Final answer:
An ovarian follicle consists of a primary oocyte surrounded by follicular cells. It undergoes various developmental stages before ovulation. Follicular cells, including granulosa and theca cells, provide support and hormones for the developing oocyte.
Step-by-step explanation:
An ovarian follicle is composed of a primary oocyte or an egg cell surrounded by follicular cells. During the follicle's development, these follicular cells differentiate into granulosa cells and theca cells, both of which play essential roles in nurturing the oocyte and hormone production. Within the ovarian follicle, the oocyte matures and prepares for the possibility of fertilization. The process of follicle development is known as folliculogenesis, and it progresses through stages including primordial, primary, secondary (also known as preantral), and tertiary (also known as antral) follicles, with the final stage being the dominant follicle from which ovulation occurs; this is when the mature oocyte is released.
The surrounding follicular cells, especially the granulosa cells, support the oocyte as it undergoes stages of maturation and provide hormonal signals crucial to reproductive function. The ovarian stroma, which forms the bulk of the ovary, houses developing oocytes each in their follicle, and this environment is rich with blood vessels, lymph vessels, and nerves that further facilitate the development of the follicles.