Brainscape's Knowledge GenomeTM

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


See full index

Physiology > Hypersensitivity > Flashcards

Hypersensitivity Flashcards

1
Q

what is a hypersensitivity reaction?

A

a condition in which the normally protective immune system has a harmful effect on the body by excessive or inappropriate immune response

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

Allergy

A

abnormal immunological response to otherwise harmless environmental stimulus
e.g. food, pollen, animal and dander

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

Autoimmune disease

A

abnormal immunological response directed against an antigen within the body

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

what are the stages of a hypersensitivity reaction?

A

sensitisation

effect

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

what is sensitisation?

A

initial asymptomatic contact with an antigen

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

what is effect?

A

harmful immune response following sensitisation and subsequent antigen contact

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

what are the types of hypersensitivity reaction?

A

1-4
1-3 = antibody mediated
4 = cell mediated

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

type 1 hypersensitivity

A

allergic or immediate
onset within minutes
develop IgE antibodies in response to harmless antigens
can be localised - allergic rhinitis and asthma
can be systemic - anaphylaxis
exposure by ingestion, inhalation, injection or direct contact

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

pathogenesis of type 1 hypersensitivity

A

contact with antigen
IgE formed as a result
coats mast cells and basophils - next time your body encounters the allergen it results in an IgE-mediated reaction by preformed IgE antibodies
Free allergen binds to 2 adjacent IgE antibodes - crosslinking
causes degranulation of cells which causes release of histamine and other mediators - prostaglandins, platelet-activating factor, leukotrienes
has varying effects on all these to cause the symptoms associated with allergy/ atopy

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

what do vasoactive amines effect?

A 
smooth muscle
blood vessel
mucous gland
platelets
sensory nerve endings
eosinophils
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what do vasoactive amines do to smooth muscle?

A

bronchospasm, abdominal cramping, rhinitis, hypovolemia and hypoxia

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

what do vasoactive amines do to blood vessels?

A

cause vasodilation and leaky capillaries
extravasation of capillary blood - causing erythema
fluid shift into the interstitial space - oedema and pulmonary oedema

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

what do vasoactive amines due to eosinophils?

A

eosinophilia -

eosinophil and neutrophil chemotaxis induced by basophil and mast cell mediators

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

what are some common allergies?

A 
drugs 
foods 
Insect venom
Inhaled or environmental allergens
blood transfusion products
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

examples of type 1 hypersensitivity

A

anaphylaxis

allergies

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

is anaphylaxis humoral or cell mediated?

A

humoral

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

how to treat anaphylaxis?

A 
adrenaline intramuscularly to lateral thigh 
airway
resuscitate
anaesthetics 
cardiac arrest call 
antihistamines slow to work
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

type 2 hypersensitivity reaction

A

cytotoxic
onset within minutes or few hours
involves IgG and IgM antibodies
5 mechanisms by which these antibodies can cause disease

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

mechanism 1 for type 2 hypersensitivity

A

Antigen-antibody complex on host tissue
activates complement cascade which creates a membrane attack complex. Inserts itself into the membrane of the cell it attacks. Allows fluid to rush into cell - swells and bursts cell - cell lysis

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

mechanism 2 for type 2 hypersensitivity

A

complement activate complement binds to Fc portion of the antibody. Some of the cascade become cleaved and chemotaxic - attracts neutrophils. Neutrophils undergo degranulation and release enzymes which generate oxygen radicals which cause cytotoxic damage to cell

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

mechanism 3 for type 2 hypersensitivity

A

activation of complement cascade causing opsonisation and phagocytosis. The phagocytes engulf cells in the spleen

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

mechanism 4 for type 2 hypersensitivity

A

antigen-antibody complex recognised by NKs, they bind to the antibody. NKs release perforins forming pores in the cells. Granzymes and granulysin enter the cell and cause apoptosis

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

mechanism 5 for type 2 hypersensitivity

A

antibody mediated cellular dysfunction, antigen-antibody complex blocks normal receptor activator from getting to receptor e.g. myasthenia or simulates a signalling molecule and over activate a receptor e.g. graves disease

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

type 2 hypersensitivities examples

A 
autoimmune haemolytic anemia
good pasture syndrome
drug-induced neutropenia
immune thrombocytopenia
graves disease
myasthenia gravis
bullous pemphigoid
pemphigus vulgaris
rheumatic fever
acite hemolytic transfusion reaction 
hemolytic disease of the fetus and newborn
hyperacute transplant rejection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

distribution of type 2 hypersensitivity diseases

A

limited to a particular tissue type

26
Q

diagnosis of type 2 hypersensitivity

A

autoantibody testing and coombs test

27
Q

coombs test

A

used to detect antibodies that act against the surface of cells

28
Q

hemolytic anemia

A

form of anemia due to hemolysis, the abnormal breakdown of red blood cells in the blood vessels or spleen
opsonisation and phagocytosis of erythrocytes

29
Q

Good pasture syndrome

A

rare, autoimmune disease which antibodies attack the basement membrane in lungs and kidneys, leading to bleeding from the lungs and kidney failure
Complement and Fc receptor mediated inflammation
Nephritis and lung hemorrhage

30
Q

Autoimmune thrombocytopenic purpura

A

opsonisation and phagocytosis of platelets causing bleeding

31
Q

Pemphigus vulgaris

A

antibody-mediated activation of proteases, disruption of intracellular adhesions . Skin blisters

32
Q

Vasculitis

A

Neutrophil degranulation and inflammation. Vasculitis

33
Q

Acute rheumatic fever

A

inflammation and macrophage activation. Myocarditis and arthritis

34
Q

Myasthenia gravis

A

antibody inhibits acetylcholine binding and down modulates receptors
muscle weakness and paralysis

35
Q

Graves disease

A

Antibody mediated stimulation of TSH receptors causing hyperthyroidism

36
Q

Pernicious anemia

A

neutralisation of intrinsic factor and decreased absorption of vitamin B12. Abnormal erythropoiesis, anemia, neurologic symptoms

37
Q

is graves disease local or systemic?

A

local as it only effects thyroid tissue but shows systemic effects because of role of thyroid

38
Q

type 3 hypersensitivity

A

immune complex hypersensitivity
onset between 2 and 6 hours
can be local or systemic
antigens causing it can be exogenous or endogenous

39
Q

pathogenesis of type 3 hypersensitivity

A

formation of antigen antibody immune complexes with slight antigen excess
complement is activated by the immune complexes via the classical pathway . This causes basophils to degranulate, releasing mediators that increase vascular permeability.
complexes circulate and are trapped in the basement membrane of small blood vessels
activated complement attracts neutrophils and causes them to degranulate
neutrophils release enzymes responsible for much of the tissue damage

40
Q

what is an immune complex?

A

antigen-antibody complex formed when the antigen is found in the blood stream, so is soluble .

41
Q

clinical examples of type 3 hypersensitivities

A 
systemic lupus erythematosus
drug-induced hypersensitivity vasculitis
poststreptococcal glomerulonephritis
polyarteritis nodosa
wegeners granulomatosis
arthus reaction
hypersensitivity pneumonitis - Farmer's/ pigeon fanciers lung
serum sickness
serum sickness-like reaction
42
Q

wegners granulomatosis

A

rare condition in which blood vessels become inflamed, affecting the ears, nose, sinuses, kidneys and lungs

43
Q

arthus reaction

A

post tetanus vaccination

44
Q

hypersensitivity pneumonitis

A

triggered by exposure to proteins present in bird droppings . The lungs become inflamed with granuloma formation - farmers lung

45
Q

serum sickness

A

a reaction to medications or often serums - such as antivenom

46
Q

systemic lupus erythrmatosus

A

nephritis
arthritis
vasculitis

47
Q

polyarteritis nodosa

A

vasculitis

48
Q

poststrptococcal glomerulonephritis

A

nephritis

49
Q

type 4 hypersensitivity

A

delayed hypersensitivity reaction, inflammation by 2-6hours and peaks at 24-48hrs
result from interaction of T cell-initiated inflammation and doesnt involve antibodies
the inflammatory responses result from the manner in which the T cells encounter and respond to the antigen
can be transferred by sensitised T cells but not serum

50
Q

Pathogenesis of type 4 hypersensitivity reactions

A

foreign antigen enters the body
uptake by langerhans cell
migration to lymph nodes and formation of sensitised T lymphocytes
secretion of lymphokines and cytokines - IFN gamma and TNF alpha by sensitised T lymphocytes
macrophage attaches to antigen
macrophage presents antigen to T lymphocytes
forms a cytotoxic T cell
autoimmune reaction - cytotoxic T cell attaches to similar antigen in healthy tissue
killer T cells release perforin and granzymes
tissue destruction

51
Q

examples of type 4 hypersensitivities

A 
contact dermatitis 
drug reactions - stevens-johnson syndrome 
Graft-versus-host disease
Mantoux tuberculin skin test for latent TB
rheumatoid arthritis
IBD
MS
Guillain-Barre syndrome
Hashimoto's thyroiditis
type 1 diabetes mellitus
52
Q

rheumatoid arthritis

A

inflammation mediated by TH1 and TH17 cytokines

53
Q

MS

A

inflammation mediated by TH1 and TH17 cytokines

myelin destruction by macrophages

54
Q

Type 1 diabetes

A

T cell mediated inflammation and destruction of islet cells

killer T cells

55
Q

IBD

A

inflammation mediated by TH1 and TH17 cytokines

56
Q

Psoriasis

A

inflammation mediated by T cell derived cytokines

57
Q

Stevens Johnson drug reaction

A

affects skin and mucus membranes

flu-like symptoms, rash and blistering . the skin eventually dies

58
Q

common drug allergies

A

penicilin and muscle relaxants

59
Q

common food allergies

A

nuts, shellfish, eggs, soy and wheat

60
Q

common insect venom allergies

A

Insect venom - bee and wasp

61
Q

common environmental allergies

A

Inhaled or environmental allergens - dust mites, animal dander, pollen, latex

Physiology (46 decks)

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