What is the primary function of the follicular phase in the human menstrual cycle?

The primary function of the follicular phase in the human menstrual cycle is to mature and enlarge a follicle. During this phase, which begins on the first day of menstruation and lasts until ovulation, several follicles in the ovaries begin to develop under the influence of follicle-stimulating hormone (FSH). One of these follicles will eventually become dominant and mature into a Graafian follicle, capable of releasing an egg during ovulation.

This maturation process involves the growth of the follicle itself and the surrounding granulosa cells, as well as the production of estrogen. The increase in estrogen levels not only supports the growth of the follicle but also initiates the preparation of the uterine lining for a potential pregnancy. Therefore, the primary focus of this phase is follicle development and egg maturation, setting the stage for ovulation and possible fertilization later in the cycle.