Female Reproduction (Segaloff) Flashcards
term that means the degeneration of those ovarian follicles that do not ovulate during the menstrual cycle
atresia
this G-protein coupled receptor ligand is released from the hypothalamus to stimulate the release of GnRH
kisspeptin (binds to kiss1 receptor on GnRH neurons)
hormone secreted by the fetal adrenal gland that increases lung maturation (increased synthesis of surfactant A and phospholipids)
cortisol
why is the LH surge in mid-cycle higher than the FSH surge?
because inhibins are suppressing FSH secretion
phase of partuition initiated by progesterone withdrawal, in which the myometrium gains capacity to contract forcibly and rhythmically and becomes more responsive to stimulatory uterotonins
phase 1 (transformation)
phase of parturition characterized by: • closed cervix • myometrium in state of relaxation • uterine insensitivity to uterotonins (e.g., oxytocin)
phase 0 (quiescence)
stage of partuition that begins after the placenta, fetal membranes and decidua are expelled
phase 3 (hemostasis and involution)
The high concentrations of ____ in pregnancy promote extensive duct development, while high concentrations of ____ stimulate alveolar-lobular formation
estrogen; progesterone
Which of the following statements regarding placental hormones is TRUE?
A. hCG stimulates placental progesterone and estrogen synthesis.
B. Placental lactogen stimulates the synthesis of mammary gland enzymes required for the synthesis of milk.
C. Placental estrogen and progesterone concentrations are less than those produced by the corpus luteum of pregnancy.
D. The placenta synthesizes androgen substrates for aromatization into estrogens.
E. Placental hCG concentrations are undetectable by the third trimester of pregnancy.
B
Recent studies suggest that thelarche and menarche are occurring earlier in U.S. girls, coinciding with a rise in obesity prevalence. Why is this?
aromatase is constitutively active in adipose tissue, and is responsible for converting androgens to estrogen, prompting development of breast tissue and menses.
What 2 cells and 2 hormones are required for ovarian estrogen synthesis?
theca cells (andrestenodione) and granulosa cells (estradiol)
How does progesterone prepare the uterus for potential implantation of a fertilized ovum?
“quiets” the myometrium; thickens the cervical mucus
at what 3 times during human development are LH and FSH secreted?
during fetal development, infancy, and puberty
cells on the outside layer of the blastocyst that secrete hCG and mediate implantation, then develop into the fetal portions of the placenta
trophoblast cells
What hormone, released from adipose tissue, acts on the hypothalamus to provide a permissive signal for the onset of puberty?
leptin
True or false: Androstenodione from granulosa cells diffuses into theca cells where aromatose converts it to estradiol.
False. Androstenodione diffuses from theca cells, which lack aromatase, into granulosa cells where it can be converted to estradiol.
event that stimulates the completion of the second meiotic division of the ovum
fertilization
phase of partuition that is the onset of labor
phase 2 (activation)
what is the main action/target of ovarian estrogen and progesterone
prepare the endometrium for implantation
True or false: the growth of primordial follicles to primary follicles is independent of FSH and is mediated by local growth factors
True. It is the subsequent growth of primary follicles that is critically dependent on FSH.
what phase of the monthly sexual cycle does a sustained level of estrogen stimulate an LH/FSH surge, by enhancing the responsivness of the pituitary gonadotrope cells to GnRH?
end of the follicular stage
Estrogens mediate the establishment of secondary sex charateristics, such as breast development, with what exception?
estrogen does not influence axillary and pubic hair growth - this is mediated by adrenal androgens
Typically, a diagnosis of precocious puberty in girls is considered when signs of puberty develop prior to how many years of age?
8
what are the roles of prolactin and oxytocin during nursing?
prolactin: released by the anterior posterior via signals from the hypothalamus in response to suckling, increases milk synthesis and secretion into the alveoli
oxytocin: concurrently secreted from the posterior pituitary, stimulates contraction of myoepithelial cells surrounding the alveoli to cause milk ejection into ducts (let down)
