How Your Skin Works

Summary

Join Chloe and the Nurb as they embark on an adventure 'Under the Surface of the Skin'! Discover the three layers of skin: the epidermis, dermis, and subcutaneous fat. Learn how the epidermis acts as a skin cell factory, producing new cells and containing melanin for color and sun protection. Explore the dermis, packed with nerve endings for touch sensation and blood vessels for temperature regulation. Uncover the role of sweat and oil glands in maintaining skin health. Finally, understand the importance of subcutaneous fat in cushioning, protecting organs, and keeping us warm. This journey unveils the skin's complexity and its vital functions.

Takeaways

• 🧪 The skin has three layers: the epidermis, the dermis, and the subcutaneous fat.
• 🌱 The epidermis is a skin cell factory where new cells are produced and rise to the surface, becoming dead skin cells that are shed.
• 🌞 Melanin in the epidermis determines skin color and provides some protection from the sun, but sunscreen is still necessary.
• 🔍 The dermis contains blood vessels, nerve endings, and is responsible for the sense of touch and temperature regulation.
• 💧 Sweat glands in the dermis produce sweat that travels to the epidermis and is released through pores to help cool the body.
• 💧 Oil glands, or sebaceous glands, in the dermis produce sebum that creates an oily layer on the skin for protection and moisture.
• 🏼 The subcutaneous fat layer cushions and protects bones and organs, and helps to keep the body warm.
• 令 Hair follicles are embedded in the dermis and grow through to the epidermis.
• 🥶 The pilomotor reflex causes the hair to stand up and creates goosebumps when you're cold.
• 🏃‍♂️ Blood vessels in the dermis constrict to retain heat when cold and dilate to release heat when hot, contributing to body temperature regulation.

Q & A

What are the three layers of the skin mentioned in the script?

The three layers of the skin are the epidermis, the dermis, and the subcutaneous fat.

What is the primary function of the epidermis?

The epidermis functions as a skin cell factory, where new cells are constantly being produced at the bottom and migrate to the top, and it also contains melanin which affects skin color.

How long does it take for skin cells to travel from the bottom of the epidermis to the surface?

It takes about four weeks for skin cells to travel from the bottom of the epidermis to the surface.

What role does melanin play in the skin?

Melanin is responsible for determining the color of the skin, with more melanin leading to darker skin. It also provides some protection against the sun.

What is the function of the dermis in relation to the sense of touch?

The dermis contains nerve endings that send messages to the brain about various sensations such as heat, cold, and touch, allowing the body to respond appropriately.

What are the functions of the sweat and oil glands in the skin?

Sweat glands produce sweat that helps regulate body temperature, while oil glands (sebaceous glands) produce sebum, which creates an oily layer to protect and moisten the skin and makes it slightly waterproof.

What is the purpose of subcutaneous fat in the body?

Subcutaneous fat serves as a cushion and protector for bones and organs, and it helps to keep the body warm.

How does the body respond to cold temperatures according to the script?

In response to cold, the body constricts blood vessels to keep warm blood away from the skin's surface, and the erector pili muscles contract causing 'goosebumps'.

What happens to the blood vessels in the skin when the body is hot?

When the body is hot, blood vessels dilate to bring blood closer to the skin's surface to cool down faster.

What is the pilomotor reflex mentioned in the script?

The pilomotor reflex is the tightening of erector pili muscles when you're cold, which pulls the hair to stand up straight and creates goosebumps.

How does the skin help in cooling the body during physical activity?

During physical activity, sweat glands produce more sweat, which evaporates from the skin's surface, cooling the body down.

Outlines

00:00

🧬 Skin Structure and Functions

This segment of the video script explores the complex structure of the skin, highlighting its three layers: the epidermis, dermis, and subcutaneous fat. The epidermis is described as a 'skin cell factory' where new cells are produced and rise to the surface, eventually dying and shedding off. Melanin, responsible for skin color variation, is also present in the epidermis and offers some protection from the sun. The dermis contains blood vessels, nerve endings, sweat glands, and oil glands, which are crucial for the sense of touch and temperature regulation. The subcutaneous fat serves as a cushion and insulator, protecting the body's bones and organs while helping to maintain warmth.

05:01

🌡️ Temperature Regulation and Skin Responses

The second paragraph delves into the skin's role in temperature regulation. It explains how blood vessels constrict in cold conditions to keep warm blood away from the skin's surface and dilate when hot to release heat. Sweat glands are also highlighted for their function in cooling the body through sweat production and evaporation. The paragraph concludes with a humorous note about the sequel to the video, suggesting a continued exploration of skin functions.

Keywords

💡Epidermis

The epidermis is the outermost layer of the skin, described in the video as a 'skin cell factory' where new skin cells are generated at the bottom and gradually move to the surface. This process takes about four weeks, and by the time the cells reach the surface, they are dead and are continuously shed off. The epidermis plays a crucial role in the skin's function as a protective barrier and is integral to the video's exploration of the skin's structure and function.

💡Dermis

The dermis is the middle layer of the skin, rich in blood vessels and nerve endings, as mentioned in the script. It is responsible for transmitting sensations such as touch, heat, and cold to the brain. The dermis also contains structures like hair follicles and sweat glands, which are essential for the skin's regulatory functions. The video uses the dermis to illustrate how the skin interacts with the environment and the body's nervous system.

💡Subcutaneous Fat

Subcutaneous fat is the layer beneath the dermis, serving as a cushion and insulator for the body. The video explains that this layer of fat helps protect bones and organs and keeps the body warm by insulating it. It is an essential component of the skin's structure, highlighting the skin's role in maintaining body temperature and protecting internal organs.

💡Melanin

Melanin is a pigment found in the epidermis that determines the color of the skin. The video mentions that more melanin results in darker skin, contributing to the natural variation in human skin color. Melanin also plays a role in sun protection by absorbing ultraviolet radiation, which is why the video emphasizes the importance of sunscreen even for those with higher melanin levels.

💡Nerve Endings

Nerve endings are the terminations of nerve fibers in the skin, as described in the video. They are responsible for sensing various stimuli such as temperature, pressure, and pain. The video uses the concept of nerve endings to explain how the skin communicates with the brain, allowing the body to respond to environmental changes and protect itself from harm.

💡Sweat Glands

Sweat glands, located in the dermis, produce sweat that travels to the surface of the skin through ducts. The video explains that sweat helps regulate body temperature by evaporating from the skin's surface, thus cooling the body down. This is particularly relevant when discussing the body's response to heat, such as during exercise.

💡Oil Glands

Oil glands, also known as sebaceous glands, are found in the dermis and produce sebum, an oily substance that travels to the epidermis. The video describes sebum as creating an oily layer that protects and moisturizes the skin, making it somewhat waterproof. This highlights the skin's role in maintaining skin health and preventing dehydration.

💡Pilomotor Reflex

The pilomotor reflex is a physiological response where small muscles at the base of hair follicles, called erector pili, contract in response to cold or emotional stimuli, causing hair to stand on end and creating goosebumps. The video uses this reflex to demonstrate how the skin reacts to environmental changes, such as temperature, to protect the body.

💡Blood Vessels

Blood vessels in the dermis play a critical role in thermoregulation, as explained in the video. They constrict in cold conditions to retain body heat and dilate in warm conditions to release heat. This process is essential for maintaining a stable internal body temperature and is a key aspect of the skin's function in temperature regulation.

💡Hair Follicles

Hair follicles are the structures in the skin from which hair grows. The video mentions that hair starts at the base of the follicle and extends to the surface of the skin. Hair follicles are part of the skin's appendages and contribute to the skin's overall structure and function, including providing a tactile sense and aiding in temperature regulation.

Highlights

The skin has three layers: the epidermis, the dermis, and the subcutaneous fat.

The epidermis functions as a skin cell factory, with cells taking about four weeks to reach the surface.

Melanin in the epidermis determines skin color and provides some protection from the sun.

The dermis contains blood vessels and nerve endings, which are essential for the sense of touch.

Nerve endings in the skin send messages to the brain about sensations like heat, cold, and touch.

Sweat and oil glands in the dermis produce substances that protect and moisturize the skin.

Sebum, produced by oil glands, creates an oily layer on the skin that is protective and slightly waterproof.

Sweat glands produce sweat that travels to the epidermis and is released through pores to cool the body.

Subcutaneous fat acts as a cushion and insulator, protecting bones and organs and helping to maintain body temperature.

Hair follicles are found in the dermis and extend through to the epidermis.

Erector pili muscles near the base of hair follicles cause the pilomotor reflex, resulting in goosebumps.

Blood vessels in the dermis constrict in cold temperatures to conserve heat and dilate in hot temperatures to cool the body.

Sweat glands produce sweat that evaporates from the skin's surface, aiding in the body's cooling process.

The skin's multiple functions include protection, sensation, temperature regulation, and moisture retention.

The skin's complex structure and functions highlight its importance in maintaining overall health and well-being.

Transcripts

KidsHealth presents "How the Body Works,"

with Chloe and the Nurb.

[MUSIC PLAYING]

[MUSIC PLAYING]

Flashlight?

Check.

Rope?

Check.

Trail mix?

Check.

Picture of my mommy?

Um, check.

Now, will you tell me where we're

going with all this stuff?

We're going "Under the Surface of the Skin!"

Skin, skin, skin, skin, skin, skin.

Ahem.

Excuse me.

[MUSIC PLAYING]

Wow.

This is pretty cool.

I mean, I see skin all the time-- soft skin, wrinkly skin,

light skin, dark skin-- but I never

thought about what's under the skin.

What's on top is just the beginning

of the skin you're in.

The skin actually has three layers.

There's the epidermis, the dermis,

and the subcutaneous fat.

I don't know who gave you your elevator operating license,

but I would like to have a word with them.

Oh Chloe, you don't need a license to operate an elevator.

OK.

My stomach's feeling better.

Whoa!

The epidermis is like a skin cell factory.

New cells are being born at the bottom all the time

and slowly making their way up to the top.

It takes the cells about four weeks to get all the way up,

and by the time they finally make it to the surface,

they're dead.

So I'm like a skin cell graveyard?

[WOLF HOWL]

Precisely.

And you're shedding dead skin cells all the time.

Wow.

What else is up here?

The epidermis also contains melanin,

and it's what makes skin darker or lighter.

The more melanin a person has, the darker their skin will be.

Skin comes in many beautiful colors,

like my lovely lavender sheen.

I've heard melanin also helps protect you from the sun.

It sure does.

But even melanin can't do it all,

and that's why we wear sunscreen to keep from getting burned.

So what has the dermis done for me lately?

Let's go find out.

Ooh, look at all this stuff down here.

I see blood vessels, and that's a nerve ending over there.

I know nerve endings send messages to the brain,

but what is the skin trying to tell the brain?

Well, it's a touchy subject.

OK, I'm going to guess that that terrible pun means

that this has to do with the sense of touch.

Smarter and smarter you get.

Think of all the things your skin touches--

rough tree bark, a cold snowball,

a nice cup of hot chocolate.

Nerve endings read all of these sensations

and tell the brain and nervous system about them,

then the brain and nervous system

decide if the body needs to respond.

So if I touch something too hot, my nervous system

tells my hand to move away from it?

Exactly.

Wow.

I never knew my skin was so smart.

And it doesn't just feel hot or cold.

Your skin also detects other touches-- oh, like tickling.

Hey!

What are those things?

Those are your beautiful, your glorious, your fabulous sweat

and oil gland.

They keep you wonderfully sticky and sweaty.

Ew.

Yes, but a good ew.

Oil glands, or sebaceous glands, make

a sticky substance called sebum that moves up

to the epidermis, where it creates an oily layer that

protects and moistens your skin.

Sebum also makes your skin a little waterproof.

But what about the sweat glands?

Oh, I'm so glad you asked.

The sweat glands start here in the dermis,

where they make sweat that travels up--

Slowly, please.

[SIGH]

[MUSIC PLAYING]

--up to the epidermis, where the sweat comes out of holes called

pores.

And the last stop on the Skin Layer Express is the--

Subcutaneous fat.

A little warning next time maybe?

Ah, fat, sweet fat.

Why do we need fat?

The body needs some fat to cushion and help

protect your bones and organs.

This layer of fat also helps keep you nice and toasty warm.

Nice.

What else is down here?

See that thing over there?

I know what that is.

That's a hair follicle.

So the hair starts all the way down here?

And goes all the way up here!

Ugh.

I bet the hair does it at a more reasonable speed.

Oh, I forgot.

Near the base of the hair-- whoa!

Ugh.

--there are little muscles called erector pili that

tighten when you're cold and pull the hair so it stands up

straight.

It's called the pilomotor reflex.

(SINGING) Fancy word.

Ugh.

And that's what makes all those little bumps pop up

on your skin.

You mean goosebumps?

The very same.

Remember those blood vessels we saw on the dermis?

Yes.

These ones!

Yes, those ones.

When you're cold, they make themselves really small

to keep all your nice warm blood far away from the cold air

outside your skin.

Don't.

You.

Dare.

You were saying?

When you're hot, those blood vessels

bring all the blood closer to the surface of the skin

so it can cool down faster.

Is that why when I run a lot, my face gets red?

It is precisely why.

And the sweat glands help here too.

They produce a lot of sweat of the surface of your skin, which

evaporates and disappears, cooling you down

in the process.

Aah!

[MUSIC PLAYING]

Next time, I'm driving.

All right, you can drive in the sequel--

"Under the Surface of the Skin 2-- Chloe Takes the Lever."

Squee.

Now gimme some skin!

[MUSIC PLAYING]

[MUSIC PLAYING]