Pituitary Gland

FSH

Primordialfollicles

Growing follicles

LH

Pituitary Gland

FSH

Growing follicles

Estrogen

-

inhibin

Pituitary Gland

Growing follicles

Estrogen LH

Mature Graafian

- +

Pituitary Gland

Estrogen LH

Mature Graafian

Corpus luteum

ovulation

- +

Pituitary Gland

LH

Corpus luteum

Estrogen and

progesterone

-

Pituitary Gland

Corpus luteum

Estrogen and

progesterone

-

Pituitary Gland

Corpus luteum

Corpus albicans

Pituitary Gland

LH

Corpus luteum

Estrogen and

progesterone

-

If implantation

occurs

Pituitary Gland

Corpus luteum

Estrogen and

progesterone

Placenta

HCG

(human chorionic gonadotropin)

If implantation

occurs

-

Uterine Cycle

Menstrual Phase

Estrogen

Proliferative Phase

Progesterone+ estrogen

SecretoryPhase

Day 1 - 4 Day 5 - 14 Day 15 - 28

Menstrual Cycle

Menstrual Phase

Estrogen

Proliferative Phase

Progesterone+ estrogen

SecretoryPhase

Decrease inProgesterone + Estrogen

MenstrualPhase

Day 1 - 4 Day 5 - 14 Day 15 - 28 Day 1 - 4

Menstrual Cycle

Combined

Ovarian and

Uterine Cycle

FSH is secreted by the pituitary

FSH stimulates growth of some of the ovarian folliclesThe growing follicles produce estrogen and inhibin

Estrogen (moderate level) and inhibin inhibits FSH release by the pituitaryHigh Estrogen stimulates increase secretion of LH by the pituitaryEstrogen also stimulates growth of the endometrium (proliferative phase)

LH stimulates ovulation resulting in the formation of the corpus luteumLH stimulates the corpus luteum to develop, which includes estrogen and

progesterone production

Estrogen and progesterone inhibit FSH and LH release by the pituitaryEstrogen and progesterone stimulates uterine gland secretion of glycogen

and continued growth of the endometrium (secretory phase)

Decrease in LH inhibits the corpus luteumresulting in a decrease in estrogen and progesterone anddeterioration of the corpus luteum, forming the corpus albicans (scar tissue)

Decrease in estrogen and progesterone causes vasoconstriction of uterinevessels resulting in menstruation

With estrogen and progesterone levels low, FSH can again be released by the pituitary, beginning a new cycle

Pituitary Gland

FSH

Primordialfollicles

Growing follicles

Menstrual

PhaseDay 1--4

Pituitary Gland

FSH

Growing follicles

Estrogen

-

Proliferative Phase

Menstrual

PhaseDay 1--4 Day 5--14

Estrogen

Pituitary Gland

Growing follicles

Estrogen LH

Mature Graafian

-

Day 1--4 Day 5--14

Menstrual

Phase

Proliferative Phase

+

Pituitary Gland

Estrogen LH

Mature Graafian

Corpus luteum

ovulation

- +

Day 5--14Day 1--4

Menstrual

Phase

Proliferative Phase

Pituitary Gland

LH

Corpus luteum

Estrogen and

progesterone

-

Day 1--4

Menstrual

Phase

Proliferative Phase

Day 5--14

SecretoryPhase

Estrogen + progesterone

Day 15--28

Pituitary Gland

Corpus luteum

Day 1--4

Menstrual

Phase

Proliferative Phase

Day 5--14

SecretoryPhase

Day 15--28

Decrease in Progesterone + Estrogen

Menstrual Phase

Day 1--4

Corpus albicans