An acidophilic, homogeneous, and acellular layer called the zona pellucida appears around the oocyte. The zona pellucida contains three zona proteins (ZPs), i.e. ZP1, ZP2, and ZP3. Filopodia of the follicular cells and microvilli of the oocyte penetrate the zona pellucida. The zona pellucida is formed by the oocyte and the follicular cells.
The secondary oocyte is expelled from the ovary together with the corona radiata, zona pellucida and follicular liquor.
(三)Corpus Luteum
Definition: After ovulation, the granulosa cells and those of the theca interna that remain in the ovary form a temporary endocrine gland called the corpus luteum (yellow body) . Structure: granulosa cells granulosa lutein cells theca cells theca lutein cells
4. Mature Follicles