Immunity 1. Immunity refers to all mechanisms used by the body as protection against environmental agents that are foreign to the body. 2.Agents: microorganismor and their products, foods, chemicals, pollen, tumor cells, viruses 3. Immune system: immune tissues and organs, immune cells, immune molecules 4. Immune response: benefits; damaging effects 6. Immunology: a science studying on organization and function of immune systemImmunity 1.Immunity:refers to all mechanisms used by the body as protection against environmental agents that are foreign to the body. 2.Agents:microorganismor and their products, foods, chemicals, pollen, tumor cells, viruses… 3.Immune system: immune tissues and organs, immune cells, immune molecules 4.Immune response: benefits; damaging effects 5.Immunology：A science studying on organization and function of immune system