The cortex of the ovary contains numerous follicles
embedded in a thick stroma. Most of the
follicles are resting primordial follicles.
Follicles which have been stimulated to develop progress through primary and secondary
stages to become mature tertiary or Graafian
follicles, in which a large fluid-filled cavity, the antrum, is surrounded
by many layers of granulosa cells. Stromal
cells around the follicle form the theca interna, which secretes estrogen,
and the theca interna. The cumulus oophorus, containing the oocyte,
seldom appears in random sections such as this.
