Introduction
Consider the average index finger. It consists of three segments starting
with the fingertip moving down to the middle phalanx and then the
proximal phalanx that attaches to the knuckle. Together these phalanges can extend, as when pointing the finger,
or flex, as when pulling a trigger.
By themselves, phalanges, or any body parts,
for that matter, are only so many proteins, lipids, carbo-hydrates,
nucleic acids, and minerals that, when com-bined, become tissue and
bone. These compounds would remain completely useless if not for the
Central Nervous System, or CNS.
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The CNS consists of the brain and spinal cord,
which together issue commands that direct bodily movement. If one
needs to kill an enemy, for instance, the CNS sends an order for the
hand to pick up and use a weapon. The CNS can just as easily command
the hand to wave, as in victory, or the bicep to flex, as in a show
of strength.
Considering that these are among the millions
of possible bodily actions that can be instigated by the CNS, it's
not unreasonable to think of the CNS as the body's chief executive.
From its superior position on the body it presides over an extensive
mass of units, otherwise known as cells, which carry out the many
tasks that allow humanity to thrive as the world's dominant species.
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