In phase 2, the volume of oocytes increases rapidly while the nuclear-cytoplasmic ratio decreases obviously, the cytoplasm is in a strong basophilia state, and the follicular cell starts to appear.

• 第2时相，卵母细胞体积增加迅速，核质比显著减小，细胞质强嗜碱性，滤泡细胞出现。