The Immune system

• What do pathogens do once inside the body?

  They can multiply and damage healthy tissue e.g. bacteria releasing toxins which make us feel unwell.
• What is the job of the immune system?

  To destroy pathogens and any toxins they produce. It also protects us incase the same type of pathogen invades us again in the future.
• What is the role of the white blood cells? (Phagocytosis)

  White blood cells can ingest and destroy pathogens. The WBC detects chemicals released from the pathogen and moves towards it. The WBC then engulfs the pathogen, it then uses enzymes to destroy the pathogen.
• What is the role of the white blood cells? (antibodies)

  Antibodies are protein molecules produced by WBC. The antibodies stick to the pathogens which triggers the pathogens to be destroyed.

  Antibodies are very specific, so if a person has measles they will develop antibodies against the measles virus. Those antibodies will only protect against measles they do not protect against any other pathogen.

  Antibodies remain in the blood for a long time, meaning they can protect us if we get infected by the same pathogen again.
• What is the role of the white blood cells? (antitoxins)


  Certain types of bacteria produce toxins which make us feel unwell. WBC produce antitoxins which stick to the toxin molecules and prevent them from damaging cells.