WEBVTT

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Between 4 and 5 weeks,

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the brain continues
its rapid growth

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and divides
into 5 distinct sections.

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The head comprises about 1/3
of the embryo's total size.

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The cerebral
hemispheres appear,

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gradually becoming
the largest parts of the brain.

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Functions eventually controlled
by the cerebral hemispheres

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include thought, learning,

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memory, speech, vision,

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hearing, voluntary movement,

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and problem-solving.