MENSTRUAL PHYSIOLOGY

The menstrual cycle is the cyclic pattern of activity of hypothalamus, pituitary,
ovary, and uterus that produces a rhythm of bleeding every month for 30 years or
more during the active reproductive phase of a woman’s life.

Menarche is the first flow that signifies potential reproductivity. Menopause is
the termination of the menstrual flow, which signifies diminished ovarian
function.

Menstrual cycle occurs with the maturation of the hypothalamic–pituitary–
ovarian axis. The hormones produced include gonadotropin-releasing hormone
(GnRH) from the hypothalamus, which stimulates follicle-stimulating hormone
(FSH) and luteinizing hormone (LH) from the anterior pituitary, which stimulate
estrogen and progesterone from the ovarian follicle.