week 6: lymphoid & immune systems Flashcards
1
Q
what do adaptive defences have?
A
immunological memory
2
Q
what are the 2 main immune defences?
A
innate
adaptive
3
Q
what does a cellular & humoral immune response begin with?
A
activation of a helper T cell (Th)
4
Q
are adaptive defences specific or non-specific?
A
specific
5
Q
what are 3 examples of cytokines?
A
interferons
IL-1
IL-2
6
Q
what are the 4 defensive mechanisms used by antibodies called?
A
neutralisation
agglutination
precipitation
complement protein activation
7
Q
what happens in secondary lymphoid organs & tissues?
A
foreign materials become trapped & destroyed
or
immune response generated
8
Q
what do granzymes do?
A
induce apoptosis
9
Q
what are 2 accessory structures of the physical barrier?
A
hairs (skin & nose)
cilia of the mucociliary escalator
10
Q
when does an autoimmune disease occur?
A
when the body’s immune defences target normal tissues
11
Q
what are 3 examples of pyrogens?
A
IL-1
interferons
bacterial toxins
12
Q
where does B cell maturation occur?
A
bone marrow
13
Q
what do NK cells destroy?
A
virus-infected cells
cancerous cells
14
Q
what are 4 examples of secondary lymphoid organs & tissues?
A
lymph nodes
spleen
appendix
tonsils
15
Q
what is the treatment for anaphylactic shock?
A
adrenaline (epinephrine)
16
Q
what does increased capillary permeability allow?
A
clotting factors, macrophages, neutrophils & complement proteins to enter damaged tissue
17
Q
where are lymph nodes located?
A
along lymphatic vessels
18
Q
what do interferons inhibit?
A
viral replication
19
Q
what do secondary lymphoid organs & tissues contain?
A
WBCs
20
Q
how many L of ISF enters the lymphatic capillaries to form lymph per day?
A
3
21
Q
are innate defences present at birth?
A
yes
22
Q
how can mild or moderate fevers be beneficial?
A
inhibit growth of some bacteria & viruses
increases cell metabolism - accelerates immune defences
23
Q
by taking up space how does normal flora prevent pathogen colonisation?
A
pathogens unable to attach to body cells/tissues
24
Q
what are cytokines & what do they do?
A
chemical messengers
recruit &/or activate WBCs
25
what are the 3 functions of lymph?
regulates ISF volume
maintains BV & BP
transports WBC & foreign materials to lymph nodes
26
what is complement activation (by antibodies)?
antibodies bind to antigen & activate complement proteins
27
what are 3 possible causes of lymphoedema?
tumours
surgery
parasitic infections
28
what does increased blood flow (by dilated arterioles) bring to the damaged area?
complement proteins
clotting factors
macrophages & neutrophils
29
what do perforins do?
create pores in the target cell membrane, allowing entry of granzymes
30
what does the lymphoid system protect the body from?
foreign materials & internal threats
31
adaptive defences are systemic, what does this mean?
not restricted to initial infection site
32
what are the 2 types of surface barriers?
physical
chemical
33
what is a systemic response to an allergen called?
anaphylactic shock
34
what does a primary immune response produce?
memory T & B cells
35
what produces interferons?
WBCs
virus-infected cells
36
what is a humoral immune response mediated by?
B cells
37
what is an antigen called in hypersensitivity?
allergen
38
what is the role of the cilia of the mucociliary escalator?
move foreign materials from the respiratory tract towards the throat
39
what does the humoral response produce during a secondary immune response?
large amounts of IgG
40
what do damaged cells release?
histamine & prostaglandins (inflammatory chemicals)
41
how does normal flora prevent pathogen colonisation?
consuming essential nutrients
taking up space
42
what 3 cells are involved in autoimmune diseases?
self-reactive cytotoxic T cells
self-reactive B cells
regulatory T cells
43
what are 2 examples of primary lymphoid organs?
red bone marrow
thymus
44
what is lymph?
excess ISF
white-milky protein containing fluid
45
what is immunocompetence?
the ability to recognise & bind 1 specific antigen
46
what is a primary immune response?
first time an antigen invades the body
47
what are 3 examples of cellular antigens?
cancerous cells
foreign cells
virus/bacteria/parasite infected cells
48
what does lymphoedema increase the risk of & why?
infection
pathogens can accumulate w/in body tissues
49
what 3 things does the release of histamine & prostaglandins cause?
dilation of arterioles
capillaries become leaky
attract macrophages & neutrophils
50
what does HIV stand for & what does it primarily infect & destroy?
human immunodeficiency virus
helper T cells
51
what do lymphatic capillaries contain?
flaplike minivalves
52
are adaptive defences present at birth?
no - acquired/develop throughout life
53
what are the 4 components of the lymphoid system?
lymphatic system
lymphoid organs & tissues
WBC
cytokines
54
what is this WBC?
neutrophil
55
what is a primary immune response & does it protect the body from illness?
small, slow, short-lived
no
56
what do pyrogens result in?
fever
57
what are cytokines produced & secreted by?
WBCs
58
what is this WBC?
eosinophil
59
what is neutralisation?
antibodies bind to specific sites on antigens to block their attachment to body cells
60
what is self-tolerance?
the ability to recognise "self-antigens" from "non-self-antigens"
61
what happens when a helper T cell is activated & what does it produce?
proliferates
antigen-specific effector & memory helper T cells
62
what are the 3 components of the lymphatic system?
lymphatic capillaries & vessels
lymph nodes
lymph
63
when do hypersensitivities occur?
body's immune defences respond to a harmless antigen (that is perceived as a threat)
64
what does increased blood flow (by dilated arterioles) cause the area to become?
red & warm
65
what does the dilation of arterioles increase?
blood flow
66
what are the 4 roles of complement proteins?
recruit macrophages & neutrophils
enhance phagocytosis by opsonisation
directly destroy cellular targets - MAC
enhance inflammatory response
67
what is an antigen?
molecule capable of inducing an immune response
68
what is immediate hypersensitivity?
acute, rapid allergic reaction
69
what is opsonisation?
complement proteins coat foreign material making it easier for phagocytes to identify & more palatable
70
what does gastric juice contain & how does it act as a chemical barrier?
hydrochloric acid & pepsin
destroy ingested foreign materials
71
what does a vaccine expose an individual to?
inactive or attenuated (weak) antigen
72
how does intact skin & mucous membranes protect the body against foreign materials?
epithelial cells form a formidable barrier
73
what are the 2 responses of an immune response?
cellular
humoral
74
what are 2 examples of soluble antigens?
bacterial toxins
venom
75
what do self-reactive B cells that differentiate into plasma cells secrete?
autoantibodies (self-reactive antibodies)
76
what are the 3 line's of defence (in order)?
1st - surface barriers
2nd - internal defences
3rd - immune response
77
what are pyrogens & what do they do?
group of proteins
reset body's hypothalamic thermostat & increase body temperature
78
what do primary lymphoid organs contain & what can they do?
stem cells
differentiate into various WBCs
79
what is precipitation?
antibodies clump together multiple soluble antigens to form large insoluble Ag-Ab complexes
80
what do lymph nodes do?
trap foreign materials = "filter lymph"
81
what is hypersensitivity mediated by?
allergen-specific IgE antibodies
82
what 6 things does the second line of defence involve?
macrophages
neutrophils
NK cells
interferons
complement proteins
pyrogens
inflammatory response
83
what is immunological memory?
the ability to remember antigens
84
what happens during an anaphylactic shock?
bronchioles constrict
systemic vasodilation
increased capillary permeability
--> decreased BP --> circulatory collapse --> death
85
what do interferons activate?
macrophages & NK cells
86
what is the aim of surface barriers?
prevent foreign materials from entering the body
87
where do lymphatic vessels carry lymph from & to?
peripheral tissues back to blood (venous circulation)
88
what is this WBC?
basophil
89
where does lymph transport WBC & foreign materials to?
lymph nodes
90
what unique surface receptor do B cells have?
membrane bound antibody receptor
91
what is agglutination?
antibodies clump together multiple cellular antigens or foreign particles to form large Ag-Ab complexes
92
what is this WBC?
lymphocyte
93
what does an allergen bind to & what does this trigger?
IgE on mast cells & basophils
release of histamine
94
what happens during a first allergen exposure?
plasma cells secrete IgE which binds to mast cells & basophils - no symptoms
95
are innate defences specific or non-specific?
non-specific
96
what is a cellular immune response mediated by?
cytotoxic T cells
97
what cytokine helps activate cytotoxic T cells & B cells?
IL-2
98
what are the 3 functions of the lymphatic system?
circulates body fluids
removes foreign materials from body fluids
transports WBC
99
what 4 ways do surface barriers prevent foreign materials from entering the body?
form a formidable barrier
trap & remove foreign materials
expel foreign materials
destroy foreign materials
100
what does the secretion of cytokines by effector helper T cells do?
activates cytotoxic T cells & B cells
("turns on" cellular & humoral immune responses)
101
what do effector cytotoxic T cells destroy & how?
cellular antigens
release perforins & granzymes
102
what are pathogens?
harmful or disease causing microorganisms
103
what do the flaplike minivalves of lymphatic capillaries permit the entry of?
ISF
WBC
foreign materials
104
what happens to Ag-Ab complexes?
phagocytosed
105
what are 3 disorders of immune function?
immunodeficiency diseases
autoimmune diseases
hypersensitivities
106
what do macrophages & neutrophils stimulate?
fibroblasts to repair damaged tissue
107
what does increased capillary permeability cause the area to do & become?
swells
painful
108
what does the presentation of antigens to T cells do?
activate them
109
what are 3 autoimmune diseases?
rheumatoid arthritis
type I diabetes
multiple sclerosis
110
what do activated cytotoxic T cells do & what do they produce?
proliferate
antigen-specific effector & memory cytotoxic T cells
111
which lines of defence belong to:
innate defences
adaptive defences
innate defences = 1st - surface barriers, 2nd - internal defences
adaptive defences = 3rd - immune response
112
how does mucus act as a chemical barrier?
traps foreign materials in respiratory & digestive tracts
113
what do lymph nodes contain?
WBCs
114
what antibodies are produced by a humoral primary immune response & which antibody is produced first?
IgM then IgG
115
what is the result of blocked lymphatic drainage?
lymphoedema
116
what do memory cells do?
"remember" antigens
launch a faster, stronger counterattack - secondary immune response
117
what happens if T & B cells fail to recognise self-antigens?
attack normal body cells/tissues
autoimmune disease
118
what is the role of hairs (skin & nose) as physical barriers?
trap foreign materials
119
what do clotting factors do & why?
form a clot
isolate area
120
what unique surface receptor do T cells have?
membrane bound T cell receptor (TcR)
121
what happens to ISF if lymphatic drainage is blocked?
accumulates in tissues causing swelling (oedema)
122
what does the second line of defence prevent?
foreign materials from spreading throughout the body
123
where does T cell maturation occur?
thymus
124
when does an immunodeficiency disease occur?
immune defences are compromised or absent & unable to mount an effective immune response
125
what do macrophages & neutrophils do?
phagocytose & destroy foreign materials via lysosomal enzymes
126
what is this WBC?
macrophage
127
where are WBCs found?
blood
lymph
lymphoid organs & tissues
128
how do NK cells destroy target cells?
release perforins & granzymes
129
what are the 3 categories of physical barriers?
intact skin & mucous membranes
accessory structures
normal flora
130
how does sweat, saliva & tears act as chemical barriers?
cleanse body surfaces
contain lysozyme - destroys bacteria
131
what 2 things can WBCs in lymph nodes do?
directly destroy foreign materials
activate immune response
132
what areas does normal flora colonise?
skin
upper respiratory tract
parts of the digestive, urinary & reproductive tracts
133
what is sebum & how does is act as a chemical barrier?
acidic skin secretion
inhibits pathogen growth & toxic to some bacteria
134
what do effector helper T cells secrete?
cytokines
135
when regulatory T cells fail to "turn off" the immune response & suppress self-reactive cells what does this lead to?
autoimmune diseases
136
what are the 2 aims of the innate defences?
prevent foreign materials from:
entering the body
spreading throughout the body
137
what are the 3 lymphocytes?
NK cells
T cells
B cells
138
what are 2 APCs & what do they do?
macrophages & dendritic cells
phagocytose & present antigens to T cells
139
what does AIDs stand for?
acquired immunodeficiency syndrome
140
how is a helper T cell activated?
TcR binds to a specific antigen presented by an APC
141
what are the 5 major classes of antibodies?
IgM
IgG
IgA
IgD
IgE
142
what are the 3 aims of the inflammatory response?
localise & contain foreign materials at an injury site
dispose of foreign materials & cellular debris
repair damaged tissue
143
what does SCID syndrome stand for & what does it involve?
severe combined immunodeficiency syndrome
no T & B cells
144
what do interferons stimulate uninfected host cells to do & what does this prevent?
produce antiviral proteins
viral replication
145
what do activated T cells do?
activate B cells
146
what do plasma cells secrete?
Ag-specific antibodies
147
what happens to self-reactive T or B cells?
destroyed
148
what are 4 chemical barriers?
*1 has 3 components
sweat, saliva & tears
sebum
mucus
gastric juice
149
what does the release of histamine cause during an allergic reaction?
bronchoconstriction
mucus production
vasodilation
increased blood vessel permeability
150
what does adrenaline result in as treatment for anaphylactic shock?
bronchioles dilate
vasoconstriction - increased BP
151
what do activated B cells do & produce?
proliferate
plasma cells & memory B cells
