1. The Body Has Methods of Protecting Itself from Diseases

2. Immune Response 1 st Defense is the Skin and Mucus 2 nd Defense occurs when injured cells release chemicals that increase blood flow to an area (cut or scrape). The blood brings Macrophage: a white blood cell that engulfs and kills pathogens 3 rd Defense macrophages along with T cells and B cells attach and kill infected cells.

3. Treating Diseases Antibiotic: will kill or inhibit the growth/reproduction of microorganisms Do Not effect viruses Lymphatic System: produces white blood cells and antibodies 2 types of White Blood Cells (1) T cells and (2) B cells

4. Antibody Immunity (see p. 1037) Antigens: foreign substances that stimulate an immune response Antibodies: proteins in the blood that correspond to an antigen B cells make antibodies T cells kill infected cells Helper T cells help B cells make antibodies Memory cells are ready and armed to respond rapidly if the same pathogen invades the body at a later time

5. Passive and Active Immunity (p.1039) Passive Immunity : Acquiring antibodies produced in someone else, such as through an injection or a mother passing them through the placenta or milk to her fetus. Ex. Person bite by a snake…injected w/antibodies from a horse that is immune to the snake venom Active Immunity : Due to a person forming his or her own antibodies after being exposed to an antigen Vaccine : Weakened, dead or incomplete pathogens/antigens injected into body to cause and immune response.