Andrew Huberman

Typically that occurs in the throat or the area right below the jaw.

If you go to the doctor, you say you're not feeling well, one of the first things they're going to do is they're going to kind of palpate gently and touch gently behind your ears, along your jawline, along your throat.

They're going to do this.

They might ask you if you have any swollen lymph nodes in your armpits or in your groin.

You may even be able to sense that swelling yourself.

And what that swelling reflects is the accumulation of lymph fluid in so-called lymph nodes.

Lymph nodes are these outpouchings or swellings along the lymph vessels where lymph fluid and the stuff within lymph fluid is sequestered.

So it's kept there for a while as opposed to just passing along through those one-way tubes.

And it is surveilled by the immune system.

Why and how is it surveilled by the immune system?

Well, first of all, remember, when your cells are active, your liver cells, your brain cells, your muscle cells,

by doing the things they do, they use nutrients and energy, glucose, they use oxygen, they use amino acids, they rely on hormones and all that stuff, and they generate waste.

They generate waste products in the form of little bits of cellar debris,

they generate ammonia, there's carbon dioxide.

We listed off some of these earlier, but keep in mind that those cells are fed by the blood supply and stuff gets into the blood supply by way of what you breathe.

So you can inhale a virus, for instance, bacteria that could be in food, bacteria from things that you touch that somehow gets beneath the skin and into your blood supply through a scratch or a cut, maybe a bite.

these sorts of things, or maybe you cut yourself with a knife that had some bacteria, it gets into your blood supply.

And so you have foreign bodies, contaminants within your blood supply.

Some of that is going to get out into the interstitial space.

Some of that will be taken up by the lymphatic system.