Quote:An unsung appendage in the female body, which has long been considered useless, may actually be essential for ovary development and fertility, a new mouse study finds.

This structure, called the rete ovarii, was first discovered in humans over a century ago, but until now, it was considered a so-called vestigial structure — not crucial in adult female anatomy, but a leftover from fetal development. Vestigial anatomical structures, or "vestiges," are generally thought to have once had a crucial function that was later lost in the course of human evolution.

But according to a new study, published March 19 in the journal eLife, the rete ovarii (RO) may actually play an important role in ovarian function, and therefore, fertility. The work also showed that the structure has three distinct regions and may respond to hormonal signals.