Chapter 7

• What does the immune system protect the body from?

  Infection
• What are the two main types of immune responses?

  • Innate immune response (non-specific)
  • Adaptive immune response (specific and acquired)
• How does the innate immune response differ from the adaptive immune response?

  Innate is non-specific; adaptive is specific
• What is a characteristic of the innate immune response?

  Immediate maximal response
• What is a characteristic of the adaptive immune response?

  Immunological memory
• What do nonspecific defenses refer to?

  Defense against any pathogen
• What do specific defenses refer to?

  Defense against a specific pathogen
• What are mechanical factors in the immune system?

  Barriers that prevent pathogen entry
• What is the role of chemical factors in the immune system?

  Inhibit microbial growth or destroy them
• What is the first line of defense in the immune system?

  Mechanical and chemical factors
• What is the primary function of intact skin?

  Physical barrier to pathogens
• What are the two layers of skin?

  Dermis and epidermis
• What is the function of mucous membranes?

  Inhibit entrance of microorganisms
• What does mucus do?

  Traps microorganisms
• What is sebum?

  Oily substance produced by sebaceous glands
• How does sebum inhibit microbial growth?

  By forming a protective film on skin
• What is the role of lysozyme?

  Breaks down cell walls of gram-positive bacteria
• What is gastric juice composed of?

  Hydrochloric acid, enzymes, and mucus
• What do transferrins do?

  Inhibit bacterial growth by binding iron
• What is microbiota?

  Microorganisms that colonize a host
• How does microbiota prevent pathogen overgrowth?

  By competing for nutrients
• Where can normal microbiota be found?

  Nasal area, mouth, skin, vagina
• What is phagocytosis?

  Ingestion of microorganisms by cells
• What types of cells perform phagocytosis?

  Phagocytes
• What are granulocytes?

  Type of white blood cell involved in phagocytosis
• What are the two types of agranulocytes?

  Monocytes and lymphocytes
• What happens to monocytes during an infection?

  They enlarge and become macrophages
• What are fixed macrophages?

  Macrophages that stay at specific sites
• What is the process of chemotaxis?

  Chemical attraction of phagocytes to pathogens
• What is adherence in phagocytosis?

  Attachment of phagocyte to microorganism
• What occurs during ingestion in phagocytosis?

  Phagocyte engulfs the microorganism
• What happens during digestion in phagocytosis?

  Enzymes break down the microorganism
• What are some conditions that impair phagocytosis?

  AIDS, cancer, and age-related decline
• What is inflammation?

  Host response to tissue damage
• What are the causes of tissue damage?

  Microbial infection, heat, chemicals
• What are the functions of inflammation?

  Destroy injurious agents and repair tissue
• What occurs during vasodilation?

  Blood vessels increase in diameter
• What causes redness and heat during inflammation?

  Increased blood flow to the damaged area
• What is edema?

  Swelling due to fluid accumulation
• What are histamines?

  Chemicals released in response to injury