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動画の字幕をクリックしてすぐ単語の意味を調べられます!
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In 1965, 17 year-old high school student, Rendy Gardner,
stayed awake for 264 hours.
That's 11 days to see how he'd cope without sleep.
On the 2nd day, his eyes stopped focusing.
Next, he lost the ability to identify objects by touch.
By day 3, Gardner was moody and uncoordinated.
At the end of the experiment, he was struggling to concentrate, had
trouble with short term memory, became paranoid, and started hallucinating.
Although Gardner recovered without long term psychological or physical damage,
for others, loosing shuteye can result in hormonal imbalance, illness,
and in extreme cases, death.
We're only beginning to understand why we sleep to begin with.
But we do know it's essential. Adults need 7 to 8 hours of sleep a night
and adolescents need about 10.
We grow sleepy due to signals of our body telling our brain we are tired,
and signals from the environment telling us it's dark outside.
The rise in sleep inducing chemicals, like adenosine and melatonin,
send us into a light doze that grows deeper,
making our breathing and heart rate slow down and our muscles relax.
This non REM sleep is when DNA is repaired and our bodies replenish themselves
for the day ahead. In the USA, it's estimated that
30% of adults and 66% of adolescents are regularly sleep-deprived.
This isn't just a minor inconvenience. Staying awake can cause serious bodily harm.
When we lose sleep, learning, memory, mood, and reaction time are affected.
Sleeplessness may also cause inflammation, hallucinations, high blood pressure,
and it's even been linked to diabetes and obesity.
In 2014, a devoted soccer fan died after staying awake for 48 hours to watch the world cup.
While his untimely death was due to a stroke, studies show that
chronically sleeping fewer than 6h a night increases stroke risk by 4.5 times
compared to those getting a consistent 7 to 8 hours of shuteye.
For a handful of people on the planet who carry a rare inherited genetic mutation,
sleeplessness is a daily reality.
This condition, known as Fatal Familial Insomnia, places the body in a night mirror state of wakefulness,
forbidding it from entering the sanctuary of sleep.
Within months or years, this progressively worsening condition leads to
dementia and death.
How can sleep deprivation cause such immense suffering?
Scientists think the answer lies with the accumulation of waste products in the brain.
During our waking hours, our cells are busy using up
our day's energy sources which get broken down into various byproducts
including adenosine. As adenosine builds up, it increases the urge to sleep,
also known as sleep pressure.
In fact, caffeine works by blocking adenosine's receptor pathways.
Other waste products also build up in the brain, and if they're not cleared away,
they collectively overload the brain
and are thought to lead to the many negative symptoms of sleep deprivation.
So, what's happening in our brain, when we sleep, to prevent this?
Scientists found something called the glymphatic system, a clean up mechanism
that removes this build up and is much more active when we're asleep.
It works by using cerebrospinal fluid to flush away toxic byproducts that accumulate between cells.
Lymphatic vessels, which serve as pathways for immune cells have recently been
discovered in the brain, and they may also play a role
in clearing out the brain's daily waste products.
While scientists continue exploring the restorative mechanisms behind sleep,
we can be sure that sleeping into slumber is a necessity
if we wanna maintain our health and our sanity.
コツ:単語をクリックしてすぐ意味を調べられます!

読み込み中…

読み込み中…

【TED-Ed】What would happen if you didn’t sleep? - Claudia Aguirre

66928 タグ追加 保存
echoke 2016 年 1 月 5 日 に公開
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