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

从外到内看，分别是外膜（或者说浆膜）、、膜下与膜。

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

消道外膜，既有结缔组织构成膜，也有光滑、分泌浆液浆膜。

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

在平滑另一边是浆膜。

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，那肠壁有很多脊和槽，像这个图片一样，肠壁还可以被分成膜、膜下、和浆膜。