Inside the stomach, the epithelial layer is made up of cylindrical cells, which dive into the lamina propria, forming pits.

在胃内，上皮层由柱状细胞组成，这些细胞深入固有层，形成凹坑。

So, the innermost epithelial layer of the tube is known as the mucosal layer, and it contains some connective tissue as well, which supplies it with blood.

所以，管子最里面的上皮层被称为粘膜层，它也包含一些结缔组织，为它提供血液。

Finally, there's the innermost epithelial layer and it absorbs and secretes mucus and digestive enzymes because this is the layer that comes into direct contact with food.

粘膜层的最内层为上皮层，它能吸收和分泌粘液和消化酶，因为它是与食物直接接触的一层组织。