Hormones play a central role in our reproductive cycle GnRH Estrogen Luteinizing Hormone “LH” Follicular Stimulating Hormone “FSH” © Circe & Bloom LLC Progesterone

Two pivotal regions in the brain: the Hypothalamus and the Pituitary Gland Front © Circe & Bloom LLC

Hypothalamus Pituitary GnRH GnRH is sent from the Hypothalamus to the Pituitary The Hypothalamus plays a vital role in the beginning part of the cycle by sending Gonadotropin hormone(“GnRH”) to the Pituitary which in turn tells it to start sending very specific, ovulatory hormones to the ovaries. The Hypothalamus regulates all kinds of other bodily functions; most importantly, it regulates stress. © Circe & Bloom LLC

Before Ovulation: positive feedback loop with a gradual build-up of hormones each signaling to each other to increase intensity to stimulate ovulation OVULATION: LH Surge happens as a result of this positive feedback loop that is responsible for ovulation. Estrogen LH & FSH GnRH © Circe & Bloom LLC

IMPLANTATION: Progesterone buildup ensures that fertilized egg is accepted, becomes implanted and is nourished. LH & FSH Progesterone After Ovulation: negative feedback loop to reduce GnRH and to stimulate increase in progesterone and changing of uterus to accept fertilized egg FERTILIZED EGG: Corpus Luteum is formed in the ovary, fertilized in the fallopian tube and begins to secrete progesterone. GnRH © Circe & Bloom LLC