Ovarian Endometrial Cycle Flashcards
when does follicular phase happen?
days 1-14
what happens in the follicular phase?
rising estrogen levels
endometrial thickening
selection of dominant “ovulatory” follicle
when does luteal phase occur?
days 14-21
what rescues the corpus luteum for continuous secretion of progesterone?
placenta; developing blastocyst which produces hCG
The corpus luteum if there is no pregnancy, becomes the?
Corpus albicans or the atretic follicle
how many oocytes are available at birth?
2 million
on the onset of puberty, how many oocytes are available?
400,000
after puberty, how many follicles are depleted per month?
1000
how many follicles are released during a female’s productive life?
400
more than 99.9% of follicles undergo atresia through?
apoptosis
primary follicles develop to the antrum stage through the presence of what hormone?
FSH
it is the stage wherein the follicle
becomes mature and becomes the graafian follicle
containing the oocyte and there is already a cavity, the
antrum, that contains the fluid
antral stage
in the absence of FSH, all the follicles undergo?
atresia
it is the selection of primordial follicles and their growth to the antral stage?
recruitment
it is the phase where recruitment happens?
Follicular phase or pre ovulatory phase
what hormone stimulates the the theca cells to convert cholesterol to androtenedione
LH; luteinizing hormone
testosterone (androstenedione) is converted to estradiol and progesterone through the action of what hormone?
FSH
where does the conversion of testosterone to estradiol and progesterone take place?
granulosa cell
where does the conversion of cholesterol to androstenedione take place?
theca cells
What day does ovulation happen?
Day 14
what is the precise predictor of ovulation?
gonadotropic surge resulting from increasing estrogen secretion of preovulatory follicles
When does gonadotropic surge occur?
34-36 hours before ovum release
When does LH secretion peak?
10-12 hours before ovulation
it is the phase where the corpus luteum develops from the Graafian follicle?
Luteal phase or post ovulatory phase
The process where the corpus luteum forms from the Graafian follicle is called?
luteinization
this hormone is the primary luteotropic factor responsible for corpus luteum maintenance
luteinizing hormone
when will corpus luteum regress after ovulation?
9-11 days
there is increased cholesterol available for production of progesterone during the luteal phase? true or false?
true
there is increase in overall increase in estrogen in the luteal phase? t or f?
false
After ovulation, estrogen levels DECREASE,
followed by a secondary RISE that reaches a peak
production of 0.25 mg/d of 173-estradiol in the
midluteal phase.
x Toward the end of the luteal phase, secondary
DECLINE in estradiol production.
what is the most potent estrogen?
17 beta estadiol
what secretes the most potent estradiol during the luteal phase?
granulosa cells of the dominant follicle and the luteinized granulosa cells of the corpus luteum
this hormone is essential in most events of the normal menstrual cycle
estrogen
what does estrogen regulate?
follicular development
uterine receptivity
blood flow
What is called the hormone of pregnancy and is amplified by estrogen?
Progesterone
What hormone converts the endometrium to the secretory stages?
progesterone
Normal menstrual bleeding is caused by
withdrawal of progesterone
order from uterine artery to the spiral artery?
Uterine artery - arcuate artery - radial artery (when it enters the uterus) - basal artery - spiral artery
where does the uterine artery originate?
internal iliac artery
when does mitotic activity of the of the epithelium and stroma end?
at the 16-17 day; up to 3 days after ovulation
this phase of menstrual cycle makes it hard to date the endometrium due to phase length variation
late proliferative phase
how long does follicular phase last?
may last as short as 5-7 days or as long as 21-30 days
what is the basis of endometrial dating in early secretory phase
glandular epithelium
what it the hallmark of secretory phase?
glycogen accumulation in the basal portion of the glandular epithelium; creation of subnuclear vacuoles and pseudostratification
What day does the hallmark of secretory phase usually happen?
Day 17
on day 18m what happens to the vacuoles?
they move to the apex of the non ciliated cells
what happens on day 19-20
glandular cell mitosis stops due to high progesterone levels
secretion of glycoprotein and mucopolysaccharide to the lumen
What is the glandular phase of secretory phase?
Early secretory phase
what is the stromal phase of secretory phase?
mid-late secretory phase
when does the stroma become edematous?
day 21-24 (mid-late secretory phase)
when does the massive coiling of the glands with luminal secretion happen?
Day 22-25 (mid late secretory phase)
when does pre decidual transformation happen to the upper 2/3 of the functionalis layer?
day 22-25 (mid-late secretory phase)
what marks the window of implantation?
endometrial changes
what hormone is responsible for the continuation of the decidualization process?
progesterone
decrease in luteal progesterone levels after the secretory phase leads to?
menstruations or bleeding
what is the key process in endometrial extracellular matrix breakdown and repair of functionalis layer?
leukocyte infiltration
what is the most striking anatomical event occuring prior to menses to prevent excessive bleeding?
vasocontriction
Anatomical events by steps happening during mestruation
severe spiral artery coiling - Blood stasis - hypoxia and vasodilation - vasoconstriction
during menstruation, prostaglandin synthase is decreased? t or f
False
synthase is increased
dehydrogenase is decreased
functions of PGF2a
vasoconstriction
myometrial contractions
inflammation
menstrual bleeding is arterial or venous?
arterial
this is the highly modified endometrium of pregnancy?
decidua
essential for hemochoral implantation
the decidua is dependent on which hormone?
Both estrogen and progesterone
decidua directly beneath the blastocyst?
basalis
decidua overlying the enlarging blastocyst and in contact with the chorion leave?
capsularis
the remainder of the decidua is lined by (aside from basalis and capsularis)
parietalis
what decidual structure is retained after delivery?
zona basalis
what decidual structure is in the middle and contains the remnants of blood vessels and glands
zona spongiosa
surface decidual structure
zona compacta
what layer of the decidua forms the placental basal plate?
decidua basalis
zone of fibrinoid degeneration
where invading trophoblast and decidua basalis meet
(absence is evident in placenta accreta)
Nitabuch layer
