Page 87 - The Miracle of the Immune System

ntil now, we have discussed the general structure of the defence
system, its organs, cells, and enemies. In this chapter, we will ex-
plore the deadly warfare between our defence system and enemy cells,
and the wonderful defence our body mounts.

The brave battle fought by of our defence system is comprised of
three important stages:
1. Identification of the enemy, first action.
2. The attack of the real army, all-out war.
3. Retreat to a normal state.
The defence system has to clearly identify the enemy before it starts
the fight. This is because each engagement differs from the other depend-
ing on the type of enemy. Moreover, if this piece of intelligence is not
properly handed on, our defence system may inadvertently attack the
body’s own cells.
The phagocytes, known as the scavenger cells of the defence system,
take the first action. They fight hand-to-hand with the enemy. They are
just like infantrymen who fight with bayonets against enemy units.
Sometimes, phagocytes cannot catch up with the increasing numbers

of the enemy, at which point big phagocytic cells, macrophages cut in. We
can liken the macrophage to cavalrymen cleaving their way through the
middle of the foe. At the same time, macrophages secrete a fluid, which