Foundations in Immunology Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Whats a pathogen?

A

Any microorganism that causes harm

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

What are physical barriers to pathogens?

A

Skin

Reproduction, respiratory and digestive tracks

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

Describe the innate immune system…

A

Non-specific
First to come into play
Will produce the same response time and again – no memory

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

Describe the adaptive immune system…

A

Highly specific
Involves antibody Production
Has immunological memory

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

Give an example of an innate response.

A

Splinter enters foot
Area around splinter gets red and swollen
Macrophages flood area

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

Where Do Macrophages Come From?

A

Bone Marrow

Monocytes differentiate into them

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

How to macrophages work?

A

Mø give off chemicals that restrict blood flow away from site of injury (redness)

Contraction of endothelial cells (swelling)

Produce Cytokines to alert other cells to the ‘danger’ and induce them to travel to the site of injury

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

What is the main role of the immune system and what does it employ?

A

Bodies 1st line of defense

Uses physical barriers - tight junctions between epithelum and mucous membranes

Uses phagocytic cells like macrophages and neutrophils

Uses soluble factors

  • Growth and Enzyme inhibitors
  • Lysins
  • Complement proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe phagocytosis…

A

Phagocytosis is triggered when the phagocyte recognises a foreign cell.

It is the internalization of foreign matter by cells into cytoplasmic vesicles. Once inside, the matter is digested by lysosomes, which contain enzymes

This also kills the phagocytic cell that did the ingesting.

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

What are the 3 activation pathways of the complement system?

A

Classical
Alternative
Lectin

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

Briefly describe the complement system.

A

The complement system consists of about 20 individual proteins which act together in an enzyme cascade to form a membrane attack complex

This makes a hole in the pathogen (bacterium) which disrupts the ability of the pathogen to maintain homeostasis and it dies.

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

What do all 3 pathways always end up with?

A

C5 convertase

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

What two pathways are effector mechanisms of the innate immune system?

A

Alternative and Lectin

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

What pathway is an effector mechanism of the adaptive immune system?

A

Classical

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

What happens with the C5 convertase?

A

It cleaves C5, which goes on to comine with C6, C7, C8 and C9 to form a MAC.

C5-8 forms the stalk and C9 forms the pore which causes cell cysis - poking hole in the cell.

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

What does the complement system achieve?

A

Opsonisation of invaders

C3a and C5a (bits that were cleaved) act as chemoattractants

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

Functions of the complement system?

A

Lysis of microbes
Promotes phagocytosis of microbes
Stimulates inflammation - activating mast cells and neutrophils
Also stimulate activation of B Cells and Ab production

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

What stops NK cells targeting our own cells?

A

Our cells have MHC class 1 proteins which signal to it that its our cells

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

Whats a cytokine?

A

Chemicals used by cells to communicate with other cells

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

Function of the lymphatic system?

A

Drainage of tissue
Absorption and transport of fatty acids
Immunity

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

Differences between lymphatic and blood vessels?

A

Lymphatic vessels are blind ended cells

Lymph vessels only carry fluid away from tissues unlike blood

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

What are the 3 phases of immune defence?

A

Recognition of danger
Production of specific weapons
Transport of weapons to site of attack

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

Where are blood cells produced and what type of organs are they?

A

Bone marrow and thymus

Primary lymphoid organs

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

What is hematopoiesis?

A

Formation and activation of blood cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Function of the thymus?

A

T-cell education

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Function of secondary lymphoid organs?

A

Site of lymphocyte activation by antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What 2 areas is the spleen divided into?

A

Red and white pulp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Function of spleen?

A

Filtration of blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What separates red and white pulp?

A

Marginal zone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is a high endothelial venule?

A

Simple columnar cells line venules,

They are slightly looser than normal venules, which allows fluid and lymphocytes to leak out of the blood vessels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What two zones are lymph nodes separated into?

A

B and T zones

32
Q

What effect does B cells have on T cells?

A

Cause B cells to make antibodies

33
Q

What are peyers patches?

A

Patches of smooth cells embedded in villi covered cells

34
Q

What does MALT stand for and what is it an example of?

A

Mucosal Associated Lymphoid Tissue - a peyers patch

35
Q

What covers peyers patches?

A

M cells

36
Q

Difference between adaptive and innate immune systems?

A

Adaptive is very specific and has immunological memory

37
Q

How does the adaptive immune system display a much larger response to an antigen in repeated exposure?

A

Presence of memory cells allow a much quicker and stronger response after primary exposure

38
Q

What are the differences between active and passive immunity?

A

Active immunity - conferred by a host response to a microbe or a microbial antigen

Passive immunity - conferred by adoptive transfer of antibodies or T lymphocytes specific for the microbe

Active immunity is the only one that generates immunological memory

39
Q

Why does passive immunity not have memory?

A

Because it isn’t your own B cells creating the response

40
Q

Where are B cells made?

A

Bone marrow

41
Q

What is the antigen receptor for a B cell

A

Surface immunoglobulin

42
Q

Why is it more important to tolerize T cells than B cells?

A

B cells cannot make antibodies in response to most antigens without the help of T cells

43
Q

What part of the pathogen are antibodies specific to?

A

The epitope

44
Q

What induces B cells to multiply?

A

Recognition of a specific epitope on a specific antigen on a specific pathogen

45
Q

What 2 chains are antibodies separated into?

A

Light and Heavy chain

46
Q

What modification is made to antibodies after B cells multiply and produce them?

A

The antibodies will have a much higher affinity for the epitope being targeted

47
Q

What chain does the antibody bind to?

A

Light chain

48
Q

What chain does the cell bind to?

A

heavy chain

49
Q

What do the heavy chains define?

A

The classes of immunoglobulin

50
Q

What are the classes of antibody?

A
  1. IGM
  2. IGD
  3. IGA
  4. IGE
  5. IGG
51
Q

Function of IGM?

A

Fixes compliment and oponization

52
Q

Function of IGG?

A

Good opsonizer

53
Q

Function of IGA

A

Protects mucosal surfaces, resistant to stomach acid

54
Q

Function of IGE?

A

Defends against parasites, cause anaphylactic shock and allergies

55
Q

What causes antibodies to be flexible?

A

Presence of a hinge between the light and heavy chains

56
Q

Why does antigen bound IGM display good complement binding?

A

Binding to epitope causes a conformational change that allows c1 protein to bind to IgM

57
Q

What actually is opsonisation?

A

The process of “tagging” a pathogen which causes fc receptors to “stick up” which causes the pathogen to be more susceptible to phagocytic action

58
Q

Why is it that mast cells can cause allergic reactions?

A

When mast cells encounter a pathogen they dump all of their contents onto the pathogen to neutralise it, some of these contents can cause an allergic reaction in the host

59
Q

What are the different ways to activate a B cell?

A

T cell dependent and T cell independent complement activation

60
Q

Describe how T-cell dependent activation works.

A

Signal from a clustered BCR (a surface IGM) along with a signal from a T cell in which a protein on the surface of a T cell recognises the same antigen as the B cell and then binds to a receptor on the B cell

61
Q

Where are T cells educated?

A

Thymus

62
Q

What is the cell surface receptor in a T cell called

A

T cell receptor

63
Q

What conditions have to be met in order for a T cell receptor to recognise antigens?

A

Has to be bound to a MHC protein

64
Q

What 2 classes of T cells are there?

A

Helper CD4+

Cytotoxic CD8+

65
Q

What types of antigens can T cells recognise?

A

ANY protein peptide that a pathogen may have due to association with MHC

66
Q

What is it important for all lymphocytes to learn to do with regard to “self”

A

Do not recognise the self antigen

67
Q

What happens to T cells that are unable to interact with MHC molecules or cannot distinguish self from non self

A

Death by apoptosis

68
Q

What determines what type of T cell thymocytes develop into?

A

Whether it binds to MHC 1 (cytotoxic) or MHC 2 (helper)

69
Q

Purpose of MHC 1?

A

Presents virally induced peptides to CD8+ T cells and trigger cytotoxic response

70
Q

Purpose of MHC 2

A

Presents exogenously produced Ag to CD4+ T cells and activate macrophages and B cells

71
Q

where is MHC 2 found

A

On antigen presenting cells

72
Q

What deciees which T cell a naive T cell turns into after MHC peptide recognition?

A

A range of different chemicals acting on the T cells

73
Q

Can helper T cells destroy pathogens?

A

No

74
Q

What do cytotoxic T cells release once exposed to infected/dysfunctional somatic cells?

A

Perforin, which forms pores in the target cell, also releases granzyme B - induces apoptosis

75
Q

How can T memory cells be formed?

A

Can arise from fully differentiated cells or from partially differentiated cells.