Sean Mackey, M.D., Ph.D.

So hundreds and hundreds of years, we're basing it on Rene Descartes' dualistic model. We still see this in medical care right now. You're a surgeon. For many, many, many, many years when I talked with the surgeons, They were firmly of the opinion that the amount of pain that a patient had after surgery was related to how much the scalpel cut and how much tissue damage was done.

So hundreds and hundreds of years, we're basing it on Rene Descartes' dualistic model. We still see this in medical care right now. You're a surgeon. For many, many, many, many years when I talked with the surgeons, They were firmly of the opinion that the amount of pain that a patient had after surgery was related to how much the scalpel cut and how much tissue damage was done.

And I think it's only more in the last 20 or so years I'm seeing surgeons really embracing this model that what people bring to the operating room table directly influences how much pain they have. Their early life experiences, all this stuff. And we'll talk about that.

And I think it's only more in the last 20 or so years I'm seeing surgeons really embracing this model that what people bring to the operating room table directly influences how much pain they have. Their early life experiences, all this stuff. And we'll talk about that.

Yeah. Had no influence on that model, which I think has had tragic consequences in the care of people, particularly with chronic pain. particularly women with chronic pain who have felt stigmatized, invalidated, because absent something that's obviously wrong out in the body of the periphery, they were just labeled as being histrionic housewives or being told it's all in their head.

Yeah. Had no influence on that model, which I think has had tragic consequences in the care of people, particularly with chronic pain. particularly women with chronic pain who have felt stigmatized, invalidated, because absent something that's obviously wrong out in the body of the periphery, they were just labeled as being histrionic housewives or being told it's all in their head.

Not just women, but also some men as well. And so it's only with that evolution of our perception or our model into a biopsychosocial model that that's gotten much better.

Not just women, but also some men as well. And so it's only with that evolution of our perception or our model into a biopsychosocial model that that's gotten much better.

Let's talk about, is there a pain receptor? So let's break it down into the foundational stuff. So we have these things called nociceptors. Complicated name. It's basically a transducer, which is another technical name. Now, you're engineering background, so you all know that a transducer is simply a device that converts one form of energy into another form of energy.

Let's talk about, is there a pain receptor? So let's break it down into the foundational stuff. So we have these things called nociceptors. Complicated name. It's basically a transducer, which is another technical name. Now, you're engineering background, so you all know that a transducer is simply a device that converts one form of energy into another form of energy.

This microphone is converting sound energy into electrical energy. The speakers convert electrical energy back into sound energy. We have these nociceptors that lie in our skin, our soft tissues, our deep tissues, our viscera, and they're specialized. And they convert different forms of energy into electrochemical impulses. They take pressure. They take heat, cold.

This microphone is converting sound energy into electrical energy. The speakers convert electrical energy back into sound energy. We have these nociceptors that lie in our skin, our soft tissues, our deep tissues, our viscera, and they're specialized. And they convert different forms of energy into electrochemical impulses. They take pressure. They take heat, cold.

They take chemical changes in the form of pH that can occur during infection. They convert those into action potentials that are then transmitted up nerves. These are little electrical impulses transmitting up generally two different nerve fiber types. These two different nerve fiber types, one is called a C-fiber, which is thinned. thin and slow. It's really pokey.

They take chemical changes in the form of pH that can occur during infection. They convert those into action potentials that are then transmitted up nerves. These are little electrical impulses transmitting up generally two different nerve fiber types. These two different nerve fiber types, one is called a C-fiber, which is thinned. thin and slow. It's really pokey.

And I don't know if I'm getting ahead if you wanted to go more into that, but you got this pokey, slow C-fiber that transmits at about one meter a second. And the frame of reference, if it helps, is think about your thumb is about a meter from your brain. So an impulse on a C-fiber from your thumb to a brain takes about a second to two seconds to get there. The other nerve fiber type

And I don't know if I'm getting ahead if you wanted to go more into that, but you got this pokey, slow C-fiber that transmits at about one meter a second. And the frame of reference, if it helps, is think about your thumb is about a meter from your brain. So an impulse on a C-fiber from your thumb to a brain takes about a second to two seconds to get there. The other nerve fiber type

It's called an A-delta fiber. It's got some nice insulation around it. It transmits 10 times faster. So it takes a little under a tenth of a second to get your thumb to your brain. And to give a real-world sense of the difference in C-fibers and A-delta fibers...

It's called an A-delta fiber. It's got some nice insulation around it. It transmits 10 times faster. So it takes a little under a tenth of a second to get your thumb to your brain. And to give a real-world sense of the difference in C-fibers and A-delta fibers...

Think back to the last time you stepped on a tack in the carpet, you hit your thumb with a hammer, you twisted your ankle coming off a curb. What happened? Think back to that experience. You get this sharp jolt of pain that goes right to your brain.

Think back to the last time you stepped on a tack in the carpet, you hit your thumb with a hammer, you twisted your ankle coming off a curb. What happened? Think back to that experience. You get this sharp jolt of pain that goes right to your brain.