Immune response

• What are the three types of innate defenses?

  Physical, chemical, and biological defenses
• What is the role of physical barriers in innate defenses?

  • Protect exposed surfaces
  • First line of defense
  • Includes skin and mucus membranes
• What is the largest organ of the body?

  Skin
• How does the skin prevent pathogen entry?

  It acts as a barrier to pathogens
• What happens when the skin is damaged?

  A scab forms to prevent pathogen entry
• What do sebum and sweat contain?

  Antibacterial and antifungal chemicals
• What is the function of nasal hairs?

  Filter dust and pathogens from air
• What do goblet cells produce?

  Mucus
• How does mucus protect the digestive tract?

  It provides a chemical barrier against bacteria
• What happens to mucus from the trachea?

  It is moved out by cilia and swallowed
• What is the pH of stomach acid (HCl)?

  2
• How does stomach acid protect against pathogens?

  It destroys pathogens ingested with food
• What enzyme do tears contain?

  Lysozyme
• What is the function of lysozyme in tears?

  It hydrolyzes bacterial cell walls
• What is an antigen?

  • A protein/glycoprotein on cell surfaces
  • Stimulates antibody production
  • Identifies self and non-self cells
• How do white blood cells recognize self and non-self cells?

  By using antigens on cell surfaces
• What are the symptoms of inflammation?

  Swelling, heat, redness, and pain
• What causes redness and heat during inflammation?

  Increased blood flow to the area
• What chemical is released by mast cells during inflammation?

  Histamine
• What is the role of histamine in inflammation?

  Increases capillary permeability
• What do basophils release during the inflammation response?

  Histamines and heparin
• What is the function of eosinophils?

  Destruction of parasites and phagocytosis
• What do natural killer cells do?

  Patrol for abnormal or infected cells
• What is the role of white blood cells in biological defenses?

  • Act as the body's defense system
  • Respond to pathogens that breach barriers
  • Include various specialized types
• What is phagocytosis?

  A rapid response to non-self antigens
• What happens during phagocytosis?

  Pathogen is engulfed and digested
• What is formed around a pathogen during phagocytosis?

  A phagosome
• What do lysosomes contain during phagocytosis?

  Hydrolytic enzymes
• What is antigen presentation?

  Displaying antigens on macrophage membranes
• What do memory B cells do?

  Provide rapid response to future infections
• What are the two ways adaptive immunity can be acquired?

  • Naturally through infection
  • Artificially through vaccination
• What is the role of lymphocytes in immune response?

  Launch the immune response against antigens
• What is the secondary response in adaptive immunity?

  A faster and stronger response to re-exposure
• What is required for T lymphocytes to respond to antigens?

  Antigen processing by other cells
• What is clonal selection?

  Binding of T lymphocytes to specific antigens
• What do helper T cells stimulate?

  Killer T cells and B lymphocytes
• What do killer T cells do?

  Attack infected or abnormal body cells
• What do memory T cells do?

  Remain in circulation for future infections
• What is the humoral response in adaptive immunity?

  • Activation of B lymphocytes
  • Production of antibodies for specific antigens
  • Occurs after cell-mediated response
• What do plasma cells do?

  Secrete specific antibodies to antigens