Have fun with Squeaks, Tiny Jessie.
Oh, hi.
Welcome back to the fort.
Squeaks is finally going on his trip around the world tomorrow.
And while I've been helping him pack, we've been talking about our senses and the body parts we use to gather information from the world around us.
While I can't go with him, we've come up with ways that I can experience what he senses during his trip.
He's going to use this camera to take pictures to show me what he saw with his eyes and record audio of the sounds that he used his ears to hear.
How else could you share your experiences?
Well, we need to figure out things to do that can take the place of your senses.
Oh, let's see who's calling.
Maybe they can help us.
It's Bill and Webb.
Hi, Jessie.
We need you to settle another argument for us.
Yes, after Bill told you about how birds hear, we decided to learn more about all the senses we have.
I say there are five senses.
Sight, hearing, touch, taste, and smell.
And I say there are more than five.
Like, what about sense of direction?
You know, the one you never seem to have when it's time to go someplace warmer in the winter.
That's not a real sense.
Quack, quack, quack, quack, quack, quack, quack, quack, quack.
Hang on a second, guys.
Sometimes you'll hear people say, we have the five senses Bill just mentioned.
But there really are more senses than that.
First, sensory organs like our eyes have special parts called receptors.
A receptor captures a specific kind of information from the outside world, then changes it into a signal that goes to the brain.
And once the signal gets to the brain, the brain directs the body what to do to respond.
Right!
When we talked about the eye, we talked about photoreceptors and how we see.
Photoreceptors take in light, then change the light into a signal.
The brain makes sense of that signal, so we know what we're looking at.
And when we talked about the ear, we covered the receptors called hair cells in the inner ear that change sound waves into signals that our brains use for our sense of hearing.
We also have receptors in our tongue, nose, and skin for our senses of taste, smell, and touch.
So that's five senses!
Well, yes, Bill, but I'm not done yet.
Some of the receptors in our skin, like the ones that help us feel if something is soft or bumpy or hard, sense pressure.
And different receptors in the skin help us to sense temperature.
When we wash our hands before we eat, these receptors sense how warm the water is.
But if the water gets too hot, a completely different kind of receptor senses that we might hurt our skin.
These are pain receptors, and they can cause the body to take action fast.
So we pull our hands out from under the hot water quickly, and the skin doesn't get damaged.
I don't like what those receptors make me feel at all.
Yeah, pain hurts.
It does hurt, but pain receptors are super important because they let us know when something's not right with our bodies, so we can figure out what's going on and hopefully fix it if we need to.
Yeah, what about these other senses?
Well, for example, we have receptors that give us a sense of balance.
If you could see deep inside your ears, you'd see a part that's made of three loops full of liquid.
And inside these loops there are little receptors that can send signals up to the brain that tell it which way your head is facing.
This is how we know which way is up, down, left, and right.
Without this sense we couldn't stand or sit upright.
I never thought about that before, but that's an important sense.
It would be hard to fly without it.
Yes, there are other senses too.
There's also a really cool one called proprioception.
Whoa, that's a big word.
I think it's a fun length proprioception way more fun to say than sight or hearing.
But What's it mean?
Proprioception is the sense of where our body is in space.
Okay, how about this?
Close your eyes and think about where the tips of your wings are, or your fingers if you have them.
Now, touch your bill, or nose.
Super easy, right?
Even though you couldn't see anything, while you were moving your body, you knew where everything was.
That's proprioception.
Where are the receptors for proprioception?
Well, they're found in places like your muscles and joints.
This sense of body awareness also helps us figure out how much force we need to use when doing different activities.
Like, picking up an empty water bottle is going to require a little less oomph than a full one.
Speaking of water, what about feeling thirsty?
That's gotta be a sense.
Nah, that's just part of the sense of taste.
No, it's not.
Remember, to be a sense, there have to be receptors.
Our tongues have receptors in them that sense different flavors, like salty or sweet.
But there's no thirst receptor.
Instead, we feel thirsty when our brain detects the amount of water throughout our body is getting too low.
Okay, but what about my sense of the passage of time?
Well, that's not a sense at all!
Quack, quack, quack, quack, quack!
Bill!
Webb!
Okay, bye guys!
You want Tiny Jessie to experience balance and proprioception for me?
What else are you going to do on your trip, Squeaks?
Dancing?
That sounds amazing!
Dancing requires both balance and muscle movement.
Although, remember, Tiny Jessie doesn't have receptors.
That's why you're bringing the camera.
So, you know what you can do?
You can learn a dance routine from one of the countries you're going to and then come back and teach me.
Then I'll get to experience the movement and balance that you did.
Alright, it's a plan!
And here's the thing, you'll have to use many of your other senses to get that routine to me.
You'll have to watch the dancers, and listen to the sounds they're dancing to, and more.
I can't wait until your back squeaks!
Although, Tiny Jessie will keep you company throughout your journey.
Thanks for joining all of us on SciShow Kids.
If you want to have fun with me, Squeaks, and all our friends, you can subscribe to SciShow Kids.
And we'll see you next time here at the Fort.
