Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Asthma > Immune Attack on Tissues: Hypersensitivity and Allergy > Flashcards

Immune Attack on Tissues: Hypersensitivity and Allergy Flashcards

1
Q

What are the potential results from detection of a foreign body?

A
  1. foreign material damaged -> immunity

2. self material damaged -> allergy/hypersensitivity

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

What is the potential result from detection of self as foreign?

A

self material damaged -> autoimmunity/hypersensitivity

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

What are the types of hypersensitivity?

A
  1. allergy (IgE)
  2. antibody sensitivity (IgM, IgG)
  3. immune complex sensitivity
  4. cell mediated sensitivity
    2-4 allergy and autoimmunity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is hypersensitivity?

A

exaggerated activated immune response which causes tissue damage

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

Type 1 hypersensitivity key components

A

ie. atopic allergy
mast cells - generate inflammatory response
allergens - harmless unless IgE antibodies recognise them
IgE

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

Examples of type 1 hypersensitivity

A

hayfever, allergic asthma, acute urticaria, eczma, food allergies, anaphylaxis

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

What happens in type 1 hypersensitivity?

A

IgE binds to IgE receptor on mast cell
allergen binds to at least 2 IgE antibodies (mast cell crosslinks)
mast cell activates and degranulates
physiological consequences: mediators released
in lungs: smooth muscle contraction
systemically/blood: increased vascular permeability and vasodilation

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

What is needed before type 1 hypersensitivity occurs?

A

priming of immune response, first exposure to allergen

allergic sensitisation

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

What occurs in the first exposure to an allergen?

A 
antigen is processed and presented on APC in MHC class 2
interacts with CD4 helper T cell (TH2)
cytokines produced (IL 4, 5, 10) - influence other cells in immune system
IL 4 and 13 cause class switching of B cell (IgM -> IgE antibodies)
IgE antibodies sit on mast cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of T helper cell promotes type 1 hypersensitivity?

A

TH2

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

How do TH2 cells promote type 1 hypersensitivity

A

produces cytokines: IL 4, 5, 10
10 - inhibits TH1 actions, co-stimulate mast cell growth
4 - class-switching B cells (IgM to IgE)
5 - stimulate eosinophils which have receptors for IgE, important in chronic response of type 1 response

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

What does it mean if someone produces high levels of IgE?

A

atopic
genetically predisposed to produce more
more likely to have atopic eczema

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

How is the structure of IgE differece to IgG and IgA?

A

IgE has an extra domain in the heavy chain whcih allows movement

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

Why do the majority of people have low levels of IgE?

A

very short half life of IgE

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

Why does IgE have a very short half life?

A

endocytosis of plasma - engulfment of plasma
IgG are protected when pH changes by binding to receptors
IgE engulfed and broken down

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

Inflammatory mediators released by mast cell

A

preformed granule mediators: histamine, heparin, tryptase - immediate
newly generated: arachidonic acid - LKT, PGDs, cytokines - longer term

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

Give the common allergens for systemic anaphylaxis

A

drugs, serum, venoms, peanuts

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

Give the route of entry for systemic anaphylaxis

A

intravenous either directly or following oral absorption into the blood

19
Q

Give the response due to systemic anaphylaxis

A 
edema 
increased vascular permeability
tracheal occlusion
circulatory collapse
death
20
Q

Give the common allergens for acute urticaria

A

insect bites

allergy testing

21
Q

Give the route of entry for acute urticaria

A

subcutaneous

22
Q

Give the response due to acute urticaria

A

local increase in blood flow and vascular permeability

23
Q

Give the common allergens for allergic rhinitis

A

pollens (ragweed, birch)

dust-mite faeces

24
Q

Give the response due to allergic rhinitis

A

edema and irritation of nasal mucosa

not far

25
Q

Give the response due to food allergy

A 
vomiting
diarrhea
pruritis
urticaria
anaphylaxis
26
Q

Why are there different responses to allergens?

A

depends on the route of entry

27
Q

Give the common allergens for asthma

A

danders (cat)
pollens
dust-mite faeces

28
Q

Give the response due to asthma

A

bronchial contriction
increased mucus production
airway inflammation
further than hayfever - lungs

29
Q

Give a test to see what someone is allergic to

A

Skin prick test
give 0.02 ml of allergen extrat interdermally into tissue
if allergic: immediate immune response (15-60 mins) swelling and redness
later: swelling increases due to further cellular recruitment

30
Q

If urticaria remains after allergen is removed what does this mean?

A

autoimmune and not allergy

31
Q

Examples of type 2 hypersensitivity allergy response

A

allergic hemolytic anemia
blood transfusion reactions
haemolytic disease of the newborn

32
Q

What happens in type 2 hypersensitivity allergy response?

A

IgG, IgA, IgM bind to neutrophils which cause tissue damage

33
Q

Describe what occurs in rhesus haemolytic disease of the newborn

A

RhD- mother
RhD+ antigen expressed on RBCs of fetus of 1st pregnancy
some left behind, mother produces antibody response against
subsequent pregnancy: anti Rh antibody crosses placenta and attacks RBCs of fetus (IgG can cross placenta)

34
Q

How is type 2 hypersensitivity exemplified by haemolytic anaemia?

A

autoantibodies produced against self-antigens on the surface of RBCs
bind and complement activated
RBC lysed/taken up by phagocytosis

35
Q

Examples of type 3 hypersensitivity response

A

dermatitis
herpetiformis
allergic alveolitis

36
Q

What happens in type 3 hypersensitivity response

A

IgG IgA and IgM
immune complex sensitivity - immune system overrun by large number of complexes and not cleared
Deposited in tissue where damage occurs

37
Q

Allergic alveolitis

A

exposure to allergen (fungal spores inhalation)
immune response
immune complexes not cleared and deposited in lungs
damage to lungs and difficulty breathing
no wheezing - SoB (inability for gas exchange)

38
Q

Examples of type 4 hypersensitivity

A

contact dermatitis
acute graft rejection
(TB, leprosy)

39
Q

What is type 4 hypersensitivity different to the others?

A

driven by cells - cell-mediated

40
Q

What happens in type 4 hypersensitivity response?

A

APC presents to T helper cell, helping T killer cell and macrophages
T helper cell continuously produces cytokines, chronically stimulating macrophages
fusion of macrohpages into epitheloid cells
these fuse to multinucleated giant cells which cause the tissue damage

41
Q

Contact dermatitis

A

metal (nickel, chromate) or plant products (poison ivy)

42
Q

Pulmonary tuberculosis

A

type 4
lungs - activated macriphages in lungs trying to clear infection chronically stimulated
extensive fibrosis, lesions, difficulty breathing

43
Q

Leprosy

A

type of leprosy depends on type of immune response

cell-mediated (type 4) - tuberculus leprosy

Asthma (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions