Know a bit about your immune system

To help keep us well and in good working order, Nature has endowed us (and all other creatures) with an immune system. The immune system is like an army of cells with three regiments. The first regiment of cells act as guards. They are posted around our body to watch out for invasion by foreign cells such as bacteria and viruses.

If an invasion takes place, a second regiment of killer cells is conscripted and sent to the site of the invasion via the blood stream where they destroy the invaders with antibodies that they manufacture specifically for each new invader. When the battle is over, a third regiment of cells is marshalled to clean up the dead organisms and other cells that have been killed.