So this is chamber number three. And then the left ventricle.

And the blood goes down into the right ventricle. And then, on the other side I'm going to label the last two chambers.

Blood flows from the right atrium to the right ventricle, then it goes to the lungs and from the left atrium to the left ventricle.

And it goes down into, you can probably guess how this one is called, is our left ventricle.

Let's open that IV, please.

So blood would flow from the left ventricle, into a place it shouldn't be going, the right ventricle.

Let's start with blood going from the right atrium, this way into the right ventricle.

On the other side you have the mitral valve, which separates the left atrium from the left ventricle.

So now the journey starts with the left ventricle.

All these different organs and tissues are gonna be getting blood from the left ventricle.

So you've already learned that the valves got endocardium.

So just like our right atrium we have one on the left.

And the first one, the pulmonary circulation, is really kind of relying on the right vetricle as the pump.

His classroom will be on on the left.

In the new cycle you have a bit of blood that's going from the right atrium to the right ventricle.

But now remember that blood is constantly moving through the heart, so in a previous cycle you actually had some blood that's coming back from the lungs and that's what's dumping into the left ventricle.

The bottom, the red part, is the muscular part. This is the strong muscular part.

I'll stand in the middle to do it right here.

And then you can see the inside of the heart.

And then it goes into the right ventricle.

And this is kind of the first part of our journey.

Let's say this toe right here.

And once the blood is in right atrium, it's going to head down into the right ventricle.

These are the chambers of our heart.

Two of the valves I'm gonna name, I'm giving them new names, something slightly different from what we've been referring to them by. These are the atrioventricular valves.

BP 80 over 30. He's in Vtach!

Keep your eye on the valves and we'll talk about them as the blood moves through.

We're gonna start our journey here at the right ventricle. So what's the first thing that kind of comes across?

From the body... to the right auricle... to the right ventricle... and out the pulmonary arteries to the lungs.

So let's get started in the upper part of the heart. The Right atrium, It's right there.

We're gonna actually follow the path of blood after it leaves the right ventricle.

So I'm gonna just take some blue paint to indicate deoxygenated blood or blood without oxygen, I'm gonna paint in how it look.

And so you see one of our monkeys, Mayday, up here doing this.

Yes.

... Right, left. Left, left, left, right, left.

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You have simultaneously two chambers that are full of blood, the right and left ventricle.

This is actually your typical desktop printer.

In the middle, you can see that little structure squeezing out, that's the left ventricle, pushing blood out through the aortic valve.

They'll say 'No, you can't go that way.' They're gonna close up. They won't allow blood to go that way.

They have on the other end of those tethers a little muscle. This makes perfect sense if you think about it.

The pulmonary veins drain blood and into the left atrium, right.

So what is that that is our left atrium.

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Left, left...