But in fact, while you're asleep, your brain is very active. Scientist believe that during sleep, the brain works to lower levels of stress hormone called cortisol. Research has shown that a lack of sleep causes blood levels of cortisol to go up, causing more stress. That fact helps to explain crabbiness in sleep deprived people. A lack of sleep can lower the levels of these hormones.
Sleep is a restful state of the body when there is little or no conscious thought.
For most people this means that from about age 11 through age 15, they should sleep not less than nine or ten hours at night. Usually after age 16, when approaching adulthood the amount of sleep can gradually be shortened to about eight hours per night. This art show features student works from many area schools. Smith Middle School had several winners in 8 th grade. Emily Farmer won Honorable Mention.