Diseases of the Immune System (8.2) Flashcards
(99 cards)
1
Q
Describe hypersensitivity reactions
A
Immune system reacts to antigens that pose no threat to the body causing cell damage and disease
2
Q
Describe the 4 major classifications of hypersensitivity reactions
A
- type I
- type II
- type III
- type IV
3
Q
Describe the form of type I hypersensitivity
A
Immediate
4
Q
Describe the form of type II hypersensitivity
A
Cytotoxic
5
Q
Describe the form of type III hypersensitivity
A
Immune complex
6
Q
Describe the form of type IV hypersensitivity
A
Delayed-type
7
Q
Provide an alternative term to describe type I hypersensitivity
A
Allergy
8
Q
Describe allergy
A
Rapid and vigorous overreaction of the immune system to allergens
9
Q
State the 3 hypersensitivity reaction types that can result in autoimmune diseases
A
- type II
- type III
- type IV
10
Q
State the 1 hypersensitivity reaction type that can result in allergies
A
- type I
11
Q
Describe the type I hypersensitivity reactions
A
Rapid and vigorous overreaction of the immune system to antigens that are normally harmless
12
Q
State what the antigens that result in type I hypersensitivity reactions are referred to as
A
Allergens
13
Q
State 3 example of typical allergic substances
A
- pollen
- latex
- peanuts
- MSG
- lobster
14
Q
State the most extreme type of hypersensitivity type I reaction
A
Anaphylaxis
15
Q
State what substance’s release is central to the immediate hypersensitivity reaction
A
Histamine
16
Q
State what cells release histamine when encountering the allergen
A
Mast cells
17
Q
State what allergic reaction are mediated by
A
IgE antibody
18
Q
State what IgE is produced by
A
Plasma cells
19
Q
State through what IgE travels through in the body
A
Bloodstream
20
Q
State what occurs when the IgE antibody comes into contact with mast cells
A
Tail end of IgE antibody bind to receptors on cell surface
21
Q
State what occurs with subsequent exposure to the same allergen
A
Allergen binds to a pair of adjacent IgE molecules through cross linking
22
Q
State what the binding via cross linking of IgE antibody to mast cells triggers
A
Signal transduction cascade that causes mast cells to release histamine
23
Q
State from what mast cells release histamine
A
Intracellular vesicles
24
Q
State by what process mast cells release histamine
A
Exocytosis
25
Describe antihistamine
Drug that counteracts the effects of histamine by blocking histamine receptors and suppressing allergic reaction symptoms
26
State 5 effects of histamine
1. blood vessel dilation
2. blood pressure decrease
3. increase in permeability of blood vessels to immune cells
4. contraction of smooth muscles lining airways (making it more difficult to breath)
5. activation of fluid-secreting cells (runny nose/tears/sneezing which expels foreign antigens)
27
State the 2 types of antibodies which are involved in the cytotoxic hypersensitivity reaction
1. IgM
| 2. IgG
28
State how long it may take for cytotoxic hypersensitivity reactions to occur
Hours
29
Provide 2 examples of cytotoxic hypersensitivity reactions in humans
1. Haemolytic anaemia - mother produces antibodies directed against Rhesus antigens on foetal red blood cells
2. Binding of penicillin to red blood cells - if anti-penicillin antibodies are present they may bind to the drug and trigger the destruction of red blood cells
30
State the 2 types of antibodies which are involved in immune complex hypersensitivity reaction
1. IgM
| 2. IgG
31
State to what the antibodies in type III hypersensitivity reactions are directed against
Soluble antigens
32
State what forms when antibodies bind to soluble antigens
Antigen-antibody immune complexes
33
State where antigen-antibody immune complexes can be deposited
Tissues
34
State what antigen-antibody immune complexes cause when deposited in tissues
Inflammation
35
State how long it may take for immune complex hypersensitivity reactions to occur
Hours/days
36
Provide 1 example of immune complex hypersensitivity reactions in humans
1. serum sickness - immune complexes form as a result of a person's antibodies binding to a foreign antigen in serum
37
State whether or not delayed-type hypersensitivity reactions are mediated by antibodies
No
38
State what delayed-type hypersensitivity reactions are mediated by
Helper T lymphocytes
39
State what helper T lymphocytes activate to produce an immune response
- macrophages
- eosinophil
- cytotoxic T lymphocytes
40
State how long it may take for delayed-type hypersensitivity reactions
Days (as the name suggests - 'delayed')
41
State 1 example of a delayed-type hypersensitivity reaction
- rash caused by poison ivy contact (has a lipid-soluble compound called 3-pentadecacatechol that crosses the cell membrane and causes new peptides to be produced which are recognised by cytotoxic T lymphocytes)
42
State what normally occurs to T and B lymphocytes that are reactive against self-antigens
Destroyed
43
Describe autoimmune disease
Diseases that result from an adaptive immune response directed against self-antigens
44
State what must fail for an autoimmune disease to occur
Self-tolerance
45
State what cytotoxic T lymphocytes attack in an autoimmune disease
Tissues
46
State how B lymphocytes act indirectly in an autoimmune disease
Secreting antibodies
47
State whether or not mast cells are activated in autoimmune diseases
Yes.
48
State whether or not autoimmune disease tend to be more commonly inherited to females or males
Females
49
State the 2 forms of autoimmune diseases
1. organ-specific
| 2. generalised
50
Describe the location of organ-specific autoimmune diseases
Particular parts of the body
51
Provide an example of an organ-specific autoimmune diseases
- multiple sclerosis (only affect brain and spinal cord)
52
Provide an example of generalised autoimmune diseases
- systematic lupus erythematosus (affects various organs and tissues of the body, such as the joints, skin, kidneys and the brain)
53
Describe the location of generalised autoimmune diseases
Occurs widely throughout the body
54
State what occurs to neurons in multiple sclerosis
Nerve cells lose the myelin sheath insulating them
55
State what occurs when neurons lose the myelin sheath insulating them
Conduction of signals along the nerve is impaired/damaged
56
State the location of neurons impacted by MS
Those in the CNS
57
State what types of lymphocytes are involved in MS
- helper T lymphocytes
- cytotoxic T lymphocytes
- plasma cells
58
State what plasma cells produce in MS
Antibodies that target proteins and lipids in the myelin sheath
59
State in what cells mitochondria are damaged to release signalling molecules that induce apoptosis
Oligodendrocyte
60
State what specialised macrophages are involved in oligodendrocyte desctruction
Microglia
61
State what type of hypersensitivity reaction is consistent with the symptoms of MS
Type IV hypersensitivity reaction
62
State what cells are responsible for the mediation of MS
T lymphocytes
63
State what the MS disease involves the activation of
Macrophages
64
Describe immunodeficiency
Immune system cannot adequately respond to antigens, or fails to react at all
65
State the 2 major forms of immunodeficiency disorders
1. primary
| 2. secondary
66
Describe primary immunodeficiency
Condition present from birth either as a result of a genetic defect or developmental abnormality
67
Describe congenital
Child is born with the deficiency - genetic defect or development abnormality
68
Provide 2 examples of primary immunodeficiency disorders
1. DiGeorge syndrome
| 2. SCID ('bubble baby disease')
69
Describe DiGeorge syndrome
Thymus fails to develop and mature T lymphocyte production is impaired
70
Describe SCID
B and T cells do not develop properly or function correctly
71
State from what a secondary immunodeficiency disorder is acquired
External factor
72
State from what a primary immunodeficiency disorder is acquired
Genetic factor
73
State the 2 things that secondary immundeficiencies can be
- permanent
| - temporary
74
State from what temporary secondary immunodeficiency can develop as a result of
Severe stress or malnutrition
75
Provide 2 examples of permanent secondary immundeficiences disorders
1. AIDS
| 2. HIV
76
State what HIV is classified as
Retrovirus
77
Describe retrovirus
RNA virus that makes a DNA copy of its genetic information by reverse transcription
78
State what occurs after transcription to retroviruses
Viral DNA is inserted into the host cell DNA
79
State what occurs after viral DNA has been inserted into host cell DNA in retroviruses
Results in the production of viral copies after DNA is expressed by the host cell
80
State what may occur even after the immune system initially responds to the HIV viruses
Some copies of the virus may survive
81
State whether or not the HIV virus can impair the immune response
Yes
82
State what type of cells are preferentially infected by HIV viruses
Helper T lymphocytes
83
State how the impairment of helper T lymphocytes by the HIV viruses disrupts the adaptive immune response
Results in the impairment of humoral and cell-mediated response activations
84
State when AIDS occurs
When the number of helper T lymphocytes becomes very low as a result of HIV infection
85
State what AIDS makes patients susceptible to
Opportunistic infections
86
State in what HIV is present in HIV-positive people
Body fluids
87
State the 3 ways HIV can be transmitted
1. by unprotected vaginal/anal sex
2. by sharing/using contaminated needles
3. from HIV-positive mother to foetus during pregnancy/baby during birth or breastfeeding
88
State what ART represents
Antiretroviral therapy
89
State what AIDS represents
Acquired immunodeficiency syndrome
90
State what HIV represents
Human immunodeficiency virus
91
State what HIV infects and destroys
T lymphocytes
92
State what the structure of the nucleic acid within the HIV viron is
Single-stranded RNA
93
State what the core of the HIV viron contains that is necessary for viral reproduction in addition to nucleic acid
Reverse Transcriptase
94
State what the response of mast cells to the presence of an allergen is dependent upon
The cell being sensitised by previous exposure to the allergen
95
Describe sensitisation
Cells of the immune system identify allergen as non-self and activate immune response which prepares for future exposure to allergen - involves the production of specific IgE antibodies against the allergen
96
State what cells produce IgE antibodies
Plasma cells in the tissue around the site of entry of the allergen
97
State where IgE antibodies attach to and upon what cells
Constant region attaches to the surface receptors of mast cells that are located in the linings throughout the body, including the airways.
98
State what mast cells that are coated with IgE antibodies are referred to as
Primed
99
State what the presence of primed mast cells means and what will occur if future exposure occurs
Person is sensitised to particular antigen and next exposure will cause allergic response
