Poison vs. venom: What's the difference? - Rose Eveleth

3,066,726 views ใƒป 2014-02-20

TED-Ed


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

00:06
Would you rather be bitten
0
6909
1284
00:08
by a venomous snake or touch a poisonous frog?
1
8193
3500
00:11
Wait, what's the difference
2
11693
1250
00:12
between poison and venom, anyway?
3
12943
2999
00:15
Let's say you have the misfortune
4
15942
1250
00:17
to be bitten by a venomous rattlesnake.
5
17192
2399
00:19
When it bites you,
6
19591
875
00:20
the snake will eject venom
7
20466
1169
00:21
from little sacks behind its eyes,
8
21635
1234
00:22
through its hollow fangs and into your flesh.
9
22869
2074
00:24
That venom will then travel through your bloodstream
10
24943
1611
00:26
and all over your body.
11
26554
1586
00:28
In most cases, snake venom contains neurotoxins,
12
28140
2497
00:30
proteins that can do all sorts of nasty stuff
13
30637
2091
00:32
like make your muscles fire uncontrollably,
14
32728
2713
00:35
burst your blood cells,
15
35441
1626
00:37
and make you go completely numb.
16
37067
1707
00:38
But you might get lucky!
17
38774
1297
00:40
Snakes don't always decide
18
40071
1249
00:41
you're worth wasting venom on.
19
41320
1205
00:42
In fact, between 20 and 80% of snake bites
20
42525
1833
00:44
are so-called "dry bites,"
21
44358
1750
00:46
where the snake is just trying
22
46108
1416
00:47
to send a message without actually killing you.
23
47524
2419
00:49
You see, venom takes energy and resources
24
49943
2165
00:52
for the snake to make,
25
52108
1333
00:53
and they don't want to waste it on a warning shot.
26
53441
2271
00:55
When it comes to poison,
27
55712
1250
00:56
on the other hand,
28
56962
1251
00:58
there's no warning shot.
29
58213
1293
00:59
If you pick up a poisonous dart frog
30
59506
1711
01:01
to admire its beautiful colors,
31
61217
1641
01:02
you've already gotten deadly poison
32
62858
1750
01:04
all over your hands.
33
64608
2280
01:06
As it seeps into your skin
34
66888
1459
01:08
and travels through your blood,
35
68347
1010
01:09
the poison starts to interfere with your nerves,
36
69357
2034
01:11
preventing your muscles from contracting.
37
71391
2215
01:13
If the frog's poison reaches your heart,
38
73606
1916
01:15
it can cause it to stop.
39
75522
2503
01:18
The distinction between venom and poison
40
78025
1416
01:19
is purely in the method of delivery.
41
79441
2295
01:21
Poison has to be inhaled, ingested, or absorbed.
42
81736
2586
01:24
Venom has to be injected into a wound.
43
84322
2836
01:27
Chemically, venoms and poisons
44
87158
1617
01:28
are both considered toxins,
45
88775
2000
01:30
so a snake bite is venomous.
46
90775
1833
01:32
A poison dart frog is poisonous.
47
92608
3334
01:35
Brown recluse spiders are venomous.
48
95942
1935
01:37
Lionfish and pufferfish are poisonous.
49
97877
2980
01:40
And some compounds can be poisons in one animal
50
100857
2442
01:43
and venoms in another.
51
103299
1460
01:44
Tetrodotoxin, a chemical 10,000 times more toxic than cyanide,
52
104759
4255
01:49
is found in pufferfish,
53
109014
1041
01:50
where it makes them poisonous.
54
110055
1469
01:51
It's also found in the deadly blue-ringed octopus,
55
111524
2500
01:54
where it's a venom delivered by bite.
56
114024
2329
01:56
Some animals can even be both poisonous and venomous.
57
116353
3378
01:59
Take the Asian tiger snake, for example.
58
119731
2003
02:01
Not only does it have venom in its fangs
59
121734
1836
02:03
but it also absorbs the toxins
60
123570
1705
02:05
from the poisonous toads it eats,
61
125275
1750
02:07
and then secretes those toxins
62
127025
1551
02:08
from special glands on its neck,
63
128576
1948
02:10
rendering it poisonous, too.
64
130524
2250
02:12
Scientists are constantly finding new animals
65
132774
1933
02:14
that employ toxins in weird, interesting ways.
66
134707
2293
02:17
Recently, researchers discovered
67
137000
1543
02:18
the very first venomous crustacean.
68
138543
2253
02:20
Out of 70,000 species of crustaceans,
69
140796
2002
02:22
only this one little remipede is venomous.
70
142798
2586
02:25
Speleonectes tulumensis has figured out
71
145384
2085
02:27
how to create a cocktail of toxins
72
147469
1831
02:29
that it delivers through its tiny fangs.
73
149300
2725
02:32
Scientists aren't totally sure how this venom works yet,
74
152025
2083
02:34
but they think that it causes the unwitting victims' neurons
75
154108
2666
02:36
to fire over and over and over again
76
156774
2708
02:39
until it becomes paralyzed.
77
159482
1666
02:41
Then, the little remipede closes in,
78
161148
1503
02:42
dissolving away the exoskeleton of its prey
79
162651
2207
02:44
and sucking out the juices.
80
164858
1917
02:46
But poisons and venoms aren't always all bad.
81
166775
3168
02:49
For thousands of years, humans have looked for
82
169943
1499
02:51
ways to harness the power of these toxic compounds for good.
83
171442
2665
02:54
Today, we have all sorts of medicines
84
174107
1806
02:55
that come from toxins.
85
175913
1585
02:57
The poison from cone snails is used as a painkiller.
86
177498
2629
03:00
Many poisonous plants have been used
87
180127
1626
03:01
to treat everything from malaria to irregular heartbeats.
88
181753
2794
03:04
And scorpion venom might one day be used
89
184547
1877
03:06
to treat heart disease.
90
186424
1851
03:08
So, what should you do if something bites or poisons you?
91
188275
3111
03:11
Don't try any of the things you've seen
92
191386
1721
03:13
on the internet or in movies!
93
193107
1659
03:14
Don't try to capture and kill the animal
94
194766
1759
03:16
that bit you,
95
196525
1161
03:17
and don't use a tourniquet or knife on your wound.
96
197686
2961
03:20
Most importantly, don't panic!
97
200647
3211
03:23
Stay calm, and seek medical attention.
98
203858
2961
03:26
Treatment will mostly depend
99
206819
1252
03:28
on what species you encountered.
100
208071
1871
03:29
But if you forget the distinction
101
209942
1464
03:31
between poison and venom,
102
211406
1534
03:32
and tell the parademics
103
212940
1252
03:34
that you were poisoned by a viper,
104
214192
1750
03:35
they'll probably forgive you and treat you anyway.
105
215942
3596
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