What causes you to Blink?

Summary

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Who Smarted? – "What causes you to Blink?"

Released: September 24, 2025
Host: Atomic Entertainment / Starglow Media

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Episode Overview

This episode of "Who Smarted?" turns the spotlight on involuntary reflexes — the automatic actions our bodies perform, like blinking, hiccupping, sneezing, and more. In a fun, interactive style, the hosts and the recurring character Aunt Stemmie guide “smarty pants” listeners through what these reflexes are, how and why they happen, the body systems in charge, and quirky facts to keep everyone giggling and learning.

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Key Discussion Points & Insights

1. What Are Involuntary Reflexes? (00:00 – 02:27)

• Many body processes aren’t under your conscious control.
  • Examples: hiccups, sneezing, coughing, yawning, shivering.
• Definition: Involuntary reflexes are automatic responses to certain triggers (stimuli) and are essential for survival.
• Notable moment: The episode’s host challenges listeners to identify five involuntary reflexes based on sound and description.

Quote:
"Bodily functions like hiccuping, sneezing, coughing, and shivering are called involuntary reflexes because they happen when…"
— Host (A), 01:44

2. Meet Aunt Stemmie! (01:15 – 03:41)

• Aunt Stemmie is a friendly, know-it-all "aunt" who loves finishing others’ sentences and is a playful expert in STEM.
• Her bantering dynamic with the host adds plenty of humor and quick explanations throughout the episode.

Quote:
"I know a lot about STEM – Science, technology, engineering, and math."
— Aunt Stemmie (B), 01:31

3. The Autonomic Nervous System (ANS): The “Boss” of Reflexes (03:41 – 05:31)

• The ANS regulates involuntary functions (heartbeat, breathing, digestion, blinking, etc).
• Two main parts:
  • Sympathetic Nervous System: Kicks in during stress (“fight or flight”), increases heart rate, dilates pupils.
  • Parasympathetic Nervous System: Calms the body, slows heart rate, aids digestion.
• Demonstrates with the startle reflex (Aunt Stemmie surprises the host!).

Quote:
"Your ANS is responsible for regulating involuntary bodily functions, some of which are super important in keeping you alive."
— Aunt Stemmie, 03:49

4. Why Do We Have Involuntary Reflexes? (05:31 – 09:05)

• Reflexes are crucial for safety, survival, and maintaining health.
  • Example: Withdrawal reflex (pulling away from something hot).
• Coughing/sneezing clear airways; shivering keeps body warm.
• Blushing is discussed as an emotional involuntary reaction.

Quote:
"Involuntary reflexes like coughing and sneezing happen to help clear the airways in your throat and mouth so you can breathe easier."
— Host, 07:39

5. Yawning: Why Is It So Contagious? (08:07 – 09:05)

• Yawning is an involuntary reflex and can be “contagious.”
• Theories: Yawning cools brain blood flow, increases oxygen, or communicates drowsiness/social cues to others.

Quote:
"Scientists don’t know for sure why we yawn when someone else yawns. But there are lots of theories."
— Aunt Stemmie, 08:31

6. How Involuntary Reflexes Work (09:05 – 10:05)

• Reflexes travel along a "relay arc"—stimulus > spinal cord > muscles.
• Fast communication helps prevent harm without the brain getting involved each time.
• Helps maintain homeostasis (body balance).

Quote:
"Involuntary reflexes work through a relay arc, which is similar to a game of telephone."
— Aunt Stemmie, 09:05

7. The Eye Experiment: Pupillary Reflex (10:12 – 11:15)

• DIY activity: Compare pupil size in dark vs. bright lighting.
  • Pupils dilate in dark, constrict in light—another involuntary reflex.

Quote:
"When you’re in a dark environment, your pupils automatically get bigger to let in more light."
— Aunt Stemmie, 10:52

8. Hiccups: What Are They Really? (11:15 – 12:47)

• Hiccups = quick contractions of the diaphragm (breathing muscle).
• Can sometimes be stopped by startling, breathing tricks, or water, but no guaranteed cure.
• The exact purpose of hiccups is a mystery, but they’re harmless.

Quote:
"Hiccupping, also known as singultus, happens because of sudden and involuntary contractions of your diaphragm muscle."
— Aunt Stemmie, 12:09

9. Reflex Trivia Game: Voluntary or Involuntary? (12:47 – 13:58)

• Listeners guess which functions are involuntary: blinking, burping, swallowing, farting, sniffing.
  • Some can be both (ex: burping, blinking).
  • Fun fact: Most people blink about 15 times per minute.

Quote:
"You can blink your eyes on your own, but most of the time, blinking is involuntary."
— Aunt Stemmie, 13:39

10. Weird Words: Deglutition and More (13:58 – 14:52)

• Deglutition = swallowing (can be both voluntary and involuntary).
• Other science-y terms for body functions: salivation (spit-making), micturition (urinating), defecation (pooping).
• No need to be embarrassed—these are vital bodily functions!

11. Blushing: Emotions as Reflections (15:05 – 15:41)

• Blushing: involuntary reflex caused by emotional stimuli, like embarrassment.
• Sympathetic nervous system widens facial blood vessels, turning your face pink or red.

Quote:
"Blushing is an involuntary response that happens when you feel an emotional stimuli like embarrassment or shyness."
— Aunt Stemmie, 15:21

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Memorable Quotes & Moments

• Aunt Stemmie (B): "Trust Aunt Stemmie. She’ll tell you." (02:10)
• Host (A): "You could have just said that." (after being made to grab a hot mug) (07:33)
• Aunt Stemmie (B): "I say, do you have any of your grandma’s leftover meat cake?" (15:47)

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Noteworthy Timestamps

• 00:00 – 02:27: Defining involuntary reflexes with funny bodily sound effects.
• 03:41 – 05:31: How the autonomic nervous system works and startle reflex demo.
• 07:05 – 07:33: Demonstrating withdrawal reflex (grabbing a hot mug).
• 10:12 – 11:15: Home experiment on pupils and pupillary response.
• 11:15 – 12:47: Hiccups explained.
• 12:47 – 13:58: Voluntary vs involuntary reflex trivia.
• 15:05 – 15:41: The science behind blushing.

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Conclusion

The episode presents science in an engaging and humorous way—combining skits, direct explanations, trivia, and simple experiments. It covers how and why involuntary reflexes exist, the body systems involved, and why these automatic responses are essential for health and survival. Through catchy banter and memorable facts, "Who Smarted?" ensures kids (and adults) have fun and walk away smarter about their own amazing, reflexive bodies.

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Transcript

[A]

And now it's time for who Smarted? Psst. Hey, smarty pants. If you've been listening to who Smarted for a while, you've probably heard some of our episodes on the human body. We've done episodes on your eyes, ears, tongue, lungs, and heart. Whoops. Sorry about that. We've done the skeletal system, nervous system, circulatory system, and immune system. We've done peeing and pooping and boogers. Excuse me. And we've covered what happens when you get a cold. Ooh, I just got a chill. Anyway, the point I'm making is that your body is an amazing machine, and much of it is under your control. However, there are some things that are not under your control. What we call involuntary reflexes. And if you were paying close attention, you just heard five of them. Can. Can you recall them? If not, here they are again. That's right. Hiccups, sneezing, coughing, yawning, and shivering are all considered involuntary reflexes because they happen automatically without you having to think about it. Now, a lot of smarty pants have written to us asking why we.

[B]

Well, you have questions, and I have the answers.

[A]

Aunt Stemmie, is that you?

[B]

That's right. It's your Aunt Stemmie.

[A]

Oh, I didn't know you were coming by today. Smartypants. Meet my Aunt Stemmie. That's not her real name, but she likes us to call her that because.

[B]

I know a lot about STEM Science, technology, engineering, and math.

[A]

That's right.

[B]

Aunt Stemmy also loves finishing other people's sentences.

[A]

Yep, not mildly annoying at all. Anyway, as I was saying, bodily functions like hiccuping, sneezing, coughing, and shivering are called involuntary reflexes because they happen when.

[B]

Your body responds to stimuli or triggers, such as certain sights, smells, sounds, and temperature changes.

[A]

Yep, they just kind of interrupt whether you want them to or not.

[B]

They sure do trust Aunt Stemmie. She'll tell you.

[A]

For the record, she's not really my aunt. We just call her that. Anyway, like I was saying, why do we have involuntary reflexes? Where do they come from? And what's actually controlling them?

[B]

And what other involuntary reflexes are there?

[A]

It's time for another whiff of science.

[B]

And history on who's Smarted.

[A]

Who'S smarted? Who's smart? Is it you? Is it me? Is it science or history? Listen up, everyone. We make smarting lots of fun on who's Smarted.

[C]

The Mysteries about True Histories podcast is back for season two. If you're a kid who would love to travel through time to solve cool Mysteries, perplexing puzzles and tricky riddles, then this podcast is the perfect audio treat for you every week. Join me, Molly and my best friend Max as we take our problem solving skills to amazing places like ancient Egypt, ancient Greece, or the Galapagos is in 1875 to help out the one and only Charles Darwin. We never know where we're going to wind up or what we're going to find, which is all part of the fun. So put on your time traveling shoes and listen as a family. You can listen to mysteries about true histories on Apple podcasts, Spotify, or wherever you listen to podcasts.

[A]

Whoops. Sorry. I thought the theme song was still playing. Not that I could have done anything about those funny noises. It's like my body has a mind of its own.

[B]

Not a mind exactly, but an automatic nervous system, or ans. Your ANS is responsible for regulating involuntary bodily functions, some of which are super important in keeping you alive.

[A]

Smartypants, can you think of something your body does automatically that helps keep you alive? Here, I'll give you an audio hint. Did you say your heartbeat? Great job. Here's another one. Did you say breathing? Nice. But that's not all.

[B]

In addition to controlling your heart rate and breathing, your ANS also handles involuntary functions like digestion, blinking, and other automatic reflexes. Right, and I wasn't finished.

[A]

Oh.

[B]

The ANS is divided into two parts. The sympathetic nervous system, which kicks in when you feel stressed or scared. Among other things, it accelerates your heart rate to pump more blood into your muscles and dilates or opens your pupils. The dark circles in the middle of your eyes so you can see better.

[A]

And the second part of the ANS is the parasympathetic nervous system. This helps the body relax and recover after stress. It slows down your heart rate, makes your pupils smaller, and stimulates digestion, among other functions.

[B]

That's right.

[A]

I know that's right. You didn't have to say that's right. Ah. What's wrong? What happened?

[B]

Nothing. I was just demonstrating an involuntary reflex called the startle reflex. Did it work?

[A]

Yes, it worked. You just scared me out of my smarty pants. And I'm sure some of the smarty pants listening were also startled.

[B]

Good. That means their startle reflex is working. But please, smarty pants, do not try this experiment at home.

[A]

Yes, please.

[B]

You see, when a person experiences an unexpected stimulus, like a sudden loud sound or a bug flying at you, it causes an involuntary reaction, such as flinching, ducking for cover, or jumping.

[A]

In other words, it triggers what is Called a fight or flight response in the sympathetic nervous system that is meant to protect you from dange.

[B]

That's right. Even little babies have a startle reflex.

[A]

Yes, but please, smartypants, no screaming at home. Or you might activate your parents or teacher's getting upset response, which you don't want. Anyway. Moving on. Smartypants, do you know why you have involuntary reflexes?

[B]

The answer is because they're essential for your survival and protection.

[A]

I was just going to say that.

[B]

Now you don't have to say. Trusty, hand me the mug of coffee I put down on your furniture.

[A]

What? Without a coaster? Okay. Ow. It's hot.

[B]

That's right.

[A]

Why did you have me grab a hot mug of coffee?

[B]

To demonstrate the withdrawal reflex. When you reflexively pull your hand away from something like a hot stove so you don't get burned. That's an example of your involuntary reflexes preventing you from getting hurt.

[A]

You could have just said that.

[B]

It's better to show you. Also, you owe me a new coffee mug.

[A]

Oh, boy. But to aunt Stemmie's point, involuntary reflexes like coughing and sneezing happen to help clear the airways in your throat and mouth so you can breathe easier. Or when your body shivers to maintain body temperature in the cold.

[B]

And don't forget.

[A]

Don't forget what.

[B]

Exactly?

[A]

Huh? Wow. I don't feel sleepy, but I can't stop yawning. Wait a second. Yawning is an involuntary reflex, too?

[B]

That's right.

[A]

And so is you saying that's right.

[B]

That's right.

[A]

I gotta say, seeing you yawn is making me yawn. Is yawning really contagious?

[B]

Scientists don't know for sure why we yawn when someone else yawns. But there are lots of theories as to why we yawn.

[A]

Like what?

[B]

Well, yawning may cool down the blood flowing to your brain, or increase the oxygen you take in. Or just communicate to others that you're tired or bored.

[A]

Are you all I see? Okay, so now that we know why we have involuntary reflexes, what I want to know is, how do they work?

[B]

Involuntary reflexes work through a relay arc, which is similar to a game of telephone. Sensors or receptors all over your body detect stimuli from outside or inside your body and send messages to your spinal cord, which then send messages to your muscles. This super fast communication helps your body conserve energy. Because your brain doesn't have to monitor and decide how to react to the stimuli, your body does it automatically for you.

[A]

Amazing.

[B]

Truly. But that's not all. Involuntary reflexes also help you Maintain homeostasis. And homeostasis is your body's ability to operate smoothly and keep its functions and internal environment in balance, no matter what the external stimuli is.

[A]

Gotcha.

[B]

Ooh. Speaking of stimuli, should we do another experiment?

[A]

Absolutely. Right after this quick break and a word from our sponsor. Now back to Whosmarted. Okay. And Stemmie, what's this experiment you want to do?

[B]

Ok, first, get a partner and dim the lights in a room. Wait a little while, then look at your partner's eyes. Notice the size of their pupils.

[A]

Aunt Stemmie, your pupils are so big.

[B]

Better to see you with my dear narrator. Now, turn the lights back on and recheck your partner's pupils.

[A]

Whoa. Your pupils are way smaller.

[B]

That, my friends, is an involuntary reflex called the pupillary response. When you're in a dark environment, your pupils automatically get bigger to let in more light. But when it's light outside, your pupils get smaller to keep light out and prevent damage to your eyes.

[A]

Nice and smartypants. If you were unable to do this experiment now, that's okay. Just do it later when you're home and with someone. So what next? Oh, no. What a time to get the hiccups. What do I do? Ah. Oh, come on. Aunt Stemmy, you scared me again.

[B]

But what about your hiccups?

[A]

Hey, they're gone. So startling. Someone really does get rid of hiccups.

[B]

It can, but so can taking deep breaths, breathing into a paper bag, or drinking a glass of water quickly. The truth is, there is no one guaranteed cure for hiccups.

[A]

Gotcha. I will say all of the other involuntary reflexes seem to serve a helpful purpose. But hiccups just kinda stink. What are hiccups? Why do they happen? And what purpose do they serve besides being really annoying?

[B]

Great question. Trusty hiccupping, also known as singletus, happens because of sudden and involuntary contractions of your diaphragm muscle, which is responsible for breathing. When your diaphragm contracts, it causes you to take a breath, and the air can cause your vocal cords to close, creating the hiccup sound. The exact reason why you hiccup isn't fully understood. But just know hiccuping is usually harmless and nothing to worry about.

[A]

Phew. That's a reflex relief. Okay, smarty pants, I think it's time to test your knowledge. I'm going to name a bodily function. Call out yes if you think it's an involuntary reflex, or no, if it's not. Ready, set, go. Blinking. Burping. Burp. Swallowing. Farting. Sniffing. How'd you do, Smarty pants. Did you get all or most of them right? Great job if you did. Of course, some of these, like burping, can be involuntary, like after you drink a carbonated beverage. And other times you can just make yourself burp on your own Burp.

[B]

That's right. Same goes for blinking. You can blink your eyes on your own, but most of the time, blinking is involuntary.

[A]

Smartypants, did you know you typically blink 15 times a minute after the show? Get a stopwatch and count, but try not to blink on your own.

[B]

Don't forget deglutition.

[A]

Deglutition, Smarty pants, Do you know what deglutition is? Is it A, making spit, B, going number one, or C swallowing?

[B]

The answer is C. Deglutition is the medical term for swallowing.

[A]

But wait, isn't swallowing voluntary?

[B]

Most times. But swallowing and other bodily functions can involve both voluntary and involuntary muscle movements. Those include salivation or the process of making saliva, or spit micturition, which is the medical term for urination, or making pee, and defecation, which is another medical term for making poop.

[A]

I knew we'd get there sooner or later. But hey, it's all stuff your body needs to do to survive.

[B]

That's right. There's no need to be embarrassed, even if it does lead to another involuntary reflex.

[A]

Huh? What you talking about, Antstemi?

[B]

Your face, trusty, it's beet red. All this pee and poop has triggered another involuntary reflex.

[A]

Oh, smarty pants. Do you know what it is? If you said blushing, you're right.

[B]

Blushing is an involuntary response that happens when you feel an emotional stimuli like embarrassment or shyness. This triggers the sympathetic nervous system to open blood vessels near the surface of the skin on your face and neck.

[A]

Which causes your face to turn red or go flush, otherwise known as blushing.

[B]

That's right. I say, do you have any of your grandma's leftover meat cake?

[A]

Nope, I ate it all. Really? You don't believe me? I'll prove it.

[B]

Oh, boy, I'd love to stay and chat more, but.

[A]

Oh.

[B]

Oh, gosh, I better get going.

[A]

That's right, a big cross continental shout out to two huge smarty fans, Cooper and Hudson in Cape Town, South Africa. Thanks so much for writing to let us know that who Smarted Is the only podcast you listen to and that you learned so much from our show. Thanks for smarting with us, smarty pants. This episode, Involuntary Reflexes was written by Leanne Don't Flinch French and voiced by Emma A. Wilson and Jerry Colber. Technical direction and sound design by Josh Hiccups Hahn. Our associate producer is Maxky. The theme song is by Brian Schiver Suarez with lyrics written and performed by Adam Farts. Davis, who Smarted was created and produced by Adam Tex Davis and Jerry Colbert. This has been an Atomic Entertainment production.