B8-004 Female Endocrinology Flashcards
GnRH stimulates the […] to release LH and FSH
anterior pituitary
stimulates growth of follicles and estrogen synthesis and secretion
FSH
stimulates follicle steroidogenesis as well as ovulation of mature follicle and formation of corpus luteum
LH
stimulates estrogen and progesterone synthesis and secretion by the corpus luteum
LH
protein involved in the regulation of GnRH
kisspeptin
mutation in kisspeptin can cause […] in humans and […] in mice
mutation in kisspeptin can cause infertility in humans and hypogonadotropic hypogonadism in mice
neurons in the […] nuclei regulate the production of kisspeptin, and therefore GnRH [2]
arcuate
anteroventral periventricular (pre-optic)
neurons in the hypothalamus release hormones into the […] that regulate anterior pituitary function
median eminence
action potentials in the Kisspeptin and GnRH neurons allow for […] in LH and FSH release
pulsatility
what types of cells does LH act on in the ovary? [3]
thecal cells
granulosa cells
luteal cells
what type of cells does FSH act on in the ovary? [1]
granulosa cells
most potent estrogen
estrodial
in women, the […] is the more significant source of androgens
adrenal cortex
(elevated androgens in PCOS)
secreted by the granulosa cells to stimulate FSHb transcription
activins
secreted by the granulosa cells to inhibit FSHb transcription
inhibins
secreted by granulosa cells of small growing follicles
used clinically as an indicator of follicle/oocyte pool
anti-mullerian hormone (AMH)
what effect does estrogen have on the HPO axis?
both negative feedback and positive feedback
stimulates prolactin behavior
estrogen
what effect does progesterone have on the HPO axis?
negative feedback
causes endometrial proliferation and increases excitability of the myometrium in the uterus
estrogen
stimulates the development of glands/vasculature in the uterus and
decreases myometrial excitability
progesterone
[…] decrease FSH
[…] stimulates FSH
inhibins decrease FSH
activins stimulate FSH
effects of estrogen at the mammary gland [3]
duct growth
fat deposition
inhibits milk synthesis
effects of progesterone at the mammary gland [2]
growth of alveolar epithelium
inhibits milk synthesis
as the follicle grows during folliculogenesis, there is increased secretion of […] by the granulosa cells [2]
estradiol
inhibin
aromatase is expressed in […] cells
granulosa
driving steroid during follicular phase
estrogen
during folliculogenesis, estrogen provides negative feedback on the arcuate nucleus, suppressing the production of […] [2]
GnRH
Kisspeptin
gonadotropin surge occurs […] prior to ovulation
36-48 hrs
in the early follicular phase, inhibin secretion is […], so FSH is […]
inhibin low
FSH higher
in the late follicular phase, inhibin secretion is […], so FSH is […]
inhibin high
FSH lower
in the late follicular phase, positive feedback of estradiol on AVPV neurons causes […] GnRh secretion
increased
(also increases GnRH-R)
[…] is the most important hormone during the luteal phase
progesterone
LH drives […] production in the theca cells
androgen
FSH drives […] production in the granulosa cells
estrogen
during the luteal phase, the granulosa cells also express receptors for LH, causing the production of [2]
progesterone
estradiol
(via cellular reorganization: removal of the basement membrane, differentiation, and altered gene expression)
during the luteal phase, P4 […] E2
P4 > E2
during the early follicular phase, P4 […] E2
P4 < E2
P4 is decreasing, E2 rising
during the late follicular phase, P4 […] E2
P4 < E2
high levels of E2 giving positive feedback on HPO axis
during what phase are high levels of E2 providing positive feedback on HPO axis?
late follicular
effects of the follicular phase on the uterus [4]
proliferation
expression of P4-R
contractions
cervix changes
(mediated by E2)
effects of the luteal phase on the uterus [4]
gland development
uterine secretions
uterine vasculature
quiescence
(mediated by P4)
peak/maximum oocytes numbers occur during […]
fetal development
neuronal remodeling occurring in the […] during puberty is responsible for changes in gonadotropin secretion
hypothalamus
(gonadal steroid-independent)
as females approach puberty, there is a […] in estrogen negative feedback
reduction
(results in an increase in gonadotropin secretion)
during a normal menstrual cycle, what day is a good approximation for the day of ovulation?
mid-cycle day
(in 28 day cycle, day 14)
ovarian secretion of estradiol is lowest when?
during menstruation
(day 0)
[…] cells express aromatase and convert androgens to estrogen
granulosa
which cells are separated from the vasculature by the basement membrane?
granulosa cells
which cells are positioned closest to the vasculature?
theca cells
estrogen induces the expression of […] on gonadotropes to enhance the gonadotropin surge
GnRH receptors
in the late follicular phase, estrogen induces the kisspeptin neurons in the AVPV via […] feedback
positive
positive feedback of estrogen in the late follicular phase increases the delivery of GnRH to the gonadotropes. This causes them to release [2]
LH
FSH
estrogen inhibits the activity of Kisspeptin neurons via the […] nucleus
arcuate
estrogen stimulates the activity of Kisspeptin neurons via the […] nucleus
AVPV
progesterone always elicits […] feedback on the hypothalamus
negative
[…] functions to slow the secretion of LH
progesterone
how would LH, FSH, and estrogen levels be affected by menopause?
LH high
FSH high
estrogen low
promotes mono-ovulation
prevents poly-ovulation
inhibin
nuclei in the hypothalamus regulating the release of GnRH [2]
arcuate nucleus
AVPV nucleus
the oogonium undergo mitosis and produce […] which are primary oocytes
primordial follicles
acts upon thecal cells to convert cholesterol into androgens
LH
stimulates the production of granulosa cells
FSH
androgens move from theca cells to granulosa cells, where FSH and aromatase stimulate its conversion to
estrogen
during which phase is estrogen causing a negative feedback loop?
early follicular
during which phase is estrogen causing a positive feedback loop?
late follicular
released mid-cycle to override the anterior pituitary and shut of production of FSH
inhibin
(only hormone being produced at this time is LH –> LH surge)
stimulates proteolytic enzymes to cut around the follicle, releasing the oocyte
LH surge
LH stimulates the corpus luteum to produce
progesterone
what phase of the menstrual cycle is represented by day 0-14 of the ovary?
follicular
what phase of the menstrual cycle is represented by day 0-14 of the uterus?
proliferative
what phase of the menstrual cycle is represented by day 15-28 of the ovary?
luteal
what phase of the menstrual cycle is represented by day 15-28 of the uterus?
secretory
[…] can stimulate the theca cells to produce more androgens
IGF-1
partially why they think PCOS has comorbid insulin resistance
what sustains the corpus luteum during the luteal phase?
LH
(LH will be slightly higher in luteal phase)
what drives high progesterone in pregnancy?
hCG
how do exogenous androgens affect the HPO axis?
inhibits kisspeptin and GnRH
low LH and FSH
(essentially acts like a GnRH antagonist)
what would you expect to see for estrogen, progesteron, FSH, and LH levels in a menopausal female?
estrogen low
progesterone low
FSH high
LH high
(FSH and LH are still trying to stimulate the ovary, but ovary is no longer responding due to lack of follicles)
kisspeptin and GnRh are […] in menopause
inhibin is […] in menopause
kisspeptin and GnRh are [elevated] in menopause
inhibin is [suppressed] in menopause
stimulates Leydig cells to produce androgens
LH
granulosa cells within the follicle express […] receptors
FSH
FSH induces the expression of […], which converts androgens to estrogens in granulosa cells
aromatase
theca cells express […] receptors
LH
LH induces the expression of […] which are required for androgen synthesis from cholesterol in theca cells [3]
CYP11A
3betaHSD
CYP17
[…] cells produce estrogen and inhibin
granulosa
[…] cells synthesize androstenedione
theca
