Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

M&I: Pathogens & Pathogenesis > Parasitology > Flashcards

Parasitology Flashcards

1
Q

What is a parasite?

A

Organism that lives on or in a host organism and gets its food from or at the expense of its host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name the 3 main classes of parasites

A
  • Protozoa
  • Helminths
  • Ectoparasites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a Protozoa?

A

Microscopic single celled organism that can be free living or parasitic

  • are able to multiply in humans and cause disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Are Protozoa able to multiply in humans?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How can protozoa transmit and where may they live in the body?

A
  • Intestine (transmitted by fecal-oral route)
  • blood or tissue (will usually need a vector)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do we characterise protozoa?

A

By their mode of movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name 4 different classifications of protozoa

A
  • Amoeba
  • Flagellates
  • Ciliates
  • Sporozoa - organisms whose adult stage is not motile
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the different shapes and structures/features of protozoa

A

Some may have flagella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some examples of the medically important Protozoa infections?

A
  • Entamoeba histolytica
  • Gordia lambton
  • Trichomonas vaginalis
  • Malarias
  • Toxoplasma gondii
  • Cryptosporidium
  • Leishmania species
  • Trypanosoma Cruzi
  • Trypanosoma brucei
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does entamoeba histolyca cause?

A

Ulcers in the duodenum, dysentery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does gordia lambton cause?

A

Diarrhoea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does trichomonas vaginalis cause?

A

Infections in the genital tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is toxoplasma gondii transmitted through?

A

Cats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does cryptosporidium cause?

A

Diarrhoea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does leishmania cause?

A

Ulcers in skin and systemic disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe what Helminths are

A

Helminths are large, multicellular organisms that are usually visible to the naked eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Can helminths multiply in humans?

A

in their adult form they can NOT multiply in humans so the amount in the body are dependant on the amount of eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Name the 3 main groups of helminths

A
  • Nematodes (roundworms)
  • Trematodes (flukes)
  • Cestodes (tapeworms)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Name some medically important N helminths

A
  • Soil - Transmitted helminths
    • Ascaris lumbricoides
    • Trichuris trichiura
    • Hookworm spp.
    • Enterobius vermicularis
  • Filarial parasites
    • Wuchereria bancrofti
    • Loa loa
    • Onchocerca volvulus
    • Dracunculus medinensis
  • Others
    • Toxocara canis/cati
    • Trichinella spiralis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the types of nematodes?

A

Soil transmitted helminths
Filarial parasites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Name some medically important T helminths

A
  • Trematodes
  • Schistosoma mansoni/haematobium/japonicum
  • Clonorchis sinensis
  • Fasciola hepatica
  • Paragonimus spp.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What type of worms are nematodes?

A

Roundworms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does clonorchis sinensis cause?

A

Carcinoma of the bladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where does fasciola hepatica live?

A

In the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is special about the male/ female trematodes?

A

Males are larger and the females live inside them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Name some medically important C helminths

A
  • Cestodes
  • Taenia saginata
  • Taenia solium
  • Echinococcus granulosus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What type of worm are trematodes?

A

Flukes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Where does paragonimus live?

A

In the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How long are cestodes?

A

2-3 metres long

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What type of worm are cestodes?

A

Tapeworms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Describe what ectoparasites are

A

Blood sucking arthropods such as ticks, fleas, lice and mites that attach or burrow into the skin and remain there relatively long amounts of time (weeks to months)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Name 4 groups of ectoparasites

A
  • Mites
  • Ticks
  • Lice
  • Fleas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Name the medically important mites?

A
  • Scabies
  • Trombiculid
34
Q

Where are scabies found?

A

Animal infected sand

35
Q

Where are trombiculid found?

A

Found in vegetation

36
Q

What are the types of ticks?

A

Hard and soft

37
Q

Name some medically important lice?

A
  • Pediculus humans capitals
  • Pediculus humanus
  • Pthirus pubis
38
Q

What are the types of parasitic host?

A
  • Intermediate

or

  • Definitive
39
Q

What is an intermediate host?

A

Host in which larval or asexual stages develop

40
Q

What is a definitive host?

A

Host in which adult or sexual stage occurs

41
Q

Which factor is correlated strongly to the distribution of parasite infections in humans around the world?

42
Q

Describe some general different modes of transmission of parasitic infections

A
  • Faeco-oral
  • Food
  • Complex life cycles
  • Others
43
Q

What are DALYs?

A
  • This is one way of measuring morbidity in NTDs (neglected tropical diseases) around the world
  • Disability-adjusted life years - One DALY represents the loss of the equivalent of one year of full health
44
Q

What is Chagas disease and how can we limit it?

A
  • Is Tyrpansoma Cruzi transmitted by bugs that live in thatched rooves and around rubbish, can feed off of animals such as chickens and goats and replicate
  • Can be limited by removing thatched roof, move animals away, keep rubbish away etc.
45
Q

Describe the life cycle of Tyrpansoma Cruzi

A
  • The bug will bite you and then may excrete into the skin
  • Tthe bite will be itchy and so if you itch it then you may cause the parasite in the feces to go into your blood - is not transmitted by the bite
  • Ttryptomastigotes will move to the midgut and replicate then if another bug bites you it can infect that bug
46
Q

Describe the acute phase of Chagas disease

A
  • Incubation 1-2 wks after bite
  • Up to months after transfusion
  • Trypanosomes in blood
47
Q

Describe chronic ‘indeterminate’ (in terms of Chagas disease)

A
  • Chronic ‘indeterminate’
  • Lifelong Infection
  • Generally trypanosomes not detectable but often positive for parasite DNA
  • Seropositive
  • 60-70%
  • Normal ECG and X ravs
48
Q

Describe chronic ‘determinate’ (in terms of Chagas disease)

A
  • Determinate’ Chronic disease
  • Seropositive
  • 30-40% of infected 10-30 years after infection
  • 5-10% develop chronic Chagas immediately after acute disease
49
Q

Describe the symptoms of acute Chagas disease

A
  • Occurs within 3 weeks
  • Generally mild or asymptomatic
    • Local swelling (Romaña)
    • Nodule or chagoma
    • Fever
    • Anorexia
    • Lymphadenopathy
  • 1-2% diagnosed
  • Symptoms last 8-10 wks
  • Rarely (young and IS)
    • Hepatopsplenomegaly
    • Acute myocarditis
    • Meningoencephalitis
    • Fatality <5% of symptomatic
50
Q

Describe the chronic changes of Chagas disease to the heart

A

enlarged heart and thin heart wall → heart failure

51
Q

Describe the effects of Chagas disease on the digestive system

A
  • Severe constipation causes megacolon and ulceration, performation
  • Can affect the esophagus, rectum and sigmoid colon
52
Q

Explain how Chagas disease causes these effects (pathogenesis) in acute, intermediate and chronic Chagas

A

Acute

  • Tissue damage by inflammation due to parasite nests of amastigotes in cardiac, skeletal and smooth muscle
  • Parasite killing by antibodies and activated innate immune response - inflammatory cytokines

Chronic inflammatory response to persistent parasites in muscle and nerve cells

  • Autoimmune mechanisms
  • May vary by parasite strain and tissue tropism
  • Predominance of Th1 cytokines and CD8+ T cells
53
Q

What is the vector of Cutaneous Leishmaniasis?

A

Sam flies - they are very small (can go through mosquito nets)

  • love chickens
54
Q

Which cells do the amastigotes of Cutaneous Leishmaniasis infect?

A

Macrophages - they will be packed full of the amastigotes

55
Q

How does Cutaneous Leishmaniasis present?

A

People will have lesions with large ulcers (there is a plaque formed that will break down and leave a large ulcer)

56
Q

What is mucocutaneous Leishmaniasis?

57
Q

Describe what causes these acute lesions (so the pathogenesis) in cutaneous leishmaniasis

A
  • Acute lesions
    • Tissue damage caused by inflammatory response to presence of parasites in
      macrophages
    • Parasite killing by Th1 pro-inflammatory responses and macrophage killing.
  • Latency
    • Parasites remain present long-term. Regulatory immune response characterized by
      balance of Th1 and anti-inflammatory responses
  • Relapse (rare)
    • Alteration in immune response (i.e change in Th1 vs. immune regulation secondary
      to HIV, malnutrition) may trigger relapse
      • Mucocutaneous disease associated with strong but inadequate inflammatory response to parasites that have metastasized to mucosa
      • Diffuse cutaneous leishmaniasis associated with uncontrolled parasite replication.
      • Recividans - recurrence of lesions at old ulcer site.
58
Q

Explain what amastigotes are

A
  • An amastigote is a protist cell that does not have visible external flagella or cilia.
  • The term is used mainly to describe an intracellular phase in the life-cycle of trypanosomes that replicates
59
Q

What are some examples of neglected tropical diseases?

A
  • Lymphatic filariasis
  • Onchocerciasis
  • Guinea worm disease
60
Q

What are the types of parasitic vectors?

A
  • Mechanical
  • Biological
61
Q

What is a mechanical vector?

A

No development of parasite in vector

62
Q

What is a biological vector?

A

When some stages of the life cycle occur

63
Q

What is the life cycle of schistosomiasis?

A
  • Eggs expelled in urine or faeces
  • Develop in fresh water
  • Invade snails
  • Asexual reproduction that amplifies parasite number
  • Infect people when they come into contact with the infected water
64
Q

How can you decrease the faeco-oral transmission of parasites?

A
  • Household sanitation
  • Access to clean water
  • Personal hygiene behaviours
65
Q

How can you decrease the food transmission of parasites?

A
  • Animal husbandry
  • Surveillance
  • Regulations and government controls
66
Q

What is chagas infected with?

A

Metacyclic trypomastigotes

67
Q

What do metacyclic trypomastigotes do?

A

Multiply in cells and burst them, spreading disease further

68
Q

What are the phases of chagas?

A
  • Acute
  • Chronic indeterminate
  • Chronic determinate
69
Q

What are the organs most affected in chronic chagas?

A

Heart and intestines

70
Q

Why does chronic chagas affect the heart and intestines?

A

Damages the autonomic nervous system

71
Q

What complications in the mega colon are caused by chronic chagas?

A

Hecatoma
Obstruction
Sigmoid volvulus
Ulceration
Perforation

72
Q

What is the pathogenesis of acute chagas?

A

Tissue damage caused by inflammatory response to parasite

73
Q

What is the pathogenesis of indeterminate chronic chagas?

A

Regulatory immune response characterised by IL-10 and IL-17

74
Q

Where are visceral leishmaniasis found?

A
  • Asia
  • Middle East/ Africa
  • Latin america
75
Q

Where (geographically) are cutaneous leishmaniasis found?

A
  • Mediterranean
  • Central and South America
76
Q

What is the lifecycle of a leishmaniasis?

A

Sandfly bite
Promashyotes enter immune cells and replicate to form amastigotes

77
Q

What is the old world vector of leishmaniasis?

A

Sergentomyia

78
Q

What are the new world vectors of leishmaniasis?

A

Phlebotomus

79
Q

What is the reservoir of leishmaniasis?

A

Domestic dogs and rodents like sloth

80
Q

How do cutaneous leishmaniasis present?

A

Small Papule that grows into a plaque

81
Q

How do you get a sample for cutaneous leishmaniasis?

A

Scrape from the edge of the plaque onto a slide, then stain with giemsa

82
Q

Describe the effects of Chagas disease on the digestive system

A
  • Severe constipation causes megacolon and ulceration, performation
  • Can affect the esophagus, rectum and sigmoid colon

M&I: Pathogens & Pathogenesis (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions