Final answer:
The follicular phase is the first stage of the ovarian cycle, where the maturation of ovarian follicles occurs, stimulated by rising FSH levels which eventually decrease as estrogen from the dominant follicle exerts negative feedback.
Step-by-step explanation:
The follicular phase is the first part of the ovarian cycle. It typically lasts about 12 to 14 days and coincides with the menses phase and the proliferative phase of the menstrual cycle. During the follicular phase, the primary event is the maturation of ovarian follicles, stimulated by the increase of follicle-stimulating hormone (FSH) released by the pituitary gland. As the dominant follicle matures, it secretes estrogen, which increases throughout the follicular phase. At the beginning of this phase, hormone levels of FSH are on the rise; however, as the dominant follicle continues to produce estrogen, the levels of FSH eventually decrease due to negative feedback mechanisms. This decrease in FSH leads to the atresia (resorption) of all but one of the developing follicles, the largest of which will proceed to ovulation.