Page 68 - The Miracle in the Immune System

66 THE MIRACLE OF THE IMMUNE SYSTEM

Their characteristic of ingestion makes them
the scavengers of the defence system. They re-
move all materials that need to be cleaned up,
such as micro-organisms, antigen-antibody com-
plexes, and other substances similar in structure
to an antigen. At the end of these processes, sub-
stances that would be qualified as antigens are di-
gested, and thus pose no further threat to the
organism.

General Alarm
When a country is involved in war, a general
mobilization is declared. Most of the natural re-
sources and the budget are expended on military
requirements. The economy is re-arranged to
meet the needs of this extraordinary situation
and the country is involved in an all-out war ef-
fort. Similarly, the defence system would also an-
nounce mass mobilization, recruiting all of its
elements to fight the enemy. Do you wonder how
this happens?
If enemy members are more than the current-
ly fighting macrophages can handle, a special sub-
stance is secreted. The name of this substance is
"pyrogen" and it is a kind of alarm call.
After traveling a long way, "pyrogen" reaches
the brain where it stimulates the fever-increasing
centre of the brain. Once alerted, the brain sets
off alarms in the body and the person develops a
high fever.
To the right, you can see macrophages
while trying to ingest foreign materials.