A lot of people know that most of the parts of our body stop functioning when we sleep, putting them into a state which allows them to rest and regenerate. When we sleep, our body naturally regenerates cells and remove toxins, which is why sleep is essential for us.
However, our bodies do not entirely stop functioning. It is a common misconception that the brain stops working when we are asleep. Recent studies show that this claim is entirely false since the brain works double-time when we are sleeping.
In this article, we are going to take a look into how the brain works while we are asleep.
What do our brains do when we are asleep?
When we sleep, our brains change from an active state to a passive state. This state puts our bodies into rest, which helps us regenerate cells. However, this state does not make our brains entirely inactive since our body systems are still working even while we are asleep. That is why our hearts beat, and our lungs allow us to breathe even while we sleep. Our brains remain functioning during sleep, which gives a signal to our heart and lung muscles to continue their work. It is safe to say that our brain only stops functioning when we’re dead. But as long as we are alive, our brains will continue to work regardless if we are awake or asleep. However, when we are sleeping, we will lose the ability to have consciousness and think.
Moreover, our brains undergo two types of sleep when we sleep – Non-REM sleep and REM sleep.
What are REM and Non-REM sleep?
Apart from the involuntary actions our brain does when we are asleep, it also undergoes two types of sleep – mainly the REM and Non-REM sleep.
For starters, non-REM sleep is the first part of our sleep, which includes three stages. Experts previously consider this stage to have four stages, until 2007, when they proposed that there is no clear distinction between stage three and four of the non-REM sleep.
The first stage of non-REM sleep is a cycle between being awake into falling asleep. This moment is when we feel drowsy until we gradually fall asleep, slowing down the heartbeat and the breathing rate. In this stage, the muscle starts to relax, and the body temperature decreases. This stage is only a light form of sleep, which usually lasts for five to ten minutes, in which our body may quickly wake up from various stimuli.
The second stage of non-REM sleep is what experts consider the period of light sleep. During this stage, there is a significant decrease in heart rate and brain waves. The muscles further relax, and the eye movement stops. This stage usually lasts ten to twenty-five minutes, and it is the stage that makes up the most percentage of our sleep. When we sleep during the night, the sleep cycle continuously repeats, in which the second stage of non-REM sleep is the most used – covering fifty-five percent of our sleep.
The third stage of non-REM sleep is what experts call – deep sleep. This stage of sleep is what we need to make us feel refreshed during the next day. This type of sleep usually lasts for twenty to forty minutes. During this stage of sleep, our body is in a deep passive state, making it less responsive to external stimuli. That is why, when a person sleeps, there are times that they are difficult to wake up. It is most probable that they are under the third stage of non-REM sleep, and in case that they do wake up, they would feel disoriented. During this stage, the heart rate and breathing rate further slow down to their lowest level. Blood pressure and body temperature also continue to drop. In this stage, there is no eye movement, and the muscle movement significantly decreases. On average, we spend fifteen percent of our sleep in the third stage of non-REM.
The REM sleep is what we call the – Rapid Eye Movement sleep. During this stage of sleep, our eyes rapidly move behind the lids, and our brain becomes more active, similar to when we are awake. Our breathing rate increases, and our body temporarily stops as we dream. It is only possible to reach the REM sleep if a person already finished the early stages of non-REM sleep. This stage of sleep is where our dreams occur.