The ABCs of Menstruation
The four phases of the menstrual cycle and ovulation are regulated by interaction between the hypothalamus, pituitary and ovaries. The hypothalamus is a gland in the brain responsible for regulating the body’s thirst, hunger, sleep patterns, libido and endocrine functions. It releases the chemical messenger called gonadotropin releasing hormone (GnRH), secreting it in a pulsatile fashion. The location of the hypothalamus is depicted in Figure 1.