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35.2. Defenses against infection. Nonspecific defenses. Skin Tears Lysozyme enzyme that breaks down bacterial cell walls Other secretions (like mucous) Inflammatory response Interferons Fever *first line of defense *second line of defense. Inflammatory response.
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35.2 Defenses against infection
Nonspecific defenses • Skin • Tears • Lysozyme enzyme that breaks down bacterial cell walls • Other secretions (like mucous) • Inflammatory response • Interferons • Fever • *first line of defense • *second line of defense
Inflammatory response • Infected areas become red and painful (inflamed)
Histamines • Chemical that increases flow of blood and fluids to the affected area(p. 1015)
Interferons • Proteins released by a host cell getting “attacked” by a virus that inhibits synthesis of viral proteins
Fever • Increase body temperature • Slows down or stops the growth of some pathogens • ***remember…a lot of bacteria/ pathogens can’t withstand high heat!***
Specific defenses • Immune system’s specific defenses distinguish between “self” and “other,” and they inactivate or kill any foreign substance or cell that enters the body. • *respond to a particular pathogen!*
Immune response • Body doesn’t recognize something • Goes into an IMMUNE RESPONSE • Specific recognition, response and memory to pathogens
Antigens vs. antibodies • Antigen any foreign substance that can stimulate an immune response • Antibodies tags antigens for destruction by immune cells
Lymphocytes • B lymphocytes and T lymphocytes are the main working cells of the immune systems
The specific immune response has two main styles of action…humoral immunity and cell-mediated immunity • Humoral refers to the immune response that happens in body fluids (B cells) • Cell-mediated (T cells) defends the body against some viruses, fungi, and single-celled pathogens