1. Notes: Chapter 39 (page 1022-1047) – Immunity from Disease

2. Pathogens Disease causing agents –Can be bacteria, protists, fungi, viruses, or parasites like tape worms –Infectious diseases are any diseases caused by a pathogen

3. Symbiosis with microorganisms Bacteria on our skin and intestines help us digest our food and keep harmful bacteria from growing and causing illness. Helps maintain homeostasis within our digestive tract

4. Host cells Viruses need be inside of host cells in order to reproduce

5. Antibiotics A substance that kills or inhibits the growth or reproduction of other microorganisms. Effective against bacteria and some fungi but NOT VIRUSES.

6. Antibiotic resistance Continued use of antibiotics selects for resistant bacteria. Soon the antibiotics do not work. –In the case of penicillin, over-prescribing and failure to use the entire dose led to resistant bacteria surviving and reproducing.

7. Our Immune system

8. Innate Immunity Body’s first defense NON-Specific defense (attacks everything) Skin, saliva, sweat, tears, inflammation Main cells are macrophages –Macrophages engulf and kill foreign invaders

9. Acquired Immunity Second defense Goes after specific pathogens (targeted) Main cells are lymphocytes –T-cells and B-cells

10. Acquired Antibody Immunity Macrophages recognize and engulf a foreign invader which activates helper T-cells Helper T-cells then activate B-cells B-cells mature into plasma cells and make antibodies against the specific pathogen Memory B-cells and T-cells hang around in case the pathogen shows up again later –Quick response next time

11. Acquired Cellular Immunity Cytotoxic T-cells are killer T-cells that destroy cancer and virus infected cells but punching them full of holes

12. Autoimmune responses Allergic reactions are immune responses to harmless substances Autoimmune diseases happens when the immune system turns on own body and attacks (example is lupus)

13. Passive Immunity When you are given antibodies made by someone else. Not lasting protection Antibodies from mother to infant through the placenta and breast feeding anti-venom

14. Body produces it’s own antibodies after being exposed to antigens –Antigens are proteins from pathogens Vaccines are weakened or dead pathogen that induces a person to make antibodies –Gives lasting protection against the disease through memory cells Active Immunity

15. AIDS, HIV and the Immune System HIV stands for Human Immunodeficiency Virus HIV is a retrovirus (RNA) that attacks helper T- cells which prevents the immune system from working properly The causes AIDS (acquired immune deficiency syndrome) Person with AIDS cannot fight off infections and they may die Passed through bodily fluids