Menstrual Cycle
Overview
○ 28-day cycles in which either a period or pregnancy occur
■ FSH, LH, estrogen, progesterone are the hormones
■ Your brain, ovaries, and uterus are all part of this
○ Timeline of the menstrual cycle is as follow:
■ Pituitary gland releases FSH and LH, which stimulates follicles
(thousands Located in ovaries, each follicle contains one oocyte)
to grow
■ Growing follicles secrete estrogen
■ When estrogen peaks, it tells the brain to stop producing FSH
and increase LH Production
■ The most mature oocyte bursts out of its follicle and starts
traveling towards the
Uterus via the fallopian tube to potentially become fertilized by a
sperm This is called ovulation!
● Its former follicular home stays in the ovary and is now called
the corpus Luteum
■ Back in ovary, the now-empty follicle, the corpus luteum,
secretes progesterone, Which tells the uterine lining
(endometrium) to plump itself up with blood and Nutrients to
prepare for implantation of a fertilized ovum
■ If an ovum gets fertilized, it implants itself into the plump wall
of the uterus.
She’s pregnant!
■ If the ovum does not get fertilized, the progesterone and
estrogen levels plummet.
