Page 15 - The Miracle in the Immune System

efore delving into the astounding details of the
war of defence fought in the innermost recesses
of our bodies, we must first have a general look at the
defence system and its elements.
Briefly, the defence system may be defined as "an ex-
tremely disciplined, hard-working and organised army
that protects the body from the clutches of external en-
emies." In this multi-faceted war, the main duty of the el-
ements fighting in the front line is to prevent the enemy
cells, such as bacteria or viruses, from entering the body.
Although it is not easy for the enemy organisms to
enter the body, they exert themselves to the utmost to
reach their ultimate goal of invading the body. When
they successfully do so, after overcoming various obsta-
cles such as the skin, and the respiratory and digestive
tracts, they will find tough warriors waiting for them.
These tough warriors are produced and trained in spe-
cialised centres such as the bone marrow, spleen, thy-
mus, and lymph nodes. These warriors are "the defence
cells" referred to as the macrophages and lymphocytes.