chapter 13 Flashcards
1
Q
What is immunology?
A
The study of the genetic, biological, and physical characteristics of the immune system.
2
Q
Define immunity.
A
The body’s ability to respond to the presence of any foreign substance.
3
Q
What are the two primary mechanisms of immunity?
A
- Innate immunity
- Adaptive immunity
4
Q
What is innate immunity?
A
A nonspecific, rapid response present from birth.
5
Q
What is adaptive immunity?
A
A specific, slower response that develops over time.
6
Q
What are antigens?
A
Markers on cell surfaces or other substances that bind to immune cell receptors, triggering immune responses.
7
Q
What are epitopes?
A
Specific binding regions on antigens, typically 5-10 amino acids long, that serve as recognition sites.
8
Q
What types of substances can act as antigens?
A
- Protein-based bacterial toxins
- Viral proteins
- Carbohydrates from bacterial cell walls
- Membrane phospholipids
- Nucleic acids like bacterial DNA
9
Q
What are immunogens?
A
Antigens that stimulate the production of specific antibodies by the immune system.
10
Q
Define tolerogens.
A
Substances that the immune system tolerates, preventing an autoimmune response.
11
Q
What are allergens?
A
Substances that cause allergies, leading to an exaggerated immune response.
12
Q
What are autoantigens?
A
Markers that the immune system misinterprets as nonself-antigens, leading to autoimmune diseases.
13
Q
What are tumor antigens?
A
Antigens presented exclusively by tumor cells, triggering lymphocyte destruction of tumor cells.
14
Q
What is the Major Histocompatibility Complex (MHC)?
A
A group of genes on chromosome 6 that codes for self-antigens, crucial for immune function.
15
Q
What role does the MHC play in the immune system?
A
It recognizes self-antigens and prevents autoimmune responses.
16
Q
What are the classes of MHC molecules?
A
- Class I molecules on nucleated cells
- Class II molecules on immune cells
- Class III genes encoding complement proteins
17
Q
What is tissue typing?
A
The laboratory testing process to determine compatibility of MHC molecules between donor and recipient.
18
Q
Define autografts.
A
Transplants from one site of an individual to another site within the same individual.
19
Q
What are isografts?
A
Transplants between identical twins who share the same genetic makeup.
20
Q
What are allografts?
A
Transplants between genetically different individuals.
21
Q
Define xenografts.
A
Transplants between different species.
22
Q
What are antibodies?
A
Proteins also known as immunoglobulins (Ig) that play a crucial role in the immune response.
23
Q
Where do antibodies circulate?
A
In the blood and act as specific receptors on B cells.
24
Q
What is the primary function of antibodies?
A
To recognize and bind to foreign antigens, forming an antigen-antibody complex.
25
What is IgG?
The main antibody in blood, capable of passing from mother to baby before birth.
26
Where is IgA found?
In body fluids like tears and saliva, protecting wet surfaces inside the body.
27
What is the largest antibody type?
IgM
28
What role does IgD play?
Located on the surface of B cells, it plays a crucial role in B-cell activation.
29
What is the primary function of IgE?
Primarily implicated in allergic reactions, triggering histamine release.
30
What components make up the immune system?
* Lymphatic vessels
* Lymphoid tissues
* Lymphatic nodules
* Tonsils
* Lymph nodes
* Spleen
* Thymus gland
* Red bone marrow
31
What is the function of lymphatic vessels?
To collect excess extracellular fluid and drain it into the cardiovascular system.
32
What is lymph?
A watery, plasma-like fluid containing white blood cells.
33
What are lymphoid tissues?
Frameworks of loose connective tissue with accumulations of lymphocytes, playing a major role in defense.
34
What are lymphatic nodules?
Oval-shaped concentrations of lymphoid tissue, not surrounded by a connective tissue capsule.
35
What is MALT?
Mucosa-associated lymphoid tissue, significant for mucosal immunity.
36
What is the role of tonsils?
To remove foreign substances entering the body through ingestion or inhalation.
37
How many lymph nodes are approximately located in the body?
Approximately 600 lymph nodes.
38
What is the primary role of the spleen?
To filter blood and lymph, removing damaged blood cells and pathogens.
39
What is the thymus gland's role in the immune system?
It plays a vital role in T lymphocyte maturation.
40
What are hemocytoblasts?
Stem cells of all blood cells residing in red bone marrow.
41
What is hemopoiesis?
The process of blood cell production, including erythropoiesis, leukopoiesis, lymphopoiesis, and myelopoiesis.
42
What are leukocytes?
White blood cells responsible for defense against pathogens.
43
What are granulocytes?
A type of leukocyte characterized by cytoplasmic granules, including basophils, eosinophils, and neutrophils.
44
What are agranulocytes?
A type of leukocyte lacking prominent cytoplasmic granules, including monocytes and lymphocytes.
45
What are the functions of neutrophils?
They are the most abundant phagocytes, essential for early stages of bacterial infection response.
46
When do eosinophils increase in number?
During hypersensitivity reactions and parasitic infections.
47
What is the role of basophils in the immune system?
They promote inflammation and contribute to allergic reactions.
48
What do monocytes differentiate into?
Macrophages upon leaving blood vessels during inflammatory reactions.
49
What are the main types of lymphocytes?
* B cells
* T cells
* NK cells
50
What is the function of macrophages?
To ingest pathogens, break them down, and present antigens to lymphocytes.
51
What are wandering macrophages?
Mobile macrophages derived from monocytes that migrate to infection sites.
52
What are fixed macrophages?
Macrophages that remain in specific tissues.
53
What role do dendritic cells play in immunity?
They are antigen-presenting cells bridging innate and adaptive immunity.
54
What are the lines of defense against microbes?
* Physical barriers
* Chemical barriers
* Cellular defenses
55
What is phagocytosis?
The process of engulfing and digesting pathogens by immune cells.
56
What is inflammation?
A protective mechanism that can be harmful if unregulated or excessive.
57
What are the steps of phagocytosis?
* Chemotaxis
* Adhesion
* Ingestion
* Digestion
58
What triggers the inflammatory response?
A break in the skin causing injury to capillaries and the release of bradykinin.
59
What is fever (pyrexia)?
A systemic response to inflammation or microbial invasion.
60
What regulates body temperature during a fever?
The hypothalamus in response to pyrogens.
61
What do neutrophils do in the immune response?
Phagocytose bacteria, clearing the infection and reducing the microbial load at the injury site.
62
What happens to monocytes when they leave the bloodstream?
They mature into macrophages, efficiently engulfing microbes and cellular debris at the site of inflammation.
63
What is fever also known as?
Pyrexia.
64
What indicates a systemic response to inflammation or microbial invasion?
Fever.
65
What controls temperature regulation in response to pyrogens?
The hypothalamus.
66
What are interferons?
Glycoproteins produced by cells infected with a virus, serving as key antiviral agents.
67
List the types of interferons.
* α (alpha) * β (beta) * γ (gamma)
68
What is the role of interferons in the immune response?
They interfere with the replication of viruses and impede the spread of pathogens.
69
What are cytokines?
Small proteins that act as chemical mediators of the immune response.
70
What are interleukins?
A diverse group of mediators numbered according to the time of their discovery.
71
What is the complement system?
A system activated by the immune system in response to invasion, enhancing both innate and adaptive immunity.
72
How many soluble proteins are involved in the complement system?
More than 35.
73
What does the complement cascade involve?
A sequential activation of proteins, leading to pathogen lysis, inflammation, and opsonization.
74
What is the third line of defense in the immune system?
The specific or adaptive defense triggered by a specific antigen.
75
What type of immunity is included in cell-mediated immunity?
Cell-mediated and humoral immunity.
76
Who controls cell-mediated immunity?
T cells.
77
What are cytotoxic T cells responsible for?
Recognizing presented antigens and attacking antigen-bearing cells.
78
What do helper T cells do?
They aid in the immune response by stimulating the growth and division of cytotoxic T cells and B lymphocytes.
79
What is the function of suppressor T cells?
To regulate the immune response by suppressing helper T cells and antibody production.
80
What role do memory T cells play in the immune system?
They provide long-term surveillance and rapid response upon re-exposure to the antigen.
81
What is the main function of B cells in antibody-mediated immunity?
To produce specific antibodies that target extracellular pathogens.
82
What happens to B cells after antigen recognition?
They become activated and differentiate into plasma cells and memory cells.
83
What do plasma cells produce?
Antibodies.
84
What characterizes the primary immune response?
A latent period with no specific antibodies, followed by antigen recognition and B cell cloning.
85
What occurs during the secondary immune response?
A rapid increase in antibody titer due to memory cells.
86
What is herd immunity?
Achieved when more individuals in a population acquire immunity, reducing pathogen transmission.
87
What is naturally acquired active immunity?
When an individual becomes ill with pathogens and recovers, producing specific immunity.
88
What is artificially acquired active immunity?
Involves controlled, intentional immunity through vaccination.
89
What is the purpose of vaccines?
To stimulate immune responses without causing disease.
90
What are attenuated microbes?
Living, nonvirulent strains of a microorganism used in vaccines.
91
What are killed microbes in vaccines?
Killed or fragmented microbes that trigger an immune response without the risk of infection.
92
What is DNA immunization?
Involves recombinant DNA to induce an immune response.
93
What are toxoids?
Altered toxins injected to provide protection against the toxin rather than the pathogen.
94
What is naturally acquired passive immunity?
Involves maternal immunoglobulins transferred from mother to fetus.
95
What is artificially acquired passive immunity?
Involves the administration of exogenous antibodies.
96
What is an allergen?
A substance that triggers an immune response, causing hypersensitivity reactions.
97
Give examples of common allergens.
* Pollen * Mold * Dust * Cat dander * Food * Insect bites
98
What characterizes immediate hypersensitivity reactions?
They can be local or systemic and involve airway obstruction.
99
What is the role of IgE in allergic reactions?
Binds to basophils and mast cells, leading to histamine release.
100
What occurs in Type II hypersensitivity reactions?
IgG or IgM antibodies destroy antigen-bearing cells.
101
What is serum sickness?
A systemic reaction after receiving animal sera or hormones.
102
What characterizes delayed hypersensitivity reactions?
They usually take more than 24 hours to manifest.
103
What is a classic example of delayed hypersensitivity?
Contact dermatitis.
104
What is myasthenia gravis?
An autoimmune disease involving antibodies against acetylcholine receptors.
105
What characterizes multiple sclerosis?
Demyelination of axons in the brain and spinal cord.
106
What occurs in Graves' disease?
Autoantibodies stimulate thyroid cells, causing hyperthyroidism.
107
What is systemic lupus erythematosus (SLE)?
A chronic autoimmune inflammatory disease affecting many body systems.
108
What is rheumatoid arthritis?
A systemic disease causing progressive damage to joints.
109
What are primary immune deficiencies?
More than 70 different types, often genetically determined.
110
What is a secondary immune deficiency?
Includes AIDS, where helper T cells are infected by HIV.
111
How does aging affect the immune system?
Increased susceptibility to disease due to declining immune function.
112
What are the factors contributing to increased susceptibility in aging?
* Decrease in metabolic rates * Stress factors associated with aging.
