Читать книгу The Art of Sleeping - Rob Hobson, Rob Hobson - Страница 30

31 MELATONIN: THE SLEEP HORMONE Melatonin is a natural hormone made by your body’s pineal gland and is the key hormone that drives our sleep/wake cycle. is is a pea-sized gland located just above the middle of the brain; during the day the pineal is inactive, but when the sun goes down and darkness occurs, the pineal is ‘turned on’ by the SCN and begins to actively produce melatonin, which is released into the blood. Usually, this occurs between the hours of 9pm and 11pm. As a result, melatonin levels in the blood rise sharply at this time and you begin to feel less alert, making sleep more inviting. Melatonin levels in the blood stay elevated for about twelve hours – all through the night – until the light of a new day breaks, when they fall back to low daytime levels by about 9am. Daytime levels of melatonin are barely detectable.