L8: Introduction to Parasites Flashcards
(104 cards)
1
Q
Risk factors for parasitic disease? 7
A
- Traveler to endemic zones
- Raw food
- Barefoot exposure to soil
- Exposure to fresh water
- Injections
- Sexual activity
- Immunocompromised
2
Q
Vectors and intermediate hosts of parasites?
Disease for each
A
- Mosquitos: Malaris, filariasis
- Flies: Leishmaniasis, trypanosomiasis, onchocerciasis
- Snail: Schitosomiasis
- Kissing bugs: Chagas disease
- Fish: Diphyllobothrium latum
- Large animals
3
Q
What can be a vector?
A
Insect
4
Q
2 categories of parasites?
A
- Protozoa: Single celled
2. Metazoa: Multi-celled
5
Q
4 types of protozoa?
A
Amoebas
Flagellates
Ciliates
Sporozoans
6
Q
2 categories of metazoa?
A
Nemathelminths
Platyhelminths
7
Q
Another word for metazoa?
A
Helminth
8
Q
Protozoans can be divided by location in body, what is this? (2)
A
- Lumen dwelling: don’t invade
2. Tissue dwelling: invade
9
Q
3 types of metazoa? with common name
A
- Nematode: Round worm
- Cestodes: Flatworms or Tapeworms
- Trematodes: Flukes
10
Q
Are protozoa pro or euk?
A
Eukaryote
11
Q
Protozoa are found where?
A
Free living in marine, fresh water and terrestrial habitats
12
Q
How are protozoa helpful?
A
Essential decomposers and part of food chain.
13
Q
Do protozoa have a cell wall?
Are they eukaryotes?
Do they have chloroplasts?
How do they move?
A
No
Yes
No
Specalized structures: cilia, flagella, pseudopodia
14
Q
Two forms a protozoan can exist as?
Define each
A
- Trophozoite: vegetative/feeding form
2. Cyst: resting form
15
Q
What is the most common mode of protozoan reproduction?
Specifically what form?
Is this sexual or asexual?
A
Binary fission
Schizogony
Asexual
16
Q
Is a protozoan has a definitive host, how does it reproduce?
A
Sexually
17
Q
What is schizogony?
A
Many fissions in which the nucleus divided numerous times and then the cell produces numerous single-celled organisms
18
Q
Mechanisms of entry of protozoa?
A
- Ingestion
- Sexual transmission
- Arthopod vectors
19
Q
Example of direct inoclulation of protozoa?
A
Malaria
20
Q
Example of indirect inoculation of protozoa?
A
Chagas’ disease
21
Q
2 mechanisms of protozoan pathogenesis?
A
- Tissue damage
2. Release of toxins from tissue and parasite
22
Q
Amoebas move by what object?
A
Pseudopodia
23
Q
How many nuclei in amoebas?
A
1-2
24
Q
How do amoebas replicate?
A
Binary fission
25
How do amoebas ingest?
Endocytosis
26
What do amoebas form under adverse conditions?
Cysts
27
Old designation of amoebas?
| New designation of amoebas?
1. Sarcodina
| 2. Amoebozoa
28
Flagellates old designation?
Mastigophora
29
How do flagellates move?
Flagella, 1 or more
30
How many nuclei do flagellates have?
1-2
31
How do flagellates reproduce?
Binary fission
32
What do flagellates form under adverse conditions?
Cysts
33
Are flagellates life cycles simple or complex?
Both.
34
Hemoflagellates have a complex life cycle of how many forms?
4, 1 of which is intracellular
35
Hemoflagellates are transferred by who?
Insect Vectors to trypansoma and leishmania
36
Trypanosoma can cause what diseases? 2
1. African sleeping sickness
| 2. Chagas' disease
37
Ciliates are known as what?
Ciliophora
38
Ciliates move how?
Cilia rotating
39
How many nuclei in ciliates?
1-2
40
How do ciliates replicate?
Binary fission
41
How do ciliates ingest nutrients?
Through cytosome
| Excrete waste through anal pore.
42
Sporozoans are known as what?
Apicomplexans?
43
What type of parasite is sporozoans?
Intracellular parasites.
44
How do sporozoans move? (2)
1. Flagella
| 2. Pseudopodia
45
How many nuclei do sporozoans?
1 or multiple nuclei
46
Sporozoans have how many developmental stages?
Several
47
Are sporozoans only able to have one host?
No
48
Sporozoans use what type of reproduction?
Sexual: Fusion
Asexual: Fission
49
End product of sporozoans sexual reproduction is what?
Oocyst
50
What is difference between intermediate host and definitive host
Intermediate host: Larval forms, asexual
| Definitive host: Adult forms, sexual
51
What are the health strategies against protozoan parasites?
1. Control presence in environment
2. Prevention of infection
3. Treatment of infection
52
Prevention of infection is through what? 3
1. Hygiene
2. Vector avoidance
3. Immunization
53
Helminths/Metazoa have what common characteristics?
1. Multicellular and complex
2. Rudimentary nervous systems
3. Outer covering of cuticle that is shed
4. Use sexual reproduction (although some are hermaphroditic)
5. Highly allergenic (Type 1)
54
Nematodes have what sexual identity?
Male and female
55
Nematodes in the GI system do what?
Ova passes out
56
Nematodes in circulatory must be what?
Be ingested by vector
57
Nematodes in other tissues must be what?
Ingested by predator
58
Cestodes have what sexual identity?
Hermaphroditic
59
Do cestodes/proglottids exit under their own power or disintegrate?
Both
60
Trematodes are usually what sexual identity?
Hermaphroditic
61
Difference between cestodes and trematodes in terms of fertilization?
Cestodes: Self fertilize
Trematodes: Cross-fertilize
62
Trematodes in GI system do what?
Ova exit in feces
63
Trematodes in circulatory do what?
Erode to lumen
64
Trematodes in pulmonary system do what?
Exit in sputum or feces
65
What is a definitive host?
Harbors adult worms and is site where sexual reproduction takes place
66
What is an intermediate host?
Harbors larval forms and asexual reproduction may take place.
67
Helminth entry into body is by what means?
Intermediate host: Ingestion of larvae in tissue
Fecal-oral: Ingestion of eggs or larvae from feces of infected host
Skin penetration: Larval forms burrow through the skin
Injection by blood-sucking insect
68
Two broad categories of helminths?
1. Nemalthelminths (Roundworms)
| 2. Platyhelminths: Flatworms
69
What is the group of roundworms called?
Nematodes
70
What are the two subdivisions of flatworms?
1. Cestodes: Tapeworms
| 2. Trematodes: Flukes
71
Nematode body?
Long, cylindrical, narrow
72
After hatching how do nematodes develop?
Molt through 1 or more larval stages
73
Which is larger in nematodes, males or females?
Females
74
Do nematodes have digestive tracts?
Some do
75
For transmission of nematodes, what can be the infectious unit?
Which passes easily?
Egg: Pinworm (easily passes)
Larva: Hookworm
76
How does a larval/hookworm act as infectious unit?
1. Penetrate bare skin, enter blood stream
2. Carried to lungs, and travel up trachea to esophagus
3. Kids swallow them into intestine and they lay eggs here
4. Poop out eggs
5. Ova hatch in soil into first larval stage. and molt into second
77
Should you pull tissue nematodes out?
No
78
Tissue nematodes larvae are released into what?
Bloodstream or Exterior of body and are taken up by insects or intermediate hosts
79
How are tissue nematodes acquired? 5
1. Larvae ingested by copepods
2. Drink copepods from bad water
3. Larval migrate through tissues and mature
4. Female adults go to subcutaneous tissue on extremities to release larva into water
80
Platyhelminths have what shape?
Flattened
81
Platyhelminths are of what sexual identity?
Hermaphroditic
82
Which platyhelminths HAVE a digestive tract?
Flukes do
83
What do platyhelminths use for attaching to tissues?
Tapeworms: Hooks
| Tapeworms AND flukes: Suckers
84
Cestodes have what two main parts?
1. Strobila
| 2. Scolex
85
The strobila is made up of what?
1. Proglottids
| 2. Gravid proglottids
86
Proglottids have what fnction?
Reproductive: Wil twitch and then dissolve releasing egg
87
Gravid proglottids have what?
Eggs
88
In intestinal cestodes, humans are what host?
Definitive host: Infected by larvae. Adult worms live in humans
89
In tissue cestodes, humans are what host?
Intermediate host: Ingest eggs to get infected. Larvae live in tissues
90
What is beef tapeworms lifecycle?
1. Ova are ingested by cattle (intermediate host)
2. Larvae ingested by humans (definitive host)
3. Proglottids and eggs in intestine.
4. Ova are shed in human feces
91
How does the pork tapeworm's lifecycle compare to the beef tapeworms?
Same
92
What happens if humans ingest pork tapeworm ova?
Cysticercosis: Larvae encyst in tissue
93
Trematodes have what symmetry?
| What shape?
Bilateral
| Leaf-shaped
94
What do suckers do in trematodes?
1. Hold on
| 2. Suck fluid
95
What are the trematodes to worry about?
Blood flukes
96
Definitive hosts of trematodes/flukes?
Humans, livestock
97
Intermediate hosts of trematodes/flukes?
Snails
98
What is lifecycle of trematode/fluke? 5
1. Larvae burrow into snails
2. Larvae multiply asexually and released into water
3. Larvae form cyst in second intermediate host or water vegetation
4. Cysts or larvae infect vertebrae host, mature and lay eggs
5. Ova passed from vertebrae host to hatch inw ater
99
Health strategies for parasitic helminths?
1. Control presence in environment
2. Prevention of infection
3. Treatment of infection
100
What are the treatment challenges to parasites?
1. Diagnosing
2. Effective medications (penetration and resistance)
3. Toxicity of medication
4. Expense of medication
5. Elimination of pathogen
101
Adult arachnids have how many legs?
4 pairs
102
What are the most important arachnid vectors?
Ticks
103
Insects have how many legs?
| How many body regions?
3 pairs of legs
| 3 body regions
104
3 entomology relationships in humans?
1. Parasitic (live on/in us) Mites, lice
2. Predatory (feed on us sometimes): Fleas, mosquitos, ticks, (great vectors)
3. Polluting: Houseflies spreading germs
