Unit 6; Immune System Flashcards
(163 cards)
1
Q
What are the three major functions of the immune system
A
protecting the body
removes dead/damaged tissue and cells
tries to recognize and remove abnormal cells
2
Q
What are examples of microbes
A
bacteria, viruses, fungi, protozoa
3
Q
What are examples of parasites
A
worms, etc.
4
Q
What are pathologies
A
diseases of the immune system
5
Q
What are the 3 main pathologies
A
- incorrect response
- overactive response
- lack of response
6
Q
What does incorrect response lead to
A
autoimmunity
7
Q
What does overactive response lead to
A
allergies
8
Q
What does lack of response lead to
A
immunodeficiency
9
Q
Are bacteria intra or extracellular
A
both!
10
Q
Are bacteria prokaryotic or eukaryotic
A
prokaryotic: no organelles, just a cell with a membrane and a cell wall
11
Q
Do bacteria need to be inside the host to reproduce
A
no, they can reproduce outside the host
12
Q
What type of drugs kill bacteria
A
antibiotics
13
Q
Are viruses intra or extracellular
A
intracellular
14
Q
Are viruses cells?
A
no, just a nucleic acid with a protein coat (cannot reproduce alone)
15
Q
What type of drugs kill viruses
A
antivirals
16
Q
How do viruses attack
A
insert themselves into cell and the viral nucleic acid takes over the cells nucleic acid
17
Q
Why are immune system organs called lymphoid organs
A
they contain lymphocytes
18
Q
What is the difference between interstitial fluid and lymph
A
just different names!
- interstitial fluid when in the tissues
- lymph when in the lymphatic vessels
19
Q
What are regions outside of the lymphoid organs called
A
periphery
20
Q
What are the two classifications of lymphoid organs
A
primary and secondary
21
Q
What are primary lymphoid organs
A
organs where lymphocytes developed
- bone marrow (all blood cells) (B cells mature here)
- thymus (T cells mature here)
22
Q
What are secondary lymphoid organs
A
organs where lymphocytes interact and initiate responses
- spleen, lymph nodes, tonsils, and gut-associated lymphoid tissue (GALT)
23
Q
What is the function of secondary lymphoid organs
A
filter blood and lymph
24
Q
What do afferent lymph vessels do
A
bring lymphocytes from periphery
25
What do efferent lymph vessels do
keep lymphocytes circulating
26
What is the pulp inside lymph nodes for
mixing of lymphocytes and other leukocytes
27
What three things do arteries and veins supply the body with
nutrients, O2, and non-lymphocytic leukocytes
28
What lymphoid organs are encapsulated
spleen and lymph nodes
29
What lymphoid organs are not encapsulated, therefore capable of diffusion
tonsils and GALT
30
What are the 6 main types of leukocytes
1. eosinophils
2. basophils
3. neutrophils
4. monocytes
5. lymphocytes
6. dendritic cells
**remember NLMEB + D
31
What are the categories that leukocytes can correspond with
granulocytes, phagocytes, cytotoxic cells, and APCs (antigen-presenting cells)
32
What are granulocytes
have prominent cytoplasmic granules
- eosinophils, basophils, and neutrophils (and mast cells)
33
What are phagocytes
can engulf and ingest pathogens
- neutrophils, macrophages, and dendritic cells (and monocytes)
34
What are cytotoxic cells
killer of other cells (even self cells)
- eosinophils, and some lymphocytes (cytotoxic T and natural killer)
35
What are APCs (antigen-presenting cells)
display fragments of pathogens on cell surface
- some lymphocytes, dendritic cells, and macrophages
36
What are antigens
substances recognized by an antibody and induces the immune response
37
What are antibodies
proteins that bind specifically to antigens and target pathogens for destruction
38
Eosinophils are what classification(s) of cell with what colour staining granules
cytotoxic granulocytes
- bright pink staining granules
39
What is the lifespan of an eosinophil
6-12 hours
40
What is the role of eosinophils
defence against parasites and allergens
41
Where are eosinophils found
digestive tract, lungs, genital tract, and skin
42
How do eosinophils respond
bind to an antibody-coated parasite and degranulate (spew granule contents) which kills the parasite
43
Basophils are what classification of cell with what colour staining granules
granulocytes
- dark blue staining granules
44
Where are basophils found
in blood (rare in numbers), mast cells in tissue
- found in digestive tract, lungs, and skin
45
What do the granules of basophils contain
histamine, heparin, and cytokines
46
What are basophils for
allergic response
47
What classification of cell are neutrophils
phagocytic granulocytes
48
What is the lifespan of a neutrophil
1-2 days
49
What is the most abundant leukocyte
neutrophils
50
What do the granules of neutrophils contain
cytokines that cause fever and inflammatory response
51
Monocytes are precursor cells of tissue ______________ and are _________ in the blood
macrophages, uncommon in blood
52
Monocytes move to the __________ to become _________________
move to tissues to become macrophages
53
What are macrophages
amoeboid cells that function as scavengers by phagocytosing old RBCs and dead neutrophils
54
What type of immunity do monocytes play a role in
adaptive immunity
- phagocytosed pathogens are digested, and fragments are placed on the cell surface (APCs)
- that's why macrophages are called big eaters
55
What type of immunity do lymphocytes contribute to
adaptive immunity
56
How much of lymphocytes are actually in circulation
5%, the rest are in lymphoid tissues
57
What are the 3 types of lymphocyte
T cells, B cells, and natural killer cells
58
What are B cells called when activated
plasma cells
59
What are dendritic cells
phagocytic antigen-presenting cells (APCs)
60
What type of cell has long thin processes (like dendrites on neurons)
dendritic cells (think of the similarity in the name)
61
Where are dendritic cells found
skin and other organs
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What is the function of dendritic cells
engulf pathogens and present their markers on the cell surface, then they travel to secondary lymphoid organs to present the antigens to lymphocytes
63
What is hematopoiesis guided by
cytokines
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What type of cell do all specialized cells come from
pluripotent hematopoietic stem cells
65
Where are B cells produced and matured
produced and matured in bone marrow
66
Why are B cells called B cells
derived from research in chickens
67
What is important about B cells
produce antibodies (can be found on the cell surface as receptors or as free antibodies in the plasma)
68
Where are T cells produced and matured
produced in the bone marrow, matured in the thymus
69
Why are T cells called T cells
mature in the thymus (T for thymus)
70
What is important about T cells
use contact-dependant signalling via T-cell receptor on the T-cell membrane
- can only bind to MHC-antigen complexes (not free Ag)
71
What does MHC stand for
major histocompatibility complex
72
What are MHCs
proteins expressed on the surface of cells that display "self-antigens" and "non-self antigens"
73
Who would have identical sets of MHCs
identical twins
74
What are class one MHCs
found on all nucleated cells
- can display self or non-self antigens
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What are class two MHCs
found only on APCs
76
What type of MHC do APCs have
class one and class two
77
What happens when an MHC is infected
display antigens on class 1 instead of class 2
78
What are the 3 subtypes of T cell
cytotoxic, helper, and regulatory
(Tc, Th, Treg)
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What are cytotoxic T cells
recognize antigens on class 1 MHCs and kills the cell
80
What are helper T cells
recognize antigens present on class 2 MHCs and promote differentiation of B cells/T cells (+ activate macrophages)
81
What are regulatory T cells
recognize antigens on class 2 MHCs and suppress other immune cells to prevent excessive immune responses
82
What're the 4 steps when a foreign invader enters
detect and identify the pathogen, communicate with other cells, recruitment of help and coordination of the response, destruction or suppression of the invader
83
What do cytokines do
affect the growth and activity of other cells
84
Which type of immunity is more rapid, and less specific
innate
85
Which type of immunity is slower, but more specific
adaptive
86
What is a hallmark of innate immunity
inflammation
87
What are the two categories of adaptive immunity
cell-mediated immunity and antibody-mediated immunity
88
What is the first line of defence in innate immunity
skin (physical barriers)
89
What is the second line of defence in innate immunity
patrolling or stationary leukocytes & blood proteins
90
What is the majority of innate immune system cells
phagocytes
91
How do phagocytes attract other cells
release cytokines
92
Chemicals that attract other immune cells are called....
chemotaxis
93
What type of cells are attracted by chemotaxins
cytokines and other immune blood proteins
products of tissue injury
bacterial products
94
What is extraversion
when phagocytes leave circulation and enter the tissue through capillary walls
95
What is opsonization
when blood proteins bind to a pathogen to "tag" it
- happens when a pathogen doesn't have surface features that a phagocyte can recognize
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What is the blood protein that tags pathogens
opsonin
97
What is a phagosome
name for the vesicle formed when a pathogen is ingested
98
Once the phagocyte (with ingested pathogen) fuses with a lysosome, it is called...
phagolysosome
99
What is pus
when dead phagocytes, tissue fluids, and debris collect at the site of injury
100
What lymphocyte is associated with innate immunity instead of adaptive
natural killer cells
101
What is the purpose of NK cells
initiate apoptosis in pathogen-infected cells
102
What important cytokines are produced by NK cells
interferons
103
What are interferons
interfere with viral replication
104
IFN a and b induce...
antiviral state in nearby cells (signal to other cells that there is a virus present)
105
IFN y...
activates macrophages and other immune cells
106
What does inflammation do to capillaries
increases capillary permeability
107
What interleukin mediates the inflammatory response
IL-1
108
What are the functions of IL-1
- act on endothelial cells lining the blood vessels
- act on liver cells to produce blood proteins involving damage control
- induce fever
- stimulate cytokine production
109
What are complement proteins
cascade of events that occurs in innate immunity by blood proteins
110
What are complement proteins activated by
sequential proteolysis
111
What do complement proteins subsequently form
MAC attack (membrane attack complex)
112
What is the MAC attack
makes holes in the pathogen membrane, which allows ions to enter and lyses the pathogen, killing it
113
What are other terms for adaptive immunity
acquired or specific immunity
114
What cells are involved in adaptive immunity
T cells and B cells
115
All lymphocytes produce:
cytokines
116
What does it mean to expand clonally
make identical copies of itself and multiply to create an "army"
117
What is specificity
each cell recognizes a different specific pathogen
118
What are naïve cells
don't know things... have never seen its particular antigen (body has never had its particular infection)
119
Once a pathogen has recognized its pathogen, it is no longer naïve, it is an ______________ cell
effector
120
What cells produce the antibodies needed in antibody-mediated immunity
B cells
121
What is an interchangeable term for antibodies
immunoglobulins
122
Where can antibodies lie
plasma or cell membrane protein of B lymphocytes
123
When activated, B cells become...
plasma cells
124
At which response level is there a delayed response period
primary response (on first exposure)
125
What is IgM
produced during primary response: activates compliment
126
What is IgA
found in secretions
127
What is IgD
were not sure what its function is
128
What is IgG
produced in secondary responses: recognized by mast cells
129
What is IgE
allergic responses
130
Where are the antigen binding sites on an antibody
on the fragment antigen binding region (Fab)
131
What part of the antibody determines which type of immunoglobulin the antibody belongs to
the stem (Fc region)
132
What is the hinge region on an antibody
between the Fc and the Fab regions on the antibody
133
Antibodies make up ___% of proteins found in plasma
20%
134
Do antibodies attack the pathogens themselves
no, they make pathogens more visible to immune cells to be destroyed
135
What are the 7 antibody functions
1. act as opsonins
2. caused antigen clumping
3. neutralize bacterial toxins
4. activate compliment
5. activate B cells
6. activate antibody-dependant immunity
7. activate mast cells to degranulate
136
Can T cells bind to free antibodies
no, must bind to antigens presented on the MHC receptor
137
What is the purpose of class 1 MHCs
defend against pathogens inside the cell
138
What do class 1 MHCs release
perforin and granzymes
139
What is perforin
formes pores in target cell (think perforate)
140
What are granzymes
enter through the pores (perforin) and trigger apoptosis
141
Tc cells can also express the ________ ligand to kill a target cell
Fas (on antibody)
142
What is the purpose of class 2 MHCs
defend against extracellular pathogens
143
How do helper T cells respond to class 2 MHCs
secreting cytokines that activate other immune cells
144
How do regulatory T cells respond to class 2 MHCs
secreting cytokines that suppress other immune cells
145
What are the 4 different responses of the 2 immunity types
1. extracellular
2. intracellular
3. allergic
4. foreign tissue
146
Bacterial invasion often results in the __________________ response
inflammatory
147
When complement proteins are activated by bacterial cell wall components, what do they act as
chemotaxins, MAC attack, and opsonins
148
What occurs in the response to bacterial invasion
- complement proteins activated
- phagocytes produce cytokines and activated cells produce antigens
- cytokines are secreted by B and helper T cells
- B cells clonally expand (becoming plasma cells)
- most cells die at end, but some become memory
149
Phagocytes and antibodies ___________ & __________ viruses on first exposure
opsonize and neutralize
150
What occurs in response to viral infection
- infected host cell produces IFNb and macrophages produce IFNa (antiviral state in nearby cells)
- cytokines secreted from host cells and macrophages activate NK and cytotoxic T cells
- T cells recognize viral peptides on class 1 MHCs and kill it
- perforin and granzymes induce apoptosis
151
For viruses that turn off the class 1 MHC expression, what happens
NK cells kill any cell without class 1 MHCs, therefore it is killed anyway
152
Allergic responses, or hypersensitivities, happen in what two types
immediate hypersensitivity and delayed-type hypersensitivity
153
What mediates immediate hypersensitivity
antibodies
154
What mediates delayed type hypersensitivity
T cells and macrophages
155
What happens in response to allergens
sensitization phase: equivalent to primary immune response
- antigen ingested by APC, activates helper T cells
- helper T cells activate B cells to make IgE
- helper T cells and B cells become memory cells
re-exposure phase: equivalent to secondary immune response
- IgE on mast cells recognizes allergen
- mast cells degranulate releasing histamine and cytokines, resulting in inflammatory response
156
What is another term for MHC
human leukocyte antigens (HLA)
157
How does transplantation work in relation to HLA
if the recipient and the donor have the same HLA type, the transplantation is possible
158
What are the two negative outcomes of a transplant
rejection of host by the donor tissue: graft vs host
rejection of donor tissue by host: host vs graft
159
What is a common example of tissue donation
blood transfusion
160
Do RBCs contain MHCs
no, remember RBCs have no nucleus, and MHCs present on only nucleated cells
161
If the wrong type of blood is introduced, what happens
blood rejects and agglutinate (clump)
- this is dangerous in the body cause blood clots can lead to a number of health defects
162
If people express antibodies for blood types that they do NOT have, what would a person with type A blood present
anti-B antibodies
163
Antibody binding of blood would cause activation of complement, which would lead to...
MAC attack; cells lyse, which would kill blood cells
