So, adenocarcinoma arises from columnar glandular epithelium.

腺癌来源于柱状上皮腺体细胞。

This causes the epithelium of the lower esophagus to constantly renew, and when it's replaced by columnar epithelium, that's called Barrett's esophagus.

这使得食管下段的上皮不断更新，当其被柱状上皮取代时，叫做Barrett食管。

The endometrium is itself made up of a single layer of simple columnar epithelium, which has ciliated and secretory cells, that sit on top of connective tissue, or stroma.

子宫内膜由单层柱状上皮构成；单层柱状上皮有纤毛细胞及分泌细胞，位于结缔组织即基质顶部。

On the other hand, adenocarcinoma is the most common type of esophageal cancer in the United States of America, and it originates in the columnar glandular epithelium, most often in the lower third of the esophagus.

另一方面，腺癌是在美国最常见的食管癌类型；腺癌起源于柱状腺上皮细胞，最常位于食管的下三分之一。

The presence of acid in the esophagus can lead to Barrett's esophagus, which is when the squamous epithelium lining the esophagus is replaced by a columnar epithelium, similar to that of the intestines, that's better adapted to withstand the acidity.

食管中存在胃酸会导致Barrett食管，即食管的鳞状上皮细胞被柱状上皮替代，变得很像小肠的上皮；柱状上皮是更加适应酸性环境的上皮类型。