Immune System The cells and tissues that recognize

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

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

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

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

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

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.

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.

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)