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A sensible guide to
producing better, brighter babies
Your body is more fascinating than any
machine.
Every day about two million of its cells wear out. But
the body replaces them automatically.
Every 15 to 30 days your body completely replaces the
outermost layer of your skin. What you see in the mirror today is not the same skin you
had a month ago.
But some cells your body will never replace: the 100
billion active nerve cells, or neurons, that make up your brain's cortex.1
Every one of them was present the day you were
born. In your mother's womb you were growing them at an average of 250,000 cells every
minute.
Each one continues to grow in size over the first few
years of life. Each one, as we've seen, is capable of sprouting up to 20,000 dendrites.
But after birth you never gain another active neuron as long as you live.*
What happens to each brain in the nine months
before birth is therefore vital to later learning ability. When pregnant women are
severely undernourished, their children can be born with fewer than half the brain-cells
of a healthy child.
As we've seen, neurons are not the only cells in the
brain. We each have up to 900 billion glial cells to nourish the neurons. These
glial cells also develop myelin, the sheathing that wraps around our axons.
These are the nerve pathways that speed messages from neuron to neuron and
* You do, however, grow new brain
cells in the cerebellum, the "little brain" that plays such a big part in
storing "muscle memory"; hence the vital importance of learning by doing.
Contents Page Preface
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