Follicular atresia

Follicular atresia is the break-down of the ovarian follicles. It occurs continually throughout a woman's life, as she is born with approximately 2 000 000 follicles and will only ovulate around 500 in her lifetime.

The granulosa cells stop growing and detach from the basal lamina. The oocyte dies and the whole unit is phagocytosed.

Theca interna cells may persist and secrete androgens, at which point they are known as interstitial cells, which are active from childbirth until menopause.