B3- Fighting disease

• What is the primary function of the body's defense system?

  To protect against pathogens
• How do the trachea and bronchi contribute to the defense system?

  They seal off pathogens from entering the lungs
• What does the stomach produce to aid in defense against pathogens?

  Hydrochloric acid
• What happens when pathogens enter the body?

  The immune system activates to destroy them
• What is the most important part of the immune system?

  White blood cells
• How do white blood cells patrol the body?

  They travel through the bloodstream to check for microbes
• What is the process called when white blood cells consume pathogens?

  Phagocytosis
• What are antigens?

  Unique molecules on the surface of invading pathogens
• What do white blood cells do when they encounter an unfamiliar antigen?

  They produce antibodies specific to that antigen
• What is the role of antibodies?

  To lock onto invading cells for destruction
• How quickly are antibodies produced after encountering a pathogen?

  Rapidly
• What happens if a person is infected with the same pathogen again?


  The immune system rapidly produces antibodies to fight it
• What is natural immunity?

  When the body remembers a pathogen and can fight it off quickly
• What do antitoxins do?

  They counteract toxins produced by bacteria
• What type of bacteria produce toxins that antitoxins counteract?

  Pathogenic bacteria
• What are the physical barriers in the body's defense system?

  Skin and mucous membranes
• What types of white blood cells are involved in the immune system?

  Lymphocytes and phagocytes
• Which type of white blood cell produces antibodies?

  B cells
• What are the two classifications of the immune response?

  Innate and adaptive immunity
• How does vaccination help the immune system?

  It helps the body develop immunity to specific pathogens
• What are memory cells?

  Cells that allow for quicker responses to future infections by the same pathogen