Phys review, michels Flashcards
when the corpus luteum sheds what happens to E and P levels? pituitary?
E and P drop
pituitary then increases FSH
increasing FSH stimulates what response in menstrual cycle
recruits large antral follicles to grow and they begin to secrete low amounts of E and inhibin
How do E and inhibin affect FSH
negative feedback
what occurs with declining FSH levels
atresia of all but 1 follicle that will now secrete high levels E
how does high E affect gonadotrophs
LH and some FSH surgres
LH surge causes what
metabolic maturation, ovulation, leutinization
corpus luteum now makes high P and some E and inhibin
response to high P and E and inhibin levels
negative feedback to LH and FSH returning to basal levels
if LH levels remain at basal level what will happen to corpus luteum
will die
3 stages of follicular development
initiation and gonadotropin independent phase
basal growth phase
rapid growth phase
what follicles are not dependent on pituitary gland
primordial, and primary
how many days is the rapid growth phase from large antral to dominant follicle
14 days
hormone producing cells
theca cells
what cells form corpus luteum
mural granulosa cells and theca cells
before ovulation what phase does the primary oocyte undergo
from prophase I to arrest in metaphase II
when does the secondary oocyte complete meiosis
at fertilization
at follicular phase what does GnRH do
pulsatile to stimulate LH act on theca cells and FSH act on granulosa cells
at end of follicular phase why is there LH surge
high levels E gives + feedback
what happens to theca cells and granulosa cells in luteal phase
theca still respond to LH
granulosa now respond to FSH AND LH
both types cells become luteal cells that secrete P and E
feedback from E and P in luteal phase
negative feedback
what are corpus albican
scar tissue in ovary form recent regression of corpus luteum
what are the parts of fallopian tube
infundibulum is opening
ampulla- fertilization takes place
isthmus
intramural segment (proximal)
estrogen effects on oviduct
increase endosalpinx epithelial size increase blood flow increase glycoproteins increase ciliogenesis increase mucus and muscular tone
progesterone effects on oviducts
dec epithelial size
dec mucus
relax muscular tone
deciliation
phases of menstrual cycle
menstrual phase
proliferative phase
secretory phase
LH surge corresponds to what event
ovulation
effects of E on cervical mucus
stimulates production of thin watery alkaline mucus
effects of P on cervical mucus
stimulates production of scant viscous, slightly acidic mucus
E effecs on bone
closure of epiphyseal plates
anabolic and calcitropic hormone
E effects on liver
increase LDL R and HDL levels, cortisol binding protein, thyroid hormone binding protein and sex hormone binding protein
CV effects of E
E cause vasodilation through NO synthesis
what does E bind to
majoirty sex hormone binding protein
also albumin
P binds to what
cortisol binding protein and albumin
how many days after ovulation dose hCG increase in pregnancy
10 days
duration of pregnancy is counted from what start date
date of last menstual cycle
how many weeks is a pregnancy counted from ovulation
38 weeks
main hormone in 1st trimester
hCG which rescues corpus luteum and stimulates corpus luteal production of estrogen and progesterone
main hormone in 2nd and 3rd trimesters
P and E under control of placenta
what are limits of placenta in hormone production
cannot make adequate cholesterol
lacks enzymes for estrone and estradiol and estriol
what does the mother contribute to placenta for hormone synthesis
LDL cholesterol
what does the fetus contribute to placenta for hormone synthesis
enzymes to make estriol
enzymes are in adrenal glands and liver
what is HPL
human placental lactogen
similar to GH and PRL
what hormone is directly proportional to size of placenta
human placental lactogen
effects of hPL
diabetogenic (antagonist to insulin)
increase glucose availability for fetus
simulates mammary growth and development
what happens to pituiatry in pregnancy
doubles in size
ADH set point is lowered
what happens to adrenal gland in pregnancy
cortisol and aldosterone levels increase
E stimulates RAAS
thyroid changes in pregnangcy
total T4 and T3 increase but free T4 normal
TSH decrease in first trimester
CV changes in pregnancy
icnreased volume
dec peripheral R
increase SV, HR, CO and contractility
Resp changes in pregnancy
increase minute and tidal volume
dec PCO2, dec FRC, dec IRV
respiratory alkalosis
renal changes in pregnancy
increase ADH, renin, ANG II, aldosterone, GFR
stages of labor
strong uterine contractions
delivery of fetus
delivery of placenta
what hormones initiate parturition
placental CRH
E
oxytocin
PGs
PRL levels during breast feeding
pulsatile
what releases oxytocin
pars nervosa
how come women who are breast feeding don’t ovulate
the increased prolactin levels neg feedback to the parvicellular cells which decrease GnRH which dec LH and FSH production so amenorrhea
roles of oxytocin
milk letdown but also limits bleeding during partuition
