{"id":278919,"date":"2020-12-17T04:35:13","date_gmt":"2020-12-17T09:35:13","guid":{"rendered":"https:\/\/canadianinquirer.net\/v1\/?p=278919"},"modified":"2020-12-17T04:35:13","modified_gmt":"2020-12-17T09:35:13","slug":"curious-kids-why-are-our-tears-salty","status":"publish","type":"post","link":"https:\/\/canadianinquirer.net\/v1\/2020\/12\/17\/curious-kids-why-are-our-tears-salty\/","title":{"rendered":"Curious Kids: why are our tears salty?"},"content":{"rendered":"
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So our tears are much less salty than sea turtles\u2019 tears, although still a little bit salty. (File Photo: Nathan Dumlao\/Unsplash)<\/figcaption><\/figure>\n

Why are tears salty? \u2014 Aarna, aged 6<\/strong><\/p>\n

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Hi Aarna, thanks for your great question! I\u2019m going to start off by telling you a little bit of a story about sea turtles. That might seem strange, but don\u2019t worry, it will all make sense soon.<\/p>\n

When mother sea turtles sneak onto the beach at night to lay their eggs, if you look really carefully you might see them shedding a few tears. Ancient legend believes mother turtles are crying because they will never get to meet their babies.<\/p>\n

But scientists have discovered sea turtles aren\u2019t really crying. Instead, they\u2019re getting rid of salt from their bodies, through weeping some very salty tears.<\/p>\n

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\nRead more:
\nCurious Kids: Why do tears come out of our eyes when we cry?<\/a>
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As sea turtles live in salty seawater, and their favourite food is jellyfish, (which are made mostly of seawater!) they build up too much salt in their bodies, which can be poisonous. So they need to \u201ccry\u201d this salt out of their bodies to survive.<\/p>\n

If we eat too much salt or it builds up in our bodies, our kidneys<\/a> help to flush it out when we go to the toilet. But sea turtle kidneys aren\u2019t as clever as human kidneys, and they can\u2019t get rid of enough salt in their wee.<\/p>\n

So, sea turtles have a special salt gland<\/a> in each eye, which is twice the size of their brains, that pumps this extra salt into their tears.<\/p>\n

These turtle tears are so salty, some animals such as butterflies<\/a> have been spotted licking these turtle tears.<\/p>\n

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When it looks like sea turtles are crying, it doesn\u2019t mean they\u2019re sad. Shedding salty tears helps them get rid of salt from their bodies.<\/span>
\nWikimedia commons<\/span>, CC BY<\/a><\/span><\/figcaption><\/figure>\n

But what about us humans?<\/h2>\n

If you\u2019ve ever licked a tear coming down your cheek, it probably tasted a little bit salty. But if our kidneys work better than turtles\u2019, and we don\u2019t eat jellyfish for breakfast, then why are our tears still salty?<\/p>\n

Well, all fluids in our bodies have a little bit of salt in them. This salt is made into electricity to help our muscles contract<\/a> and our brains to think. The amount of salt in our body fluids (like tears, sweat, and saliva) is about the same as the amount of salt in our blood<\/a> \u2014 just under 1%, or about two teaspoons of salt per litre.<\/p>\n

So our tears are much less salty than sea turtles\u2019 tears, although still a little bit salty.<\/p>\n

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\nRead more:
\nCurious Kids: how do sea creatures drink sea water and not get sick?<\/a>
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3 types of tears<\/h2>\n

The saltiness of your tears can actually vary depending on what kind of tears<\/a> your eyes are making.<\/p>\n

That\u2019s right, your eyes \u2014 or a part of your eyes called the lacrimal gland, to be precise \u2014 make three different types of tears. These are called basal tears, reflex tears and emotional tears.<\/p>\n