Immune System & Defences

• What are the two main components of the body's defense system?

  • Physical and chemical barriers
  • Immune system
• What acts as a physical barrier to pathogens?

  Skin
• How does skin help protect against pathogens?

  It secretes oils and antimicrobial substances
• What adaptations do noses have to prevent pathogen entry?

  Little hairs and mucus
• How do cilia help in the respiratory system?

  They move mucus to the throat
• What happens when pathogens enter the body despite defenses?

  The immune system hunts them down
• What is the primary type of cell in the immune system?

  White blood cells
• What are the three important functions of white blood cells?

  1. Phagocytosis (engulfing pathogens)
  2. Producing antitoxins
  3. Producing antibodies
• What is phagocytosis?

  Engulfing and destroying pathogens
• What do antitoxins do?

  Counteract toxins produced by pathogens
• What are antigens?

  Foreign substances detected by the immune system
• What are antibodies?

  Proteins made by white blood cells
• What happens after the immune system identifies a pathogen?

  It produces many specific antibodies quickly
• What does it mean to be immune to a disease?

  The body can quickly destroy pathogens
• How does the body survive daily pathogen attacks?

  • Physical and chemical barriers
  • Immune system response
  • Continuous monitoring by white blood cells