On the other side of the smooth muscle layer is the serosa.

在平滑肌层的另一膜层。

From the outside in, these are the adventitia, or serosa; the muscular layer; the submucosa and the mucosa.

从外到内看，分别外膜（或者说膜）、肌层、黏膜下层与黏膜。

The outermost layer is either the adventitia, a thick fibrous connective tissue, or the serosa, a slippery serous membrane.

化道的外膜，既有结缔组织构成的纤维膜，也有光滑、分泌液的膜。

Okay, so the intestinal wall, like this one, has lots of ridges and grooves, and also can be separated into the mucosal layer, submucosal layer, muscle layer, and serosa.

好，那肠有多的脊和槽，像这个图片一样，肠还可以被分成黏膜层、黏膜下层、肌层和膜层。

But of course it's much more than just a storage tank — it's lined with the same four main layers found through most of the GI tract — the mucosa, submucosa, muscularis externa, and serosa — but it's got a few special modifications.

当然，它不仅仅一个储存罐。它内衬着与大部分胃肠道相同的四个主要层——粘膜、粘膜下层、外肌层和膜——但它有一些特殊的修改。