Jac Chapter 5 Flashcards
Immunity (152 cards)
1
Q
What is acquired immunity?
A
An immunity that develops during a person’s lifetime
Acquired immunity can be developed through natural exposure or vaccination.
2
Q
Define active immunity.
A
The production of antibodies by a person in response to exposure to a particular antigen
Active immunity can result from infection or vaccination.
3
Q
What is adaptive immunity?
A
An immune response that is specific to a particular antigen and develops through contact with an antigen
Adaptive immunity involves memory cells for future responses.
4
Q
What is an allergen?
A
An antigen that elicits an allergic response
Common allergens include pollen, dust, and certain foods.
5
Q
Describe an allergic response.
A
Rapid immune response to normally harmless antigens; involves production of IgE antibodies and release of histamines
Allergic responses can lead to symptoms like sneezing, itching, and swelling.
6
Q
What is an allergy?
A
An abnormal immune response to a substance that is harmless for most people
Allergies can vary in severity from mild to life-threatening.
7
Q
What is anaphylaxis?
A
Acute and potentially lethal allergic reaction to an allergen
Anaphylaxis requires immediate medical attention and treatment.
8
Q
What are antibodies?
A
Proteins produced by plasma cells in response to antigens, reacting specifically with the antigen that induced their formation
Antibodies are also known as immunoglobulins.
9
Q
What are antigen-binding sites?
A
Regions of an antibody molecule to which an antigen binds
These are also referred to as variable regions.
10
Q
What are antigen-presenting cells?
A
Cells of the immune system that present antigens to helper T cells using MHC-II markers
They play a crucial role in initiating the adaptive immune response.
11
Q
Define antigens.
A
Molecules or parts of molecules that stimulate an immune response
Antigens can be proteins, polysaccharides, or other types of molecules.
12
Q
What is artificial active immunity?
A
The deliberate administration of disabled antigens to elicit the production of antibodies
This is typically achieved through vaccination.
13
Q
What is artificial passive immunity?
A
The administration of antibodies to provide an immediate, specific immune response
This type of immunity does not involve the body producing its own antibodies.
14
Q
What is an attenuated pathogen?
A
A pathogen that has been treated to no longer cause disease while still living
Attenuated pathogens are often used in vaccines.
15
Q
What are autoimmune diseases?
A
Diseases in which the immune system makes antibodies against the body’s own tissues
Examples include lupus and rheumatoid arthritis.
16
Q
What are B lymphocytes?
A
White blood cells that recognize antigens and produce antibodies specific to an antigen
B lymphocytes are crucial for humoral immunity.
17
Q
What is the role of bone marrow?
A
The site of blood cell formation
Bone marrow is a primary lymphoid organ.
18
Q
What is a capsid?
A
The protein shell enclosing the genetic material of a virus
The capsid protects the viral genome.
19
Q
Define cascade in the context of the immune response.
A
A multi-step process in which each step triggers the next in a set order
Cascades are crucial for signal amplification in immune responses.
20
Q
What are cell surface markers?
A
Proteins present on the plasma membrane that distinguish various cell types
They help the immune system identify self from non-self.
21
Q
What is cell-mediated immunity?
A
Immune response mediated by immune cells
This type of immunity involves T cells.
22
Q
What are cellular pathogens?
A
Disease-causing agents made up of cells that can reproduce independently
Examples include bacteria and fungi.
23
Q
What are chemical barriers?
A
Innate barriers that use enzymes to kill pathogens and prevent invasion
Examples include lysozyme in saliva and tears.
24
Q
What is chemotaxis?
A
Movement of a cell or organism in response to a chemical substance
This is often seen in immune cell migration toward infection sites.
25
What are cilia?
Fine hair-like outfoldings formed by extensions of the plasma membrane involved in movement
## Footnote
Cilia can help clear pathogens from respiratory pathways.
26
What is clonal expansion?
Multiple cycles of cell division of a lymphocyte specific to a particular antigen
## Footnote
This results in large numbers of identical lymphocytes.
27
What is clonal selection?
An event in lymph nodes where lymphocytes with receptors that recognize a new antigen come into contact with that antigen
## Footnote
Clonal selection is key for effective immune responses.
28
What are clones in immunology?
Groups of cells, organisms, or genes with identical genetic make-up
## Footnote
Clones arise from the division of a single lymphocyte.
29
What are complement proteins?
Proteins that assist other innate immune cells and can destroy bacterial cells by lysis
## Footnote
They play a role in the complement system.
30
What is the constant region of an antibody?
The section of an antibody that does not vary between antibodies of the same class
## Footnote
This region determines the class of the antibody.
31
What are cytokines?
Signalling molecules of the immune system
## Footnote
They mediate and regulate immunity and inflammation.
32
What are cytotoxic T cells?
T cells activated by cytokines to kill infected body cells
## Footnote
They play a crucial role in eliminating virus-infected cells.
33
What are dendritic cells?
A type of antigen-presenting cell and phagocyte that can activate T lymphocytes
## Footnote
They are essential for linking innate and adaptive immunity.
34
What is degranulation?
The process by which immune cells release chemicals stored in granules
## Footnote
This includes the release of histamines during allergic reactions.
35
What is dermicidin?
An antimicrobial protein found in secreted sweat acting as a chemical barrier
## Footnote
Dermicidin helps protect the skin from pathogens.
36
Define endotoxins.
Toxic parts of the outer membrane of some Gram-negative bacteria released when bacteria die
## Footnote
Endotoxins can trigger strong immune responses.
37
What are enveloped viruses?
Viruses with an outer envelope composed of part of the host cell's plasma membrane
## Footnote
This envelope is acquired when the virus buds from the host cell.
38
What are eosinophils?
A type of white blood cell that kills larger parasitic agents
## Footnote
Eosinophils are involved in allergic reactions and asthma.
39
What are extracellular locations?
Locations within the body that are outside cells, such as blood plasma
## Footnote
These areas are crucial for the movement of immune cells.
40
What are exotoxins?
Toxins secreted into the surrounding medium by a microorganism as it grows
## Footnote
Exotoxins can cause significant damage to host tissues.
41
What is the first line of defence in the immune system?
Part of the defence provided by barriers of the innate immune system that prevent entry of pathogens
## Footnote
This includes physical and chemical barriers.
42
What are granzymes?
Active protease enzymes present in granules that form part of immune defences
## Footnote
Granzymes are released by cytotoxic T cells to induce apoptosis in infected cells.
43
What are helper T cells?
A class of T cell that activates B cells and cytotoxic T cells
## Footnote
They play a central role in orchestrating the immune response.
44
What is histamine?
A substance involved in inflammation and allergic reactions
## Footnote
Histamine causes blood vessels to dilate and become more permeable.
45
What is humoral immunity?
Immune response mediated by soluble molecules in blood and lymph that disable pathogens
## Footnote
This response primarily involves B cells and antibodies.
46
What are human leukocyte antigens?
Antigens present on human cell surfaces that determine the ‘self’ status of a person’s cells
## Footnote
These antigens are crucial for immune recognition.
47
What is the immune system?
The body system that helps resist infection and disease through specialized cells and proteins
## Footnote
The immune system includes innate and adaptive components.
48
What are immunoglobulins?
Antigen-binding proteins produced by B cells and released in blood and lymph
## Footnote
They are essential for the immune response.
49
What are immunoglobulin E (IgE) antibodies?
A type of antibody produced in response to exposure to an allergen
## Footnote
IgE is primarily involved in allergic reactions.
50
What is immunological memory?
The ability of the adaptive immune response to remember antigens after primary exposure
## Footnote
This allows for a faster response upon re-exposure to the same antigen.
51
What is the incubation period?
The time period between infection and the first appearance of symptoms of a disease
## Footnote
This period can vary significantly depending on the pathogen.
52
What is inflammation?
An innate reaction by the immune response to foreign particles or injury resulting in redness and swelling
## Footnote
Inflammation is a protective response that promotes healing.
53
What is the inflammatory response?
A reaction to an infection typically associated with reddening of the skin due to increased blood supply
## Footnote
This response helps to isolate and eliminate pathogens.
54
What is innate immunity?
The type of immunity that is present from birth, fast-acting but not long-lasting, producing non-specific responses
## Footnote
Innate immunity acts as the first line of defence against pathogens.
55
What are interferons?
Proteins secreted by some cells in response to a virus infection that help uninfected cells resist infection
## Footnote
Interferons play a role in the antiviral response.
56
What does intracellular mean?
Anything that is within a cell
## Footnote
Pathogens like viruses can be intracellular.
57
What are leukocytes?
White blood cells involved in protecting the body from infectious disease
## Footnote
They include lymphocytes, neutrophils, and monocytes.
58
What are ligands?
Any molecule that binds to a specific target to form an active complex
## Footnote
Ligands can be hormones, neurotransmitters, or antigens.
59
What is lymph?
Interstitial fluid surrounding tissues filtered through capillaries into the lymphatic system
## Footnote
Lymph plays a key role in the immune response.
60
What are lymph nodes?
Organs of the lymphatic system where B cells and T cells are activated
## Footnote
Lymph nodes filter lymph and are sites of immune activity.
61
What is the lymphatic system?
A network of tissues and organs that plays a key role in the immune response
## Footnote
It includes lymph nodes, lymph vessels, and the spleen.
62
What is lysis?
Destruction of cells by rupturing the membrane of the cell
## Footnote
Lysis can be caused by immune responses or toxins.
63
What are lymphocytes?
Class of white blood cells found in all tissues, including blood and lymph nodes
## Footnote
They play a crucial role in specific immunity.
64
What is lysozyme?
An enzyme present in body secretions that helps in the first line of defence
## Footnote
Lysozyme breaks down bacterial cell walls.
65
What are macrophages?
Phagocytic antigen-presenting cells derived from monocytes
## Footnote
They engulf foreign material and present antigens to T cells.
66
What is the major histocompatibility complex (MHC)?
Receptor proteins on the surface of cells that identify the cells as ‘self’
## Footnote
MHC molecules are crucial for T cell recognition.
67
What are mast cells?
Immune cells containing histamine involved in allergic responses and inflammation
## Footnote
Mast cells release histamine upon activation.
68
What is the membrane-attack complex (MAC)?
One of the defence mechanisms resulting from activation of complement proteins that destroys pathogen cells
## Footnote
MAC leads to osmotic shock and cell lysis.
69
What are memory cells?
Long-lived cells specific to an antigen that can respond to future reinfection
## Footnote
Memory cells are a key component of immunological memory.
70
What is MHC-I?
A type of major histocompatibility complex found on nucleated cells
## Footnote
MHC-I presents antigens to cytotoxic T cells.
71
What is MHC-II?
A type of major histocompatibility complex found on specific white blood cells
## Footnote
MHC-II presents antigens to helper T cells.
72
What are microbiological barriers?
Innate barriers involving normal flora in the body
## Footnote
These barriers prevent the colonization of harmful pathogens.
73
What are mucous membranes?
Cellular linings of the inner spaces within the airways, gut, and urogenital tract
## Footnote
Mucous membranes provide a physical barrier against pathogens.
74
What is mucus?
A gelatinous fluid secreted by cells of the mucous membranes
## Footnote
Mucus traps pathogens and particles.
75
What does naïve refer to in immunology?
An immune cell that has not yet been activated
## Footnote
Naïve T and B cells circulate until they encounter their specific antigen.
76
What is natural active immunity?
A type of immunity in which the body produces antibodies in response to a normal infection
## Footnote
This form of immunity provides long-lasting protection.
77
What is natural immunity?
A form of specific immunity in which antibodies are produced through natural means
## Footnote
Natural immunity can occur through infection or maternal antibodies.
78
What is natural killer cells?
Special white blood cells involved in the innate immune response that kill virus-infected cells
## Footnote
They are part of the body's first line of defence.
79
What is natural passive immunity?
A form of immunity in which an individual receives antibodies from natural means
## Footnote
This often occurs through breastfeeding.
80
What is neutralisation?
The process of binding of an antibody to toxins or antigens, inhibiting their action
## Footnote
Neutralisation prevents pathogens from infecting cells.
81
What are neutrophils?
The most common type of white blood cell; a kind of phagocyte
## Footnote
Neutrophils are often the first responders to infection.
82
What are non-enveloped viruses?
Viruses that lack an outer membrane; also referred to as naked
## Footnote
Non-enveloped viruses are typically more resistant to environmental conditions.
83
What are non-self antigens?
Antigens that do not belong to the body’s own cells
## Footnote
Non-self antigens are recognized as foreign by the immune system.
84
What is opsonisation?
The coating of the surface of pathogen cells by complement proteins
## Footnote
Opsonisation enhances phagocytosis.
85
What are pathogen-associated molecular patterns?
Molecules found in pathogens but not in a host, allowing them to be recognized as foreign
## Footnote
PRRs on immune cells recognize these patterns.
86
What are pathogens?
Agents that cause diseases in their hosts
## Footnote
Pathogens can be bacteria, viruses, fungi, or parasites.
87
What is passive immunity?
Short-term immunity acquired from an external source of antibodies
## Footnote
Passive immunity does not involve the host's immune response.
88
What are pattern recognition receptors (PRR)?
Protein receptors present on phagocytic cells that enable recognition of pathogens
## Footnote
PRRs recognize generic patterns associated with pathogens.
89
What is perforin?
A protein released by some immune cells that produces a pore in the membrane of cells undergoing an immune attack
## Footnote
Perforin is crucial for the function of cytotoxic T cells.
90
What are phagocytes?
Types of white blood cells, including neutrophils and macrophages, that can engulf and destroy foreign material
## Footnote
Phagocytes are key players in the innate immune response.
91
What is phagocytosis?
Bulk movement of solid material into cells where the cell engulfs a particle
## Footnote
Phagocytosis is essential for clearing pathogens.
92
What is a phagosome?
A membrane-bound vesicle formed within a phagocytic cell that encloses the engulfed pathogen
## Footnote
Phagosomes fuse with lysosomes to digest pathogens.
93
What are physical barriers?
Innate barriers that act to prevent the entry of pathogens into the body
## Footnote
Examples include skin and mucous membranes.
94
What are plasma cells?
B cells that are short-lived and secrete soluble antibodies against a specific antigen
## Footnote
Plasma cells are essential for the humoral immune response.
95
What is the primary antibody response?
Production of antibodies induced by the first exposure to an antigen
## Footnote
This response is typically slower than secondary responses.
96
What are primary lymphoid organs?
Part of the lymphatic system that comprises the bone marrow and thymus
## Footnote
These organs are where lymphocytes mature.
97
What are prions?
Infectious particles made of protein that lack nucleic acids
## Footnote
Prions are associated with neurodegenerative diseases.
98
What is the resolution stage?
The final stage of inflammation, in which the normal state is restored
## Footnote
This stage is crucial for healing.
99
What is sebum?
The oily secretion produced by sebaceous glands of the skin
## Footnote
Sebum acts as a barrier to pathogens.
100
What is the second line of defence?
Part of the defence provided by immune cells and soluble proteins of the innate immune system against pathogens
## Footnote
This includes phagocytes and inflammatory responses.
101
What is the secondary antibody response?
The rapid production of high levels of specific antibodies to a foreign antigen upon re-exposure
## Footnote
This response is faster and more efficient than the primary response.
102
What are secondary lymphoid organs?
Part of the lymphatic system that comprises the lymph nodes and the spleen
## Footnote
These organs are sites of immune activation.
103
What are self-antigens?
Antigens on cells that are recognized by self-receptors as being part of the same body
## Footnote
Self-antigens are crucial for self-tolerance.
104
What is self-tolerance?
Inability of an adaptive immune system to respond to the body’s own self-antigens
## Footnote
Self-tolerance prevents autoimmune diseases.
105
What is specificity in the immune response?
The ability to recognize and respond to a specific antigen
## Footnote
Specificity is a hallmark of adaptive immunity.
106
What is a T cell receptor?
A molecule found on the surface of T cells responsible for recognizing antigen fragments
## Footnote
T cell receptors bind to peptides presented by MHC molecules.
107
What are T lymphocytes?
White blood cells that mature in the thymus and participate in the adaptive immune response
## Footnote
T lymphocytes include helper and cytotoxic T cells.
108
What is the third line of defence?
Part of the defence provided by the immune cells of the adaptive immune system
## Footnote
This includes the actions of T cells and B cells.
109
What are toxoids?
Inactivated toxins used for active immunisation
## Footnote
Toxoids can stimulate an immune response without causing disease.
110
What is vaccination?
An artificially active process in which an individual is injected with antigens or weakened pathogens
## Footnote
Vaccination induces the production of antibodies and memory cells.
111
What are vaccines?
Soluble antigens derived from causative agents of diseases administered to individuals
## Footnote
Vaccines provide protection by stimulating an immune response.
112
What is a virion?
The extracellular form of a virus that can transfer between hosts
## Footnote
Virions contain the viral genome and proteins needed for infection.
113
What are viroids?
Simple forms of viruses that lack a capsid
## Footnote
Viroids primarily affect plants and can cause disease.
114
What are viruses?
Non-cellular pathogens that use the host cell to replicate their genetic material
## Footnote
Viruses can infect all forms of life and are dependent on host cells for reproduction.
115
What are antigens?
Any molecules or parts of a molecule that initiate an immune response
## Footnote
Antigens can be proteins, polysaccharides, or other types of molecules.
116
What are MHC markers?
Self-antigens found on the surfaces of all nucleated cells
## Footnote
In humans, MHC markers are also known as HLA markers.
117
What happens to cells with MHC markers that differ from a person's own?
They are identified as non-self and come under immune attack.
118
What types of pathogens can cause diseases?
Bacteria, fungi, protozoa, viruses, and prions.
119
How do some bacteria enhance their virulence?
By producing an external capsule.
120
What are viruses composed of?
Genetic material enclosed within a protein capsid.
121
What is the unique reproduction requirement of viruses?
They can only reproduce within the living target cells of their particular hosts.
122
What are prions?
Infectious particles made of protein and lacking nucleic acids.
123
What are allergens?
Substances that produce an inappropriate immune reaction in susceptible individuals.
124
What components are involved in allergic responses?
Mast cells, IgE antibodies, and histamine.
125
What is the primary function of the immune system?
To protect the body from infectious microbes.
126
What are the two major subdivisions of immunity?
Innate (non-specific) immunity and adaptive (specific) immunity.
127
What does innate immunity refer to?
Non-specific defence mechanisms that respond to foreign pathogens.
128
What is adaptive immunity?
Antigen-specific immune response.
129
What are the three lines of defence against infectious disease?
First line: physical and chemical barriers, Second line: innate immune response, Third line: adaptive immune response.
130
What are the physical barriers in animals?
Intact skin and mucous membranes.
131
Name some chemical barriers in the immune system.
Mucus, tears, saliva, and urine.
132
What is the role of 'normal flora' in the body?
Acts as a microbiological barrier to pathogenic bacteria.
133
What initiates the second line of defence in innate immunity?
Immediate operation if pathogens overcome the first line of defence.
134
What are pathogen-associated molecular patterns?
Molecules common to many pathogens but absent in the host.
135
List some innate leukocytes.
* Natural killer cells (NK)
* Mast cells
* Eosinophils
* Macrophages
* Neutrophils
* Dendritic cells.
136
What is phagocytosis?
The process by which macrophages, dendritic cells, and neutrophils attack and eliminate extracellular pathogens.
137
What are complement proteins?
Soluble proteins that destroy extracellular pathogens.
138
What do interferons do?
Signal nearby cells to reduce the chance of a viral infection.
139
What are the three stages of the inflammatory response?
Vascular stage, cellular stage, and resolution stage.
140
What are the signs of inflammation?
Redness, swelling, heat, and pain.
141
What is the role of the lymphatic system in immunity?
Produces lymphocytes and transports them to lymph nodes.
142
Where do all immune system cells originate?
Stem cells in the bone marrow.
143
What are primary lymphoid organs?
Sites where immune cells are produced and mature, such as bone marrow and thymus.
144
What are secondary lymphoid organs?
Sites where immune cells are activated by antigens, such as lymph nodes and spleen.
145
How do antigen-presenting cells initiate an adaptive immune response?
By displaying antigens to MHC-II markers and presenting them to helper T cells.
146
What is the role of helper T cells in the adaptive immune response?
Activate both branches of the adaptive immune response through cytokines.
147
What distinguishes adaptive immunity from innate immunity?
Adaptive immunity is specific to particular pathogens.
148
What is the humoral component of adaptive immunity?
Targets extracellular antigens through antibodies produced by B lymphocytes.
149
What do cytotoxic T cells do?
Attack pathogen-infected cells and cancer cells.
150
What is active immunity?
Production of antibodies and memory cells by exposure to an antigen.
151
What is passive immunity?
Receiving antibodies from an external source.
152
What is the purpose of vaccinations?
Introduce weakened or dead forms of a pathogen to produce antibodies and memory cells.
