1. Immune System
The cells and tissues that recognize and attack foreign substances in the body

2. Causes of Disease
Noninfectious Disease: Cannot be spread from one individual to another
Infectious Disease: Caused by a pathogen and can be spread from one individual to another
Pathogen: A microorganism, a virus, or a protein that causes a disease

3. Pathways to Pathogens Air Contaminated Objects Person to person
Animals
Food and Water

4. Putting Pathogens in their place
Pasteurization
Vaccines & Immunity
Antibiotics
Immunity: The ability to resist or to recover from an infectious disease

5. Cells of the Immune System
Macrophages: Engulfs pathogens and other materials
T cell: Coordinates the immune system and attacks many infected cells
B cell: A white blood cell that makes antibodies
Antibody: A protein made by B cells that binds to a specific antigen.
Antigen: Substances that stimulate an immune response

6. Memory B Cells
A B cell that responds to an antigen more strongly when the body is reinfected with an antigen than it does during its first encounter with the antigen.

7. Fevers
Fevers of a couple degrees help immune cells reproduce and help your body fight infections
Fevers more than a couple degrees can be dangerous however.

8. Challenges to the Immune System
Allergies (When the immune system overreacts to antigens that are not dangerous to the body.
Autoimmune diseases (A disease in which the immune system attacks the organism’s own cells; ex: rheumatoid arthritis, diabetes, multiple sclerosis)
Cancer (A disease in which the cells begin dividing at an uncontrolled rate and become invasive)
AIDS (acquired immune deficiency syndrome); When HIV (human immunodeficiency virus) kills helper T cells. People with AIDS rarely die from AIDS itself, rather from other diseases they cant fight off)