And in between, the mesencephalon, thanks to evolution, remains undivided.

在这两者之间，由于进化，中脑仍然是不可分割的。

We call these chambers the prosencephalon, the mesencephalon, and the rhombencephalon -- or forebrain, midbrain, and hindbrain.

我们称这些脑室为前脑、中脑和菱形脑室或者前脑、中脑和后脑。

The least dramatic changes occur in the three most caudal or lower sections: the mesencephalon, the metencephalon, and the myelencephalon.

最不明显的变化发生在最尾侧或下部的三个部分：中脑、后脑和髓脑。