Lecture 34: Menstrual Cycle and Ovulation (Part 2) Flashcards
During days 1-10, describe the effects of FSH?
FSH stimulates follicular growth
-produces estrogen that inhibits LH
During days 10-14, describe the effects of estrogen?
Estrogen stops inhibiting LH and instead promotes LH production
- triggers ovulation
- promotes endometrium to undergo rapid growth
What two hormones are required for estrogen production?
FSH and LH
After ovulation, LH acts on the cells of what strcutre?
corpus luteum
What produces inhibin?
Granulosa cells of follicle
-stimulated by both FSH and LH
What do inhibins do?
Inhibit FSH production
What do activins do?
Promote FSH production
What part of the menstrual cycle utilizes positive feedback?
Days 10;14: Estrogen creates LH surge
What inhibits FSH and LH in the luteal phase?
Estradiol
Progesterone
Inhibin
When do levels of estradiol, progesterone, and inhibin decrease?
End of luteal phase
-promotes GnRH to release FSH and LH
During the follicular phase, what is the major product of the follicle?
Estradiol
-needs both theca and granulosa cells
During the follicular phase, what is the major product of the corpus luteum?
Progesterone
During the menstrual cycle, where can a rise in temperature be found?
Day after ovulation
What defines the menstrual phase of the menstrual cycle?
Day 1-5
-shedding of endometrium tissue resulting in menstrual bleeding
What defines the proliferative phase of the menstrual cycle?
Day 5-14
- Proliferation of basal stromal cells and epithelial cells
- components of endometrium
- high levels of estrogen
What defines the secretory phase of the menstrual cycle?
Day 14-28
- basculatrization of endometrium
- progesterone production: differentiation of stromal cells into predecidual cells
What is PCOS?
Polycystic Ovarian Syndrome
- abnormal ovarian steroidogenesis: elevated LH and low FSH + elevated testosterone
- increased androgen levels (DHEA)
What are symptoms of PCOS?
- Obese
- Hirsutism
- Infertility
- Oligomenorrhea
What is Turner Syndrome?
45, XO
- absence of second chromosome
- primary hypogonadism: germ cells don’t develop
- elevated FSH levels
What are symptoms of Turner Syndrome?
- Short stature
- Delayed puberty
- Infertility
- Webbed neck
- Learning disabilities
What marks menopause?
No menstrual period for 12 months
-low levels of inhibin –> high levels of LH and FSH
What are symptoms of menopause?
- Irregular periods
- Vaginal dryness
- Hot flashes
- Night sweats
- Mood changes
- Sleep problems
- Weight gain and slowed metabolism
