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Joe Herbert Ph.D. – Stress Interferes With the Rhythm of Life: Why This Matters

The whole of life is locked into a rhythm.  A slow-motion camera focused on any road would reveal two surges in traffic: one in the morning, the other in the evening.  We call them rush hours, but they are really a reflection of the way that our lives are organized.  Underlying this is the way we alternate periods of sleep and wakefulness.  This, in turn, is closely linked to the occurrence of day and night.

Anyone who travels knows the effects of disturbing these rhythms.  Jet-lag stops yousleeping when you should, alters your mood and interpersonal relations, makes it difficult to think clearly and effectively, and generally degrades the quality of life.  But only for a few days: luckily, we recover, and go back to our usual ways. Were it to last for, say, several weeks, our lives would be disrupted and we would almost certainly seek medical advice.

Body rhythms are controlled by a clock in the brain, called the SCN (suprachiasmatic nucleus). It lies just behind the eyes, which reflects the fact that light controls it. Left to itself, it would generate a rhythm that would be approximately, but not accurately, 24 hours: so it’s a self sustaining clock – it doesn’t an external stimulus to keep it going. Light from the eyes synchronizes it to the external day-night rhythm so that the body clock now ticks at exactly 24 hours. One of the important functions of the SCN clock is to generate a daily rhythm of cortisol, the hormone from the adrenals.

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