..


The Conversation

  • Written by John Furness, Academic, University of Melbourne

This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky! You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.

Why do you blink when there is a sudden loud noise close by? – Angus Graveson, age 8, Hobart.

When a noise surprises us, our eyes blink without us even realising. It happens unconsciously, without us telling our brain to do it.

This is called a blink reflex. It has an even longer name, actually. We call it “the acoustic startle-reflex eye blink”. The blink happens especially fast - in about a hundredth of a second – so you don’t have time to think about it.

Humans have developed this reflex over many years because it has helped us keep our eyes safe and that has helped us survive.

Why do you blink when there is a sudden loud noise close by? The blink happens especially fast - in about a hundredth of a second. Pixabay

Eyes are very sensitive, easily damaged and obviously very useful, so they deserve protecting. The loud noise might be a warning that there is something falling nearby, or flying towards you. Our brain tells our eyes to quickly shut, to help protect them from any damage.

Why do you blink when there is a sudden loud noise close by? The outer part of our eye is called the cornea. Flickr

The blink reflex also happens when a strange or unfamiliar object touches the outer part of our eye, called the cornea. That one is called the corneal blink reflex.

Our eyes and ears pass messages to special nerves, called the sensory nerves, to cells in the bottom part of our brain, in the brain stem. The part of our brain that receives the message is called the pons.

Read more: Curious Kids: Why do our ears pop?

A message is then sent back to a nerve in our face which controls our eyelid, telling it to close. Because the message only passes through the bottom part of our brain, in the brain stem, we don’t realise the message has been sent. It happens automatically, or unconsciously.

Try closing your eyes for a second now, and then open them again. To do that, a message passed a different part of our brain called the cerebral cortex.

Why do you blink when there is a sudden loud noise close by? Bright lights can damage special cells in the back of the eye. Libreshot

Sudden bright light also causes our eyes to close. This reflex is a little bit different, because it sends a message to the cerebral cortex, so we know when it happens. It also makes it a little bit slower. Bright lights can damage special cells in the back of the eye, which are important to see. We need to avoid very bright light, so you shouldn’t look at the sun.

Read more: Curious Kids: Do sharks sneeze?

Startle responses also happen in other parts of the body, like when there is a loud noise, when we suddenly see something, or when we feel a touch or a push we didn’t expect. The responses make some muscles in our jaw, neck, and legs tighten, and releases a hormone, called adrenaline. The startle response makes us more alert, sharpens our senses and gets us ready to run from a threat, or protect ourselves from it. The adrenaline makes the heart beat faster, which we can sometimes feel.

Why do you blink when there is a sudden loud noise close by? Our eyes shut when something suddenly comes towards them, like a ball flying through the air. Pixabay

For example, this can happen when something suddenly comes toward your eyes, like a ball flying through the air. You will automatically turn away and cover your eyes, to protect them.

Both humans and animals experience these reflex responses. They happen automatically to help protect us.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. You can:

* Email your question to curiouskids@theconversation.edu.au * Tell us on Twitter by tagging @ConversationEDU with the hashtag #curiouskids, or * Tell us on Facebook

Why do you blink when there is a sudden loud noise close by? CC BY-ND Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.

Authors: John Furness, Academic, University of Melbourne

Read more http://theconversation.com/curious-kids-why-do-you-blink-when-there-is-a-sudden-loud-noise-close-by-99437

Politics

A good independent can do more

George Neophytou is a lawyer in Paynesville who is standing as an independent candidate for the legislative assembly, East Gippsland District in the State Election. He is not a member of any politi...

Scott Morrison interview with David Koch Sunrise

Aged Care Royal Commission; polls   DAVID KOCH: Appalling cases of abuse against people in aged care have triggered a Royal Commission into the industry. The last financial year saw the number of ser...

A vision for farming and a road map to rural innovation

Minister for Agriculture David Littleproud has commissioned Ernst & Young to develop a strategic vision for the future of Australia’s rural innovation system.   Delivering a shared vision will...

Business News

Careers Campsite

‘Careers Campsite’ to bring over 100 job opportunities and career advice directly to Western Sydney youth tomorrow   Skillsroad, Australia’s number one destination for career advice and entry-leve...

United Co.: Leading young Australian entrepreneur building start up precinct

United Co., set in the heart of buzzing Fitzroy, is Melbourne’s newest business and innovation centre with collaborative work spaces and luxury offices which has been masterfully created out of the ...

Ben Bradshaw 2018 Brisbane Young Entrepreneur of the Year

Ben Bradshaw, the founder behind Fortitude Valley based Disrupt Digital, has taken out the top title of 2018 Brisbane Young Entrepreneur of the Year. Over 300 of the city’s top young professionals ...

Travel

Holiday Hacks: How to beat the travel companies at their own game

HACK YOUR WAY TO A CHEAPER HOLIDAY How to beat the travel companies at their own game and save money during the next school holidays   19 September 2018: As any parent who’s tried to book a holid...

Experience European Glamour with Ecruising

In May 2019, Ecruising is inviting travellers on an exciting itinerary that includes not one, but two, quintessential French Riviera events – the high-octane Monaco Grand Prix and the iconic Canne...

Factors to Consider When Buying a Campervan

You’ve been waiting to buy a Winnebago campervan and now it’s your chance. You’ve saved up and you’re ready to start living the road trip lifestyle. You’re in for a great time and adventure. Of cour...

You might also like