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）、肌层、黏膜下层与黏膜。

A generous amount of bicarbonate is also secreted by a number of glands lying in the submucosa of the duodenal wall.

十二指肠肠壁上分布的大量腺体，也可分泌大量的碳酸氢盐。

Now, surrounded by the muscularis externa is the submucosa, which consists of a dense layer of tissue that contains blood vessels, lymphatics, and nerves.

在肌层包裹下的是粘膜下层；它由一层致密组织构成，其中含有血管、淋巴和神经。

Beyond the mucosa, there is smooth muscle followed by more connective tissue, and together, these two layers make up the submucosa and this is where the bronchial mucinous glands live.

黏膜层外是平滑肌细胞，之后是更多结缔组织，这两层共同组成粘膜下层，是黏液腺所在之处。

Finally, in the bronchi, but not the bronchioles, there is also a layer of cartilage below the submucosa which stiffens the bronchus and helps to keep it open.

最后，在某些支气管中，黏液下层之下还有一层软骨；这些软骨可以使支气管变硬并且保持开放。

Normally, the wall of the entire gastrointestinal tract is made of 4 layers: the inner mucosa, the submucosa, a muscular layer, and an outer layer called the adventitia.

正常情况下，整个胃肠道的壁由4层组成：粘膜层、粘膜下层、肌层和外层（即外膜）。

So for example, if a tumor has invaded the esophageal submucosa but it hasn't spread to lymph nodes or distant organs, it's categorized as T1, N0, M0, which falls under stage I.

举个例子，如果食管癌已经入侵了食管黏膜下层，但还没有转移至淋巴结或远端器官，那就可以被分为T1、N0、M0，意味着处于I期。

In the gut, there's a layer of smooth muscle just under the submucosa, which sits under the mucosa, which is the innermost layer of the gut nearest to the lumen.

在肠道，黏膜下层之下有一层平滑肌，黏膜下层即位于黏膜层的下层，而黏膜是肠道最内层（离肠腔最近）。

For initial stages, when the cancer has invaded just the mucosa and submucosa, options include esophagectomy, endoscopic tumor resection, or mucosal ablation - which is when the cancerous mucosa is removed by radiofrequency.

早期肿瘤只入侵黏膜和黏膜下层，治疗选择包括食管切除术、内镜下肿瘤切除术或黏膜消融术，即用射频消融被肿瘤侵袭的黏膜。

In the bronchioles you've got the lumen, the mucosa which includes the inner lining of epithelial cells as well as the lamina propria, and the submucosa which is where the smooth muscle lives.

在细支气管内，有腔体、粘膜（包括上皮细胞的内层、固有层），以及粘膜下层，也就是平滑肌所在的地方。