Transcript Inadequate flow of oxygen into the respiratory system due

• The immune system defends against
germs and microogransisms through a
series of steps called the immune
response.
• Through this response, the body
recognizes and defends itself against
bacteria, viruses, and other foreign
substances harmful to the body.
Antigen –
Foreign substance, such as a bacteria or toxin
that prompts the generation of antibodies to cause an
immune response
Antibody –
Immunoglobulin protein, made by B-cells,
that reacts only with the specific antigen that induced its
formation
*An antigen matches an antibody much as a key matches a lock
and whenever they match, the antibody destroys the antigen.
Immunoglobulin –
serum protein synthesized by
lymphocytes and plasma cells that has known antibody
activity
– There are different kinds: IgG, IgM, IgA, IgE, IgD
• Leukocytes- white blood cells
- “The immune system’s army”
• Two types of white blood cells:
- Phagocytes
- Lymphocytes
• Ingest microbes, foreign
particles, and other cells
• Three main types:
-Granulocytes
-Macrophages
-Dendrils
• Allows the body to remember and
recognize previous invaders in
order to help the body destroy
them
• 2 main types:
– T-cells
•Helper T-cells
•Cytotoxic (killer) T-cells
– B-cells
How does
the Immune
Response
Work?
– Begins when a pathogen enters the body.
– Antigen carrying cells (phagocytes) such as macrophages,
granulocytes, or dendril cells encounter the pathogen and “eat” it.
– They display its antigen fragments on their cell surface and become
antigen-presenting cells.
– Those cells interact with a T-helper cell so that they can recognize the
same antigen.
– One of the antigen carrying cells releases a chemical signal, interleukin-I
to get the T-helper cell to secrete Interleukin-2, which signals the
cytotoxic T-cells and B cells to produce antibodies against the antigen
The next step of the process can either go to
the Cytotoxic T cells or to the B-Cells
The cytotoxic T cells that recognize the particular
antigen displayed on the surface of the infected cells bind
to the infected cells and produce chemicals that kill the
infected cell. Death of the infected cells results in the
destruction of the pathogen.
When T cells activate B
cells, they go into
different plasma cells.
The plasma cells flood
the bloodstream with
antibodies that bind to
the antigens on the
surface of the pathogens,
so that the macrophages
can destroy them.
Sometimes, the B cells
become memory B cells
that survive for many
decades to give
“immunity” to diseases
after you have had them
once or have been
vaccinated.
- An
allergic reaction is the
body’s way of responding to an
invader
- An allergic reaction is the
body’s overreaction to a
harmless substance (an
allergen)
-almost anything can trigger an allergic reaction
-body senses antigen (trigger)
-white blood cells and antibodies attack the antigen
(response)
-immunoglobulin E, or IgE.
-an allergic reaction is an overreaction to the antigenhypersensitivity
-finally, cancellation
*negative feedback loop
-Antibody promotes production and release of
chemicals and hormones called "mediators."
– -Histamine is one well-known mediator.
– -they activate more white blood cell defenders.
– -It is these effects that cause the symptoms of the
allergic reaction.
– -If the release of the mediators is sudden or
extensive, the allergic reaction may also be sudden
and severe.
• Certain foods, vaccines and medications, latex
rubber, aspirin, shellfish, dust, pollen, mold,
animal dander, and poison ivy are common and
well known allergens.
• Peanuts, penicillin, bee stings, and fire ant
stings, are known for causing dramatic reactions
that can be serious and involve the whole body.
• Minor injuries, hot or cold temperatures,
exercise, or even emotions may be triggers.
• Allergies and the
tendency to have allergic
reactions run in some
families
• Many people who have
one trigger tend to have
other triggers as well.
• People with these medical conditions tend to
have allergies as well:
-lung conditions that affect breathing, such as
chronic obstructive pulmonary disease
-asthma
-frequent infections of the nasal sinuses, ears,
or respiratory tract
-nasal polyps
-sensitive skin
 Skin - Redness, itching, swelling, blistering, weeping,
crusting, rash, eruptions, or hives (itchy bumps or welts)
 Lungs - Wheezing, tightness, cough, or shortness of
breath
 Head - Swelling of the face, eyelids, lips, tongue, or
throat; headache
 Nose - Stuffy nose, runny nose (clear, thin discharge),
sneezing
 Eyes - Red (bloodshot), itchy, swollen, or watery
 Stomach - Pain, nausea, vomiting, diarrhea, or bloody
diarrhea
•the people who undergo allergies when the
season changes suffer from hay fever
-immune system’s response to
foreign material in the air you breathe
-most commonly pollen and mold
--spring and fall most common
seasons for hay fever
o medical attention is always recommended (except for
minor symptoms)
- Because allergic reactions can progress and
worsen in minutes
o evaluated quickly in the emergency department -in case of
severe reaction
- Blood pressure and pulse checked
- An examination determines whether you need
help breathing.
- Often, an IV line is placed in case you need
anti allergy medications quickly.
•allergy medications, such as
Benadryl (diphenhydramine)
•For rashes, use anti- inflammatory
steroid cream, such as
hydrocortisone
•usually hospitalization.
•oxygen for breathing difficulties
•intravenous fluids to boost blood pressure in
anaphylactic shock.
For relief of long-term allergies such as hay fever
or reactions to dust or animal dander:
- Long-acting prescription antihistamines, such as
cetirizine (Zyrtec), fexofenadine (Allegra), and
loratadine (Claritin)
- Nasal corticosteroid sprays are widely
prescribed for nasal symptoms not relieved by
antihistamines.
Acute
Allergic
Reactions
Anaphylaxis
• This is an acute, hypersensitive allergic reaction.
• This is a multi-system syndrome resulting from a
mediator release, and unlike ordinary allergic
reactions, anaphylaxis can lead to death.
• Reaction can occur within seconds to just a few
minutes
• Can cause airway constriction, skin and intestinal
irritation, and altered heart rhythms.
• In very severe cases, the reaction can result in
complete airway obstruction, shock, and death.
Why does this Occur?
• Triggered by substances that are
consumed or injected into the body that
will then get into the blood stream
• About 25% of the time, the mediators
flooding the blood stream cause an
opening of capillaries (tiny blood vessels)
which then results in a drop in blood
pressure, lightheadedness, or loss of
consciousness = anaphylactic shock.
Symptoms can include
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Cramps or pain in the abdomen
Chest discomfort or tightness
Diarrhea
Breathing problems
Difficulty swallowing
light-headedness
Fear or feeling of anxiety
Flushing or redness of face
Nausea or vomiting
Swelling of the face, eyes, or tongue
Weakness
Wheezing
Unconsciousness
• Other risk factors that can contribute to severity of the
reaction:
- Age: most fatalities are over age 45
- Gender: occurs more often in males
- A severe reaction to radiocontrast media, Hymenoptera
stings, neuromuscular agents, and plasma expanders are
greater in adults than in children
•When a long period of time has elapsed since the last
reaction, there is a lower risk to reaction the next time
•Anaphylaxis to insect bite or penicillin without exposure
for 10 years, next exposure is in the range of 10%-20%
•Food allergy can disappear without exposure for 3 years
Chronic lung disease characterized by
inadequate flow of oxygen into the
respiratory system due to inflamed and
swollen airways.
Chain Reaction:
Inflamed Airways
Swollen &
Sensitive Airways
Surrounding Muscles
Tighten
http://kidshealth.org/kid/closet/movies/asthma_movie.html
Symptoms
Non-Allergic
◊ Not associated with
allergic reactions
◊ Triggered by
anxiety, stress,
weather, exercise..
Etc.
◊ Regular Symptoms
Allergic
◊ Triggered by
allergic reactions
◊ Triggered by
inhaled allergens:
pollen, dander, etc.
◊ Regular Symptoms
and more
Triggers
Archadonic
Acid Cascade
Leukotrienes
& Histamines
• Antibodies in blood/body fluids identify a
foreign object
• Antigens trigger response to destroy the
invading microorganism
• Production of leukotrienes & proinflammatory response
• Muscle contractions and
inflammations
• Symptoms
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Chest tightness
Wheezing
Coughing
Shortness of Breath
Nasal Flaring with
each breath
• Range from minor
to severe
• Can be life
threatening
• Can be maintained
No Cure only Control
 Allergens : Dust, pollen, animal hair,
plants
 Chemicals: Sprays, perfumes, cleaning
products
 Medicines: Aspirin, antibiotics
 Foods: Fish, peanuts
 Weather
 Infections/Sicknesses
 Physical Activity
 Controls symptoms, requires less
maintenance and medication, allows
normal activity, prevents attacks
 Avoiding triggers
 Long-term medicines – reduce symptoms
and inflammation; Inhaled
corticosteroids, Theophylline,
Cromolyn and nedocromil,
Leukotriene modifiers
 Short-term medicines
 Allergy shots
 Inhaler – straight to lungs
 Leukotriene Modifiers
Stress
Lack of self-confidence
Embarrassment
Negative Emotion
Personal restraints: limiting what you can eat,
trying to avoid triggers, etc.
Weight Gain: lack of ability to do physical activity
http://www.emedicinehealth.com/allergic
http://www.users.globalnet.co.uk/~aair/anaphylaxis.htm
http://www.homehealth-uk.com/medical/anaphylaxis.htm
http://www.emedicinehealth.com/severe_allergic_reaction_anaphylactic_
shock/article_em.htm
http://www.asthmasymptom.org/cause-of-asthma.html
http://www.webmd.com/asthma/guide/asthma-treatment-care
http://asthma.about.com/od/signssymptomsofasthma/p/managesymptom
s.htm
http://www.aafa.org/display.cfm?id=8&sub=17
http://www.webbooks.com/eLibrary/Medicine/Physiology/Immune/Antigen.htm