Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

IMS > Immunology > Flashcards

Immunology Flashcards

(83 cards)

Start Studying
1
Q

What is the immune system?

A

A very complex group of many molecules, cells, tissues and organs that provide protection from microbes, tumour cells or foreign material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is an antigen?

A

Any substance that when recognised by the immune system will trigger an immune response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Label this

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is an antibody?

A

A specific protein made in response to an antigen

Produced by B cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What do neutrophils do?

A

They rapidly enter infected tissues in large numbers (first line and non-specific)
-release toxic chemicals
-release chemicals to attract other immune cells
-phagocytose organisms
-create extracellular traps using DNA

Especially useful in bacteria/ fungal infections
Form pus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are basophils/mast cells?

A

Both release histamine (causes vasodilation)
This helps in the defense against multicellular parasites
Can cause tissue damage in allergy

Multicellular parasites = helminths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are eosinophils?

A

Contain red granules containing toxic proteins and free radicals
These help in the defence against multicellular parasites
Can cause tissue damage in allergy

Multicellular parasites = helminths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are dendritic cells?

A

Located in tissues that are common points for initial infection (skin/lungs/GI tract)
Main role is as an APC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are monocytes/macrophages?

A

Role = phagocytosis/APC/Recruit other immune cells

Monocytes are found circuating in the blood
Macrophages are found in tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are natural killer cells?

A

Release perforins and granzymes
Trigger apoptosis in infected host cells
Trigger apoptosis in cancerous cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the key immunological sites?

A

Bone marrow
Thymus
Lymph nodes
Spleen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Label these immunological sites

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the role of the bone marrow as an immunological site?

A

Site of production of white/red blood cells and platelets
Also site of B cell maturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the role of the thymus as an immunological site?

A

Site of T cell maturation
Gland behind the sternum
Larger in children

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the role of lymph nodes as immunological sites?

A

Found throughout body (neck, armpit, groin)
Connected via channel of lymphatic vessels
Act as sieves to filter out any infection/cancer from lymph fluid
APCs in lymph fluid can meet many naive B and T cells in a lymph node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the role of the spleen as an immunological site?

A

Made up of white and red pulp
White pulp acts like a big lymph node
Red pulp filters out old red blood cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the difference between innate and adaptive immunity?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the physical barriers of innate immunity?

A

Intact skin & mucous membranes
Mucus and cilia
Tears and eyelashes
Sweat and body hair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the chemical mediators of innate immunity?

A

Lysozyme
Interferon
Complement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What immune cells are part of innate immunity?

A

Macrophages
Neutrophils
Natural killer cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the two types of adaptive immunity?

A

Humoral (B-cell)
Cell mediated (T-cell)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the difference in passive and active immunity?

A

Passive - you receive antibodies somebody else has made (naturally or artificially)
Active - you make your own antibodies
Passive gives short term protection
Active gives long term immunity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the effectors of the complement cascade?

A

MAC (membrane attack complex)
Anaphylatoxins
Opsonisation (priming of pathogens for phagocytosis)
Neutrophils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are naive B cells?

A

Circulating B cells which when activated, initiate the germinal centre response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are Memory B cells?
Dormant B cells that arise from B cell differentiation and initiate a stronger more rapid antibody response
26
What are plasma cells?
Terminally differentiated B cells which contain abundant antibodies
27
What are cytotoxic T cells?
T cells which express CDB and recognise antigens associated with MHC class 1 molecules They are capable of destroying virally infected or allogeneic cells
28
Describe the structure of a lymph node
Insert picture
29
What are the three steps of the innate immune system?
1. Complement activation 2. Phagocytosis by macrophages and neutrophils 3. Natural Killer cells
30
What are the three activation pathways of the complement cascade?
Classical Lectose or mannose-binding Alternative
31
Please could you talk me through the steps of the classical pathway
32
What kind of protein are many of the complement factors?
Serine proteases
33
Please could you talk me through the steps of the lectin pathway
Mannose-binding lectin binds to mannose (sugar found on surface of pathogens) MBL binds MASP 1 & 2 which activate C2 and C4 Rest of pathway identical to classical pathway
34
Please could you talk me through the steps of the alternative pathway
Low rate auto activation of C3 Auto-actiivated C3b binds factor B and properdin on pathogen surface which activates more C3 and activates C5 ## Footnote Rest of the pathway the same as classical (C6-9)
35
Which peptides in the complement pathway are anaphylatoxins?
C3a, C4a, C5a
36
What do anaphylatoxins do?
Trigger degranulation of endothelial cells, mast cells and phagocytes Enhance vascular permeability C3a and C5a are chemoattractants for neutrophils
37
Explain the process of opsomisation by C3b
C3b binds pathogens C3b is cleaved to iC3b Macrophages have receptors for iC3b which facilitates phagocytosis
38
What cells are involved in the cellular response?
Neutrophils Monocytes Natural Killer cells
39
What immune cells are capable of phagocytosis?
Macrophages Dendritic cells Neutrophils
40
What are the steps in phagocytosis?
1. phagocyte sticks to microbe 2. ingestion of microbe by phagocyte 3. formation of phagosome 4. fusion of phagosome with lysosome 5. digestion of ingested microbe by enzymes 6. formation of residual body containing indigestible material 7. discharge of waste materials
41
Where are macrophages located and what do they do?
Loacted in the skin, lungs, intestines First defence against pathogens
42
What are the three activation states of macrophages?
resting, primed, hyper-active
43
What do resting macrophages do?
- collect tissue debris - eliminates apoptotic cells - low major histocompatibility complex class 2 expression
44
What do primed macrophages do?
Primed by interferon gamma produced by natural killer cells and helper t cells Increased expression of MHC 2 Increasingly phagocytotic
45
What do hyperactive macrophages do?
- stimulated with things produced by gram negative bacteria - stop proliferating, become larger and very phagocytotic - produce cytokines
46
Are neutrophils short or long lived?
Short (around 5 days)
47
How do natural killer cells induce apoptosis of infected cells?
They release cytotoxic granules containing perforin and granzyme B (suicide enzyme) Fas binds Fas ligand on target cell Saves healthy host cells by recognising MHC-1
48
What are Helper T cells?
T cells which express CD4 and recognise antigens associated with MHC class 2 molecules
49
How are B cells activated?
Antigen binds to B cell receptors B cells becomes APC Th2 cell recognises APC Clonal expansion leading to proliferation into plasma and memory b cells
50
Explain the germinal centre response
B cells proliferate by clonal expansion in the lymph nodes in the “dark zone” There is also class switching and hypermutation
51
What is VDJ recombination?
A process that takes place during B cell development which allows them to generate a diverse range of receptors (on the variable section of an antibody)
52
Whats the difference between IgG, IgM, IgA, IgD, IgE?
They are all different types of antibodies IgG is the most abundant IgM is the first antibody response made (doesn't need T cells) (others not very relevant)
53
What is the difference in antibody production in the primary and secondary immune response?
Primary response - mostly IgM produced as quick but less specific Secondary response - mostly IgG produced due to memory cells, highly specific and effective
54
Which MHC class am I describing? - found on all nucleated cells and platelets - bound by CD8 on cytotoxic T cells - displays peptide fragmentss of proteins from within the cell
MHC class 1
55
Which MHC class am I describing? - Found on B cells, macrophages, monocytes, antigen presenting cells and some T cells - bound by CD4 molecules on helper T cells - displays antigens derived from extracellular proteins whcih have been aquired through phagocytosis
MHC class 2
56
What is the difference in structure of MHC class 1 and 2 molecules?
MHC class 1 is made of alpha chains 1,2,3 and beta 2 microglobulin MHC class 2 is made of chains alpha 1 and beta 1
57
Define the term tolerance
A specific immune non-reactivity against certain antigens ## Footnote Clonal deletion - Naive B and T cells that have receptors to self antigens are destoryed before they finish maturing
58
Define the term anergy
When the immune system is unable to do a normal immune response against a specific antigen ## Footnote B and T cells become "frozen" and are unable to activate
59
What is hypersensitivity?
**Over-reaction** of the immune response causing tissue damage
60
What is the difference between allergy and autoimmunity?
Autoimmunity is hypersensitvity reactions agaisnt self antigens but allergy is against exogenous antigens
61
What is an immunodeficiency?
Absent or defective immune response
62
What is the mechanism of type I hypersensitivity?
Exposure to allergen Allergen binds to IgE on mast cells IgE cross linking Triggers degranulation Releases histamine, eosinophil/neutrophil chemotactic agent, proteases
63
In type 1 hypersensitivity what is the effect of the release of histamine, eosinophil/neutrophil chemotactic agent and proteases?
Histamine - vasodilation Eosinophil/neutrophil chemotactic agent - increased inflammatory cells Proteases - tissue damage
64
What are some examples of Type I hypersensitivity (IgE mediated) ?
Ezecma, asthma, hay fever, anaphylaxis
65
What is the mechanism of type II sensitivity?
Antibodies from our own immune system (IgG or IgM) bind to target antigen on cell surface Triggers one of 3 mechanisms - cytotoxic T cell binds to antibody which releases granzymes and triggers apoptosis - activates complement pathway - antigen is a cell surface receptor so the antibody blocks the normal receptor altering the cell function
66
What are some examples of Type II sensitivity?
Graves disease Blood transfusion reactions
67
What is the mechanism of Type III hypersensitivity?
Increased antibody production in response to antigen Antibodies enter the blood and bind to soluble antigens Immune complexes form Immune complexes get lodged in the basement membrane of blood vessels Activates complement cascade
68
What are some examples of Type III sensitivity?
Lupus Rheumatoid arthritis
69
What is the mechanism of type IV (delayed) hypersensitivity?
*Sensitisation* - exposure to antigen - engulfed by APC - antigen presented to naive CD4 T cells - naive CD4 cell matures to a TH1 cell *Once sensitised* - Repeat exposure to antigen - Antigen binds to TH1 cell - cytokines releases - macrophages activated - cytotoxic t cells activated
70
What are some examples of Type IV (delayed) hypersensitivity?
Coeliac disease Type 1 diabetes
71
Why do autoimmune diseases arise?
Due to type II/III/IV hypersensitivity reactions against self antigens
72
What are the two types of tolerance and explain the difference
**Central **- in bone marrow/thymus when self lymphocye is maturing **Peripheral** - if self lymphocyte escapes into circulation
73
Is there a specific group where autoimmune diseases are more common?
Yes - younger women
74
How are autoimmune diseases commonly treated?
With immunosupression often using steroids
75
What are some common examples of autoimmune diseases?
Lupus Type 1 diabetes mellitus Graves disease
76
What causes allergy?
Type I hypersensitivity reactions against certain exogenous antigens
77
Which conditions make up the atopic triad?
Asthma Eczema Hay fever
78
What are three examples of primary (genetic) immunodeficiency?
Di George syndrome SCID (severe combined immune deficiency) CVID (combined variable immune deficiency)
79
What are three examples of secondary (acquired) immunodeficiency?
Malnutrition Drugs HIV/AIDS
80
Why does HIV/AIDS mean you can acquire immunodeficiency?
HIV infects CD4 + T helper cells Takes over T cell to enable viral replication T cell function falls Increased risk of opportunistic infections
81
What different types of vaccines are there?
Administering… - the whole microbe (inactivated/killed) - part of the microbe - genetic material of the microbe
82
What classes of HLAs do we have to try get as similar as possible for organ transplantation?
A, B, DR
83
What determines which HLAs we have?
Inherited from parents, three from mother and three from father Expressed in a co-dominant manner So we have 6 markers

IMS (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions