The Science Behind Sleep

By Mabel Soriano, 11th Grade

Nothing is better than a good night of sleep and incredibly so, this is scientifically proven. We all know that sleep is crucial to our well-being, either because we did a quick google search or after years of our parents telling us so. However, I doubt you know why sleep is important and what happens to your body when you don’t sleep properly. 

From a medical point of view, “sleep is a state of natural unconsciousness from which one can be aroused. The actual brain activity is not apparent besides the continued maintenance of bodily functions.” In other words, when we’re asleep our brain is technically resting, meaning that it’s doing the bare minimum work in order to keep us alive. As we all know, the brain controls everything from our blood pressure to our hand movements. In fact, doctors pronounce a person dead when they don’t have any brain activity although their heart is pumping blood because, without the brain, our body can’t control itself. Without proper brain activity, we can’t walk or eat, and we can barely blink. 

This being said, the brain also controls sleep. In order to understand the process of sleep, we need to know a little bit about CNS anatomy. The Central Nervous System (CNS) or neuraxis consists of the brain, the brain stem, and the spinal cord. The CNS has two parts: the somatic nervous system (SNS) which controls voluntary movement in the body, and the autonomic nervous system (ANS) which regulates the functions of some of the internal organs. The reticular activating system or RAS is a functional system in the brain—although mostly on the brain stem— that is essential for levels of wakefulness. Within the RAS, there resides the RF. The reticular formation (RF) is a small, thick cluster of neurons nestled within the brain stem, controlling breathing, the heartbeat, and levels of consciousness by communicating with other parts of the CNS to inform of incoming stimuli and consequently, inhibits a proper response. 

This is a lot of information at once so let’s dissect it into smaller parts and maybe with words within the English language. Okay so let’s start with the basics, shall we? The brain has three parts and each one of these parts usually performs different tasks. As described above, sleep is mostly controlled by two things: the RAS and RF. Both of these are located in the brain stem (think of the back area of your neck). So in theory, we could assume that by shutting down these two systems we fall asleep–but sadly things aren’t that simple. 

Remember those stimuli that were mentioned before? Well, our levels of wakefulness are controlled by stimuli, which are things or events that evoke a specific functional reaction in an organ or tissue. A stimulus can be temperature, stress, sunlight, allergens, etc. The stimulus and the whole process of falling asleep are explained in the circadian rhythms. “Circadian rhythms are physical, mental, and behavioral changes that follow a 24-hour cycle. These natural processes respond primarily to light and dark, and it affects most living things.” The circadian rhythms are regulated by our biological clocks which are organisms’ natural timing devices. They are composed of specific proteins and hormones that interact with cells throughout the body. 

At some point, we all have wondered why we get tired around nighttime and stay awake throughout the day. This is because of our circadian cycle which is based on the amount of sunlight or artificial light we receive. Below, there is a picture that describes a teenager’s average circadian cycle.

Now we understand how sleep works and why our body decides to stay awake throughout the day and sleep during the night. When properly aligned, a circadian rhythm can promote consistent and restorative sleep. But when this circadian rhythm is thrown off, it can create significant sleeping problems such as insomnia. Additionally, research has revealed that circadian rhythms play an integral role in diverse aspects of physical and mental health. 

Our circadian cycle can be disturbed, for example, by staying up too late or not sleeping at all, caffeine, and medication consumption. Without the proper signaling from the body’s internal clock, a person can struggle to fall asleep, wake up during the night, or be unable to sleep as long as they want into the morning. Their total sleep quantity and quality can be reduced. As a whole, a misaligned circadian rhythm can negatively affect sleep in many ways, increasing the risk of insomnia and excessive daytime sleepiness. Given the essential role of sleep for productivity and overall health, there are often significant consequences when we lack sleep. 

All things considered, the value of sleep is indisputable. Sleep boosts the immune system, strengthens the heart, prevents weight gain, improves memory, recovers the body from exhaustion, and from a psychological aspect, a good night of sleep equals a better mood. Sleep is innate and irreplaceable for the maintenance of the human body. Therefore, let’s indulge and sleep in from time to time!


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