tailieunhanh - Lecture Biology: Chapter 43 - Niel Campbell, Jane Reece

Chapter 43 - The immune system. You should now be able to: Distinguish between innate and acquired immunity; name and describe four types of phagocytic cells; describe the inflammation response; distinguish between the following pairs of terms: antigens and antibodies; antigen and epitope; B lymphocytes and T lymphocytes; antibodies and B cell receptors; primary and secondary immune responses; humoral and cell-mediated response; active and passive immunity;. | Chapter 43 The Immune System Overview: Reconnaissance, Recognition, and Response Barriers help an animal to defend itself from the many dangerous pathogens it may encounter. The immune system recognizes foreign bodies = “not self” and responds with the production of immune cells and proteins. Two major kinds of defense have evolved: innate immunity and acquired immunity. How do immune cells of animals recognize foreign cells? µm Fig How do immune cells of animals recognize foreign cells? For the Cell Biology Video Leukocyte Adhesion and Rolling, go to Animation and Video Files. Innate immunity is present before any exposure to pathogens and is effective from the time of birth. It involves nonspecific responses to pathogens. Innate immunity consists of external barriers plus internal cellular and chemical defenses. Acquired immunity = adaptive immunity, develops after exposure to agents such as microbes, toxins, or other foreign substances. It involves a very specific response to pathogens. Animal Immunity INNATE IMMUNITY Recognition of traits shared by broad ranges of pathogens, using a small set of receptors Non-specific • • Rapid response • Recognition of traits specific to particular pathogens, using a vast array of receptors • Slower response ACQUIRED IMMUNITY Pathogens (microorganisms and viruses) Barrier defenses: Skin Mucous membranes Secretions Internal defenses: Phagocytic cells Antimicrobial proteins Inflammatory response Natural killer cells Humoral response: Antibodies defend against infection in body fluids. Cell-mediated response: Cytotoxic lymphocytes defend against infection in body cells. Figure Overview of animal immunity For Innate Immunity, recognition and response rely on shared traits of pathogens Both invertebrates and vertebrates depend on innate immunity to fight infection. Vertebrates also develop acquired immune defenses. The immune system recognizes bacteria and fungi by structures on their cell walls. An immune response . | Chapter 43 The Immune System Overview: Reconnaissance, Recognition, and Response Barriers help an animal to defend itself from the many dangerous pathogens it may encounter. The immune system recognizes foreign bodies = “not self” and responds with the production of immune cells and proteins. Two major kinds of defense have evolved: innate immunity and acquired immunity. How do immune cells of animals recognize foreign cells? µm Fig How do immune cells of animals recognize foreign cells? For the Cell Biology Video Leukocyte Adhesion and Rolling, go to Animation and Video Files. Innate immunity is present before any exposure to pathogens and is effective from the time of birth. It involves nonspecific responses to pathogens. Innate immunity consists of external barriers plus internal cellular and chemical defenses. Acquired immunity = adaptive immunity, develops after exposure to agents such as microbes, toxins, or other foreign substances. It involves a very specific response