Main purpose of sleep is for maintaining a healthy body. In point of fact, we cannot live without sleep, just as we cannot live without food or water. Since this is the case, it should come as no surprise that we spend approximately one-third of our lives sleeping.
During sleep, a number of important biological processes take place:
- The brain is responsible for the storage of new information as well as the elimination of toxic waste.
- The ability of nerve cells to communicate with one another and to reorganize themselves is critical to normal brain function.
- The body is responsible for the repair of damaged cells, the restoration of lost energy, and the release of molecules such as hormones and proteins.
These processes are essential to the well-being of our bodies as a whole. Without them, our bodies would not be able to operate properly.
Let’s take a more in-depth look at the purpose of sleep, as well as the consequences of not getting enough of it.
What is the purpose of sleep?
The function of sleep is still largely a mystery to scientists. However, there isn’t just one reason why we have to sleep, and this is a fact that is generally acknowledged by most people. It’s probably essential for a lot of different biological reasons.
To this day, researchers have found that sleep benefits the body in a variety of different ways. The most widely accepted explanations and hypotheses are outlined in the following paragraphs.
The conservation of energy
According to the theory of energy conservation, in order to save energy, we have to get enough sleep. Because our metabolism slows down while we sleep, we are able to cut back on the number of calories that we require to keep ourselves awake.
The fact that our metabolic rate drops while we are sleeping lends credence to this theory. According to research, the average human being can reduce their daily energy consumption by 35 percent by sleeping for eight hours instead of staying awake the entire time.
According to the energy conservation theory of sleep, one of the primary functions of sleep is to minimise the amount of energy that is expended by a person during the hours of the day and night when it is inconvenient and ineffective to go out and hunt for food.
According to yet another theory, which is known as the restorative theory, the body needs sleep in order to repair and rejuvenate itself.
The hypothesis is that during sleep, cells are able to repair themselves and regrow. This is supported by a number of significant processes that take place during sleep, including the following:
- muscle repair
- the synthesis of protein
- growth of tissue
- hormones being released
The functioning of the brain
According to the brain plasticity theory, getting enough sleep is necessary for proper brain function. To be more specific, it enables the reorganisation of your neurons, which are also known as nerve cells.
When you sleep, the glymphatic system in your brain, which is responsible for waste clearance, cleans out the waste from the central nervous system. It rids your brain of the harmful byproducts that have accumulated there over the course of the day. When you wake up, your brain will be in a good position to function properly thanks to this.
According to research, one of the ways in which sleep helps the memory is by converting short-term memories into long-term memories. Another way sleep helps the memory is by erasing, or forgetting, unnecessary information that would otherwise clutter the nervous system.
Sleep has an effect on a variety of facets of cognitive operation, including:
- problem-solving skills
- decision making
In a similar vein, getting enough sleep is essential for mental health. Because of this, healthy brain function and emotional steadiness are both supported by the increased brain activity that occurs during sleep in the areas of the brain that are responsible for regulating emotion.
Some of the regions of the brain that become more active during sleep are as follows:
- medial prefrontal cortex
The amygdala is a good example of how sleep can help regulate emotional states because of its role in the fight-or-flight response. The fight-or-flight response is controlled by this section of the brain, which is found in the temporal lobe. It is what governs your response whenever there is a potential danger, such as when you are put in a stressful situation.
When a person gets an adequate amount of sleep, the amygdala is able to react in a manner that is more adaptive. On the other hand, a lack of sleep makes the amygdala more likely to have an exaggerated response.
According to the findings of various studies, a healthy mental state is directly related to adequate sleep. On the one hand, issues with mental health can contribute to the onset and progression of sleep disturbances, but on the other hand, sleep disturbances can also be caused by mental health issues.
Maintaining of Weight
The hormones that control hunger are affected by the amount of sleep you get. These hormones include ghrelin, which stimulates hunger, and leptin, which heightens the sense of satiety that one experiences after consuming food.
Ghrelin levels drop when you’re asleep because your body consumes fewer calories than it does when you’re awake.
However, a lack of sleep causes ghrelin levels to rise while simultaneously lowering leptin levels. Because of this imbalance, you will feel more hungry, which may increase the likelihood that you will consume more calories and gain weight.
According to findings from recent studies, chronic sleep deprivation, even as few as five nights in a row of short sleep, may be associated with an increased risk of the following:
- metabolic syndrome
- type 2 diabetes
Effectiveness of insulin
Insulin is a hormone that facilitates the process by which your cells convert glucose, also known as sugar, into energy. But if you have insulin resistance, your cells won’t respond to insulin the way they normally would. This can eventually result in the development of type 2 diabetes because it causes high blood glucose levels.
It’s possible that sleep can help prevent insulin resistance. It maintains the health of your cells so that they can more easily take in glucose.
During sleep, glucose is used by the brain at a lower rate, which assists the body in better regulating overall blood glucose levels.
Sleep is absolutely necessary for maintaining a sound and robust immune system. According to research, not getting enough sleep can weaken the immune system, making the body more susceptible to illness caused by pathogens.
Your body produces cytokines, which are proteins that fight infection and inflammation, while you are sleeping. Cytokines are produced in large quantities. In addition to this, it generates specific antibodies and immune cells. These molecules, when working together, eliminate disease-causing germs, thereby preventing illness.
When you are sick or under a lot of stress, getting enough sleep is especially important. At these times, the body requires an increased amount of immune cells as well as proteins.
Good for heart Health
Scientists believe that getting enough sleep is beneficial to heart health, but they are unsure of the reasons why. This is because of the correlation between having heart disease and having sleep problems.
According to the Centers for Disease Control and Prevention (CDC), an adult needs a minimum of seven hours of sleep each night. Consuming less than that on a consistent basis can lead to a variety of health issues, many of which can be detrimental to the health of your heart.
Insufficient sleep has been linked to a number of heart disease risk factors, including the following:
- hypertension; high blood pressure
- a higher level of activity in the sympathetic nervous system
- elevated levels of inflammation
- excessively high levels of cortisol
- weight gain
- Insulin resistance as a noun
When you sleep, what happens to your body?
During sleep, your body goes through four distinct stages. This cycle repeats itself several times throughout the course of the night for periods of time ranging from seventy to one hundred twenty minutes each time. During a period of sleep that lasts anywhere from seven to nine hours, the stages typically occur four to five times each.
Non-rapid eye movement sleep (also known as NREM sleep) and rapid eye movement sleep (also known as REM sleep) are the two primary stages that make up this pattern. There is one stage of rapid eye movement (REM) sleep and three stages of non-REM sleep that make up the four stages of sleep.
Non-REM sleep, which is when you are not dreaming, is characterised by the absence of any eye movement, whereas REM sleep, which is when you are dreaming, is characterised by rapid eye movement.
The following is a rundown of the four stages of sleep:
Stage 1: Non-REM sleep
The first stage of sleep is when you first start to feel sleepy. Your brain waves, heart rate, and eye movements will all slow down as you enter a light sleep stage of the sleep cycle.
This portion of the process lasts for approximately 7 minutes.
Stage 2: Non-REM sleep
In this stage, you will be in a light sleep just before you enter your deep sleep.
Your eye movements come to a stop, your body temperature drops, and your heart rate slows down while your muscles continue to relax. After a momentary peak, your brain waves begin to decelerate.
The second stage of sleep is where you spend the majority of your time while you are asleep at night.
Stage 3: Non-REM sleep
In stages 3 and 4, deep sleep begins. Your muscles and eyes become immobile, and the waves produced by your brain continue to slow down.
Deep sleep is restorative. Your body restores its energy and makes repairs to its muscles, cells, and tissues while you sleep. This phase is necessary for you to wake up feeling alert and refreshed the following day.
Stage 4: REM sleep
This stage begins approximately one hour and thirty minutes after you first fall asleep. During REM sleep, rapid eye movement occurs, in which your eyes rapidly move from side to side.
During REM sleep, your brain waves and eye movements speed up. REM stands for rapid eye movement. Both your heart rate and your breathing speed up as well.
REM sleep is the stage of sleep in which dreaming most commonly occurs. During this stage, your brain is also processing information, making it an essential stage for both learning and memory.
How much sleep do you require each night?
The number of recommended hours of sleep changes according to a person’s age. It also differs from person to person, but the Centers for Disease Control and Prevention recommend the following durations according to age:
- 14 to 17 hours between birth and three months.
- 4 to 12 months: 12 to 16 hours over the course of a 24 hour period, including naps
- 11 to 14 hours per 24 hours, including naps, for children aged 1 to 2 years
- 10 to 13 hours per 24 hours, including naps, for children aged 3 to 5 years
- 9 to 12 hours for children aged 6 to 12 years
- 13 years old to 18 years old: eight to ten hours
- 18 to 60 years old: seven hours or more
- 7–9 hours per day for those aged 61–64
- 7 to 8 hours per day for those older than 65
What happens if you don’t get enough sleep?
Your body will have a difficult time functioning properly if you don’t get enough sleep. A lack of sleep has been linked to a variety of chronic health conditions, including those that affect the heart, kidneys, blood, brain, and mental health.
An increased risk of injury is associated with not getting enough sleep, and this is true for both adults and children. For instance, drowsiness behind the wheel can lead to catastrophic car accidents and even fatalities in some cases.
In adults over the age of 60, a lack of quality sleep is linked to an increased risk of falling and breaking bones.
Some of the potential negative effects of not getting enough sleep are as follows:
- Alterations in Mood
- memory problems
- the inability to focus and concentrate
- insufficient motor function
- a compromised immune response
- weight gain
- hypertension; high blood pressure
- Insulin resistance as a noun
- diseases that come back over and over again, like diabetes and heart disease
- increased chances of passing away at a younger age
Sleep is essential to our physical and mental well-being. It provides your body and brain with the opportunity to repair, restore, and reenergize themselves.
If you don’t get enough sleep, you may experience negative side effects such as impaired memory and concentration, lowered immunity, and mood swings.
The average adult requires between seven and nine hours of sleep per night. Talk to your primary care physician or a specialist who specializes in sleep if you are having trouble falling or staying asleep. They will be able to identify the underlying cause and provide assistance in enhancing the quality of your sleep.