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What is immunity?

What is immunity?. Resistance to a disease causing organism or harmful substance Two types Active Immunity Passive Immunity. Active Immunity. (You) The body produces the antibodies Your body has been exposed to the antigen in the past either through:

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What is immunity?

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  1. What is immunity? • Resistance to a disease causing organism or harmful substance • Two types • Active Immunity • Passive Immunity

  2. Active Immunity • (You) The body produces the antibodies • Your body has been exposed to the antigen in the past either through: • (Natural)-Exposure to the actual disease causing antigen • (Induced)-Vaccines • What is this second type of exposure called?

  3. Vaccine • Antigens are deliberately introduced into the immune system to produce immunity • Because the bacteria has been killed or weakened, minimal symptoms occur • Have eradicated or severely limited several diseases from the face of the Earth, such as polio and smallpox

  4. How long does active immunity last? • It depends on the antigen • Some disease-causing bacteria multiply into new forms that our body doesn’t recognize, requiring annual vaccinations, like the flu shot • Booster shot - reminds the immune system of the antigen • Others last for a lifetime, such as chicken pox

  5. Passive Immunity • (You don’t)The body doesn’t produce the antibodies • Natural:A mother will pass immunities on to her baby during pregnancy • Artificial:the injection of antibodies, such as gamma globulin • Protection from passive immunity diminishes in a relatively short time, usually a few weeks or months.

  6. Immune system in plants Mechanical barrier Chemical barrier -oil Chemicals gums • -cuticle • epidermis

  7. Adverse Events associated with Immunity ??????????????????????????

  8. Immune deficiency Immune deficiency is a malfunction or a deficiency in one or more components of the immune system.

  9. Aquired Immune Deficiency Syndrome • Caused by the Human Immunodeficiency Virus • Discovered in 1983 • Specifically targets and kills T-cells • Because normal body cells are unaffected, immune response is not launched

  10. Autoimmune Disease • Autoimmune diseases are diseases where the immune system begins to attack itself. • Ex: • Rheumatoid Arthritis – crippling disease of the joints. • Lupus – disease of blood and organs. • Multiple Sclerosis – disease of nervous system • Cause(s): unknown • Cures/Treatments: No known cures. Usually treated with drugs.

  11. Rhesus incompatibility

  12. Rh factor • Problems can occur during pregnancy when the baby's blood has the Rh factor and the mother's blood does not • can be prevented in most cases with the medication called immunoglobulin (RhIg).

  13. Passive .vs. Active Immunity • Active Immunity This is immunity where the body is “actively” producing antibodies to fight infection. Exposure to the actual disease : the body actively creating antibodies to fight it. Vaccination:An injection of a weakened strain of an infectious microbe (pathogen) that causes the body to undergo active immunity (produce antibodies). • Passive Immunity This is immunity where antibodies are given to a person from the blood of another person or animal. This immunity only lasts for a short period of time. ex: Breastfeeding mothers pass antibodies to their children through the milk.

  14. Allergies Allergy - An exaggerated response by the immune system to otherwise harmless substances called allergens. Allergen: a normally harmless substance that causes an allergic reaction. ex: dust, pollen, mould, food, insect stings Types of Allergic reactions There are two types of allergic reactions. a. Immediate – occurs within seconds and normally lasts for about 30 mins. b. Delayed – takes longer to react and can last for a much longer time.

  15. Immune Disorders~Allergies~ • Immune system mistakenly recognizes harmless foreign particles as serious threats • Launches immune response, which causes sneezing, runny nose, and watery eyes • Anti-histamines block effect of histamines and bring relief to allergy sufferers

  16. Allergies • Histamine causes blood vessels to widen and become leaky. • Fluid and white blood cells leave capillaries. • The area of leakage becomes hot, red and inflamed • Histamine causes smooth muscles to constrict.

  17. What happens during an allergic reaction? • During an allergic reaction antibodies cause histamines to be released from certain cells. Histamines cause: a. Swelling of tissues b. Release of fluids (runny noses and eyes) c. muscle spasms (some cases) Anaphylaxis or anaphylactic shock: This is the sudden and severe allergic reaction to a substance that can cause death. Treatments for Allergies • Avoidance of material – especially food. • Epinephrine – “epi – pen” • Antihistamines -- benadryl

  18. Mast cells, one of the major players in allergic reactions, capture and display a particular type of antibody, called immunoglobulin type E (IgE) that binds to allergens. Inside mast cells are small chemical-filled packets called granules. Granules contain a variety of potent chemicals, including histamine. • Immunologists separate allergic reactions into two main types: immediate hypersensitivity reactions, which are predominantly mast cell-mediated and occur within minutes of contact with allergen; and delayed hypersensitivity reactions, mediated by T cells (a type of white blood cells) and occurring hours to days after exposure.

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