The nodes above give a detailed classic view of how the menstrual cycle works. Something to add to this, however, would be how the hormones released during the menstrual cycle are the driving force within itself.

Hormonal Control of the Menstrual Cycle:

Overall, the menstrual cycle as controlled by hormones is as follows. The hypothalamus controls the secretion of hormones by certain cells throughout the body. Specifically during the menstrual cycle, the hypothalamus produces "messenger hormones," or neurohormones, which trigger the secretion of luteneizing hormone and follicle stimulating hormone, each of which are important chemicals controlling the feedback loop that is the menstrual cycle.

The menstrual cycle has 2 phases, the follicular phase and luteal phase. During the follicular phase, estrogen is released by follicles in the ovaries, which in turn stimulates the secretion of LH from the anterior pituitary. This will happen until the follicle fully matures and ovulation happens. At this point, the luteal phase occurs, in which LH causes the corpus luteum to release progesterone and estrogen. The levels of these two hormones will then reach a point at which the hypothalamus and pituitary gland will turn off, lowering the amounts of LH and FSH present.

Estrogen and progesterone secretion are caused by a rise in follicle stimulating and luteneizing hormone. The rise in FSH and LH are caused by the decrease in estrogen and progesterone. This coincides with the menstrual cycle, in which at ovulation, FSH and LH are at a high and estrogen and progesterone are at a low. The turning being ovulation, is the point at which FSH and LH decrease and estrogen and progesterone increase.