Mistake-proofing or Poka-yoke in the human body. Yes - as with
   most things, nature did it first.

   Coughing is a natural reaction that prevents the error of
   foreign bodies from entering into the lungs. The sensitive wall
   linings of the respiratory tract detect and eject minute
   particles through coughing.

   Veins have valves that are designed to prevent the error of
   back-flow of blood as it travels through the system. They also
   allow some blood to collect within the system without busting as
   they have a larger internal diameter

   Arteries have thick walls that can withstand the high pressure
   that blood from the heart exerts on the circulatory system

   Tearing is a necessary reaction to the entry of foreign bodies
   into the eye

   Mucus membrane traps bacteria and prevents the error of
   pathogens entering the system

   The skin is the first defence against entry of foreign bodies
   and the oils and enzymes prevent harmful bacteria into the human
   body

   Inflammation reaction of swelling happens when blood vessels
   leak fluid into the tissues. The chemicals attract white blood
   cells (phagocytes) that eat germs and dead/ damaged cells. This
   reaction prevents the spread of harmful toxins and pathogens to
   the rest of the human body and is a form of natural
   error-proofing