Epithelial tissue covers both the inside and the outside of that you-tube.

上皮组织覆盖了管子的内部和外部。

Our muscle, nervous, and epithelial tissue types are more uniform, more obviously grouped together.

我们的肌肉、神经和上皮组织类型更均匀，更明显地组合在一起。

And all of your epithelial tissues are avascular — meaning they don't have a blood supply.

你所有的上皮组织都是无血管的，这意味着它们没有血液供应。

Without epithelial tissue, you'd essentially be a mushy pile of unarticulated goo.

如果没有上皮组织，你基本上就是一堆无法连接的粘液。

Which brings me to the other trait that we use to classify epithelial tissue — its layering.

这让我想到了我们用来分类上皮组织的另一个特征——它的分层。

When we talk about your epithelial tissue we're really talking about two things.

当我们谈论你的上皮组织时，我们实际上在谈论两件事。

Of course, when we talk about epithelial tissue protecting you, it's not always protecting you from the outside world.

当然，当我们谈论上皮组织保护你时，它并不总是保护你免受外界的伤害。

Today you learned how your unsung epithelial tissue creates the inner and outer boundaries that keep you alive.

今天你们学到了无名的上皮组织是如何创造内部和外部边界，让你们活着的。

They theorised that, in the absence of worms, the inflamed epithelial tissues in normal mice might instead identify the egg-white protein as an intruder.

他们推测，在没有蠕虫的情况下，正常小白鼠体内发炎的上皮组织可能会将蛋清蛋白识别为入侵者。

And that is where your unsung epithelial tissue steps in, like a burly gym teacher with a whistle and plan.

这就是你默默无闻的上皮组织介入的地方，就像一个身材魁梧的体育老师，吹着口哨，做着计划。