White Blood Cells

• What is the function of white blood cells?

  to fight pathogens
• What are the 2 main types of white blood cells?

  lymphocytes and phagocytes
• What are the 2 ways in which lymphocytes fight pathogens?

  Antitoxins & Antibodies
• How do Antitoxins work in lymphocytes?

  Lymphocytes produce antitoxins that bind to the toxins produced by some pathogens. This neutralises the toxins
• How do Antibodies work in Lymphocytes?

  Lymphocytes produce antibodies that target and help to destroy specific pathogens by binding to antigens (proteins) on the pathogens’ surfaces.
• Label the Process of Antibodies in a Lymphocyte:

  A) lymphocyte

  B) antibody

  C) antigen

  D) pathogen

  E) antibody attached to antigen

  
• How do Phagocytes fight off pathogens? (3)

  1. Phagocytes are attracted to areas of infection
  2. The Phagocyte surrounds the pathogen & engulfs it
  3. Enzymes that digest & destroy the pathogen are released
• What are the non-specific defences of the skin against pathogens? (3)

  • physical barrier to infection
  • produces antimicrobial secretions
  • microorganisms that normally live on the skin prevent pathogens growing
• What are the non-specific defences of the nose against pathogens? (2)

  • Cilia and mucus trap particles in the air, preventing them from entering the lungs.
  • Trachea and bronchi produce mucus, which is moved away from the lungs to the back of the throat by cilia, where it is expelled.
• What are the non-specific defences of the stomach against pathogens?

  Produces strong acid (pH 2) that destroys pathogens in mucus, food, and drinks.