B and T Cells Where They Come From: Immunity Series

Here we are back again. It’s Coach Garey. We’re talking about immunity and there are some of the more interesting details about immunity. 

We’re going to get to the point of strengthening immunity, boosting immunity, and balancing immunity. Balancing may be really the keyword here, but in the meantime, I wanted to talk a little bit about how the immune system is actually constructed and how it works in your body. It’s pretty dang interesting.

You may know this. If I ask you where the immune system lives, you might say the gut, a lot of people say that these days, but in fact, the cells that are in charge of preventing illness and wiping out those invading pathogens, those cells originate, they originate in the bone marrow. Okay? Basically there are STEM cells in the bone marrow that mature over time. Some of them turn into B cells. Leukocytes, those are white blood cells. And some of those cells, as they’re maturing, they leave the bone marrow. Now how do they do that? They travel with the blood. Okay? They get into the circulatory system. They wind up in this gland called the thymus, right? It’s here in the center of your chest and it is a gland that operates and turns those STEM cells from B cells into T cells.

Let’s say B is for bone. That’s where the B cells mature and then T for the thymus. The T cells actually grow, occur, and mature up until the age of about puberty. By the time you’re 13 or 14, this thymus gland has actually devolved. Instead of evolving it devolves and is no longer a gland, it becomes sort of a piece of fat and all the T cells you need for your entire life have already been produced by the time you reach puberty. You’ll never run out. You’ll have T cells the rest of your life. But that is just the very interesting, weird thing about the body and how it operates. The thymus gland is no longer a thymus gland, it’s just a little lump of fat in there, and it’s done its job of creating those T cells.

What we’re talking about here is white blood cells. That’s how they travel around in the blood system. And I want to ask you a really quick question. 

How many cells in the body are touched by blood? 

Where does the circulatory system extend to? You see a picture in an encyclopedia or in a book or on a website. You see arteries and you see veins, but more often than not, you don’t see the full extent of the circulatory system, which 80% of it is comprised of capillary beds that spread through your entire body. So, if you just thought about it for a second, if you remove the skin, what you would see is a very red body. Blood is everywhere.

I had an accident the other day I was walking the dog and another dog was coming I was going to pass over to the other side of the road, but there was a ditch and a gully, and it was a little deeper than I thought and I didn’t get up to the road. I fell, I slipped, and crashed down on my knee. When I got home, I had a skinned knee and there was just all red. All these capillaries are just extending out everywhere, touching every cell.

The point I’m getting to, is that white blood cells travel in the circulatory system and they’re actually bigger than red blood cells, quite a bit bigger. And they just lumber around the edge of the capillaries, the edge of the arteries. And it’s like a little eating machine. One of those little munching machines that gobbles up all and scavenges all the debris, all the metabolic debris and things that aren’t needed anymore and too much cholesterol hanging around, it gobbles it up, and it disposes of it through a process of detoxification, which has to do with your liver. 

I just wanted to impress upon you that we’re not scientists here, but it’s very, very interesting how the immune system is pre-programmed to work and do everything that you need it to do throughout your lifetime.