Visualizing hidden worlds inside your body - Dee Breger

Transcriber: Andrea McDonough
Reviewer: Bedirhan Cinar

I'm going to take you on a journey into some hidden worlds inside your own body using the scanning electron microscope. These microscopes use a beam of electrons to illuminate things that are too small to be seen by the photons of visible light.

And to put this in context, if you mentally divide one tiny millimeter into a thousand parts, each one of those parts is a micrometer, or micron for short. If you then divide one micron into another thousand parts, each one of those is a nanometer. And it's nanometers and microns that are the domain of the scanning electron microscope.

So, let's start with something on the body that we can measure at about 100 microns wide, and that would be a human hair, which now you can see is covered with scales, just like all of our hairs, and in fact, just like all mammal hairs. We're going to plunge into the body now, and we've landed in the thyroid gland.

Here we're looking at proteins that are being secreted into a storage chamber where they are going to develop into the mature thyroid hormones before being released into the body. And at this point, you might be wondering if these colors are real. The answer is no. Electron images only happen in black and white.

I often colorize my images for various reasons, but I don't change the structures, so the structures that you're seeing are all exactly as they were when I photographed them in the microscope. We're going to take a detour and zoom in on the heart muscle now. And the heart muscle has this curious structure that's kind of like corrugated cardboard. That's what allows the heart to expand and contract as it's beating.

Let's go look at a lung with pneumonia. Here we've got a white blood cell poking around in an air sac, looking for something to clean out like a little vacuum cleaner. This is your immune system at work. So what are the kinds of things that we don't want to be breathing, besides bacteria and viruses? Well, we all know to stay away from asbestos and now we can see why.

This is a close-up view of the mineral that asbestos is made from, and now you can see that it's composed of many tiny, fine little needles. Each one of those needles is a single crystal. And in this picture, they're beginning to pry apart and tangle up into a spiky mess, not for breathing.

What else might we want to avoid breathing? Well, how about diesel fuel? We're looking here at the particles of diesel soot, and these are extraordinarily tiny. In fact, each one of these little particles is only about 50 nanometers wide.

We'll go and look at some blood now. We've got a collection of nice, fat, happy, healthy red blood cells, but they're all tangled up in a network of fibers. This is how the body makes a blood clot. And so, it surrounds a group of red blood cells and other cells and traps them so the blood can't flow.

We've got two more blood cells here, but they're not normal like the ones in the blood clot image. These are distorted. You can see that they're curling up and beginning to grow what's going to become spikes. These are sickle cells and these are what cause the condition of sickle cell anemia.

We've gone into the mouth now and we've landed on dental plaque, which you can see is covered with bacteria, and in fact, dental plaque is host to about 1,000 different species of bacteria. Lovely to think about.

And now we are on to other teeth. We're on the surfaces of the, or the internal surfaces of the teeth themselves. The smaller one is a baby tooth that had just fallen out of the mouth of a young friend of mine, and I want to call your attention to the little holes. Those little holes are the tops of a whole network of tiny little tubes that circulate nourishing fluids inside your teeth.

And we can see those tubes a little better in the larger picture because some of them are in cross-section. But in fact, this larger picture is showing you a portion of a tusk, which you may know is simply a great big, elongated tooth, so you would expect to see the same features between your teeth and a tusk.

But that larger tusk picture is also rough by comparison to the young baby tooth. That's because it's many, many thousands of years old. It's also partly fossilized. And, between these two pictures, now you can see how your teeth relate to the tusk of an Ice Age mammoth.

We're shooting up north now into the brain, and we can see these pink cells down at the bottom. Those are the neurons of memory. And I'm going to leave you with this picture because I know you're going to take a lot of happy memories away from your exciting day at TED and now you can visualize where those memories are being stored in your own brain.

Thank you.