The Immune System 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

Cells that are part of the Immune System 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: Phagocytes Ingest microbes, foreign particles, and other cells Three main types: -Granulocytes -Macrophages -Dendrils

Lymphocytes 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 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.

Allergies - 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)

Etiology (Causes) -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 antigen- hypersensitivity -finally, cancellation *negative feedback loop

Etiology (continued) -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.

Allergens 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.

Many people who have one trigger tend to have other triggers as well. More Info 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.

Even More Info 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

Symptoms of Allergic Reactions 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

More Info 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

Treatment medical attention is always recommended (except for minor symptoms) - Because allergic reactions can progress and worsen in minutes 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) Treatment for minor reactions allergy medications, such as Benadryl (diphenhydramine) For rashes, use anti- inflammatory steroid cream, such as hydrocortisone

Treatment for severe reactions usually hospitalization. oxygen for breathing difficulties intravenous fluids to boost blood pressure in anaphylactic shock.

Treatment (Continued) 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 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

Asthma 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 Symptoms http://kidshealth.org/kid/closet/movies/asthma_movie.html

Types Of Asthma 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

Why do symptoms occur? Archadonic Acid Cascade Leukotrienes & Histamines Triggers • Antibodies in blood/body fluids identify a foreign object • Antigens trigger response to destroy the invading microorganism • Production of leukotrienes & pro- inflammatory response • Muscle contractions and inflammations • Symptoms

Symptoms • Range from minor to severe Chest tightness Wheezing • Can be life threatening • Can be maintained Chest tightness Wheezing Coughing Shortness of Breath Nasal Flaring with each breath

Triggers & Treatments 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

Effects 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

Sources 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/managesymptoms.htm http://www.aafa.org/display.cfm?id=8&sub=17 http://www.web-books.com/eLibrary/Medicine/Physiology/Immune/Antigen.htm