The release of eggs (at secondary oocyte stage) after rupturing of graafian follicle is called ovulation. After the ovulation, the granulosa cell as well as the stroma cells form theca interna rapidly multiply to fill the cavity of graafian follicle which becomes corpus luteum. If fertilization occurs, corpus luteum grows further and secrete hormone progesterone. If fertilization does not take place, corpus luteum regresses and forms a white body called corpus albicans.