The ovulated secondary oocyte is still surrounded by the zona pellucida and a few layers of cells called the corona radiata.

• 小斑处因水解酶激活、解聚作用而破裂，次级卵母细胞、第一极体、透明带、放射冠和一部分卵泡液由此排出，经腹腔进入输卵管。