Describe the functional relationships between volume changes and gas flow into and out of the lungs.

Video transcript

Welcome everyone. Let's look at our next question here. It says the functional relationships between volume changes and gas flow into and out of the lungs are governed by the principles of Boyle's law and the mechanics of respiration. Which of the following statements accurately describes the relationship between volume changes and gas flow. According to Boyle's law, A, when the volume of the lungs increases, the pressure inside the lungs decreases and vice versa. This pressure difference drives the flow of gasses into and out of the lungs. Choice B when the volume of the lungs increases, the pressure inside the lungs increases and vice versa. This pressure difference drives the flow of gasses into and out of the lungs. Choice C. When the volume of the lungs increases, the pressure inside the lungs remains constant. This pressure difference drives the flow of gasses into and out of the lungs. And choice D when the volumes of volume of the lungs increases, the pressure inside the lungs is unrelated to gas flow in and out of the lungs. Well, we got a lot of words here. Let's start with recalling what Boyle's law says and it does describe the relationship between volume and pressure. When it comes to gasses, Boyle's law says when the volume, uh, the gas increases, just drew a little up arrow, the pressure of that gas decreases, I just drew a little down arrow there. So looking back at our answer choices, we would say that when the volume of the lungs increases, the pressure inside the lungs should decrease according to Boyle's law. So that's going to eliminate choice B which says that when the volume of the lungs increases, the pressure increases. And Choice C which is that the pressure inside the lungs will remain constant when the volume of the lungs increases. And then finally, choice d when the volume of the lungs increases, the pressure inside the lungs is unrelated to gas flow in and out of the lungs. This will also be incorrect because when that volume increases and the pressure decreases. So put volume up pressure down, that ends up meaning that the pressure drops below atmospheric pressure, which means that air goes into the lungs flowing from a region of higher pressure to a region of lower pressure and vice versa. When you end up having the lungs contract pressure increases, then air goes out of the lungs to a region of lower pressure. So our answer choice must be choice. A when the volume of the lungs increases, the pressure inside the lungs decreases and vice versa. And then this pressure difference drives the flow of gasses into and out of the lungs. So that's our answer. Choice and choice c pretty straightforward question. As long as we can remember what Boyle's law tells us about this relationship. See you in our next video.