Placeholder Image

Subtitles section Play video

  • 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, losing 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.

In 1965, 17 year-old high school student, Rendy Gardner,

Subtitles and vocabulary

Operation of videos Adjust the video here to display the subtitles

B1 US TED-Ed sleep adenosine brain gardner awake

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

  • 36815 3181
    echoke posted on 2016/01/05
Video vocabulary