What are your Fingernails made of?

Summary

Who Smarted? - Episode Summary: "What Are Your Fingernails Made Of?"

Release Date: May 19, 2025
Host/Author: Atomic Entertainment / Starglow Media

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Introduction to Fingernails

In the captivating episode titled "What Are Your Fingernails Made Of?" of the educational podcast Who Smarted?, listeners embark on an enlightening journey exploring the often-overlooked yet fascinating world of fingernails. The narrator begins by prompting young listeners to closely examine their fingernails, highlighting their everyday interactions with them—such as painting, chewing, or tapping—before delving into their biological significance.

Key Quote:

• Narrator [00:02]: "What do you notice at the end of your finger? Dirt. Pizza sauce. A booger. More specifically, what do you see at the end of your finger? That's right, your fingernail."

Anatomy and Composition of Fingernails

The episode elucidates that fingernails are composed of keratin, a type of dead tissue, distinguishing humans and other primates from other mammals that typically have claws. Despite being made of dead tissue, fingernails play a crucial role in enhancing the sensitivity of fingertips, allowing for better tactile perception.

Key Quotes:

• Narrator [01:07]: "Did you know your fingernails are made of dead tissue? Hmm. Did you know your fingernails have no nerves in them, which is why you don't scream when you clip them?"
• Phalanx [04:17]: "The answer lies in the Matrix."

The Nail Matrix and Growth Process

A significant portion of the episode is dedicated to explaining the nail matrix—the hidden part of the nail beneath the skin where keratin cells are produced. The narrator addresses the paradox of how dead tissue can contribute to nail growth, revealing that new cells generated in the matrix push the older, dead cells outward, facilitating continuous growth.

Key Quotes:

• Narrator [06:32]: "Now, the matrix is well hidden, but those of us who are aware can see it. All of you, take a close look at your fingers."
• Phalanx [06:05]: "Did you know your nails and hair are both made of a kind of tissue called keratin?"

Factors Influencing Nail Growth

The podcast delves into the variables that affect the rate at which nails grow. On average, fingernails grow about 3 to 4 millimeters per month, while toenails grow slower at approximately 1.5 millimeters per month. Factors such as hand dominance, seasonal changes, and nutritional intake like vitamin D from sunlight play pivotal roles in influencing nail growth rates.

Key Quotes:

• Narrator [07:22]: "On average, fingernails grow between 3 and 4 millimeters a month. Toenails grow slower, only 1.5 millimeters a month from their own matrix."
• Phalanx [07:40]: "Nails grow faster in the daylight during the summer thanks to a lot of nail strengthening, vitamin D from the sun."

Gender Differences in Nail Growth

An intriguing revelation in the episode is the difference in nail growth rates between genders. Contrary to popular belief that women grow longer nails, men’s nails actually grow faster. This surprising fact underscores the podcast’s commitment to dispelling common misconceptions.

Key Quote:

• Lunula [08:49]: "Do you think you know the answer? May surprise you. Even though women tend to grow their nails longer than men, men's nails actually grow faster."

Nails vs. Claws: Functional Advantages

The discussion transitions into a comparative analysis between human nails and animal claws. While claws are adept for tasks like climbing and digging, nails offer superior dexterity for fine motor skills such as using tools, turning pages, or picking up small objects. This distinction highlights the evolutionary advantages that nails provide to humans and other primates.

Key Quotes:

• Narrator [09:00]: "You know, Lumela, your nails look almost as long as claws."
• Lunula [09:18]: "Cats, dogs and other mammals use their claws to help them climb trees and dig into the ground, but they're not very good at grabbing small things like board game pieces, Lego bricks, or even a smartphone."

Nail Biting: Prevalence and Implications

Addressing a common behavior among children and teenagers, the podcast explores nail biting. Approximately 20 to 30% of people engage in this habit, driven by factors such as stress relief, hunger, or simply because it feels good. While generally harmless, nail biting can pose risks by damaging the protective barrier that nails provide against bacteria and viruses, potentially leading to infections.

Key Quotes:

• Narrator [05:03]: "Did you know your nails and hair are both made of a kind of tissue called keratin?"
• Narrator [05:49]: "Any guesses why so many people bite their nails? Is it to relieve stress? Because they're hungry? Or because it feels good?"

Record-Breaking Long Nails

Adding an element of awe, the episode recounts the story of Sridhar Chillal from India, who held the world record for the longest nails on a single hand. Chillal’s nails reached an astonishing length of nearly 29 feet and 10 inches over 66 years, a feat inspired by his teacher’s reaction to a broken nail. This anecdote serves as both an inspirational tale and a cautionary example of the extremes of nail growth.

Key Quotes:

• Narrator [14:09]: "Sridhar Chellal of India let the nails on his left hand grow for 66 years and they reached a length of 29ft and 10 inches."
• Phalanx [15:12]: "I don't recommend growing your nails that long."

Nails as Indicators of Health

The episode emphasizes the diagnostic potential of nails in revealing underlying health conditions. Changes in nail shape, color, or texture can signal issues such as lung disorders, iron deficiencies, diabetes, thyroid problems, or kidney and liver diseases. Listeners are encouraged to consult adults or healthcare professionals if they notice any unusual changes in their nails.

Key Quotes:

• Narrator [13:35]: "Did you know that your nails, which are on the outside of your body, can actually reveal a lot about what's going on inside your body?"
• Phalanx [14:13]: "Would you call having nearly 30 foot long fingernails unusual?"

Engaging Characters: Phalanx and Lunula

Throughout the episode, animated characters Phalanx and Lunula add humor and interactivity, enhancing the educational experience. They engage in playful dialogues that intertwine scientific facts with entertaining banter, making the learning process enjoyable and memorable for young listeners.

Notable Interactions:

• Phalanx [04:25]: "I'm your new neighbor. You left your front door wide open."
• Lunula [08:16]: "My name's Lunula. You left your door wide open. And these sunglasses look cool."

Conclusion

The episode concludes by reinforcing the importance of fingernails beyond their superficial appearance. By understanding their structure, growth, and health implications, children are encouraged to appreciate and take better care of their nails. The integration of humor, storytelling, and factual information makes "What Are Your Fingernails Made Of?" a standout episode that successfully combines education with entertainment.

Final Thoughts:

• Narrator [15:21]: "A double shout out to Autumn and Emmy in British Columbia, Canada. We hear you love smarting with us because you love to laugh while learning about our world."

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Who Smarted? continues to solidify its reputation as an engaging and informative podcast for children and families by seamlessly blending humor with educational content. This episode not only enlightens listeners about the biology and functionality of fingernails but also encourages curiosity and critical thinking about everyday aspects of the human body.

Transcript

[Narrator]

Hey, smarty pants, Listen up. Take a close look at your finger. Any finger. Even your thumb. Careful. Don't poke yourself in the eye. So what do you notice at the end of your finger? Dirt. Pizza sauce. A booger.

[Phalanx]

Ew.

[Narrator]

More specifically, what do you see at the end of your finger? That's right, your fingernail. Take a good look at it. Just chances are you don't give your fingernails too much thought. Sure, some of you might paint them or chew them or tap them on the table. And yes, some of you stick them in your nose. But chances are you take your fingernails and toenails for granted. But did you know they're actually very important parts of your body? In fact, they make humans unique. While many furry mammals have claws, primates such as humans, apes, monkeys and orangutans have nails. And your fingernails are very useful, like when you have an itch. But there are also some really odd things about your fingernails you might not know. For instance, did you know your fingernails are made of dead tissue? Hmm. Did you know your fingernails have no nerves in them, which is why you don't scream when you clip them? At the same time, your fingernail makes your finger more sensitive to the things you touch. Huh? Did you know your nails can reveal things happening inside of you?

[Lunula]

Whoa.

[Narrator]

If you want to know what else your nails are good for besides scratching, tapping, picking, chewing on and painting, then get ready for another whiff of science. On who smarted? Who's smarted?

[Phalanx]

Who's smart? Is it you?

[Narrator]

Is it me? Is it science or history? Listen up, everyone. We make smarting lots of fun. On who's smarting?

[Phalanx]

It is estimated that over 4 million people have been abducted by alien life forms. But only one of them asked for it. This is Elio of Earth.

[Narrator]

If any aliens are listening, come and.

[Phalanx]

Get me from Disney and Pixar.

[Narrator]

Yes, it's really happening.

[Phalanx]

He'll go where no one has gone before.

[Lunula]

Welcome to the community.

[Narrator]

This is the most beautiful place I've ever seen. This is the bathroom.

[Phalanx]

Disney and Pixar's Elio. Rated PG. Parental guidance. Suggested only in theaters June 20th.

[Narrator]

Okay, smarty pants, be honest. Do you bite your nails? If so, you're definitely not alone. 20 to 30% of all people bite their nails, including nearly half of all kids and teenagers. Any guesses why so many people do it? Is it to relieve stress? Because they're hungry? Or because it feels good? The truth is, any of those answers could be correct, since the real cause of nail biting remains a mystery to scientists. What we do know is nail biting is a common nervous habit. And while usually harmless, there is some risk involved in it. You see, nails are like mini shields for your body. Fingernails and toenails can prevent viruses and bacteria from getting inside you. But those blocked germs can find a way into your body through your mouth. If you bite your nails also, you might damage your nails. And as I'm sure some of you know, breaking or cracking a nail can be pretty painful. While the nail itself is just dead tissue, there are tons of sensory nerve endings underneath your nail. The force of the nail against these nerves makes both fingers and toes more sensitive. Sensitive, which is why your fingertips are so good at sensing cold or heat. And why your toes feel so much pain when you stub them on a table leg. Now, I just said that your nails are dead. But as you and I know, your finger and toenails grow and have to be cut. So how's it possible for something that's dead to keep growing?

[Phalanx]

The answer lies in the Matrix.

[Narrator]

Whoa. Who are you? How'd you get in here? And what's with the sunglasses?

[Phalanx]

I'm your new neighbor. You left your front door wide open. And these sunglasses protect me from poking my eyes. I've come to show you the Matrix.

[Narrator]

The Matrix? As in an alternate reality created by machines from a movie your parents have probably seen?

[Phalanx]

No, I mean the body part called the Matrix. It's the secret behind your nails. My name is Phalanx.

[Narrator]

As in the ancient Greek military formation of troops carrying spears?

[Phalanx]

No, I'm named after the bones in your fingers and toes.

[Narrator]

I'm sensing a pattern.

[Phalanx]

I smell hamburgers.

[Narrator]

Oh, yeah, I was grilling earlier.

[Phalanx]

Red meats, like steaks and burgers, are loaded with bread, protein and iron, which help make stronger nails. May I have one?

[Narrator]

Sorry, I ate them all. But I got strawberries and blueberries, if you'd like.

[Phalanx]

I see a red fruit and a blue fruit. Which should I choose?

[Narrator]

Why not have both?

[Phalanx]

Excellent fruits like blueberries and strawberries protect your nails from damage. Salmon, eggs, whole grains, tomatoes, peppers, carrots, almonds, beans and milk can also strengthen your nails.

[Narrator]

These foods also help another part of your body. Care to take a guess what it is? Is it, A, your hair, B, your teeth, or C, your eyeballs?

[Phalanx]

I heard a lot of correct answers. Smart crowd.

[Narrator]

The smartiest. The answer is, A, your hair.

[Phalanx]

Did you know your nails and hair are both made of a kind of tissue called keratin? Believe it or not, horses hooves and bird feathers are made of the same stuff. It's that Dead tissue you were talking about earlier, right?

[Narrator]

The tissue that's dead but still gross.

[Phalanx]

Do you know what makes it grow?

[Narrator]

Is it the matrix?

[Phalanx]

Yes, the matrix. A body part inside your fingers where keratin cells are made. Those cells start out alive, but they die as the matrix makes newer cells. The new cells push the old dead ones out through your skin. That's how your fingernails and toenails grow. Now, the matrix is well hidden, but those of us who are aware can see it. All of you, take a close look at your fingers.

[Narrator]

Don't poke out your eyes.

[Phalanx]

If your nails aren't painted, you should see something at the base of them. Especially your thumbnail. It looks like part of a whitish circle. See it?

[Narrator]

I do.

[Phalanx]

That's the edge of the matrix.

[Narrator]

Whoa.

[Phalanx]

Nails are always growing from the matrix. On average, Fingernails grow between 3 and 4 millimeters a month. Toenails grow slower, only 1.5 millimeters a month from their own matrix. Many factors can impact the growth of your nails. For example, right handed people's nails grow faster on their right hands, while left handed people's nails grow faster on their left hands. Probably because it's your more active hand. Tapping your fingers or typing on a phone or computer can stimulate nail growth. And nails grow faster in the daylight during the summer thanks to a lot of nail strengthening, vitamin D from the sun.

[Lunula]

And men's and women's nails grow at different speeds.

[Narrator]

Whoa. Who are you? How'd you get in here? And what's with the sunglasses?

[Lunula]

My name's Lunula. You left your door wide open. And these sunglasses look cool. I'm partners with Phalanx. Have you shown him the matrix?

[Phalanx]

I have.

[Narrator]

Lunula. That's an unusual name.

[Lunula]

It means little moon. I'm named after the part of the matrix you can see, that whitish half circle or moon. But you can't see it under my long nails since they're painted.

[Narrator]

That's a lovely shade of black. But wait, you said men's and women's nails grow at different speeds. So who do you think has faster growing nails, smarty pants?

[Lunula]

Do you think you know the answer? May surprise you. Even though women tend to grow their nails longer than men, men's nails actually grow faster.

[Narrator]

I did not know that. You know, Lumela, your nails look almost as long as claws.

[Lunula]

Yes, they're good for scratching, but they're not claws. Primates evolved from having claws about 2 to 3 million years ago. And there's a good reason why. Take a look at this cat's paws.

[Narrator]

Wait, I don't have a cat.

[Phalanx]

You really should close your front door.

[Lunula]

Cats, dogs and other mammals use their claws to help them climb trees and dig into the ground, but they're not very good at grabbing small things like board game pieces, Lego bricks, or even a smartphone.

[Narrator]

It would hurt to pick your nose with claws, too.

[Lunula]

I'm just saying fingernails make it easier to use tools, pick bugs off of someone, or turn the pages of a book. Even long nails work better for all that than claws, though.

[Phalanx]

Extra long nails can cause some problems, especially nails that haven't been cut for 66 years. Have you heard the story of a teacher who convinced their student to grow the world's famous longest fingernails?

[Narrator]

Nope, but we're about to, right after this quick break. This episode is brought to you by ixl. As someone who's constantly balancing work and life, I know how tough it can be to make sure kids get the academic support they need, whether they're homeschooled or in a traditional classroom. That's why IXL has been a lifesaver. It's an online learning program that covers math, language arts, science, and social studies with interactive practice problems, games and video tutorials. Plus, it makes learning fun, just like who Smarted for homeschool parents, IEXCEL is the perfect supplement to your curriculum, giving kids personalized learning at their own pace. And for parents of traditional school kids, it is a great way to reinforce what they're learning in class, whether they need extra help or are just looking for a challenge. Make an impact on your child's learning. Get IXL today. Podcast listeners get an exclusive 20% off when you sign [e-mail] smarted. Visit iexcel.com smartid now to give your child the best learning support available. Ixl Where Learning Clicks this podcast is brought to you by Squarespace. If you've got an idea, a brand, or a business, Squarespace can help you bring it to life online so easily and so quickly. I started with their Blueprint AI tool, and it's honestly kind of magical. You answer a few simple questions about your project, and it instantly builds a beautiful custom website with design, layout, and it even had text suggestions that went perfectly with the idea that I was creating. It's like having a designer and copywriter on your team, but it's all done by the app. Then I discovered how easy it is to offer services and get paid. You can add bookings, send invoices, accept payments, and even schedule automated emails, all right from your site. No plugins, no chaos, no extra apps and figuring all that out. Just a smooth, professional setup that actually works right out of the box. It saved me a ton of money and time. So if you're ready to build something real, head to squarespace.com smarted for a free trial. And when you're ready to launch, use offer code smarted to save 10% off your first purchase of a website or domain. That's squarespace.com smarted. Hey smartypants, have I got exciting news for you here. I'll give you a hint. Yep, that's right. New episodes of Mysteries About True Histories are coming soon, so head on over and see what wild time traveling adventures our young problem solvers are up to this season. And if you've never heard of Mysteries About True Histories, AKA math, just trust me. You're going to love hearing how Max and Molly use math, history, geography, logic puzzles, and fun to solve mysteries about true histories. From the creators of who Smarted comes Mysteries About True Histories starting May 15, with new episodes every Thursday. Subscribe and download anywhere you listen to WhoSmarted. Now back to WhoSmarted. We've been taking a close look at.

[Phalanx]

Our nails don't poke yourself in the eye, right?

[Narrator]

Did you know that your nails, which are on the outside of your body, can actually reveal a lot about what's going on inside your body? It's true. Doctors often look at fingernails to determine if a person has certain health conditions. For example, the shape and color of your nails could reveal lung disorders, iron deficiencies, diabetes, thyroid problems, or kidney and liver diseases. Or if you accidentally banged your finger or nail, it may change shape and color, especially if you get a bruise. At any rate, check with an adult if you notice anything unusual about your fingernails.

[Lunula]

Would you call having nearly 30 foot long fingernails unusual?

[Narrator]

I sure would. But fun fact. Sridhar Chellal of India let the nails on his left hand grow for 66 years and they reached a length of 29ft and 10 inches. That's like five refrigerators stacked on top of each other. He stopped cutting his nails when he was 14 years old, way back in 1952, he says his teacher inspired his decision. The teacher had a long nail and became angry when Shalal's friend broke it. When Shalal asked his teacher why he became so angry over a nail, the teacher said Chalal wouldn't understand because he didn't have long nails himself. So Chalal decided to let his nails grow and grow. Engram Engram Chillal couldn't use his left hand for much of his life, but he's proud of his accomplishment and he holds the world record for the longest nails on a single hand. He since cut his nails and they are now on display at the Ripley's Believe it or Not Museum in New York.

[Phalanx]

I don't recommend growing your nails that long.

[Lunula]

It will keep you from chewing on them or picking your nose like the narrator is doing.

[Narrator]

What? No, I was just scratching an itch, I swear. A double shout out to Autumn and Emmy in British Columbia, Canada. We hear you love smarting with us because you love to laugh while learning about our world. Well, if that isn't the best description of who smarted I've heard in a while, I don't know what is. Thanks this episode Nails was written by Dave Beaudry and voiced by Chris Okawa, Charlotte Cohn and Jerry Colbert. Technical direction and sound design by Josh Hahn. Who Smarted is recorded and mixed at the Relic Room Studios. Our associate producer is Max Kamasky. The theme song is by Brian Suarez with lyrics written and performed by Adam Tex Davis. Who Smarted was created and produced by Adam Tex Davis and Jerry Colbert. This is an Atomic Entertainment production.

[D]

Modern parenting is tough, but to raise happier and healthier kids, parents need to focus on their well being too. I'm Dr. Laurie Santos and in the new season of my podcast the Happiness Lab, I'll be looking at happier parenting. We'll tackle many of the challenges facing modern parents, from loneliness to struggles over screen time and technology. We'll explore research backed strategies moms and dads can use to achieve more joy and less stress while raising the next generation. Listen to the Happiness Lab wherever you get your podcasts.