Repro 5 Flashcards
In early to mid follicular phase what does LH do
Goes to thecal cells stimulates production of androgens
Where do androgens go during early to mid follicular phase after stimulated by LH
Diffuse into granulosa cells where FSH stimulates conversion to estrogen
What does estrogen do after being stimulated by FSH in early to mid follicular phase
Provides neg feedback to granulosa cells to continually produce estrogen
What else do greanulosa cells secrete during early to mid follicular phase
Produce anti Müllerian hormone
- inhibits pool follicles so no more recruited mid cycle
Low levels of estrogen exert
Negative feedback to GnRH, FSH, OH
What causes LH surge during late follicular phase and ovulation
Increasing estrogen and progesterone flips to positive feedback on hypothalamus increases GnRH
Increase in FSH but inhibin decreases
What secretes progesterone
Granulosa cells
When does ovulation occur
16-24 hours after LH peak
What is LH necessary for
Oocyte maturation
When meiosis resumes (1st division)
What does mature follicle release during ovulation
Prostaglandins and proteolytic enzymes
What do proteolytic enzymes do during ovulation
Breakdown collagen and connective tissue holding follicle together
What do prostaglandins do during ovulation
Contribute to rupture of follicle or ovary wall
How is secondary oocyte swept into fallopian tube during ovulation
By fimbrae
Corona radiata
Oocyte when swept out of ovary with some granulosa cells attached
What do cells left over do in ovary
Become corpus luteum
During early to mid luteal phase what do thecal and granular cells do
Transform into luteal cells (LH)
What are luteal cells
Lipid droplets and glycogen granules accumulated in cytoplasm and secrete progesterone
What happens to estrogen and progesterone during early to mid luteal phase
Steadily rise and provide negative feedback to hypothalamus and anterior pituitary
- decreases GnRH, LH, FSH
What is dominant during luteal phase
Progesterone
- continues to influence endometrium in preperation of pregnancy
What are thick secretions during luteal phase for
Cervical plus preventing bacteria and sperm
What is corpus luteum life span
12 days
Late luteal when pregnancy does not occur
Spontaneous apoptosis of corpus luteum to become corpus albicans
What happens with hormones during late luteal
Progesterone and estrogen fall, FSH and LH increases
What does maintenance of endometrium depend on
Progesterone
- when decreased vessels in surface contract causing surface cells to die
