Immune System

• Phagocytosis


  Process by which certain white blood cells engulf pathogens
• White blood cells

  • Continually patrol the body, have three important functions: phagocytosis, producing antitoxins, producing antibodies
• Stomach


  • Produces hydrochloric acid to kill pathogens
• Trachea, esophagus, lungs


  • Trachea, bronchi, and bronchioles are covered in mucus to trap particles, lined with cilia to move mucus and particles up to the back of the throat
• Immune system


  Hunts down pathogens that make it into the body
• Producing antibodies

  White blood cells produce small proteins that lock onto foreign antigens and signal other white blood cells to destroy them
• Producing antitoxins


  White blood cells produce small molecules that can bind and counteract toxins produced by pathogens
• Nose and mouth


  • Have hairs and mucus to trap pathogens and particles
• Human body's defense system

  Split between physical and chemical barriers and immune system
• Immunity to a disease is achieved when the body produces antibodies quickly to destroy pathogens before they can develop
• Antigens are substances detected as foreign by the immune system
• Antibodies are specific for particular antigens
• Skin


  • Acts as a physical barrier that pathogens can't get through, secretes oils and antimicrobial substances