Step One: Defend
When an invader attempts to enter the body, it must first cross
multiple barriers such as our mucus membranes and skin. If the
invader enters the body, white blood cells quickly recognize the
pathogen as an invader and begin to coordinate the defense system.
Soon, other defender cells, such as killer cells, macrophages and
phagocytes come to help destroy the invader. White blood cells
begin to produce an antibody to defend against any future attacks.
The body produces more than one billion different antibodies to
combat many types of invaders.
Step Two: Attack
These invaders are then attacked and destroyed by natural killer
cells. The killer cell binds to its target, aims its weapons and
then delivers a lethal burst of chemicals that produces holes in
the target cell's membrane. Fluids leak out and the cell
bursts.
Step Three: Cleanse
Macrophages, the "garbage men" of the body, have tentacles that
grab the destroyed organisms and engulf them. The function of the
macrophage is to ingest any foreign particles, including aged body
cells.
Step Four: Repair
Damaged areas are repaired and the normal, healthy condition of the
body is restored. Mast cells release histamine and heparin which
stimulate other cells to open the blood vessels, thereby increasing
circulation and allowing the process of cell and tissue
regeneration.
