Module 5: Immune System Flashcards

1
Q

What are bacteria?

A

Prokaryotes (free living organisms)

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

What are viruses?

A

Non-cellular entities that are parasites of cells

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

Do viruses have a nucleus?

A

No

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

Do viruses have a genome?

A

Highly variable, in terms of DNA or RNA, single- or double-stranded

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

Do viruses have ribosomes?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Outer structure of viruses?

A

Envelope (membrane) or nucleocapsid

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

Replication strategy of viruses?

A

Rely on host cell for replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a bacteriophage?

A

Viruses that infect bacteria (lytic or lysogenic)

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

What does lytic mean?

A

Capable of destroying/rupturing cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does lysogenic mean?

A

Nucleic material attaches to host’s DNA and remains dormant

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

What is the matrix/tegument of a virus?

A

Structure between the envelope and nucleocapsid of herpesvirus particles - stabilisation of viral envelope

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

What is a icosahedral capsid?

A

20 sides with 12 corners

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

What is a nucleocapsid virus?

A

Genome + capsid

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

What is a helical capsid?

A

Continuous helix of capsomers forming a cylindrical nucleocapsid

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

What is an enveloped virus?

A

Virus with additional membranous covering over the capsid in some animal viruses - do this by budding off host cell

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

What is difference between matrix and tegument?

A

Matrix = for stabilisation off of plasma membrane
Tegument = for stabilisation off of nuclear membrane

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

What are viral enzymes?

A

Enzymes contained within nucleocapsids, which aid in viral replication

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

What is negative RNA?

A

Single-stranded RNA not recognised by ribosomes; viruses carry this RNA into host cells to turn into positive RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are rod (bacilli) bacteria?

A

Rod-shaped bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are spiral bacteria?

A

Curve-shaped bacteria

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

What are sphere (cocci) bacteria?

A

Spherically shaped bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the periplasmic space?

A

Space between outer and inner membrane

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

What is a lipopolysaccharaide?

A

Large complex molecule comprised of polysaccharides linked to lipid molecules

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

Why are pilli/fimbrae important for bacteria?

A

Allow bacteria to attach to gut wall

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

How do bacterial flagella stay attached?

A

Have a flared foot that anchors inside cell

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

Structure of gram-positive bacterial cell wall?

A

Peptidoglycan (cell wall), periplasmic space, plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Structure of gram-negative bacterial cell wall?

A

Thin peptidoglycan + outer membrane containing lipopolysaccharide, periplasmic space, plasma membrane

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

What is a gram stain?

A

Test to determine if bacteria is gram positive or gram negative

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

What is a cytopathic effect?

A

Structural changes in host cells caused by viral invasion

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

What is shedding?

A

Release of infectious virus from infected host by any means

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

What is a reservoir?

A

A place or organism where microorganisms survive, multiply, and await transfer to a susceptible host

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

What are virulence factors?

A

Properties of pathogen that allow it to successfully invade and cause disease in a host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

5 transmission pathways?

A
  • Respiratory
  • Faecal-oral
  • Zoonotic
  • Blood-borne
  • Sexually transmitted
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is cholera?

A

Disease that causes fatal diarrhoea and dehydration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What do cholera bacteria look like?

A

Kidney-shaped bodies with long flagella tail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Transmission type of cholera?

A

Faecal-oral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How is cholera treated?

A

Self-limiting disease; can be treated through oral rehydration therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is influenza?

A

Highly contagious orthomyxovirus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Structure of influenza virus?

A

Single-stranded, enveloped, negative RNA virus (8 segments of genome)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Transmission type of influenza?

A

Respiratory (sneezing, coughing, droplets)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are reservoirs of influenza?

A

Humans, pigs, birds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

How is influenza treated?

A

Generally self-limiting by an immune response; or, oseltamivir (Tamiflu)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What does tamiflu do?

A

Inhibits neuraminidase, which is attachment of infected cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is antigenic shift?

A

Process by which two or more different virus strains, or strains of two or more different viruses, combine to form a new subtype having a mixture of the surface antigens of the two or more original strains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is antigenic drift?

A

A mechanism for variation in viruses involving accumulation of mutations within the genes that code for antibody-binding sites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is listeriosis?

A

Serious infection caused by food contaminated with Listeria monocytogenes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What do listeriosis bacteria look like?

A

Gram positive, motile, rod-shaped bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What are reservoirs for listeriosis?

A

Humans, animals, soil, water; however, contamination actually comes from food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What is transmission type of listeriosis?

A

Eating contaminated foods (often soft cheeses and meats)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

How does listeriosis act like a virus, despite being a bacteria?

A

Invades gut cells by having sipper-like interactions with surface proteins that causes endocytosis; then produces proteins that dissolve capsule and bacteria proliferates; excess bacterium have actin filaments that help then invade neighbouring cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is whooping cough caused by?

A

Bacteria called bordetella pertussis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Structure of bordetella pertussis?

A

Gram negative, non-motile, coccobacillus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Reservoirs of whooping cough?

A

Humans - particularly asymptomatic adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Transmission of whooping cought?

A

Aerosols and direct contact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Catarrhal stage of whooping cough?

A

Lasts 2 weeks, may be mistaken as a cold; culture will be positive during this stage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Paroxysmal stage of whooping cough?

A

2 to 4 weeks, intense coughing and characteristic whooping cough upon inhalation; fatal in infants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Convalescent phase of whooping cough?

A

After 4 weeks; paroxysms decline and confers lasting immunity, though pneumonia, otitis media may occur after

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

How does whooping cough invade the cell?

A

Rides in the mucus and attaches to ciliated cells and proliferates; then releases toxins which destroy the cilia leading to a buildup of mucus

59
Q

What are antibiotics?

A

Drugs that kill or prevent the growth of bacteria (not viruses) without killing healthy body cells

60
Q

What is caused by a lack of surveillance from the immune system?

A

Cancer

61
Q

What is caused by a lack of proper control of the immune system?

A

Autoimmune disease and allergies

62
Q

What is caused by a weak/ineffective immune response?

A

Infectious disease

63
Q

2 immune systems?

A
  • Non-specific, innate
  • Specific, adaptive
64
Q

What is the innate immune system?

A

Rapid response that does not distinguish one invader from another

65
Q

What is the adaptive immune system?

A

Does differentiate invaders; has a memory and adapts

66
Q

What lines of defence are innate immunity?

A
  • 1st external: skin, mucous membranes, secretions
  • 2nd internal: phagocytic cells, antimicrobial proteins, inflammatory response, NK cells
67
Q

What lines of defence are adaptive?

A
  • 3rd: humoral (antibodies) and cell-mediated response
68
Q

Where are leukocytes synthesised?

A

Bone marrow, through leukopoiesis

69
Q

What is a common lymphoid progenitor?

A

Cells created by HSCs; gives rise to B cell and T cell precursors

70
Q

What is a myeloid progenitor?

A

Gives rise to most non-specific, innate immune defence cells

71
Q

3 types of granulocytes?

A

Neutrophils, eosinophils, basophils

72
Q

What is haematopoiesis?

A

Blood cell formation

73
Q

What immune cells are found in the blood? (5)

A
  • NK cells
  • T cells
  • B cells
  • Monocytes
  • Basophils
74
Q

What immune cells are found in the tissues?

A

Macrophages and mast cells

75
Q

2 types of T cells?

A

Helper T cells and cytotoxic T cells

76
Q

What are lymphocytes?

A

Type of WBC that attack foreign matter and act as source of viral defence

77
Q

Role of neutrophils?

A

Drawn to site of infection; phagocytose bacteria

78
Q

Role of eosinophils?

A

Lead body’s counterattack against parasitic worms, lessen severity of allergies by phagocytising immune complexes

79
Q

Role of basophils?

A

Promote inflammatory response

80
Q

What are monocytes?

A

Immature macrophages

81
Q

2 anatomical barriers of immune system?

A

Skin and mucous membrane

82
Q

Most superficial layer of skin?

A

Made of dead, keratinised cells, with little-to-no nutrition and a low pH; also replaces itself every 10-14 days

83
Q

How does the mucous membrane act as a barrier?

A

Mucous traps bacteria; moved by ciliated cells to be removed

84
Q

What are 3 physiological barriers of immune system?

A

Temperature, pH, chemical mediators

85
Q

How does temperature act as a barrier?

A

Body’s natural temperature is not favourable for most pathogens

86
Q

How does inflammation act as a barrier?

A

Inflammatory response is caused by leaking fluid of damaged cells/tissue, which causes an influx of phagocytic cells

87
Q

What is the complement system?

A

Cascade of reactions; occur in response to stimuli which indicate foreign material

88
Q

What is an alveolar macrophage?

A

Dust cell that does phagocytosis and has lots of lysosomes to cleave the ingested material; first line of defence against invading respiratory pathogens

89
Q

2 main types of phagocytic cells?

A
  • Neutrophils
  • Macrophages
90
Q

What are dendritic cells?

A

Spiny-looking cells with functions similar to macrophages, but instead of killing pathogen, they sample and report to T cells

91
Q

What is a phagolysosome?

A

Structure resulting from fusion of phagosome and lysosome

92
Q

Role of NK cells?

A

Convince infected cells to undergo apoptosis; kill intracellular pathogens

93
Q

3 major events of an inflammatory response?

A

Vasodilation, increased capillary permeability, influx of phagocytic cells

94
Q

What do histamines do?

A

Dilate blood cells

95
Q

What is opsonisation?

A

Coating of a pathogen with antibodies to promote and enhance phagocytosis

96
Q

First responder leukocytes of an inflammatory response?

A

Neutrophils

97
Q

Secondary responder leukocytes of an inflammatory response?

A

Monocytes, which will then mature into macrophages

98
Q

What is extravasiation?

A

Recruitment of neutrophils to exit blood near site of infection

99
Q

What are cytokines?

A

Chemical messengers produced in response to a stimulus, which enhance inflammatory response

100
Q

What is rolling?

A

Macrophages attaching and detaching from endothelial lining through blood cells

101
Q

What is an antigen?

A

A toxin or other foreign substance that induces an adaptive immune response in the body, especially the production of antibodies

102
Q

What are the epitopes/the antigenic determinants?

A

Certain regions of an antigen molecule that antibodies attach to to stimulate immune responses

103
Q

2 types of adaptive immunity?

A

Humoral and cell-mediated

104
Q

What is humoral immunity?

A

Humoral immunity is the aspect of immunity that results in antibody production (extracellular)

105
Q

What is cell-mediated immunity?

A

Immune response that does not involve antibodies, but rather, involves the activation of cells like phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen (intracellular)

106
Q

2 main types of lymphocytes?

A

B cell, T cell

107
Q

Where do T cells mature?

A

Thymus

108
Q

Where do B cells mature?

A

Bone marrow

109
Q

What is a naive lymphocyte?

A

Mature B or T cell that has not yet encountered an antigen

110
Q

What are the secondary lymphoid organs?

A

Spleen and lymph nodes

111
Q

Role of lymph nodes?

A

Filter substances that travel through the lymphatic fluid, and contain lymphocytes

112
Q

What is an effecter B cell?

A

Plasma cell

113
Q

What are the effecter T cells?

A

Cytotoxic T cell (CD8+),
Helper T cell (CD4+)

114
Q

What are antigen receptors?

A

Molecules capable of recognising specific antigens

115
Q

What happens to a lymphocyte when the antigen binds to the receptors?

A

Division and differentiation

116
Q

Why is it important that lymphocytes are circulated readily through the body?

A

Because they can only recognise one antigen type, so they should be exposed to as much area as possible

117
Q

What is clonal selection?

A

Process which immature B and T cells undergo, in secondary lymphoid organs, so only certain types are permitted to mature to fight a specific antigen

118
Q

What is clonal expansion?

A

Increase in the number of cells by mitotic cell division alongside clonal selection

119
Q

What are memory B cells? Role?

A

Long-lived cells that do not secrete antibodies but will respond to antigens upon a second exposure

120
Q

What is the role of immunoglobulin (Ig)?

A

Soluble B-cell receptor (BCR) secretion

121
Q

How does an immunological memory develop?

A
  1. Naive lymphocyte will encounter an antigen for the first time
  2. Primary immune response kicks in 5-10 days and is short lived
  3. Weeks to years later, the response will be more rapid (3-5 days) and long lived (secondary immune response)
122
Q

What is IgM?

A

First antibody formed by B cells during the immune response; confined to intravascular space due to large size

123
Q

What is IgG?

A

Second antibody formed by B cells during the immune response; can move into extravascular space (the first responder in the case of a secondary immune response)

124
Q

Where do antibodies come from?

A

Plasma cells (secretion)

125
Q

Structure of an antibody?

A

Y shaped molecule, two heavy chains and two light chains, with two identical binding sites

126
Q

How does the antigen bind to an antibody?

A

Non-covalent (reversible) binding, many factors involved such as hydrophilic/phobic

127
Q

Why is an IgG response more effective than an IgM response?

A

Because IgG has a higher affinity

128
Q

What is IgA?

A

Secretory antibody (mucosal antibody)

129
Q

What is IgE?

A

Produced for parasitic infections and allergic reactions

130
Q

Functions of antibodies?

A

Opsonisation, neutralisation, agglutination, complement system activation

131
Q

What are cytokines?

A

Intercellular messengers; proteins that act on receptors to make the immune system work

132
Q

What are the 3 modes of cytokine action?

A

Autocrine, paracrine (main), endocrine

133
Q

What are MHC molecules?

A

Major histocompatibility complex molecules, also called HLA (human leukocyte antigens); hold little pieces of antigen so that the T cell can interact with the antigen

134
Q

What is antigen processing?

A

The degradation of proteins into peptides that can bind MHC molecules for presentation to T cells

135
Q

What T cell recognises MHC class I?

A

CD8

136
Q

What T cell recognises MHC class II?

A

CD4

137
Q

What is the costimulatory molecule?

A

A molecule along with cytokines and dendritic cells that activates i.e. reports to the T cell

138
Q

How are B cells activated?

A

By cell-to-cell contact with Helper T-cells, and by direct contact with a pathogen (MCH II / CD4)

139
Q

How are macrophages activated?

A

Interaction with T helper cells turns the macrophage into overdrive (MCH II / CD4)

140
Q

What is the difference between a T cytotoxic cell and an NK cell?

A

Cytotoxic cells only recognise and kill MHC class I antigen class cells whereas NK cells are generalised

141
Q

What is MHC class I?

A
  • Produced in all nucleated cells
  • Present endogenous (intracellular) antigens
142
Q

What is MHC class II?

A
  • Produced by all antigen-presenting cells (APCs) like dendritic cells or macrophages
  • Present exogenous (extracellular) antigens
143
Q

How do Helper T cells clear infection?

A

Produce cytokines