Immunity Analogy

Imagine that the human body is like a country and the cells are the individual people that live in the country

  • Groups of cells may form organs, just like people may form societal groups like sporting clubs or occupations

Pathogens are foreign bodies that cause disease, similar to the way in which criminals cause mayhem and damage

  • Pathogens can either cause damage endogenously (i.e. attack from abroad) or exogenously (i.e. attack from within)

The immune system is the body’s defence force and is comprised of three distinct levels of defence 

  • The first line of defence are surface barriers which function like physical borders (walls, moats, oceans) to keep criminals out
  • The second line of defence is the innate immune system, which is akin to the nation’s standard police force
  • The third line of defence is the adaptive immune system, which is akin to a nation’s special forces (army, super heroes, etc.)

Both the innate and adaptive immunity fight off infection concurrently, however there are key differences between the two:

  • The innate immune system is quick to respond but is non-specific (just like police are first on the scene but lack special training)
  • The adaptive immune system is slower to respond but is specific (special forces take longer to mobilise but are better trained)
  • The innate immune system present antigens (information about specific pathogens) to the adaptive immune system
  • Based on the antigens (information) presented, appropriate antibodies (weapons) are made to combat the threat

Immune System Analogy