CH 9 Female Reproductive Sys Flashcards
What regulates Gonadotropin Releasing Hormone from the pituitary?
+ (leptin), - (beta-endorphin, IL-1, Prolactin, GABA, dopamine)
What occurs during the 14 day follicular phase?
FSH on Granulosa Cells stimulates follicular recruitment, growth, estrogen synthesis and upregulation of LH receptors. (now LH can stimulate granulosa cells)
What occurs during 14 day Luteal Phase?
LH peak is responsible for ovulation and corpus luteum formation (and progesterone/estrogen formation by corpus lutem) - LH on Theca cells stimulates androstenedione production (–>17B-estradiol in granulosa cells)
How does estradiol effect the hypothalamic-pituitary-ovarian axis?
enhances LH and inhibits FSH release
How do Inhibins A & B effect the hypothalamic-pituitary-ovarian axis? What cell secretes them?
reduce FSH secretion at anterior pituitary; secreted by Granulosa Cells (B) & Corpus Lutem (A)
How do theca cells and granulosa cells work together to produce progesterone?
Theca cells can synthesize androgens (cholesterol–>androstenedione) and Granulosa cells take them and aromatize them to Estradiol.
What causes and How does the preovulatory LH surge make progesterone the primary steroid hormone rather than estrogen?
Caused by Estrogen; increase expression of P450 complex (cholesterol –> pregnenolone), & 3-beta-hydroxysteroid dehydrogenase (progesterone). decrease expression of enzymes that convert progesterone to estrogens.
What is Inhibin A used to measure?
Corpus Lutem function under control of LH
What is Inhibin B used to measure?
Granulosa Cell function under control of FSH
What causes ovulation?
surge of LH causes release of oocyte and corona radiate (also stimulates oocytes to resume meiosis I)
What happens to Corpus Luteum after ovulation?
produces progesterone and estradiol, suppress LH and FSH via GnRH.
What happens to Corpus Luteum if fertilization occurs?
regression prevented by Placental hCG (stimulates granulosa cells to produces progesterone, 17-hydroxyprogesterone, estrogen, inhibin A, and relaxin)
When does the Corpus Lutem regress to give way to placental hormones?
after first trimester
What are the 3 phases of the endometrial cycle?
Proliferative, Secretory, Menstrual
What do each of phases of the endometrial cycle do?
Proliferative [follicular phase] (induced by estrogen - upregulation of estradiol and progesterone receptors); Secretory Phase [luteal phase] (progesterone-induced differentiation of endometrial cells/implantation window); Menstrual Phase (shedding of endometrium)
What is the metabolic fate of estrogen?
estradiol (+androstenedione) –> estrone in peripheral tissues –> estriol in liver for secretion –> 2 methoxysterone
What is the metabolic fate of progesterone?
progesterone –> pregnenolone –> pregnandiol
How does estrogen effect the Uterus?
stimulates endometrium proliferation, sensitizes to oxytocin, produce cervical mucus
How does estrogen effect the Ovaries?
mitotic effects on granulosa cells; increase FSH-mediated differentiation
How does estrogen effect the Liver?
decreases total cholesterol, increase synthesis of steroid binding proteins (increase total amnt of steroid hormone)
How does estrogen effect bone?
antiresorptive
What are the major physiological effects of progesterone?
stimulate release of mature oocyte, facilitate implantation, maintain pregnancy
How does progesterone effect the myometrium?
hyperpolarization, prevent electrical coupling between cells, decrease extracellular Ca++ influx
How does progesterone effect the endometrium?
proliferation
What does Mifepristone do?
abortive effects; counteracts progesterone
How does progesterone effect the breast?
antagonize prolactin effects in mid- to late pregnancy
What does the outer layer of the blastocyst become?
Trophoblast
What are the 2 cell types within the Trophoblast?
inner cytotrophoblast, outer invasive syncytiotrophoblast
What produces hCG? Where is it found?
syncytiotrophoblast, found in fetal and maternal circulation
What does hCG do?
maintain corpus luteum to ensure production of progesterone
What produces Human Placental Lactogen hPL? Where is it found?
hPL is produced by the syncytiotrophoblast, found ni fetal and maternal circulation (after 6ty week of pregnancy)
What does Human Placental Lactogen do? hPL
embryonic development and metabolism (produce IGFs, hormones, pulmonary surfactant)
What produces Human Growth Hormone-V hGH-v? Where is it found?
hGH-V is produced by the placenta, found in MOTHER ONLY
What does Human Growth Hormone-V do? hGH-V
becomes the maternal GH (stimulates IGF-1, increase glucose and amino acids for fetus)
What is the principal source of progesterone at ovulation and at 8 weeks?
corpus lutem then syncytiotrophoblast
How does the Feto-placental Unit work?
placenta creates estriol from fetal DHEAS (fetal adrenal DHEAS –> fetal liver [16-alpha-OHDEAS] –> placenta [estriol]
How does the placenta make progesterone if it cannot convert acetate to cholesterol?
maternal liver converts acetate to cholesterol, which goes to placenta to make progesterone
What do the 4 phases of parturition consist of?
Phase 0 (transition from quiescence to activation);
Phase 1 ('activation' - via stretch+tension of cervix fetal hypothalamic-pituitary-adrenal axis, increase prostaglandin synthesis, upregulation of smooth muscle contraction proteins);
Phase 2 (active uterine contraction, prostaglandins induce myometrial contractility);
Phase 3 (postpartum uterine involution/shrinking)What are the stages of mammary gland development?
STAGE I: Estrogen (+GH, IGF-1, Epidermal Growth Factor) causes ductal elongation. Progesterone (+estrogen, cortisol, prolactin, TH) causes ductal branching & budding. STAGE II: Prolactin (+IGF-1, hPL, cortisol, insulin, oxytocin) causes expansion & differentiation.
What hormonal changes occur during female puberty?
initiated by low-amplitude nocturnal pulses of Gonadotropin, which increases serum estradiol (+GH, IGF-1, EpidermalGF). (skeletal maturation, breast development, ovarian/follicular growth, hair growth, menses) - also notice a huge rise in Leptin concentration (parallel to body fat mass)
What hormonal changes occurring during female menopaus?
decreased estradiol and inhibin levels (impaired negative feedback on GnRH); increase in FSH and LH levels, increase androstendione levels.
40 yr. old woman presents with irregular menstrual cycles and hot flashes, night sweats, vaginal dryness, dyspareunia (painful intercourse), loss of libido, loss of bone mass (osteoporosis). What is her likely diagnosis?
menopause
How does prolactin effect GnRH release?
inhibit
