Sleep – Do We Truly Sleep When We Sleep?

Sleep is an important process in humans. The question that we need to answer is, do we truly achieve the goal of getting adequate rest and other benefits of sleeping. Saying this in another word, the fact that we spend long hours sleeping does not necessarily mean that we are having a good quality sleep. Why is this so? Could it be that we don’t pay much attention to this process because we don’t know the importance of sleep to the body?

Sleepy Brain

Definition Of A Quality Sleep

A quality-sleep is characterized by adequate sleep-duration which is not too long or too short. During this period, our brain goes through the sleep-stages needed to bring about the restoration of our entire body. Quality-Sleep is as important to survival just as food and water. This definition highlights some important attributes of a quality sleep

  1. Sleep is an active process during which our brain takes us through some cycles
  2. It must have a certain pattern and duration that is considered healthy and appropriate.
  3. It has benefits of restoring our body to a restful state in preparation for the next day’s activities
  4. Lack of quality rest is hazardous to our health and survival as humans

While We Sleep…..

As opposed to what we mostly believe, sleep is not a passive process during which our body temporarily becomes lifeless. It is an active process characterized by events in our brains that are aimed at improving our state of health and bring us healing. Our sleep quality is essential to how our brain functions; similarly our brain is an important control center for our sleep process

 

What are these brain activities that go on while we are sleeping?  During a sleep-cycle, there are interactions between the various centers of the brain responsible for:

  • The transition from the state of wakefulness to the sleepy state,
  • Coordination of our sleep-time with the solar night and day (circadian rhythms with the light-dark cycle).
  • Production of the hormone melatonin, which helps to initiate the sleeping process once the lights go down
  • Sending and processing stored images and sounds in our brain during the wake period and incorporating them into our dreams sounds.
  • Flushing of built-up toxins in our brain.

8-Health Benefits of A Quality Sleep

(1)      Enhancement of our memory  While sleeping, all the experiences we go through during the wake-period, as well as new things we have learned, are consolidated in our brain memory bank for long-term use. It explains the importance of sleep to a student before going into the examination hall, as well as the importance of good night sleep before going to give a presentation in the office the following morning. This consolidation of memory also applies to the ability of our immune cells to remember previous infections they attacked during the day. Thus preparing them for a prompt attack if exposed to the same germ again in future.

(2)       Regulation of stressors and emotions (Hypothalamus and amygdala)

sleep and emotion

During sleep, all the day-time stressors and the various emotions attached to them are processed and sorted out. This will remind us of the popular adages which encourage us  (a) To Sleepover our problems or negative emotions before making decisions or taking actions, and (b) Never break your heart over any stressors of life because everything may look different in the early morning light.

(3)       Boosting of some immune system regulators

sleep and immunesleep and inflammation

It is common knowledge that adequate nigh rest is important in prevention and recovery from viral infections such as common cold. The mechanism involved is rather complex. Lack of sleep raises the level of some markers of inflammation (C-reactive protein and some proteins we call cytokines). Increased levels of these inflammatory markers in circulation have negative consequences on the body system and may play a role in heart diseases. It also explains in part the observed prevalence of heart attack in the early morning hours.

sleep and ghrelin

(4)       Positive impact on the hormone (ghrelin) that regulates appetite during the day

Sleep and appetite

Ghrelin is the hormone in our body that regulates our appetite. By doing this, ghrelin plays an important role in the regulation of our weight. Therefore, having adequate night sleep helps us in our effort to shed the excess fats in our body. On the other hand, lack of adequate sleep constitutes a stressor to our body. Stress produces cortisol which can lead to excess fat store around the body

(5)       The release of growth hormone necessary for muscle building and removal of dead tissue

Sleep and Growth hormonesleeep and growth hormone

Growth hormone is released by a gland called the Pituitary gland in the brain. It is known that this hormone is maximally released in the first hour of sleep. This hormone is responsible for growth and muscle building in normal persons of both sexes from early childhood to late adulthood. In addition, the growth hormone is also essential in the removal of dead tissues from the body.

Stress

(6)       Stress Relief and Lowering of Stress Hormone-Cortisol  Sleep deprivation constitutes stressors which result in the release of stress hormones- Cortisol. In as much as this steroid hormone helps in the repair of the wears and tears in the body, excess cortisol poses life-threatening health hazards. Excess cortisol in the body can lead to depression; it can als0 cause deposition of excess fat around the belly.

(7)       Weight Control    

Through its control of stress and cortisol production and the night release of the appetite hormone (Ghrelin) an individual who sleeps well at night has a good control of His/Her body weight.

sleep and cortisol

(8)    Disease and Early death prevention

sleep and heart attack

During Sleep, there are systems in the brain that help in the clearance of accumulated toxins in the brain. Clearance of some of these toxins has been shown to prevent against the development of Alzheimer’s disease. Similarly, the beneficial effect of sleep on the control of cortisol and other stress chemicals (Cathelocamines) protects against unexpected death from a heart attack in the middle of the night.

Sleep Stages

It’s night time, we close our eyes in preparation for sleep. Our body becomes less mobile and we become less conscious of our surrounding. Even though our body is less mobile or even not mobile at some stages during the sleep cycle, our brain is wide awake to begin its night duty.

sleep and brain activities

Electrical activities which throw us into the various stages of sleep are continually discharged from the brain.  These electrical activities come in form of waves of electrical currents which can be picked up by a test called the Electro-encephalogram (EEG).

sleep and brain EEG

There is another test called the Polysomnography that is capable of measuring other bodily activities such as the eye movement, the pattern of breathing, the heart rate during the various stages of sleep.

Non-REM and REM sleep

There are two basic types of sleep:  Rapid-eye-movement (REM) sleep and non-Rapid- eye- movement (non-REM) sleep. The non-REM sleep occurs in four different stages.  Different brainwave activities are specific to each of the stages. An individual goes through all stages of non-REM and REM sleep

During one sleep cycle, we go from non-REM-1 to non-REM-2 to non-REM-3 to non-REM-4 then back to non-REM-3 to non-REM-2 to non-REM-1 then to REM. These transitions (non-REM 1-2-3-4-3-2-1-REM) make one sleep cycle. We go through approximately five cycles in the course of the night, each lasting 90-110 minutes.

 

sleep EEG  

Sleep latency. This is the time period between lying down to sleep and real dosing off. The latency stage of sleep is shortened by the use of alcohol. It explains why some people have a wrong belief that use of alcohol helps them to sleep well.   

Stage 1 non-REM sleep is the first we fall into immediately after falling off to sleep. It is usually a relatively light sleep during which an individual can be easily aroused. The eye movement, heartbeat, and breathing are slowed down. We become less mobile though there may be occasional twitching of the muscles. Stage 1 usually last several minutes

wave spindles

Stage 2 non-REM sleep is another period of light sleep when the heartbeat and respiration slow down even more. The muscles are further relaxed and the eye movement stops. The brainwave activities also slow down with brief burst or spiking of electrical activities. An individual spends more time in this stage than in any other stage in a cycle.

Sleep deep

Stage 3 non-REM and stage 4 non-REM are usually combined into one (N3). This is a stage of deep sleep that truly marks a refreshing restful night. In this stage, an individual cannot be easily aroused. It is characterized by very slow waves called delta waves. It is during the Stages 3&4 non-REM that children experience sleepwalking, bedwetting, sleep-talking and night terror.  The amount of time spent in stages 3 and 4 sleep is usually longer in the first half of the night than in the second half.  

Stage 5 or REM.

Sleep and REM

This is the last stage in one sleep cycle which occurs every 90-110 minutes. Brain waves mimic activity during the waking state. The eyes remain closed but move rapidly from side-to-side under the closed eyelid. It is during this stage that dreams mainly occur even though some dreams may appear in the non-REM stages too. The whole body is totally paralyzed so that the individual does not attempt to act in response to the content of the dream. It is at this stage that the restorative power of sleep takes place. This is when the growth hormones and other helpful events of sleep take place.

How Much Sleep Do We Really Need?

The amount of sleep needed by an individual varies with age. There are general guidelines recommended by the National Sleep Foundations which can be followed. Quantity

  • Newborns (0-3 months): -14-17 hours each day (previously 12-18 hours)
  • Infants (4-11 months): – 12-15 hours (previously it was 14-15)
  • Toddlers (1-2 years): – 11-14 hours (previously it was 12-14)
  • Preschoolers (3-5): – 10-13 hours (previously it was 11-13)
  • School-age children (6-13): – 9-11 hours (previously it was 10-11)
  • Teenagers (14-17): – 8-10 hours (previously it was 8.5-9.5)
  • Younger adults (18-25): – 7-9 hours (new age category)
  • Adults (26-64): – 7-9 hours
  • Older adults (65+): – 7-8 hours (new age category)

 

 

7- Tips To A Healthy Sleep.

There are some habits we engage in which prevents us from sleeping well at night. Changing some of these habits is the key to achieving good night rest.

  • Keep a regular schedule for your sleeping time.
  • Create a relaxing bedtime routine such as putting off all electronics and bright lights.
  • Avoid alcohol at night
  • Stay away from big meals at night
  • Manage your thoughts
  • Avoid caffeine intake after lunch.
  • Avoid improper use of sleeping aids

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