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46 terms

Female Reproductive Endocrinology

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Steroidogenesis
this is what "rules the roost" in keeping a woman fertile; controls ovulation and folliculogenesis
Ovulation
this event occurs at day 14 of the menstrual cycle
Menses
this event occurs on days 0-4 (normally) of the menstrual cycle
Primordial Follicle
this follicle is part of the nongrowing ovarian follicular reserve; the types of follicles woman we born with
Primary Follicle
this follicle is in the first stage of growth; it is growing and getting ready
Dominant/Preovulatory (Graafian) Follicle
this follicle is quite large; contains a subpopulation of cells that makes hormones and growth factors
Theca Cells
this outer layer of the preovulatory follicle has CYP17 and therefore makes androgens (progesterone, androstenedione, testosterone); respond to LH
Granulosa Cells
this inner layer of the preovulatory follicle has CYP19 and therefore makes estrone, estradiol, and progesterone; respond to FSH and later LH (in response to FSH stimulation)
DHEAS
this is a stabilized form of DHEA with sulfur on it; released from the adrenal and can be used by ovarian follicles as a substrate to make E2; can be used as a marker
CYP19
this is aromatase; makes E2 from testosterone
CYP17
this cytochrome makes cortisol and androgens in the adrenal cortex
CYP11A
this is 20,22-desmolase / CYP450 side chain cleavage; forms pregnenalone from cholesterol
Corpus Luteum
this is the remnant of the follicle after ovulation; secretes a large amount of progesterone from theca cells and progesterone and E2 from granulosa cells
Primordial, Primary, and Preantral Follicles
these have very low (almost negligible) levels of androgens, testosterone, progesterone, and E2
Preovulatory/Dominant/Graafian Follicle
in this type of follicle, androgen production increases heavily in theca cells while E2 production increases heavily in granulosa cells
StAR
this transporter sends cholesterol to the mitochondria from theca cells; allows it to be converted to pregnenalone and then into androgens; mutated in CAH
Androstenedione
this androgen precursor can be made into testosterone; secreted heavily by theca cells upon LH stimulation
Preovulatory Granulosa Cells
uses androstenedione from theca cells to make testosterone which is then converted by CYP19 to make E2; mediated by FSH
Granulosa Lutein Cells
these granulosa cells respond to LH; major product is progesterone with E2 being a minor product
Growing Cohorts
a group of follicles that is recruited each month to grow and get ready from which one will be selected
Preovulatory FSH Surge
this surge in FSH occurs right before ovulation
Inhibin B
this acts on gonadotropes in the pituitary to suppress FSH and activin; works with E2 to decrease FSH during the mid follicular phase
E2 During Mid Follicular Phase
at this time, this hormone is at low levels but blocks FSH secretion at the level of the GnRH pulse generator
E2 During PreOvulatory Phase
at this time, this hormone increases in strength and now stimulates FHS secretion and inhibits inhibin production to free activin so that FSH can be released
FSH in Luteal Phase
at this time after ovulation, this hormone decreases because of negative feedback from inhibin A, increased levels of P4, and E2
Follicular Phase
this is the proliferative phase of the menstrual cycle; it includes the events leading up to ovulation including the preovulatory gonadotropin surge and slowly increasing levels of E2 and P4
Luteal Phase
this is the secretory phase of the menstrual cycle; it includes the events after ovulation including elevated P4 and E2 that slowly declines up until the point of menses
LH at Midfollicular Phase
unlike FSH, this hormone is purely regulated by hormone feedback (rather than inhibins and activin); at this phase, low levels of E2 are providing negative feedback
LH at Preovulatory Phase
at this phase, this hormone is stimulated by rising levels of E2; occurs just prior to its surge, which is extremely powerful
LH at Luteal Phase
at this phase, this hormone is drops in concentration due to elevated P4 and E2
Progesterone (P4)
this hormone is negligible during the follicular phase but then shoots up during the luteal phase because it is created by the corpus luteum
Basal Body Temperature
this rise in temperature can be used to see if a woman is ovulating; occurs because P4 is thermogenic, so it increases temperature after it is released during ovulation
P4R
these receptors are expressed in the hypothalamus where the GnRH pulse generator is; this allows it to block the pulse frequency and thus stop LH (preferentially) and FSH secretion, blocking fertility and menstruation
Progestin Contraceptives
these introduce P4 into the body exogenously, allowing for a sustained elevated P4 level, causing LH and FSH secretion to be blocked by messing up the pulse generator and blocking fertility
E2 During the Menstrual Cycle
this hormone begins to rise in the midfollicular phase, and then drops slightly at the luteal phase only to level off and be sustained by the corpus luteum following the drop
ER-Alpha
this receptor for this hormone is found in the hypothalamus where it messes up the GnRH pulse frequency and blocks FSH (preferentially) and LH secretion
Sustained Levels
if this occurs with either GnRH, LH, FSH, or the androgens, it causes a lack of fertility; levels must be cyclic for fertility to occur
Hyperandrogenemia
this is a problem that occurs when the body receives too many androgens; androgens are converted to E2 via CYP19, and thus the pulse frequency of GnRH can be affected, blocking FSH (preferentially) and LH secretion
Infertility
this is clinically defined as the inability to conceive after one year of unprotected sex
Primary Infertility
this type of fertility occurs when a woman is G0P0 and cannot conceive
Secondary Infertility
this type of infertility occurs when a woman is G1P1 or more but cannot currently conceive
Inhibin B
this acts on gonadotropes of the anterior pituitary to decrease secretion of GnRH and FSH; leads to atresia of nonselected follicles; in ovary, allows for steoidogenesis and production of growth factors
Activin
stimulates FSH secretion to stimulate growth of young recreuited follicles; promotes E2 production and LH receptor expression via FSH; blocked by inhibin B
Gonadotropin Surge
this is the surge of LH and FSH before ovulation, with LH being secreted in much larger amounts
Endometrial Proliferation and Angiogenesis
this change in the endometrium occurs at the time of ovulation due to rising levels of E2 and P4
Endometrial Shedding, Menstruation, and Repair
this change in the endometrium occurs in the late luteal phase due to sustained high levels of progesterone, causing decreased amounts of PR and ER-alpha receptors, no longer allowing E2 or P4 to work on it