What is immunity?

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.

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

8. Adverse Events associated with Immunity ??????????????????????????

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

10. 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

11. 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.

12. Rhesus incompatibility

13. 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).

14. 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.

15. 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.

16. 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

18. 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.

19. 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

20. 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.