|
|
Night Life The one thing that we as individuals have in common is that we sleep, well most of us do. Each night we lie in our beds, close our eyes and enter into a world that is virtually unknown to us. Scientists have studied the functions of sleep and have created many theories as to why we sleep, why we dream and what is happening in our brains during the sleep cycles. The article Night Life discusses a few of these theories and particularly the discusses the function of sleep. During our sleep cycle there are five stages of sleep. The fist four stages are called non-REM sleep (NREM) and the last stage of sleep called REM (Rapid Eye Movement). During the NREM stages our muscles are relaxing, our heart rate slows down and the neurons that send information from are brain to other parts of the body are slowing down. Each stage lasts about ninety minutes, starting at stage one and moving up slowly to the fourth stage. Once we get to stage four, the deepest stage in NREM sleep we go back to stage three and two, waking slightly.
|
