Health and lifestyle, REM and NREM sleep, sleep

Sleep fit!

So I am a bit late with this post but I was, I guess, taking a necessary rest. Speaking of rest, our next topic is sleep. In our health and wellness series we have talked about healthy lifestyle choices, positive thinking and exercise. Today I will spend some time discussing the need for adequate sleep to promote proper rest.

sleep1

On the seventh day, after creating the world, God rested. This alone speaks volumes about the importance of rest in any undertaking, as massive as world building or … even in writing. If you are serious about making healthy choices then you cannot or ought not to neglect getting sufficient rest.
Sleep is not passive; the body is in an active state with wide ranging brain activity during sleep, perhaps more so than during waking times. The waveforms obtained from persons in sleep are surprisingly varied, as shown by the samples below.

sleep2                                          sleep3

There are three wave forms which provide good indicators of the state of wakefulness or sleep of an individual:
• brain waves (EEG),
• eye movement (EOG) and
• muscle tension (EMG).

Providing the right conditions are met, sleep promotes self-healing during the time when the body is unconscious with a reduced response to external stimuli. During this time different parts of the brain are stimulated whilst other parts remain dormant.
Sleep patterns may be divided into stages 1 to 4 followed by an REM (rapid eye movement) phase. As the body begins to relax the wave forms of the wakeful mind begin to get slower and to be more consistent in their pattern than during full wakefulness. This aspect of sleep, just before stage 1, appears to be the most beneficial from a physiological standpoint.

  • Following this the body begins to shift into stages 1 and 2 of sleep. During this time the brain waves get even slower and there is a subtle change from stage 1 to stage 2 of sleep. The sleeper can be easily awakened from rest at this time.

 

  • As sleep continues the sleeper shifts into stage 3 with even slower waves and eventually into stage 4. These stages are what we call “deep sleep”. A person prematurely awakened during these stages will be confused and befuddled. The brain waves generated during stages 3 and 4 are very different from those derived when awake.

 

  • Following stage 4 is the REM stage of sleep. The brain is very active and waveforms very much like those during wakefulness are produced. This stage is characterized by the eyes moving or darting in all directions very rapidly and by a simultaneous loss of muscle tone very much like being paralyzed- the heart and other essential muscles remain functioning. Dreams are vivid and realistic during this phase.

sleep4

 

Sleep starts at stage 1 then moves through the other stages to REM for ninety minute cycles during the course of the night. At every cycle the length of REM increases.
The endocrine system releases several hormones during sleep. Of special note is the growth hormone responsible in part for repair in the body. Renal functions and alimentary activity are reduced during this time.
Interestingly those who undergo chronic sleep loss will find themselves in a situation where cortisol (stress hormone) levels do not decrease in the manner they should under normal sleeping conditions. Instead the levels are increased and could promote insulin resistance which in turn could predispose one to diabetes and obesity.
For those of you who are conscious about your calorie intake, this may peak your interest: sleep and food are intimately related. The levels of hormones which regulate appetite have been found to be linked with sleep deprivation. The less you sleep the more calories your body requires to be satiated.
Some effects of lack of sleep on body functions:
Higher cortisol levels possibly leading to insulin resistance and diabetes and obesity.
• Lower leptin levels (hormone in fat cells to suppress appetite) leading to higher calorie requirement.
• Higher gherlin levels (a peptide which stimulates appetite) leading to a desire for high –carbohydrate foods.
• Impairment of glucose tolerance.

sleep5

 

In my own case, during the recuperation phase after being shot and undergoing reconstructive and plastic surgery, the brain sent signals to the body to sleep for restorative and repair work to be conducted during these so called dormant times. Needless to say recuperation involved a lot of sleeping, both natural and medically induced. We have now much more research to show that sleep is not passive but indeed an active and vital process for our well- being.

References:
http://www.medscape.org/viewarticle/502825
http://elementsoflife.quora.com/What-Happens-in-the-Body-When-We-Sleep
http://www.quora.com/Biology-1/Why-do-we-sleep-What-happens-at-a-cellular-level-while-we-sleep

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