The Mystery of SLEEP!
Remember this scene from the movie - WANTED, where the villain was kept captured in an isolated ship and was provided with everything but sleep. Everyone enjoyed that scene where he struggled to keep his eyes open. Now imagine this happening to you, for some reason you were forced to remain awake for long hours at a stretch, lets take it to be for one or two days. What happens to you? Your head is heavy, your eyes are swollen and paining from inside. You will be full of grumpiness, grogginess, irritability, and forgetfulness. Gradually your head starts spinning and you start to hallucinate. You cannot think of anything but a BED. Just one day without sleep and see what happens to you. Scientists consider it as essential as air, water, and food for an effective human existence. No doubt why we spend almost one-third of our life sleeping. Such is the importance of sleep in our lives and yet we ignore it the most. Our ignorance scales to the extent that we don’t even know why we actually sleep in the first place.
So what do you think? Why do we sleep?
Sleeping as a process was considered simple at an early age. The sun used to go down and humans would have no light to use their sight to make themselves function for any work. Slowly they would start sliding into semi-consciousness and eventually sleep. However, with the changing time and technology, biologists discovered a real mechanism behind it.
There is this internal ‘body clock’ which operates as a periodic cycle, known as Circadian rhythm. It begins when you wake up in the morning. Eventually, as time passes you'll become increasingly tired, this increases the production of an organic compound called adenosine in the brain. It promotes sleep and suppresses arousal. Its level rises each hour, resulting in tiredness. The feeling of tiredness is at a peak in the evening leading up to bedtime. Subsequently, the body breaks down the adenosine compound during sleep, making it ready to be secreted once again starting with the next day’s morning. That’s how amazing the human body is interlinked with mother nature. Interestingly the primitive times logic of light and sight are also proved to be true but in a different sense.
The presence of light is said to influence this circadian rhythm. The region in the brain called the hypothalamus contains a cluster of cells that processes the signals received by our eyes when it is exposed to natural or artificial light. This actually helps the brain detect whether it is day or night. As natural light disappears in the evening, the body will release melatonin, a hormone that induces drowsiness. When the sun rises in the morning, the body will release the hormone known as cortisol that promotes alertness. Thus the natural cycle continues. However, technology has interrupted this as it intervened in many of its forms starting from television boxes to the latest smartphones. Recall that everynight experience, when you are extremely drowsy, just about to close your eyes and sleep tight to fall into the bardo of dream. But exactly at that point of time, your phone vibrates and you cannot help but to open it and check. Scrolling the feed you don’t even realize when that small buzz became hours and the drowsiness is gone, as if forever. Do you have any idea why this happens? It’s because when your eyes are exposed to the artificial light of the screen, the cells present in the hypothalamus process it and conveys as daylight to the brain, restricting the formation of melatonin keeping you awake for hours together making you reluctant to sleep anymore. At this point, there is no release of cortisol anymore and hence you are awake but not active. So even if your Instagram presents an active status of yours to the world you are purely lifeless at that time. Now, after knowing the reason behind sleep your curiosity may be demanding an explanation as to what happens during the time we are asleep. Here’s the answer.
Once we fall asleep, our bodies follow a sleep cycle divided into four stages. The first three stages are known as the Non-Rapid Eye Movement (NREM) sleep, and the final stage is known as Rapid Eye Movement (REM) sleep. As the names suggest it is exactly related to the movement your eyes perform after we are consciously asleep.
Stage 1 (NREM)
The transition between wakefulness and sleep is characterized by this first stage and consists of light sleep. Just like your brain waves, which are more active when you are awake, your muscles relax and your heart rate, breathing, and eye movements start to slow down. Usually, Stage 1 lasts for several minutes.
Stage 2 (NREM)
This second NREM sleep stage is characterized by deeper sleep as your heart rate and breathing rates continue slowing down and the muscles become more relaxed. Eye movements will stop and there will be a decrease in your body temperature. Brain waves also remain slow, apart from certain brief moments of higher frequency electrical activity. Typically, stage 2 is the longest of the four stages of sleep.
Stage 3 (NREM)
To make you feel refreshed and alert the next day, this stage plays an important role. Heartbeat, breathing, and brain wave activity all reach their lowest levels, and the muscles are as relaxed as they will be. This stage will be longer at first and will decrease throughout the night in duration.
Stage 4 (REM)
Around 90 minutes after you fall asleep, the first REM stage will occur. Guess what happens here? Your eyes start moving back and forth, rapidly. (Don’t believe it? So did I, until the day I myself observed this exact eye movement of my younger sister when she was in a deep sleep. This was the only utilization of her sleeping with half-open eyes.)It will steadily increase your breathing rate, heart rate, and blood pressure. Dreaming will normally occur during this stage, and your arms and legs will become paralyzed (this is believed to happen to prevent you from acting on your dreams physically). As the night progresses, the length of each REM sleep period increases.
Until you wake up, these four phases will repeat cyclically during the night. The length of each loop would last about 90-120 minutes for most individuals. Around 75 - 80% of each period is NREM sleep. You may also wake up briefly during the night but not remember the next day. These episodes are referred to as "W" stage.
Mind-boggling! What an irony? The only simplest thing in life (the dearest sleep), which so far appeared to be most doable turn out to be so complex. Never mind, you will still manage to sleep like a baby, I'm sure. Sleep is still a debatable topic in the medical field because it's hard to experiment with. Even after experiments, the observations and results are difficult to reach, because the subject here, most of the time cannot actually express the things that happen to him/her during the sleep experiments. Hence remains the grey areas in the exact theories. But don't worry you will be fed the best useful information regarding it via wonderwisdom. Till then lay on the bed, grab the pillow, close your eyes, sleep tight, and DREAM, because this will be the topic for next week. Hope you keep your dreams lined up to comment on our next post. For now, share this one with those who love their sleep.
Happy Reading!
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