Though sleep is something we all need, most of us don't know enough about it. We know it's usually enjoyable, and most of us wish we could get more, but there's a bit more to it than just that, and it's important to learn about it to maximize its benefits.
Sleep is regulated by two different body systems:
The first is the Sleep/wake homeostasis which tells us when we need to sleep and helps us maintain sleep to make up for the hours we have been awake.
The second system is known as our circadian rhythm. The circadian clock causes energy to rise and dip throughout the day. It's controlled by the Suprachiasmatic Nucleus (SCN), a group of cells in the hypothalamus which responds to light coming through the optic nerve. Adults will experience lows in the mid day between 1-3 pm and in the early morning 2-4 am. Teens have a delay in their circadian clock which does not allow them to sleep when necessary and makes getting up for school extremely difficult. Their 'lows' occur between 3-7 am (sometimes longer) and 2 to 5 pm - so the next time your son or daughter look like they were up all night, cut them some slack!
Even though we will naturally experience these dips, we can lessen the fatigue by giving ourselves proper rest. When we sleep our mind and body enter an altered state of consciousness, and our senses/voluntary muscles slow down. Our body will go through REM (rapid eye movement) and non-REM stages. The REM stage is the deep sleep when we dream and our body has a chance to heal up - I heard some call it biological maintenance! I feel the older I get, the more sleep I need, so how much is enough? The National Sleep Foundation recommends 7 to 9 hours of sleep for adults and more for teens due to their circadian delay.
So make sure you guys are getting enough sleep!