Beginning of Essay
Set deep in our brains is a tiny gland called the pineal gland. This tiny gland is in charge of the endocrine system, the glandular system that controls most of our bodily functions. The pineal runs our Œbody clocks', and it produces melatonin; the hormone tha ....

Middle of Essay
.... Our eyes send it a message of how much sunlight they see, and when it's dark. The sunlight prohibits the gland from producing melatonin, so at night, when there's no sun, the sleep-inducing hormone is released into our bodies. Because of the pineal gland and melatonin, humans have known to sleep at night and wake during the day since long before the age of alarm clocks. Humans don't produce melatotin right from birth; it is transfered in utero to babies through the placenta. For their first few days of life, babies still have to receive it from breast milk. Our levels of melatonin peak during childhood, then decrease at the beginning of puber ....