What would happen if you didn’t sleep? - Claudia Aguirre

13,879,339 views ・ 2015-11-12

TED-Ed


Please double-click on the English subtitles below to play the video.

00:07
In 1965, 17-year-old high school student, Randy Gardner
0
7470
4945
00:12
stayed awake for 264 hours.
1
12415
3627
00:16
That's 11 days to see how he'd cope without sleep.
2
16042
4018
00:20
On the second day, his eyes stopped focusing.
3
20060
3181
00:23
Next, he lost the ability to identify objects by touch.
4
23241
4109
00:27
By day three, Gardner was moody and uncoordinated.
5
27350
3567
00:30
At the end of the experiment, he was struggling to concentrate,
6
30917
2889
00:33
had trouble with short-term memory,
7
33806
1801
00:35
became paranoid,
8
35607
1500
00:37
and started hallucinating.
9
37107
1904
00:39
Although Gardner recovered without long-term psychological
10
39011
2730
00:41
or physical damage,
11
41741
1668
00:43
for others, losing shuteye can result in hormonal imbalance,
12
43409
3691
00:47
illness,
13
47100
1092
00:48
and, in extreme cases, death.
14
48192
2409
00:50
We're only beginning to understand why we sleep to begin with,
15
50601
4426
00:55
but we do know it's essential.
16
55027
1938
00:56
Adults need seven to eight hours of sleep a night,
17
56965
2951
00:59
and adolescents need about ten.
18
59916
2254
01:02
We grow sleepy due to signals from our body
19
62170
2509
01:04
telling our brain we are tired,
20
64679
2307
01:06
and signals from the environment telling us it's dark outside.
21
66986
3526
01:10
The rise in sleep-inducing chemicals,
22
70512
2369
01:12
like adenosine and melatonin,
23
72881
2255
01:15
send us into a light doze that grows deeper,
24
75136
3212
01:18
making our breathing and heart rate slow down
25
78348
2603
01:20
and our muscles relax.
26
80951
2626
01:23
This non-REM sleep is when DNA is repaired
27
83577
3498
01:27
and our bodies replenish themselves for the day ahead.
28
87075
3406
01:30
In the United States,
29
90481
1580
01:32
it's estimated that 30% of adults and 66% of adolescents
30
92061
4620
01:36
are regularly sleep-deprived.
31
96681
2443
01:39
This isn't just a minor inconvenience.
32
99124
2379
01:41
Staying awake can cause serious bodily harm.
33
101503
3338
01:44
When we lose sleep,
34
104841
1318
01:46
learning,
35
106159
845
01:47
memory,
36
107004
824
01:47
mood,
37
107828
710
01:48
and reaction time are affected.
38
108538
2245
01:50
Sleeplessness may also cause inflammation,
39
110783
2602
01:53
halluciations,
40
113385
1222
01:54
high blood pressure,
41
114607
1350
01:55
and it's even been linked to diabetes and obesity.
42
115957
4467
02:00
In 2014, a devoted soccer fan died
43
120424
3482
02:03
after staying awake for 48 hours to watch the World Cup.
44
123906
4185
02:08
While his untimely death was due to a stroke,
45
128091
2731
02:10
studies show that chronically sleeping fewer than six hours a night
46
130822
3792
02:14
increases stroke risk by four and half times
47
134614
3984
02:18
compared to those getting a consistent seven to eight hours of shuteye.
48
138598
4338
02:22
For a handful of people on the planet who carry a rare inherited genetic mutation,
49
142936
4620
02:27
sleeplessness is a daily reality.
50
147556
2507
02:30
This condition, known as Fatal Familial Insomnia,
51
150063
4073
02:34
places the body in a nightmarish state of wakefulness,
52
154136
3473
02:37
forbidding it from entering the sanctuary of sleep.
53
157609
3306
02:40
Within months or years,
54
160915
1831
02:42
this progressively worsening condition leads to dementia and death.
55
162746
4748
02:47
How can sleep deprivation cause such immense suffering?
56
167494
3831
02:51
Scientists think the answer lies with the accumulation of waste prducts
57
171325
3983
02:55
in the brain.
58
175308
1607
02:56
During our waking hours,
59
176915
1567
02:58
our cells are busy using up our day's energy sources,
60
178482
3242
03:01
which get broken down into various byproducts,
61
181724
2661
03:04
including adenosine.
62
184385
2288
03:06
As adenosine builds up,
63
186673
1784
03:08
it increases the urge to sleep, also known as sleep pressure.
64
188457
4456
03:12
In fact, caffeine works by blocking adenosine's receptor pathways.
65
192913
5360
03:18
Other waste products also build up in the brain,
66
198273
2696
03:20
and if they're not cleared away, they collectively overload the brain
67
200969
4017
03:24
and are thought to lead to the many negative symptoms of sleep deprivation.
68
204986
4550
03:29
So, what's happening in our brain when we sleep to prevent this?
69
209536
4402
03:33
Scientists found something called the glymphatic system,
70
213938
3308
03:37
a clean-up mechanism that removes this buildup
71
217246
3109
03:40
and is much more active when we're asleep.
72
220355
2864
03:43
It works by using cerebrospinal fluid to flush away toxic byproducts
73
223219
5426
03:48
that accumulate between cells.
74
228645
2352
03:50
Lymphatic vessels, which serve as pathways for immune cells,
75
230997
3973
03:54
have recently been discovered in the brain,
76
234970
2896
03:57
and they may also play a role in clearing out the brain's daily waste products.
77
237866
6085
04:03
While scientists continue exploring the restorative mechanisms behind sleep,
78
243951
5015
04:08
we can be sure that slipping into slumber is a necessity
79
248966
4236
04:13
if we want to maintain our health and our sanity.
80
253202
3728
About this website

This site will introduce you to YouTube videos that are useful for learning English. You will see English lessons taught by top-notch teachers from around the world. Double-click on the English subtitles displayed on each video page to play the video from there. The subtitles scroll in sync with the video playback. If you have any comments or requests, please contact us using this contact form.

https://forms.gle/WvT1wiN1qDtmnspy7