Andrew Huberman

There's going to be cellular waste in the form of actual physical debris.

There are going to be metabolites.

There's going to be ammonia, basically a bunch of waste product is going to then get kicked out of those cells into what's called the extracellular space.

Now, a couple of times today, I'll talk about what's referred to as the interstitial space.

The interstitial space is the area around the cells of the various tissues and organs of your body.

and fluid and these waste products gets kicked out into that interstitial space between the cells.

So once it's there, it needs to be cleared out of there.

How is it cleared out of there?

Some of it will be taken back up into the blood supply

And with it, a lot of water, a lot of fluid.

I didn't mention this yet, but a lot of fluid, a lot of water gets out of the vasculature and into those cells and into the interstitial space around those cells while it's delivering all those nutrients and goodies that we talked about a minute ago.

Now, some of the waste product and the water, so carbon dioxide and water, et cetera, will be taken back up by the blood supply.

How does that happen?

Well, there are capillaries that are referred to as venous capillaries, okay?

So we talked about the arterial system, which delivers oxygenated blood.

There's also another system called the venous system, which takes deoxygenated blood back up to be oxygenated by the lungs.

And it does that, of course, in concert with the heart.

So we have the arterial system that delivers oxygenated blood.

There are rare exceptions of arteries that deliver non-oxygenated blood to tissues such as the lungs, but let's just set that aside for now.

We've got these arterial system that delivers oxygenated blood.