When sleep improves, the chances of recovery increase
In the modern world, many of us steal time by sacrificing sleep. This is a very bad habit and a sign that we do not value our health.
Sleep is a product of brain activity. A person cannot go without sleep for a long time.
Sigmund Freud provides the following information about sleep: "Sleep is a condition characterized by the loss of interest in the external world from a psychological perspective. Its biological purpose is rest. Dreaming, on the other hand, is the mental life during sleep. Four main mechanisms of sleep have been identified: condensation, movement, secondary processing, and the prominent representation of thought and statement".
The sleep center, as one of the oldest formations, is located in the medulla oblongata. The main sleep center is the central gray matter of the midbrain, containing serotonin neurons in the striatum, which eliminate unnecessary information flows in the brain with the help of the neurotransmitter serotonin. Afterward, it acts on neurons through gamma-aminobutyric acid, which is the main inhibitory neurotransmitter.
The reticular formation collects information from sensory organs about the change between day and night and sends it to the hypothalamus, the part of the brain responsible for regulating the 24-hour sleep-wake cycle.
In contrast, the parasympathetic nervous system is responsible for ensuring that the body accumulates and restores its energy reserves during sleep, rest, and relaxation.
The hippocampus, located in the medial temporal lobes, is considered the center that produces dreams.
Melatonin is a sleep hormone produced by the brain in darkness. It is synthesized by the pineal gland and activates the sleep center while inhibiting the function of the cerebral cortex.
Characteristics of sleep include falling asleep, phase transitions, duration of sleep, sleep quality (deep sleep, frequent awakenings, dreaming), and waking up refreshed. Nighttime sleep consists of 4-5 cycles, each beginning with slow-wave sleep and ending with REM (rapid eye movement) sleep.
Sleep is typically divided into two main phases: slow-wave sleep and REM sleep. The duration of slow-wave sleep in an adult is about 1.5 to 2 hours. This is followed by a 5-10 minute REM sleep phase. There are 4-5 cycles during the night. As a person approaches wakefulness, the slow-wave sleep phase shortens and the REM phase lengthens. Therefore, deep sleep is the most important phase of sleep. This delta sleep allows us to feel good, avoid pain, see better, and perform efficiently in business and sports. The REM phase occurs about one hour or an hour and a half after falling asleep.
The fourth stage of sleep is characterized by dreaming. During this stage, the brain is highly active, and we experience vivid dreams while being in deep sleep. This phase is easily recognized by rapid eye movements or REM. Each cycle consists of 4 phases of slow-wave sleep and 1 phase of REM sleep. The first phase is 10% of sleep, the second is 50%, the third is 25%, and the remaining 15% is REM sleep. The period associated with dreaming does not exceed two hours during the night. It is crucial to go to bed no later than 11:00 PM, and sleep should last 8-9 hours. Sleep must cover the period from midnight to 5 AM, as it is during this time that the maximum amount of the longevity hormone melatonin is produced.
During the circadian phase of sleep, various biochemical processes occur in the brain and the body. Initially, the movement functions of a person who has fallen asleep significantly decrease. The only movements during sleep are related to turning over, or the occasional twitching of arms and legs. Sensory organs continue to function weakly, so we may feel the bite of a mosquito, loud sounds, or the sensation of being touched. Painful conditions caused by illness may also be felt during sleep, but they are incorporated into the dream narrative. For example, if the heart feels squeezed, it may appear in the dream as if something is wrapped around it or as if the person is trapped in a small space, while thirst may be represented by the image of water or a waterfall.
According to scientific research, during sleep, the brain tests all the functions of the body. It organizes information about the day’s activities, events, and data, storing them in the appropriate memory areas. During this time, a person dreams. In the dream, the brain depicts real, unreal, painful, or imagined situations.
Therefore, in our dreams, there are often fragments of emotionally charged events, such as fear or happiness, influenced by situations we encountered during the day or images from our surroundings, leading to remarkable, complex dream sequences. Humanity continues to research the process of dreaming.
Sleep disorders are considered an early sign of many diseases, and this has been proven in medicine. When sleep is restored, the chances of recovery increase. A person with regular sleep is more active in life, has better memory, emotions, and cognitive functions, and overall, their brain functions optimally.
Sleep norms vary with age: a 1-year-old child needs 16-18 hours, a 7-10-year-old child needs 10.5 hours, a teenager aged 14-16 needs 8.5-9 hours, adults need 9-10 hours, while the elderly may need only 4-5 hours. Therefore, the duration of sleep should not be taken lightly, as its importance is no less than that of heartbeats.
Kainysh BAYMAGANBETOVA,
Instructor in the Department of Health Policy and Organization, Faculty of Medicine
