From: david.j.worrell@gmail.com

On Friday, August 18, 2017 at 6:27:18 PM UTC-7, thang ornerythinchus wrote:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4008810/

Snippets: ->

Sleep can be defined as a reversible behavioural state in which an
individual is perceptually disengaged from and unresponsive to the environment.

Sleep is a complex physiological and behavioural state that has two
primary states based on physiological parameters. These are rapid eye movement (REM) and non-rapid eye movement (NREM) sleep. An electroencephalogram in which electrodes measure brain electrical
activity is used to identify the two states (Fig. 1).

NREM sleep is divided into four stages, which are associated with a progressive increase in the depth of sleep [12].

FYI. In 2007, stages 3 and 4 were combined into a single 'stage 3'
representing deep sleep. So Stage 3 is now the deep sleep stage.
And thus, they say now there are three NREM stages.

Dreaming can occur in the NREM stages of sleep. Also, in REM.
Dreaming in the NREM stages tends to be "more mundane", whereas
dreaming in the REM stage tends to be "more vivid and bizarre".

REM sleep is characterized by muscle atonia, bursts of REM and
dreaming. Therefore, REM sleep is considered to be a condition with an activated brain in a paralysed body.

According to a 2005 Gallup Poll in the US, the average self-reported
sleep duration of healthy individuals is 6.8 h on weekdays and 7.4 h
on weekends

(that's about my patterns - maybe a bit longer on weekends, a bit
shorter during the week).

That's pretty close to what I usually do too.

Naps can markedly reduce sleepiness and can be beneficial when
learning skills, strategy or tactics [32]. Napping may also be
beneficial for athletes who have to wake early routinely for training
or competition and those who are experiencing sleep deprivation [32].

I like taking a midday nap, and yet often I don't.

One of the most studied areas of sleep deprivation research relates to effects on alertness and performance [34]. In this instance
‘performance’ is generally defined as goal-directed behaviour
requiring mental effort. Performance deficits due to sleep deprivation
are well acknowledged and understood, and it is estimated that the consequences cost billions of dollars worldwide per year due to
accidents, direct healthcare costs, and reduced efficiency and
productivity [34]. Learning and memory deficits are also evident after
sleep deprivation. It appears that sleep is important not only
following learning for consolidation of memory, but also for preparing
the brain for next-day memory formation [35].

there is also recent evidence suggesting that sleep deprivation may
cause or modulate acute and chronic pain [36]. Sleep deprivation may
thus enhance or cause pain, and pain may disturb sleep by inducing
arousals during sleep. A cycle may then eventuate, starting with
either pain or sleep deprivation, with these two issues maintaining or augmenting each other [36].

sleep improves immune responses and that most immune cells have their
peak pro-inflammatory activity at night [37]. Disruptions in endocrine
and physiological circadian rhythms due to sleep deprivation may
result in impaired immune responses, giving rise to an increased risk
of illness.

Both laboratory and epidemiological studies support the notion that
chronic partial sleep loss can increase the risk of obesity and
diabetes [42]. Potential mechanisms include changes in glucose
regulation by insulin resistance, dysregulation of neuroendocrine
control of appetite and/or increased energy intake [42, 43]

--- SoupGate-Win32 v1.05
* Origin: www.darkrealms.ca (1:229/2)