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

3,079,258 views ・ 2014-02-20

TED-Ed


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

00:06
Would you rather be bitten
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by a venomous snake or touch a poisonous frog?
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Wait, what's the difference
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between poison and venom, anyway?
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Let's say you have the misfortune
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to be bitten by a venomous rattlesnake.
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When it bites you,
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the snake will eject venom
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from little sacks behind its eyes,
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through its hollow fangs and into your flesh.
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That venom will then travel through your bloodstream
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and all over your body.
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In most cases, snake venom contains neurotoxins,
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proteins that can do all sorts of nasty stuff
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like make your muscles fire uncontrollably,
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burst your blood cells,
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and make you go completely numb.
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But you might get lucky!
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Snakes don't always decide
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you're worth wasting venom on.
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In fact, between 20 and 80% of snake bites
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are so-called "dry bites,"
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where the snake is just trying
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to send a message without actually killing you.
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You see, venom takes energy and resources
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for the snake to make,
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and they don't want to waste it on a warning shot.
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When it comes to poison,
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on the other hand,
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there's no warning shot.
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If you pick up a poisonous dart frog
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to admire its beautiful colors,
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you've already gotten deadly poison
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all over your hands.
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As it seeps into your skin
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and travels through your blood,
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the poison starts to interfere with your nerves,
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preventing your muscles from contracting.
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If the frog's poison reaches your heart,
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it can cause it to stop.
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The distinction between venom and poison
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is purely in the method of delivery.
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Poison has to be inhaled, ingested, or absorbed.
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Venom has to be injected into a wound.
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Chemically, venoms and poisons
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are both considered toxins,
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so a snake bite is venomous.
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A poison dart frog is poisonous.
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Brown recluse spiders are venomous.
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Lionfish and pufferfish are poisonous.
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And some compounds can be poisons in one animal
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and venoms in another.
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Tetrodotoxin, a chemical 10,000 times more toxic than cyanide,
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is found in pufferfish,
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where it makes them poisonous.
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It's also found in the deadly blue-ringed octopus,
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where it's a venom delivered by bite.
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Some animals can even be both poisonous and venomous.
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Take the Asian tiger snake, for example.
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Not only does it have venom in its fangs
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but it also absorbs the toxins
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from the poisonous toads it eats,
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and then secretes those toxins
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from special glands on its neck,
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rendering it poisonous, too.
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Scientists are constantly finding new animals
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that employ toxins in weird, interesting ways.
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Recently, researchers discovered
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the very first venomous crustacean.
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Out of 70,000 species of crustaceans,
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only this one little remipede is venomous.
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Speleonectes tulumensis has figured out
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how to create a cocktail of toxins
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that it delivers through its tiny fangs.
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Scientists aren't totally sure how this venom works yet,
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but they think that it causes the unwitting victims' neurons
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to fire over and over and over again
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until it becomes paralyzed.
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Then, the little remipede closes in,
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dissolving away the exoskeleton of its prey
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and sucking out the juices.
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But poisons and venoms aren't always all bad.
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For thousands of years, humans have looked for
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ways to harness the power of these toxic compounds for good.
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Today, we have all sorts of medicines
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that come from toxins.
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The poison from cone snails is used as a painkiller.
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Many poisonous plants have been used
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to treat everything from malaria to irregular heartbeats.
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And scorpion venom might one day be used
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to treat heart disease.
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So, what should you do if something bites or poisons you?
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Don't try any of the things you've seen
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on the internet or in movies!
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Don't try to capture and kill the animal
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that bit you,
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and don't use a tourniquet or knife on your wound.
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Most importantly, don't panic!
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Stay calm, and seek medical attention.
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Treatment will mostly depend
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on what species you encountered.
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But if you forget the distinction
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between poison and venom,
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and tell the parademics
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that you were poisoned by a viper,
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they'll probably forgive you and treat you anyway.
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