In the second stage, the primary follicles develop into secondary and eventually tertiary, or graafian follicles.

第二阶段，初级卵泡形成次级卵泡，最终形成第三极卵泡，即格拉夫卵泡。

In a secondary follicle, the primary oocyte is still in the prophase step of meiosis 1, but now the follicle has additional layers of granulosa cells, as well as theca cells.

次级卵泡中的初级卵母细胞还是停留在第一次减数分裂前期，而卵泡多了几层颗粒细胞，以及卵泡内膜细胞。