Inside every human body, there are roughly
37.2 trillion cells each and every one working hard to maintain.
A healthy, effective system 24 over seven,
and they all take their jobs very seriously.
Welcome to the inside of a human body.
Is this right? It's probably not. All right,
listen up, rookie Red blood cells.
Directly ahead is the inferior vena cava.
The minute a new batch of rookies,
you'll be immediately sent to the front lines.
So make sure you get everything straight.
I guess I'm no longer the new girl on the team.
It's time to step up my game.
I know everyone else just sees me as a directionally challenged dummy.
All of my deliveries would be on time
if I wasn't making sure yours were too.
De name is macrophage. I've got to come
into my own so I stop dragging down everyone else.
No more depending on others. I can
handle anything that comes my way.
I transport carbon dioxide to the lungs
and deliver oxygen to cells throughout the entire body.
I'm a red blood cell, and that's my job.
Today, I will complete my route through
the circulatory system and not get lost.
Two, three, four. We are working for you.
Another day of sending 0202 all through
out the body, every nook and cranny build.
That is confusing. And I'm lost. I'm lost.
Though we may seem hopeless, we are selfless work for you and.
Let's get down to work. Let's get
down to work every day and struggle. But I gotta pull through
another day. I'm out here slicing, slicing, filthy germs and viruses.
Show your ugly face won't let them get away.
I'll chase and chase some. We are
professionals for cells have worked for you. And so.
Let's get down to work. Let's get down to work.
Every day is a battlefield. You better
prepare 37 trillion and we are only two. Still, I.
So we don't know who you are.
You think we're working hard? Of us together
are supporting you with all of our hearts.
No matter what kind of strife, troubles risk our lives,
we always take pride in what we do, and health comes first.
Are you working? Yes, I'm working. Are
you working? Working. Working for you.
Blood circulation.
Okay. I'm standing in front of the inferior vena cava,
which should be easy. Inferior vena cava to the heart.
To the lungs. Simple. And then I just
loop my way back. Let's do this.
Okay, so I'm going to turn this corner up here.
Here we go. And they got. Pull the noodle.
Why does this stuff always happen to me?
I was just getting my life together.
I should have known it would all end
with me getting impaled. I don't want to die.
Not cool. What the heck are you doing?
Cutting in front of me like that? Target sighted. Time to die.
Are you all right? Red blood cell.
You're not injured, right? White blood cell.
I can't believe you saved me. What were
you wandering around here for anyway?
There's nothing here. Just lymphatics. What?
Seriously, How did I get turned around already? Lost again.
Uh, just a bit. Oh. Oh, my goodness.
He wouldn't have even been hurt if it wasn't for me.
I have to get it together. I can't
keep putting other people in danger.
Come on. I'll show you the way again, huh?
Amazing. I've never seen this kind of determination from her before.
She's doing this job on her own no matter what.
Her aura is practically screaming it.
I should step back and let her do this.
You know, How about I see you later?
Keep up the good work. I will.
Sorry, baby. This. We're still doing a little construction.
Please watch your step. Yeah, Thanks. Really appreciate the warning. Little platelet
red blood cell. Are you okay? Yeah.
I mean, aside from the crippling embarrassment,
I'm pretty okay. I'm sorry. I'm so sorry.
Anyway, I better get back to work.
Maybe look in the direction you're actually going.
I'm sorry. You're right. I'm sorry. This is going to go well.
So many delicious things to choose from.
Right. I could really go for some glucose.
Oh, it's so hard to pick.
Dextrose, also known as glucose. Red blood cells are fond of sugar.
Unlike white blood cells, red blood cells don't have a mitochondria,
so glucose is their only source of energy.
All right. Finally, back on the right
path to the inferior vena cava. So far, so good.
This is 1146 reporting. I'll be patrolling
the entire body for the day.
Copy that. I'm hanging in the liver if you need backup.
You did really good work today. My shoulders are so stiff.
Okay. Maps right side up. This should be the right vein.
The venous valve governs the directional flow of blood.
Prevents blood from backing up and ensures
it flows one way through the vessels.
I just walked in. How were you already going the wrong way.
The valve is one way only. That's
the same exit you just came from, right? Totally.
See that? Now this girl. Don't cry.
And don't tell them the map was upside down.
Inferior vena cava, the largest vein in the human body,
collects blood from the lower body and then
delivers it to the right atrium of the heart.
Vena cava route any day of the week.
It's just a straight shot. So it's a breeze.
Yeah, but the uphill climb always waves me out.
Right? This is it. You're doing super
great, so just keep it up.
It's a straight, easy path. This is where
we make up for lost time.
Hey, look who made it most of the way alone today.
Do you want me to show you how to get to the heart?
Whoa. She's looking real determined. I don't think she even heard me.
Your attention, please. The path is extremely congested with traffic up ahead,
so you'll have to leave your carts behind.
You may advance once you place your carts in the corral.
Welcome. You are now entering the heart.
Please follow all instructions and make sure to circulate quickly.
Attention Blood cells Place carts in the designated area before advancing.
Hello, Red blood cells. Hope you're doing
well. And welcome to the heart.
I'm going to take this time to explain lung and body circulation.
Please pay close attention. You're about to embark
on a non-stop thrill ride known as heart circulation.
So I hope you're all prepared. First, lung circulation.
You'll be traveling from the right atrium
to the right ventricle and through the pulmonary artery.
Once you arrive in the lung, you will
hand over your carbon dioxide and receive oxygen in exchange.
Then you'll travel through the pulmonary vein to the left atrium.
So begins body circulation. Travel through the aorta
from the left ventricle and head out to the capillaries.
Here you'll hand over oxygen and nutrients
and in exchange receive waste like carbon dioxide. Almost done.
Your complete body circulation by returning to the right atrium.
Thank you so much for joining me.
Can't wait to see you next time you return to the heart.
I wish you all the best of luck.
Hello? Red blood cells. Hope you catch that.
Not at all. To the heart. The
final hurdle looms before our hero.
The place that mystifies me to this very day. The heart.
Oh, my gosh. It's this way.
This one is all you red blood cell.
That's the spirit. Got this?
All right, Hart, Here we come.
Cells that work.
Souls.
Attention cells. You will soon arrive at the heart.
Please be careful as you pass through.
Attention. I finally met. It the heart,
an organ made entirely of muscle.
It maintains circulation by receiving blood from the veins
and pumping it back out to the arteries.
This action is repeated approximately 100,000 times per day.
The right atrium receives venous blood from
the upper and lower vena cava,
which it then pumps into the right ventricle.
Please wait your turn behind the white line.
No. Hey, don't push. Jeez. Careful. Kinda crowded in here.
Welcome to the heartland. You are now in the right atrium.
Please refrain from pushing. Rushing to circulate can be dangerous.
Now approaching the junction for the inferior
vena cava and the superior vena cava. Expect heavy traffic.
Please be careful to keep hold of
hats, glasses and other personal belongings.
The tricuspid valve will be opening shortly.
No, don't leave me.
I'm sorry. Please. I need to go back. I need my.
Got my notes. Oh, no.
Did my notes come?
What's with that neutrophil? Seems kind of sketchy.
Please keep moving and do not stop until you pass through
tricuspid valve. The three flaps of tissue
between the right atrium and right ventricle.
When the heart constricts, the pressure creates
a flow and pumps blood into the right ventricle.
This also prevents the blood from flowing back into the right atrium.
The right ventricle where carbon dioxide rich venous blood gathers.
So happy. Welcome to the right ventricle
as it is constricting at the moment.
Please do not stop around the tricuspid valve.
No. My precious hat. Excuse me. Can you pass this up to her?
Pulmonary artery. The artery that pumps venous blood into the lungs.
Oh, where to now? Just straight ahead, huh?
A hop, skip and a jump. And I'm
practically there. This is going so well.
Next up, time for the gas switcheroo.
The lungs where carbon dioxide is released and oxygen received. Wow.
I can't believe I made it all the way to the pulmonary.
Welcome to the pulmonary alveoli. We're happy
to have you here with us.
Your carbon dioxide is being collected.
Oh.
Thank you for waiting. Your oxygen is ready to retrieve.
You know, come to think of it. Hello.
As for you, I'll treat myself to an appetizer.
Hey, I've got to give it to you.
I never guessed you were in that box the whole time.
This was the first place that white blood cell ever rescued me.
Pulmonary vein. The passage for the flow of oxygen rich blood.
Looping on back to the heart.
I'm just going to keep moving.
The aorta from the aorta. The path splits into two smaller arteries,
traveling to all capillaries in the body.
The capillaries, pathways that distribute oxygen and nutrients
to the cells and retrieve waste such as carbon dioxide.
So close. Just got to deliver this oxygen and I'm done.
Um. Do you know which way right is? That's your right hand.
You're holding the pen width. So it's that way.
This. Stick to the wall. Oh, here.
Let's see if I can help you.
Hey, mister, will you say die filthy? For me.
I just heard there's a small abrasion somewhere nearby.
Another one. So right up here.
Oh, darn it. The road's closed up ahead.
Ha! There we go. Infiltration complete. Yep.
And look at that one. Sucker served up to order.
So that innocent red blood cell is going
to be our first target. Is she?
All we have to do is wait here,
and then we can bash her face right in
there.
This whole day is going so great.
That was a close one. Oh, you already handle those guys.
Shh. Get rid of this. Uh huh.
Wait, you're just dumping this on me? I can do this.
I can do this. All on my
own. I am rocking this day.
This is so tight, so narrow, So very small.
Come on. Power through a red blood cell. Oh. Get it.
I'm here to deliver your oxygen.
Oh, perfect. Can't tell you how much
I appreciate you squeezing on in here.
Had a tough route, huh? No, not at all.
That's just part of the job.
Oh, that was a tight deadline.
I did it. I really finally did it. I made
a full circulation without getting lost.
Yo, killer T, what are you doing
here? Don't think that really matters.
A kid dancing down there. She's the red
blood cell that needed you to show her around, right?
Really? On your own. You managed to circulate
all the way here? That's right.
I never could have done it without your guidance.
So she finally did her job without any help for once.
Wow. Almost impressive how inept she is. Hey,
there's no reason to be like that.
Trust me, there's plenty of things you
and I happen to be pretty awful at, too.
It just so happens that she's pretty
awful at, you know, not getting lost.
But still, she never gave up on trying
to grow, not even for a second.
And maybe she needed a hand to hold.
Maybe she had to make some mistakes, but she kept pushing.
Let's not blow this out of proportion.
You never needed my help. You just
used what's tucked away between those ears.
I had never really given it much thought.
But those red blood cells, they've got
a tough job traversing this vast body. It's an epic journey.
She put so much effort into her
job and still every day tries to improve herself.
I'm real. She is. She's amazing. You so very much.
I'm just so happy right now.
And killer t, I know we've got a hard job,
too, but immune cells tend to frighten red blood cells.
And really, I think we need to understand them.
Maybe one day every cell can respect
each other for what they contribute.
I know you get me killed. Just shut up. Rah, rah ra.
Uh oh. Why? Stop
spouting sentimental platitude, you spineless, feeble, jabbering sap.
You just keep going on and on and on.
Okay, hold on. What's happening? You listen to me.
We kill without mercy, even our own allies if we need to.
That is the sole purpose of immune cells like you and me.
You want everyone to be your best friend?
You want to sit around sipping tea,
shooting the breeze with red blood cells?
Or maybe you're hoping to snag an invite
to a neighborly game of cards with some new buddies, huh?
Is that it? You want to feel
the thrill of losing a game of old maid?
Time to grow up and say goodbye
to those pathetic pipe dreams, pal.
So that seems like a really detailed fantasy there,
the two of us. We're assassins. You got that?
Yeah, I guess you were born with
a knife hidden in your heart.
And you better keep it sharp and ready.
You're a killer. And don't you forget it.
My heart. Do you understand me, maggot? Sure.
It's like you're trying to piss me off.
Oh, hey, white blood cell. Come here.
I have the most awesome news. Believe it or not,
I just made my rounds without any help at all.
Yeah. What the heck happened to your face? Nothing.
It's fine, really. Killer t, I mean,
a mugger? No. Or maybe an antigen.
Honestly, don't even worry about it. I can't even feel it anymore.
So, anyway, you were saying you made the circulation? Yeah, I did.
That's great. Tell me all about it.
I mean, about what you guys do.
So where should I start? Okay. Right
after I ran into you earlier.
The first stop I made was in the vena cava.
That's where all the veins in the body lead to.
So it's freaking enormous in there.
And then I went to the heart, and it was so crowded.
And I was all smushed, like, smushed. Right.
And then. And then when I was in the heart,
I dropped my notes and I was like, no.
But then they keep flying back to me.
So then after that, I went to
the lung and the pulmonary alveoli,
which is this funny, lumpy, bumpy shape from the outside.
And I never thought of it like
that. Lumpy. Bumpy. Exactly. And then.
Yeah. I can fight germs all day with this baby.
Can I hold it? I got lost.
But at least I learned something today. Sure. Good excuse.
Maybe I'll get lost more often then.
I'm not jealous of those cowards. Not at all. Keep
The knife in your heart. Keep it sharp.
And how exactly do you do that?
You gotta learn just like I did.
Next time on cells at work. Thymocytes.
All right. It's time to get to work.