Respiratory | Mechanics of Breathing: Pressure Changes | Part 1

equal to intrapleural

pressure

, so because this is zero, so what does it really equal? So this is equal to negative four minus zero, which is negative four millimeters of mercury. And so what does that mean? That negative muse mercury formula means that it's trying to deflate, that's why the chest wall because of this, if you look at the actual transthoracic

pressure

, naturally, this is actually going to be one that tries to come this way, right? ? If we're going to want to inflate it, it's actually going to cause a deflated pressure, so transthoracic pressure is a deflated pressure.

Okay, so we've done transthoracic transpulmonary. There's the last one. We can mention it very quickly and it's again intraalveolar pressure right here minus. the atmospheric pressure, so if we were to write that down just for the fun of it, it would be the intrapulmonary pressure, so the trans

respiratory

pressure we'll call it t RP, so the trans

respiratory

pressure is equal to ti p-pull minus D P of the atmospheric pressure okay, what does that equal is equal to zero minus zero, so it's going to be zero millimeters of mercury and again we're doing all of this at rest, this is going to be zero millimeters of mercury.

Let's compare this to what it would look like later each time we do the inspired inspiration process. Again, with all these pressures, let's go over them quickly. Transrespiratory pressure is intrapulmonary pressure minus atmospheric pressure. so it's zero millimeters of mercury, so there's no real gas flow moving in any direction here and there's no pressure differences across this transpulmonary pressure, this one is really important. This in transthoracic are the most important pressures: transthoracic pressure I' Sorry, transpulmonary pressure is the least intrapulmonary to enter plural and we said again that you will take this zero millimeters of mercury that was 760 again, we could write like this, my name is intrapleural , which could be 756 or it's here on the right, minus four no.

It doesn't matter, you'll still get the same number, which will be positive, four millimeters of mercury again. What does that mean? This means we are trying to expand ours. That you want what you earned here. Do you want this real time? In order to inflate properly, you want it to be able to inflate, so positive pressure means you are trying to inflate the structure now. If we look at the transthoracic pressure, what's happening here is a little bit interesting, because it's taking the intrapleural pressure. The pressure is subtracted from the atmospheric pressure, but what do you really have left?

You're really only left with the intrapleural pressure, so if that's the case, then your transthoracic pressure is equal to your actual intrapleural pressure, negative four millimeters of mercury. What does that mean? So it goes back to what we said is due to this natural outward elasticity or recoil of the chest wall, because that's trying to move this parietal pleura away from the visceral pleura, which is increasing this volume. What else did he do? we said we said it was also due to the natural elasticity and surface tension of the lungs that is trying to push the actual visceral pleura away from the Laurel product, what is that doing to the volume?

It's increasing my volume and what that would do to the pressure in this area will decrease the pressure and that's why this should make sense, well now that we've done it, we've gone over a ton of pressures and a ton of different formulas and numbers. I'm sorry. So what we're going to do is go over how these pressures change every time we go through the inspiratory process, so if you stay with us, go to the second

part

, we'll look specifically at how the nervous system is affecting this entire respiratory structure here and how that is actually producing pressure differences.

Alright, engineers, I'll see you in

part

two.