Immune System Flashcards
(128 cards)
1
Q
1st line of defence (innate defence)
A
Surface barriers such as skin and mucous membranes
2
Q
2nd line of defence (innate defence) is composed of internal defences such as
A
Internal defences such as phagocytes, natural killer cells, inflammation, anti microbial proteins, fever
3
Q
Combined 3rd line of defence (adaptive defences)
A
Humoral immunity such as B cells
Cellular immunity such as T cells
4
Q
Skin as an (almost) impenetrable barrier- what is it
A
Heavily keratinised epithelial barrier, immune cells in its layers
5
Q
Skin barrier- what does it secret on surface
A
Antimicrobial secretions
6
Q
Skin barrier- why is the Keratin important
A
Keratin is a fibrous protein which is acid, alkali and enzyme resistant
7
Q
Mucosal membranes line which parts of the body
A
Entry and exit points such as eyes, nose, mouth, lungs, gut, etc
8
Q
What do mucosal membranes do
A
They physically trap microorganisms with sticky mucous
9
Q
In nose how is mucous pushed towards the mouth to be swallowed
A
By cillia
10
Q
Mucin dissolves to do what
A
Dissolves in water to form sticky mucous traps
11
Q
Defensins are
A
Skin and mucous membranes
12
Q
Immune cell mobilisation step 1
A
Leukocytosis- Neutrophils enters blood from bone marrow
13
Q
Immune cell mobilisation step 2
A
Margination- Neutrophils cling to capillary walls
14
Q
Immune cell mobilisation step 3
A
Diapedesis- Neutrophils flatten and squeeze out of capillaries
15
Q
Immune cell mobilisation step 4
A
Chemotaxis- Neutrophils follow chemical trail
16
Q
Which immune response are lymphocytes a part of?
A
The adaptive immune response. Make up 25% of WBCs
17
Q
Which immune cell recognised foreign antigens
A
Lymphocytes
18
Q
B-cells develop in
A
Bone marrow. There is a plasma cell and memory cell
19
Q
T-cells develop in the ??? And there are 3 types
A
Thymus. There are T-helper cells, cytotoxic T cells and suppressor T cells
20
Q
Natural Killer cells develop in
A
Bone marrow and other immune tissues
21
Q
What don’t Natural Killer cells have?
A
No classical Antigen receptor
No memory capacity
22
Q
What is the third subclass of lymphocyte called
A
Natural killer cells
23
Q
What is the function of Natural Killer cells
A
Recognise abnormalities in infected cells or tumour cells as well as some microorganisms and destroy
24
Q
How do NK cells work/ how do they kill!
A
By signalling apoptosis (eg virus infected cells)
Causing pore formation via perforin
Firing proteases at cells
25
Antimicrobial proteins- what are Interferons (IFNs)
Small proteins released by virus infected cells that interfere with protein synthesis in other cells
26
Antimicrobial proteins- what are the three types of IFNs (think Greek alphabet)
Alpha, beta, gamma
27
Which IFNs inhibit viral replication and activate NK cells?
Alpha and beta
28
Which IFNs mobilises the immune system ?
Gamma from lymphocytes
29
What is the function of the complement system in Antimicrobial proteins? (Think immune defence types)
Enhances both the innate and adaptive immune defences
30
~20 different proteins in the blood produced by the liver which when activated form
Protein pores called membrane attack complexes- lysis
Coat pathogens in opsonins so phagocytes can bind
31
What can the complement system do to inflammation?
Enhance inflammation
32
the classical pathway is made of ??? that activates the ??? system
Antibodies (classical pathway) that activate the complement system
33
True or false, the complement system is a reactive cascade
True, each enzyme activated the next
34
How is the complement system restricted?
By both short activation times and specific inhibitors
35
Fever is what type of response
An innate
36
What is a fever caused by
WBCs and macrophages releasing pyrogens in response to foreign substances
37
Where and why do pyrogens cause thermostat
In hypothalamus to raise body temperature
38
What is the function of fever
Inhibit microbe growth, sequester iron and zinc within liver and spleen (less available for bacteria)
Increase metabolic rate of tissues to speed repair
39
What is febrile seizure
A common neurological disorder in infants and young children which alarmist always resolve spontaneously and almost never cause long term harm
40
What is cellular senescence
Ageing cells losing their ability to divide permanently
41
True or false: senescent cells are harmless
False. They release toxic and inflammatory byproducts
42
What is the 3rd line of defence against infection know as
Specific immunity or acquired immunity
43
Acquired immunity features three main response things (S.S.M)
Specific to a pathogen or foreign substance
Systemic: happens everywhere in body
Memory: for future encounters
44
Adaptive immune system: humoral immunity is what
Antibody mediated immunity created by B-lymphocytes
45
Which fluids does humoral immunity work through?
Through blood and lymphatic system
46
What does humoral immunity specialise in
Bacteria, toxins and some viruses
47
Adaptive immune system: cellular immunity what is it
Cell mediated immunity with T-lymphocytes
48
What does cellular immunity specialise in
Infected cells, parasites and cancer cells
49
An antigen is
Anything that can trigger an immune response. Most are large complex molecules with multiple possible binding sites
50
Antigens are immunogenic and stimulate ??? Multiplication
They stimulate lymphocytes to multiply
51
Antigens are reactive and react with activated ???
They react with activated lymphocytes. Small molecules that only cause reactions called Haptogens or incomplete antigens eg RAT tests for covid
52
Humoral immune system: Blood groups are determined by
By which Antigenic receptors on your RBCs and
by which antibodies against those receptors are in your plasma
53
Lymphocyte life cycle: B and T lymphocyte precursors originate in
Red bone marrow
54
Lymphocyte life cycle: precursors destined to be T cells migrate to
The thymus and mature there
55
Lymphocyte life cycle: precursors destined to be B cells mature in
Bone marrow.
56
Self tolerance of lymphocytes means what
Each lymphocyte must not attack self antigens. Failures of self tolerance can cause the body to attack itself
57
Immunocompetence of lymphocytes means what in terms of binding and recognising antigens?
Each lymphocyte must be able to recognise and bind to one antigen. It dies if it can’t. Many copies of this antigen receptor are in the surface of each lymphocyte
58
Clonal deletion occurs when
Cells responding to self antigens are told to apoptose
59
Antigen sequestering is what
Some self antigens are simply not exposed to the immune system
60
Privilege Tissue status is when some body tissues
Apoptose immune cells that would activate against them
61
Suppression by regulatory T-cells is when
Activated cells are suppressed throughout their life.
62
Clonal anergy is when
Cells are inactivated
63
Receptor editing is when B cells are given a second chance to
B cells are given a second chance to change receptor if stimulated by self antigens
64
B cells differentiate into
Memory B cells or
Plasma cells
65
IgM is a class of antibody that is
1st to be produced, clinically indicates current infection.
66
What are IgM antibodies good at
Agglutination and activating complement. They are pentameric but also exist as a monomer bound to B cells
67
What are IgA antibodies
Mostly secreted in saliva, sweat, intestines, breast milk.
They stop attachment of microbes to epithelium. Are dimeric but some monomer in blood
68
What are IgD antibodies bound to and act as
Bound to B cells surface, acts as antigen receptor
69
What are IgG antibodies
Most abundant type in blood, main antibody of late primary and secondary responses.
70
What are IgG antibodies good at
Fixing and activating complement. Have passive immunity via crossing placenta, shows past infections
71
IgE antibodies are secreted by
Secreted by plasma cells in skin and mucosa
72
IgE antibodies work against
Parasites
73
In allergies, IgE antibodies bind to
Mast cells and basophils tissue cause histamine and inflammatory chemical release
74
Primary antibody production from first exposure is small and slow or big and quick?
Small and slow
75
Secondary antibody production is
Faster and stronger due to memory cells already available
76
Active humoral antibody immunity is either ??? Acquired or ??? Acquired
Naturally acquired through contact with pathogen or
artificially acquired though vaccine
77
Passive humoral antibody immunity is acquired through either
Naturally acquired through mother to fetus or
Artificially acquired via injection of exogenous antibodies
78
Types of vaccines
- inactivated pathogen
Live but attenuated
- Parts of a pathogen
- Toxoid
- Viral vector
- mRNA
79
True or false: t lymphocytes can turn into effector or memory T cells
True
80
Memory T cells assist in
The quick response to secondary infections
81
Three types of effector T cells
Helper T cells
Cytotoxic T cells
Regulatory T cells
82
Helper T cells help activate and control
Activate B cells and other T cells and macrophages
Control and direct the adaptive immune response
83
Cytotoxic T cells are specific killers that directly
Destroy virus infected cells, fast multiplying bacteria, old cells and cancer forming cells. Similar to NKs but act against specific targets
84
Regulatory T cells help suppress
T cell activity once no longer needed
85
How do cytotoxic T cells know what cells to kill?
Via MHCs as all cells constantly display bits of their innards on their membrane like a passport for immune cells to survey
86
How does displaying MHCs cause cytotoxic T cells to attack
Potentially the cells have antigens in them, so it warns cytotoxic T cells if that cell is infected
87
MHC type 2 receptors are ??? and release ??? which ??? other immune cells
all immune cells. MHC class 2 releases signals to attack, activating other immune cells
88
second line of defence initial response is
inflammation
89
??? called lectins, also known as the ??? pathway is one of three ways to activate the ??? system
Proteins called lectins (Lectin pathway)
complement system
90
the complement system can be activated spontaneously by lack of ??? known as the ??? pathway
Spontaneously by lack of inhibitors (alternate pathway)
91
which immune cell type phagocytoses microbes to produce antigens on their cell surface and then present these antigens to lymphocytes to initiate adaptive immune response?
Dendritic cells
92
which immune cell type is an Antigen Presenting Cell?
Dendritic cells
93
opsonins are what type of protein?
complement protein aka antibody
94
Natural killer cells recognise when there is a lack of ??? Surface proteins and destroy these cells
Major histocompatibility complex
95
Signalling of cells for apoptosis is seen by ??? Cells which then destroy the cell
Natural Killer cells
96
How do interferons help by interfering with protein synthesis in other cells? By inducing the synthesis…
They induce the synthesis of protective proteins in the cell they have entered to protect against the virus.
97
What interferes with the replication of virus mRNA in neighbouring cells when released by infected cell?
Interferons- small proteins
98
Alpha and Beta interferons inhibit ??? Replication and activate NK cells
Viral replication
99
Gamma interferons mobilise the ??? System
Immune system
100
Membrane attack complexes are ??? That are produced by liver and are in the blood
Proteins
101
TRUE or FALSE: membrane attack complexes come together to form protein pores in the membrane of target cells and enhance inflammation
True
102
Each enzyme activated the next enzyme and thus restricted by both short activation times and specific inhibitors- what immune system is this?
The complement system
103
TRUE OR FALSE: Fever is a type of adaptive defence
False it is an innate defence
104
White blood cells and macrophages release ??? To induce fever
Pyrogens
105
interferons are small ??? released by infected cells
small proteins
106
what type of immunity is known as specific or acquired immunity, adaptive or innate?
adaptive immune
107
which immunity type works through blood and lymphatic system? humoral or cellular?
humoral
108
immunogenic antigens stimulate ??? to multiply
lymphocytes
109
antigens can react with activated ???
lymphocytes
110
TRUE or FALSE: antigens are usually large complex molecules with multiple binding sites known as antigenic determinants
TRUE
111
immunogenic antigen response is when ??? are stimulated to multiply by the presence of ???
lymphocytes, antigens
112
blood groups contain antigenic ??? and antibodies in plasma against particular receptors
receptors
113
autoimmune disorders occur when b-cells fail to recognise ???
self
114
TRUE or FALSE: in humoral immunity, Clonal Deletion is when B-cells responding to self antigens are ‘told’ to apoptose
TRUE
115
lymphocytes (B and T cells) are born in which immune tissue?
bone marrow
116
what does P.L.A.N stand for with the work of antibodies?
P: precipitation
L: lysis from complement system
A: agglutination
N: neutralisation
117
passive humoral antibody immunity is when antibodies are
antibodies are passed from mother to child
118
active humoral antibody immunity is when antibodies are acquired
acquired from contact with pathogen resulting in memory cells
119
artificial active humoral antibody immunity is from dead ???
dead or attenuated pathogens
120
artificial passive humoral antibody immunity is passed through what type of vaccine injection?
injection of exogenous antibodies
121
what cells display class 1 major histocompatibility complexes?
all cells that become infected except for red blood cells
122
Type 1 major histocompatibility complexes are recognised by
cytotoxic T cells and naive CD8 cells
123
Class/type 2 major histocompatibility complexes are displayed by which cells
antigen presenting cells such as dendritic cells, macrophages and B-cells
124
Class 2 MHCs are recognised by what cell
Helper T-cells
125
deficiency in responding to an attack can be genetic (primary) and ??? (secondary) immunodeficiency
acquired (secondary)
126
acute (immediate) hypersensitivity is mediated by which antibody? (MADGE)
antibody IgE
127
TRUE or FALSE: acute hypersensitivity occurs by IgE causing degranulation of mast cells & basophils
True
128
which two types of hypersensitivity is caused by antibodies
type 2 and 3
