Final answer:
The structure causing a prominent bulge in the ovary is the tertiary follicle, which contains a developing oocyte, granulosa cells, and an antrum. It develops under the stimulation of FSH and LH and eventually ruptures during ovulation.
Step-by-step explanation:
The part of the ovary that causes a prominent bulge in the surface of the ovary is the tertiary follicle. The growth of these follicles is stimulated by the hormone follicle-stimulating hormone (FSH), and the production of estrogen is facilitated by granulosa and theca cells in response to luteinizing hormone (LH). A tertiary follicle develops into a mature follicle, which eventually ruptures and releases the oocyte in an event known as ovulation.
Within a tertiary follicle, you can find a primary or secondary oocyte, multiple layers of granulosa cells, and a fully formed antrum. The formation of the follicle from its primordial stage to the tertiary stage is known as folliculogenesis.