Unit 3 - Chapter 14 Flashcards
Immune response that occurs when no infection exists- Hypersensitivity reactions
Allergy
Types of hypersensitivity reactions
Inhaled materials
Ingested materials
Injected materials
Contacted materials
Type I hypersensitivity antigen
allergen-specific IgE
Type I hypersensitivity binds to:
Fc receptors on mast cells, basophils, and eosinophils
Type I hypersensitivity results in
degranulation and a release of histamine
Type I hypersensitivity is also called
immediate hypersensitivity
Symptoms of type I hypersensitivity
Runny nose to stressful breathlessess
possible death by asphyxiation
Example of Type I hypersensitivity
Plant pollen, hay fever
Time of Type I hypersensitivity
generally w/in 10-15 minutes
Type II hypersensitivity antigen
IgG
Responds to chemically reactive small molecules bound to the outside of cells
What happens in Type II hypersensitivity when small molecules bind with IgG
They become new and foreign antigen on the cell surface
In type II hypersensitivity, new IgG is made against:
new epitopes
-this damages host cells and degrades host tissues
Symptoms of type II hypersensitivity
Rash, itchiness
Example of type II hypersensitivity
penicillin
Time it takes for a type II hypersensitivity reaction
4-24 hours
Type III hypersensitivity is caused by
immune complexes of antigen and IgG
In type III hypersensitivity, what happens?
Our antibodies coat things so much that they get heavy- called immune complexes
in type III hypersensitivity, where do complexes deposit?
in the walls of the blood vessels or alveoli
in type III hypersensitivity, immune complexes trigger:
complement and induce inflammation to damage tissues
Symptoms of type III hypersensitivity
Rash, respiratory issues, damaged kidneys
Examples of Type III hypersensitivity
Porcin
Insulin
Time for a type III hypersensitivity reaction to develope
w/in a few hours
Type IV hypersensitivity is mediated by
antigen-specific effector T cells NOT MEDIATED BY ANTIBODIES LIKE THE FIRST 3
For type IV hypersensitivity, contact with cells results in
uptake and presentation
For type IV hypersensitivity, What are examples of CD8 T cells reaction
poison ivy
For type IV hypersensitivity, what is an example of a CD4 reaction
nickel allergy
Type IV hypersensitivity is also called
delayed-type hypersensitivity (DTH)
Symptoms of type IV hypersensitivity
inflammation of skin
Time it takes for type IV hypersensitivity reaction to develop
1-3 days
IgE is designed to:
get rid of parasites
IgE binds to:
Fc receptors on eosinophils, basophils, mast cells
How do stimulated cells attack a parasite?
with granules
Why don’t people in developing countries typically have allergies?
People are more likey afflicted with parasites, therefore the IgE is too distracted to fight allergies
Multicellular parasites display:
human-like parasites
they are larges– no phagocytosis
symptoms intended to rid the body of a parasite
sneezing coughing vomiting diarrhea itching
B cells switch to IgE when?
When Th2 cells direct them
What binds to several specificities of IgE?
Mast cells
What triggers degranulation of IgE
Crosslinking
Location of mast cells
mucosal and epithelial tissues
structure of mast cells
contains granules
Lifespan of IgE in the blood:
on cells:
in the blood: incredibly short- shorter than any other antigen
on cells: can last weeks to months
Crosslinking of ___ activates the mast cell to releaxe histamine and other chemicals
IgE
Histamine binds to:
This causes:
Endothelial cells on blood vessels
causes vessel permeability
Histamine leads to:
inflammation and smooth muscle contraction
Histamine results in:
constriction of the airway
Location of eosinophils
mostly tissues, especially connective tissues
These are 1 or 2 percent of WBC count
structure of eosinophils
contains granules
Activation of eosinophils
Degranulation of toxic chemicals
unusually high numbers of eosinophils
eosinophilia
Eosinophils can cause damage to:
endocardium and nerves
Chronic allergies caused by eosinophils can lead to
inflamation and airway damage leading to chronic asthma
Location and structure of Basophils
location- tissues
structure- granules
Basophils may be able to direct _____ responses by secreting certain :
Th2
cytokines
Protein antigens that resemble parasite antigens
Allergens
Type I hypersensitivity, allergens are proteins from: (6)
Plants Animals Medicines Pollen grains Dried feces of dust mites Dander from dried skin and saliva
Allergens become airborne to be:
They are then picked up by:
inhaled and caught by the mucus in the lungs
by antigen presenting cells to present to CD4 T cells
CD4 T cells activate:
B cell production of IgE and bind to mast cells
allergies target ____ individuals
atopic
Infantile dermatitis
If mother is atopic and IgE is transported in amniotic fluid or through breast milk to the baby- gives the baby allergies as well
Immediate and late phase response allergy testing
intradernal skin test
result of allergy in an intradermal skin test
wheal and flare
immediate response of allergies is due to
degranulation of IgE bound mast cells where the histamine triggers redness and swelling
late phase allergic reaction involves
widespread swelling because of the chemicals released by mast cells
inflammation of airways so that they may become constricted and blocked with mucus
asthma
With asthma, mast cells:
Degranulate in in airways
asthma response is measured by
breathing capacity
asthma is often caused by:
dust mites, cockroaches, rodents and pets
types of Asthma treatment
administration of an IgG that is specific for IgE
IgG binds up the IgE and prevents it from binding to mast cells
Types of allergy treatment
Administration of small amounts of allergens to desensitize the immune system
retraining the immune system through many shots
Allergens in the blood- widespread activation of mast cells in the blood vessel epithelium
Anaphylaxis
What causes systemic anaphylaxis
Degranulation
Increase in vascular permeability and constricton of smooth muscle results in:
a drop in blood pressure
Anaphylaxis can cause
anaphylactic shock
organ damage
asphyxiation
causes of anaphylaxis
insect stings, drug injections, foods
Treatment of anaphylaxis
epiniphrine injections
how do epinephrine injections treat anaphylaxis
Epithelial junctions of blood vessels tighten to prevent fluid loss
BP increases
Relaxes the constricted airways
Allergic rhinitis, AKA
Hay fever
cause of hay fever
plant/mold spores
Symptoms of rhinitis and asthma include
Runny nose and violent bursts of sneezing
Local edema
Obstruction of nasal airways
Nasal discharge with eosinophils
Irritation of nose and throat
Inflammation of conjunctiva- itchiness, tears, inflammation
For allergic asthma, allergens activate:
mast cells in the lower resp tract
For allergic asthma, what does degranulation cause?
An increase in fluid and mucus with bronchial constriction
Chronic inflammation with allergic asthma is mediated by:
eosinophils, neutrophils and Th2 cells
this can cause a mucus plug, causing air to be trapped in the lungs
Allergic asthma is often triggered by:
smoke, immune responses, etc.
Allergic asthma is considered what type of hypersensitivity?
Type IV
