So you know what else we need? Bulk flow.

你知道我们还需要什么吗？容积运动。

Bulk flow is like public transportation — it moves large numbers of molecules, quickly.

容积运动就像公共交通——它快速移动大量分子。

So, the principles that make respiration possible are relatively simple — diffusion and bulk flow.

因此，使呼吸成为可能的原理是相对简单的——扩散和容积运动。

The bulk flow part of things is handled by some of your system's biggest and most obvious moving parts.

事物的容积运动部分由系统中一些最大和最明显的移动部分处理。

That's why your respiratory system is the way it is: It's set up to take full advantage of both bulk flow and simple diffusion.

这就是为什么你的呼吸系统是这样的：它的设置充分利用了容积运动和简单扩散。

It's only by working together and using both the bulk flow and simple diffusion of oxygen that they can make possible the process of cellular respiration.

只有通过协同工作，同时利用容积运动和氧气的简单扩散，它们才能使细胞呼吸的过程成为可能。

So it's your alveoli where diffusion meets bulk flow. Because while you're picking up oxygen and dispensing with CO2 one molecule at a time, you're doing it in enormous quantities at any given second.

所以你的肺泡是扩散与容积运动相遇的地方。因为当你吸收氧气并一次释放一个分子的二氧化碳时，你在任何给定的时刻都在做大量的事情。

First, of course, you've got to introduce the food to your digestive system. What you know as eating, or ingestion, is basically just creating a bulk flow of nutrients from the outside world into your tissues.

首先，当然，你必须把食物引入你的消化系统。你所知道的吃或摄入，基本上只是从外部世界创造大量营养流入你的组织。

But today you learned how it does work — including the mechanics of both simple diffusion and bulk flow, and the physiology of breathing, and the anatomy of the conducting zone, and the respiratory zone, of your respiratory system.

但是今天你们学到了它是如何工作的——包括简单扩散和整体流动的机制，呼吸的生理学，以及你呼吸系统的传导区和呼吸区的解剖学。