
113
What groups belong to sarcomastigophora
Amoeba and flagellates
114
What groups belong to sarcomastigophora
Amoeba and flagellates
115
What are the common names for sarcodina and mastigophora?
Sarcodina - Amoeba
Mastigophora - flagellates
116
What is a mastigont system?
A structure in flagellates that includes the flagella, basal body, and associated organelles for movement and attachment
117
What are some examples of species that fall under apicomplexa and coccidia? (4)
Plasmodium, cryptosporidium, toxoplasma and eimeria
118
What’s the common name for eimeria or cystoisospora?
Coccidia
119
What groups do amoeba fall under?
Protozoa
Sarcomastigophora
120
What group do cilliates fall under?
Protozoa
121
What are the four groups under Protozoa?
Apicomplexa (coccidia), ciliates, flagellates, amoeba
