1. Mr. Ramos The Immune System

2. Introduction to the Human Immune System The immune system protects the body from disease. White Blood Cells (WBC), or leukocytes, fight pathogens, abnormal cells, and chemicals, such as toxins. Never Let Monkeys Eat Bananas Neutrophils (65%) Lymphocytes (25%) Monocytes (6%) Eosinophils (3%) Basophils (1%)

3. Introduction to the Human Immune System In addition to cells, the immune system has organs that work together to protect the body: Bone Marrow Spleen Lymph Nodes Thymus Tonsils Appendix Peyer’s Patches

4. First Line of Defense: A Barrier to Infection Pathogens must get inside your body to cause disease. The body’s first line of defense is a barrier to keep pathogens out. Skin Mucous Membranes Stomach Acid Sweat Tears Saliva

5. Second Line of Defense If pathogens manage to pass the first line of defense and enter the body, the second line of defense takes over: Inflammatory Response – redness & swelling Fever is an increase in body temperature Natural Killer Cells, Phagocytes, & Antimicrobial Proteins The first and second line of defense are nonspecific. This means they respond to any pathogen.

6. The Third Line of Defense The immune response is the body’s third line of defense. Specific pathogens are attacked. T-cells and B-cells are lymphocytes that are part of the immune response. T-cells attack and kill harmful cells. B-cells produce antibodies. An antibody is a protein that attaches to a foreign substance, known as an antigen. Each antibody is specific to its antigen like a lock and key.

8. Types of Immunity To have immunity is to be able to resist a disease. Two types of immunity: Active immunity Passive immunity

9. Active Immunity Results from exposure to a specific pathogen Can occur naturally when a pathogen enters the body Can occur artificially through vaccination

10. Passive Immunity Is created by transferring antibodies made by one organism into another organism. Often acquired at birth from mother to offspring Breast milk passes antibodies from mother to offspring.

11. Antibiotics Antibiotics are drugs used to fight bacterial infections. Penicillin was the first antibiotic discovered in 1928. It is not very effective today due to antibiotic resistance. Antibiotics do not kill viruses or protists.