The Geometry of the ovarian Follicle. (A) In the follicle the oocyte is embedded in somatic tissue. The innermost layer are the cumulus cells (yellow) followed by a layer of granulosa cells (pink), and an outer layer, the theca (brown), that is enervated by blood vessels. Formation of androgens is restricted to the theca, while the formation of estradiol is restricted to the granulosa cells. (B) The computational domain represents a 1D cross-section of a follicle and expands over time. The outer part of the domain (brown) is the theca, the intermediate layers (pink) represent the granulosa; cumulus cells and the oocyte are in the center (yellow). (C-D) A more refined computational domain that also includes the follicular fluid (blue) on one side of the cumulus oocyte complex.