Page 187 - The Miracle of Hormones

Communication in Nerve Cells

Sodium Potassium Extracellular fluid
Extracellular fluid
channel channel

Cytoplasm Cytoplasm

Ions have an important function in a neuron. There is one positive sodium ion, one
positive potassium ion, two positive calcium ions, and one negative chloride ion. The
proportion of potassium inside the neuron is larger compared to that on the outside
while the proportion of chloride and sodium is lower. What we have to notice here is
that this arrangement must be specially designed and maintained in order to keep
these balances in a definite proportion; it cannot happen by chance.

An Evident Fact

There is another feature that distinguishes neurons from the rest of
our cells. Other cells in our bodies are constantly being renewed but neu-
rons do not change. With age, their number decreases but the nerve cells
present in a person's old age are the same ones he had in his youth. What
has been described to this point has been a really simplified account of
communication systems in the neurons that function throughout a per-
son's life. Even someone with intelligence and knowledge would have
difficulty understanding these things; cells and hormones have per-
formed these functions very successfully without error in the millions of
individuals that have lived in the world since the beginning.
How did these highly complex systems in each one of our nerve
cells come into being? How did the incredible harmony among the hun-
dreds of millions of cells in our bodies come into existence? How is such
marvelous communication system ensured without confusion arising?
How does this system, which depends on remarkably delicate balance
and timing, work without making an error?

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