What you can't see with the naked eye is that the lining of the stomach (the mucosa) is interrupted by multiple tiny openings, each of which leads to a tiny hormone-producing tunnel.

而肉眼所看不到的是，胃的组织膜(即黏膜)被很多微小的开口所阻断，每个开口均通向产生激素的一个个微小通道。

youdao

What you can't see with the naked eye is that the lining of the stomach (the mucosa) is interrupted by multiple tiny openings, each of which leads to a tiny hormone-producing tunnel.

而肉眼所看不到的是，胃的组织膜(即黏膜)被很多微小的开口所阻断，每个开口均通向产生激素的一个个微小通道。

youdao