Although we do not usually pay too much attention to it, the truth is that our sleep-wake cycle It is always accompanying us, determining through a biological clock what are the times of the day when we should rest, and when we are ready to start our activities.
When referring to the biological clock, we do so about a neuronal management center, which is located within the hypothalamus, and which has the objective of giving orders to the constituent elements of the brain, about the processes of starting, maintaining and ending sleep. , based on natural time slots that accompany sunlight, but are altered by routine.
Sleep-wake cycle and intermediate stages
The circadian rhythm is fulfilled in approximately 24 hours, hence its name (circadian means about a day). When the biological clock is in sync, we stay awake during daylight hours and sleep when darkness falls.
In addition, all processes are modulated. For example, while we sleep we do not need to take in calories. During the night the body synthesizes melatonin, a hormone secreted by the pineal glandwhich reinforces the synchronization of the sleep-wake cycle.
The sleep-wake cycle is made up of three phases or stages: wakefulness, slow or non-REM sleep, and REM sleep. While we sleep we go through four to six cycles a night in stages of 90 to 110 minutes each. This is essential for restful sleep.
Sleep begins with the non-REM phase, characterized by slow brain waves, and ends in a REM phase of fast brain waves. These are similar to those of wakefulness, but with less muscle tone.
Alterations of the sleep-wake cycle
There are many factors that can alter the sleep-wake cycle. These alterations occur when the biological clock goes out of control. The disorders can be basically two:
Difficulty getting to sleep,
They can be circumstantial or become a long-term problem. The causes can be:
external: jet lag, night work.
internal: interruption of the biological clock due to organic causes, lifestyle, poor sleeping habits.
Another problem is a irregular rhythm of the sleep-wake cycle. It is characterized by the lack of a precise sleep pattern. Sleep is often fragmented into short periods. It occurs when the brain does not work optically, due to mental illness or the lack of an accurate light-dark cycle.
How to recover the sleep-wake cycle
While we all tend to go to sleep and wake up at the same time, each person is different. The only sign that your sleep is adequate is feeling good during the day.
In fact, work demands and the demands and limitations of social life impose certain patterns that can affect the biological rhythm. In this way they increase the feeling of tiredness, malaise, insomnia and depression.
Causes of the sleep-wake cycle
In fact, under normal conditions, the relationship between this biological clock and external luminosity is practically perfect, but then we stay awake one night, and that makes us continue to be tired as soon as it dawns, so we are going to stay in bed a little longer, affecting sleep management. And, as a consequence, we are likely to be exhausted throughout the day.
What factors modify the sleep-wake cycle?
Some of the external elements that can change the sleep-wake cycle appear, such as genetic ones, known as clock genes, which produce genetic abnormalitiesexplaining the same why we have sleep disorders, several very similar to those of our parents.
Hormonal factors also play a predominant role, such as menstruation in women, or menopause. Both in them and in men, different endocrinological diseases can be determinant, so studies must be carried out when symptoms are evident.
In some case, the drug useeven those that were prescribed by a trusted doctor, can cause delays or advances in the functions of the biological clock.
In summary, these conflicts between the biological clock and our reality must be investigated by professionals so that they can offer us a solution, either in the form of medication or, better yet, by advising us on appropriate behaviors that facilitate the synchronization between the two.