Sleep may be a static process for the body, it is definitely not static in the brain. The brain goes through a complex cycle during sleep called the sleep cycle. There are two types of sleep called Rapid Eye Movement (REM) and Non Rapid Eye Movement (NREM) and there are 4 stages of sleep. It will start with stage 1 NREM sleep and then it will progress through the other stages of sleep within a number of minutes or hours. After the first sleep cycle has been completed, it will return to stage 2 and become REM sleep, which is a much deeper sleep where dreams occur. During REM sleep, it will go through stages 2-4 and then return back to stage 2 toward the end.
Interruptions during sleep can alter the process slightly. A person that is fast asleep in stage 3 NREM could return back to stage 1 if they are disrupted during the process by a noise or if they have to wake up for some reason. It will usually take a few hours uninterrupted sleep to get some quality REM where dreaming occurs. The REM type of sleep is what tends to be the most beneficial for the brain and body. It is where the brain and body will recover, while the NREM stages act more like a precursor.
Guest post and infographic courtesy of Austin neck pain specialists, Advanced Pain Care.