32. Intro to the immune system 1 and 2 Flashcards

1
Q

what are the 2 types of overreactions of the immune system

A

autoimmunity - Type 1 Diabetes, rheumatoid arthritis, MS, IDB

Allergic reactions- eczema, hay fever, asthma

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

what are 2 types of immune under reaction

A

Cancer - HIV, EBV, HCV

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

name some ways a pathogen can enter the body

A

digestive system, respiratory system, urogenital system
skin damage

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

what is the physical barrier of infection

A

skin

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

what makes the skin a good barrier

A
  • Physical barrier - tightly packed, highly keratinized cells
  • Physiological factors
    • Low pH (5.5)
    • Low oxygen tension
  • Sebaceous glands – hydrophobic oils, lysozymes, ammonia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what does mucus line

A

all the body’s cavities that are in contact with the external environment

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

what antibody is in mucus

A

secretory IgA

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

what are the three barriers to infection

A

skin, mucus, commensal bacteria

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

define the innate immune response

A

Innate immunity is present continuously, it is a defence mechanism that is present from birth.
The same generic response occurs to many different microbial species.

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

define the acquired (adaptive) immune response

A

Acquired (adaptive) immunity is (usually) induced by the presence of ‘foreign’ or non-self-materials.
A unique response is generated to each individual pathogen

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

which out of innate and acquired has immunological memory and a lag time from exposure to response and is specific

A

adaptive/acquired

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

cytokines - interferons- are released from virally infected cells to signal neighbor cells. what does this cause

A

it destroys RNA and reduce protein synthesis
undergo apoptosis
activate immune cells such as NK cells

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

describe macrophages

A

phagocytose bacteria
release pro inflammatory mediators TNFa

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

describe phagocytosis

A
  1. PRRs on macrophages bind to PAMPs on pathogen, which signals the formation of the phagocytic cup
  2. Cup extends around the pathogen and pinches off – phagosome
  3. Phagosome fuses with lysosome – phagolysosome
  4. Pathogen killed and contents degraded
  5. Debris released into extracellular fluid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

macrophages express ………. and they release……….

A

MCH-II
TNFa

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

what do mast cells do

A

deal with pathogens too big for phagocytes

mast cells release histamine, tryptase, TNF, Chemokines, leukotrienes, prostoglandins

associated with allergy

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

describe neutrophils in innate immunology

A

Transendothelial migration is the recruitment of neutrophils to the site of infection during acute inflammation:

  1. slower blood flow, allowing neutrophils to undergo margination
    • Neutrophils travel close to endothelial cells instead of centre of the vessel
  2. Neutrophils can then encounter and bind to adhesion molecules expressed by the endothelial cells (e.g. selectins, ICAM-1)
  3. Neutrophils migrate across the endothelium via diapedesis
  4. Once in the tissues, the neutrophils travel to the exact site of injury via chemotaxis
  5. Neutrophils are then activated by PAMPs and pro-inflammatory mediators such as TNF⍺
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Neutrophils can then encounter and bind to adhesion molecules expressed by the endothelial cells such as

A

selectins, ICAM-1

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

. Neutrophils migrate across the endothelium. what is this process called

A

diapedesis

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

Once in the tissues, the neutrophils travel to the exact site of injury what is this process called

A

chemotaxis

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

Neutrophils are then activated by PAMPs and pro-inflammatory mediators such as

A

TNF⍺

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

what does TNFa stand for

A

Tumour Necrosis Factor alpha

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

what does PRR stand for

A

Pattern Recognition Receptors

24
Q

what does PAMPs stand for

A

Pathogen associated molecular patterns

25
what are the 3 ways neutrophils kill
phagocytosis, degranulation (release of anti-bacterial granules), NETS (net like structure that traps pathogens leading to phagocytosis)
26
what are the 3 modes of ingestion by neutrophils
Phagocytosis Endocytosis - molecules bound to membrane receptors are internalized pinocytosis - ingestion of fluid of surrounding cells
27
lysosomes contain what
hydrolytic enzymes
28
when the phacocytic cup pinches off it creates a
phagosome
29
what fuses with the phagosome
lysosome
30
when the phagosome and lysosome combine it creates a
phagolysosome
31
what are the 3 antigen presenting cells
dendrites, macrophages, B cells
32
what is pinocytosis
ingestion of fluid of surrounding cells
33
what are NK cells
Natural Killer Cells
34
what do NK cells release to kill by degranulation
perforin
35
NK cells respond to what class of presenting cells
MHC class I - virally infected and cancerous cells
36
what else do NK cells produce
IFNy
37
macrophages express its antigens through.....
MHC-II
38
dead and dying neutrophils produce what
pus
39
MHC- II can only be found on....
antigen presenting cells aka dendrites, macrophages and B cells
40
which cells present MHC-I
all nucleated cells in the body
41
Basophils granules contain what
histamine
42
eosinophils are associated with what
allergy
43
Basophils act as effector cells in what reaction
allergic reactions
44
what is the complement system
activated in response to inflammation and creates a chemical cascade of chemical reactions
45
where are the complement proteins produced
liver
46
what are the 3 pathways for the complement system
Classical Mannose Binding Lectin Alternative
47
take me through the complement system
1. C3 is cleaved as it is an inactive precurser 2. Cleaved into c3a and c3b. 3. Active c3b associates with another compliment system protein to produce C5 convertase 4. This causes cleavage of C5 into C5a and C5b 5. Active C5b produces a pore-forming channel which is inserted into the cell wall which causes Cell death. This is called MAC
48
what is the alternative pathway in the complement system
after C3 cleaved into C3a and C3b, C3b can then amplify the reaction via the alternative pathway, causing more C3 to cleave into C3a and C3b
49
what are C3a and C5a responsible for
acute inflammation (they are anaphylatoxins)
50
what is MAC
membrane attack complex
51
what is the classical complement system path initiated by
IgM and IgG/ CRP
52
dendrites are MCH-???? beacuse they are ...............
MHC-II beacuse they are antigen presenting
53
what activates complement via MBL pathway
mannose-binding lectin
54
what is opsonisation
when a pathogen is marked for phagocytosis by being bound by an antibody
55
what else does C3b also do besides become C5
opsonisation - leading to phagocytosis
56
IgG can act as an
opsinin
57
name some opsinins
1. C3b 2. C-reactive protein (CRP) 3. IgG / IgM antibodies