Physiological Factors of Sleep: What You Need To Know

[Abu Tareque]

Physiological Factors of Sleep: What You Need To Know

                                                                       
                                                       

Have you ever noticed how little things irritate you if you don't get enough sleep at night? Studies have shown that sleep deprivation makes our moods more irritable. As a result, you react negatively to small things. A study by the American Psychological Association also reported that adults who slept less than eight hours a night had relatively higher rates of stress symptoms.
Sleep is an essential and involuntary process, necessary for various body functions. It is associated with our physical and mental functioning, immune system, immediate reaction capacity, metabolism and chronic disease prevention. Sleep helps our brain to repair and recover Its function. Sleep is to the brain as fuel is to the car. When the car tank is full of fuel we can get away where we want to go. But over time, the car becomes immobile when it runs out of fuel. Our brain works exactly the same way. The only difference is the fuel. The brain's fuel is sleep. Without enough sleep, our body and brain do not get proper rest, so mental processes such as emotions, memories, new information processing and subsequent information retrieval cannot be completed properly. Moreover, lack of sleep can increase irritability, depression, anxiety and other mental problems. Scientists have proven that lack of sleep causes chemical imbalances in the brain. Our body produces and regulates various hormones. These hormones act as chemical messengers for the brain. Hormones play a major role in various important physiological functions including appetite, weight, mood, immunity, physical growth, emotional healing etc.  If sleep is not enough, this whole system has faced some negative effects.

Stages of Sleep
According to the American Academy of Sleep Medicine (AASM) there are mainly 2 stages of sleep. Non-rapid eye movement sleep (NREM sleep) and Rapid eye movement sleep (REM sleep). NREM again has 3 stages. Each stage plays an important role in brain health. For example-
First stage:- Very light sleep (5-7 minutes): During this time we enter the world of sleep from consciousness, the brain waves decrease.
Second stage:- Light sleep (20 minutes): Muscles begin to relax, body temperature and heart rate begin to decrease.
Third stage:- Deep sleep: In this stage, deep sleep occurs, blood pressure decreases, body temperature and heart rate decrease, various hormones are released, body tissues and immune system are repaired.
Fourth Stage :- REM sleep: During this time the brain is more active, the eyes move faster, the body is more relaxed, in this stage we dream, long-term memories are consolidated, learning and emotion processing takes place.
According to the National Sleep Foundation (USA), these stages can take anywhere from 40 minutes to 140 minutes to complete.  And these stages are very helpful for brain and physical damage recovery and development.  These steps occur several times in a cycle to keep our body functioning.  And that's why we need a total of 6 to 8 hours of sleep every day.

Physiological Factors of Sleep
If we know the various physiological processes, hormones and glandular functions involved in sleep, we will be more aware of the importance of sleep at early night and it will be easier for us to take the necessary steps to solve sleep problems. There is a brief discussion of various physiological processes involved in sleep below:

The Hypothalamus
In nature, when the sunlight decreases, the suprachiasmatic nuclei (SCN) located in the hypothalamus of the brain receive that information from the retina. The SCN sends signals to other hypothalamic nuclei and the pineal gland to control body temperature and hormone production such as cortisol and melatonin. The suprachiasmatic nucleus (SCN) is known as the central circadian rhythm generator and it controls almost all circadian rhythms in the body. The SCN stores all the information, when we are going to sleep, when we are waking up, or when we are doing some other activity and makes the body accordingly. Rhythmic secretion of melatonin is controlled by the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. The pineal gland secretes melatonin when instructed by the SCN. This phenomenon is compared to the opening of the "door of sleep". Melatonin helps us fall into deep sleep. During this period, successive stages of sleep become complete and brain performance increases. Because melatonin is associated with darkness, turning on artificial light at night disrupts melatonin secretion. Again, due to sleeping at different times each night, this disturbance occurs in the central circadian rhythm to track exactly when we go to sleep. If I do not get enough sleep at night, the hypothalamus cannot function properly. As a result, the entire system is disturbed. The body's homeostasis is lost.

The Amygdala
The amygdala is in charge of our emotional responses. We need adequate sleep for it to function properly. Because we know that emotion processing takes place during REM sleep. When we're sleep-deprived, the amygdala is overactive, causing our immediate emotional reactions to intensify. A study using MRI brain scans found that the amygdala was about 60% more responsive in sleep-deprived participants than in non-sleep-deprived participants. So, after insufficient sleep at night, your anger may increase, you may become overactive, and road accidents may increase.

The Prefrontal Cortex
The amygdala is not the only emotion regulation area of ​​the brain. Another area involved in emotion regulation is the prefrontal cortex. It helps us control our impulses. It cannot function properly without good sleep at night. As a result, communication between the amygdala and the prefrontal cortex, which work closely with each other, is disrupted. Then this makes us more emotional /impulsive. As a result, frequent mood swings are found, and restless behavior and increased impulsive behavior are found.

Cortisol Hormone
Cortisol is a hormone produced by the adrenal glands that play a significant role in our "fight or flight" response. It helps us to be alert. Unfortunately, when we don't get enough sleep, too much cortisol is produced. It puts our bodies under constant stress. As a result, we cannot relax. This is why people under a lot of stress suffer from insomnia. Increased levels of cortisol keep them awake. Increased pressure can make you hypersensitive to all kinds of physical and emotional stimuli.

Body Temperature
Sleep requires controlled temperature, light, and sound. These three elements of the night environment are conducive to sleep. We know that during the NREM stage of sleep, our body temperature decreases. The hypothalamus prepares the body for deep sleep by regulating body temperature. Then we fall into a deep sleep. So from this, we understand that there is a relationship between sleep and the temperature of the environment.

 On the psychological side, if we treat sleep time as our rest time if we can go to sleep every day at the same time if we don't check the time repeatedly before sleep if we can stay away from all kinds of devices anhour before sleep if we can exercise sometime during the day. Then hopefully a positive solution to sleep problems will be found.

We all know that we have a total of 24 hours to work. It is up to your decision whether you sleep at night during melatonin secretion or sleep in the morning or during the day in the absence of melatonin. After knowing these details, can we break these natural rules of sleep?

Writer: Abu Tareque, Psychologist, Daffodil International University.