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Flashcards in Immune system L2 Deck (78)
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1
Q

why do we need an immune system

A

protect against infection

crucial to human survival

2
Q

what classes of pathogen does the immune system protect against

A

bacteria
viruses
fungi
parasites (protozoa, worms)

3
Q

what diseases does bacteria casue

A

food poisoning

tuberculosis

4
Q

what diseases do viruses cause

A

small pox

AIDS

5
Q

what disease does fungi cause

A

thrush

ringworm

6
Q

what diseases do parasites cause

A

malaria

sleeping sickness

7
Q

what pathogens are the largest –> smallest

A
worms
protozoa
fungi
bacteria
viruses
8
Q

what is the microbiome

A

microbial communities of tissues (skin, oral mucosa, gastrointestinal tract)

9
Q

immune system and pathogenic vs commensals

A

Immune system must be able to recognise difference

whether they cause damage or not

10
Q

what do commensals cause on host

A

cause no damage to host, can perform important functions

can become pathogens if they are in the wrong location

11
Q

if the immune system has a diverse nature of pathogens what is the response

A

range of defence mechanisms

12
Q

if the immune system has a vast range of pathogens what is the response

A

vast range of antigen receptors

13
Q

if the immune system has a rapid growth of microbes what is the response

A

rapid inflammatory response

14
Q

if the immune system minimises damage to host what is the response

A

regulatory mechanisms

15
Q

why must the immune system respond quickly

A
  • no damage to host

- immune system must have regulatory systems to control response

16
Q

what is recognition in immune response to infection

A

locate and identify pathogen

17
Q

what is defence in immune response to infection

A

repel or destroy pathogen

18
Q

what are the cardinal features of immune system

A

specificity
memory - immune cells
self-discrimination – all different cells in body, what is self and what is not self

19
Q

what are the levels of defence against pathogens

A

physicalbarriers

then innate immune system adaptive immune system

20
Q

how do innate and adaptive immune responses link

A

feedback between the two

21
Q

what happens when the pathogen penetrates physical barriers

A

engaged by cells and soluble factors of innate immune system

22
Q

what does the skin and mucosal provide as a physical barrier

A

tough impenetrable barrier but when it is breached by physical damage (such as wounds or burns) it exposes soft tissue and renders them vulnerable to infection

23
Q

which barriers are stronger

A

skin

24
Q

which barrier are more vulnerable

A

mainly mucosal membranes

25
Q

what routes of entry can infect via mucosal surfaces

A

airway
GI tract
reproductive tract

26
Q

what routes of entry can infect via external epithelial surfaces

A

external surfaces
wounds and abrasions
insect bites

27
Q

what must pathogens be like to be transmitted via airway

A

light enough to be airbourne

28
Q

what are the two types of immune response

A

innate

adaptive

29
Q

where is the innate immunity

A

peripheral organs

30
Q

what does the innate immunity detect

A

infectiousagents

31
Q

what does innate immunity do

A
  • containment/elimination of infectious agent using non-specific mechanisms
  • alert the acquired immune system regarding the nature of the infection
32
Q

where is the adaptive immunity

A

lymphoid organs

then peripheral

33
Q

what does the adaptive immunity do

A

control/eliminate infectious agent using newly generated tools, specific for the infectious agent

34
Q

how does the innate immunity work

A

‘recognising non-self’
pathogens are foreign
presence of cell wall is foregin

35
Q

what is the innate immune response

A

cellular involvement

e.g. phagocytosis

36
Q

what are neutrophils

A

phagocytic cells, also classified as granulocytes as contain granules in cytoplasm

37
Q

what are the granules like in neutrophils

A

are very toxic to bacteria and fungi, and cause them to stop proliferating or die on contact

38
Q

what aremacrophages

A

efficient phagocytic cells

39
Q

what do macrophages do

A

ability to roam outside of the circulatory system is important, because it allows macrophages to hunt pathogens with less limits
macrophages can also release cytokines in order to signal and recruit other cells to an area with pathogens

40
Q

what are mast cells function

A

the activation of these cells by complement, which causes the mast cells to degranulate, and leads to the release of inflammatory mediators such as histimine

41
Q

what happens in the recognition process for innate immunity

A

bacterial cell surface induces cleavage and activation of complement
complement covalently bonds to bacterium, other attracts effector
complement receptor on effector cell binds to complement fragment on bacterium
effector cell engulfs bacterium kills it

42
Q

what happens in the innate immune recognition

A

pattern recognition receptors contain toll like receptors
TLRs, some on the surface, some inside
viruses quite often invade straight into cells, need substance inside cell to detect it to defend against
PRRs recognize pathogen associated molecular patterns (on bacteria surface)

43
Q

how many pattern recognition receptors are there

A

several receptors expressed by the same cell

44
Q

what is the structure of pattern recognition receptors

A

multiple domain structures

broad binding specificity

45
Q

where are the pattern recognition receptors present

A

plasma membrane, endosomes and cytosol

46
Q

what response is caused at pattern recognition receptors

A

Immediate response

47
Q

what is involved in adaptive immunity

A

T lymphocytes

B lymphocytes

48
Q

what do T lymphocytes express

A

T cell receptors

49
Q

what do T lymphocytes do

A

interact with other cells

can kill cells, or facilitate immune responses by other cells

50
Q

where are the T cells generated

A

thymus

51
Q

where are the B cells generated

A

bone marrow

52
Q

what cells are linked to the T lymphocytes

A

Killer T cells (CD8+), Helper T cells and regulatory T cells (CD4+)

53
Q

what do B lymphocytes do

A

make antibodies (immunoglobulins)-cell surface and secreted
Can improve the antibodies made over time
protection against extracellular pathogens & toxins

54
Q

how many specificity is there per receptor of cell

A

one specificity

55
Q

what happens when the B cell receptor antigen binds

A

resembles antibody attached to cell surface

specific ligand, mediates the activation of the B cell

56
Q

where are lymphocytes generated

A

primary lymphoid organs

57
Q

what is in the primary lymphoid organs

A

bone marrow

thymus

58
Q

what happens in secondary lymphoid organs

A

mature naïve lymphocytes are maintained and adaptive immune response initiated

59
Q

what is in the secondary lymphoid organs

A

lymph nodes, tonsils, spleen, Peyer’s patches, mucosa associate lymphoid tissue (MALT)

60
Q

what do lymphocytes do

A

circulate in the blood and lymph

61
Q

where are lymphocytes found

A

found in large numbers in lymphoid tissue or organs

62
Q

which cells are innate immunity

A

neutrophil
eosinophil
basophil
monocyte

63
Q

which cells are both innate and adaptive immunity

A

dendritic

64
Q

which cells are adaptive immunity

A

B cells

T cells

65
Q

how long is the innate response

A

rapid (hours)

66
Q

how long is the adaptive immunity response

A

slow (days to weeks)

67
Q

what is the innate immune response like

A

fixed

68
Q

what is the adaptive immune response like

A

variable

69
Q

what is the specificities of the innate immune response

A

limited number

70
Q

what is the specificities of the adaptive immune response

A

numerous, highly selective

71
Q

what is the innate immune response like during

A

constant

72
Q

what is the adaptive immune response like during

A

improve during response

73
Q

what are the stages of an immune response - innate (immediate 0-4hrs)

A

infection
recognition by non-specific effectors
remove infectious agent

74
Q

what are the stages of an immune response - early induced (early 4-96hrs)

A

infection
recognition by non-specific effectors
inflammation recruitment and effector cell activation
remove infectious agent

75
Q

what are the stages of an immune response - adaptive (late > 96hrs)

A
infection
transport of antigen to lymphoid organs
recognition by naive B an T cells
clonal expression and differentiation to effector cells
remove infectious agent
76
Q

why do vaccines work

A

due to immunological memory

77
Q

what does yersinia pseudotuberculosis cause

A

mimics acute appendicitis

78
Q

what does Yersinia pseudotuberculosis

do

A

interact with immune system is very different