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Wondrous alchemy is produced in the hypothalamus which lies just beyond the midbrain-end. It synthesizes hormones to control growth, raise and lower temperature, regulate the body's water-balance and activate sexual behaviour. The hormones funnel into the pituitary gland below, where they are stored or released into the blood-stream. Nearby is the pineal gland- —the vestige of a primitive third eye—in fact, a light activated biological clock that regulates sex-gland activity.
The thalamus, at the top of the brainstem helps to regulate consciousness. Information from nearly every area of the body is relayed by it to the cerebrum above. The limbic system, composed of various parts, is the emotional brain.
Above spreads the vaulted cerebrum, the two-thirds of the brain where human thought and creativity originate. Hundreds of millions of microscopic threads of white matter form an array of connections between the cortex's nerve centres and distant parts of the brain. The corpus callosum knits together the two hemispheres and unites the special powers of both hemispheres, one specializing in analytical and verbal skills, the other adept in space and pattern perception. The left one which dealt in the abstract symbols of language and numbers, was logical and sequential in processing information. The right one generated mental images, grasped things as a whole, was holistic and simultaneous in its thinking. Recent studies have established that the brain divided (by cutting the corpus callosum) can function as ably as the brain intact.
Less than a 1/4 inch thick, the cerebral cortex1 forms a fissured mold snug against the skull. It is composed of six layers of cells meshed in some ten thousand miles of connecting fibres per cubic inch. Each hemisphere is further divided into four lobes (1) Frontal lobe (2) Parietal lobe (3) Occipital lobe and (4) Temporal lobe. Every voluntary movement from hand-shake to the wink of an eye is controlled by motor cortex in the frontal lobe. Sensory cells that respond to touch, heat, cold, pain and body-position cluster the parietal lobe. Visual cortex
1. The cortex measures about 24 square feet and is about 1/4 inch thick.
(xviii)
