phys- pregnancy Flashcards
what are the 4 stages of pregnancy
- initiation
- fertilization
- implantation
- secretion of HCG to rescue the corpus luteum
- gestation
- parturition
- lactation
____ and ____ relax and soften pelvic ligaments
estrogen and relaxin
why does lactation not occur during pregnancy
inhibition by placental estrogen and progesterone
when is the blastocyst formed (fertilization)
days 3-4
estrogen and progesterone levels ___ pregnancy
increase throughout
the normal optimal menstrual cycle days of implantation are what and why
days 20-24 because of progesterone
what is parturition (stage 3 of pregnancy)
labor, delivery, and birth
mucus plug dislodges, cervical canal dilates, uterine myometrium contracts
what is pitocin
pharmaceutical synthetic form of OT
fertilization must occur within ___ of ovulation
24 hours
which hormone stimulates production (secretion) of milk
prolactin
how does inflammation cause premature labor
increased macrophages (due to increased pulmonary surfactant), uterine stretching, bacterial infections, allergic reactions, and multi-fetus pregnancies
⇒ activation of NF-kB in the uterus
⇒ increased production of IL-8 inflammatory cytokines and prostaglandins
⇒ cervical softening
what is involution
when the uterus shrinks to its pregestational size after delivery
____ makes estrogen and progesterone during the first trimester
____ makes estrogen and progesterone after that
corpus luteum makes estrogen and progesterone during the first trimester
placenta makes estrogen and progesterone after that
how long does sperm survive in the female reproductive tract
usually 48 hours but up to 5 days
in non-lactating women, how long does it take for ovulation to resume
7 to 10 weeks postpartum
*** not to be used as a contraceptive method ***
levels of maternal ___ may be used as an index of fetal health
maternal urine hCG
early on, the placenta makes ____ but as it matures it makes ____
early on, the placenta makes hCG but as it matures it makes estrogen and progesterone
what is the zona reaction
a structural change in the zona pellucida- happens when fertilin on the sperm fuses to the integrin receptor on ovum’s membrane:
cortical granules released and ZP3 degraded so that no polyspermy
⇒
2nd ovum meiosis completed
⇒
fusion of sperm and ovum
how does the female reproductive tract aid in sperm migration
myometrium contractions
oviduct smooth muscle contractions
allurin (chemical that attracts sperm to the ampulla so it can reach the egg)
withdrawal of placental estrogen and progesterone at parturition initiates
lactation
prolactin (the major hormone resoponsible for lactogenesis) is synthesized/ secreted by lactotrophs in ____, and then released under the control of ___ and ___
prolactin (the major hormone resoponsible for lactogenesis) is synthesized/ secreted by lactotrophs in the pituitary, and then released under the control of thyrotopin releasing hormone (stimulatory) and dopamine (inhibitory)
how does CRH affect fetal lungs?
placenta secretes CRH ⇒ increases fetal ACTH ⇒ fetal cortisol ⇒ promotes fetal lung maturation
only the placenta makes ___
while the placenta and the fetus make ___
only the placenta makes progesterone
while the placenta and the fetus make estrogen
when does the placenta become functional
what are these functions
5 weeks after implantation
functions:
- organ of exchange- digestive, respiratory, renal
- prevents immunologic rejection
- secretes hCG (2nd and 3rd tri), estrogen, progesterone
what hormones stimulate the synthesis of milk enzymes during gestation
prolactin
which hormone causes milk ejection
OT
when and what is gestation (stage 2 of pregnancy)
about 38 weeks from conception or 40 weeks from LMP
when the physical changed in the mother meet the demands of pregnancy
where is the site of fertilization
oviduct
normally the ampulla (upper third)
hormone that helps form the cervical plug
progesterone
when does the blastocyst embed and become the trophoblast
days 6 to 8
embeds b/c of enzymes
when is labor initiated
when OT receptor concentration reaches a critical threshold that permits the onset of strong coordinated contractions in response to ordinary levels of circulating OT
____ are needed to synthesize estrogen during pregnancy
both the fetus and the placenta
what is the outcome of the high estrogen levels during labor that increase the production of prostaglandins
collagen fibers are degraded by enzymes causing cervical ripening (softening)
increased OT receptors in the myometrium causing increased responsiveness to OT
what is the outcome of the high estrogen levels during labor that increase the concentration of myometrial receptors for OT
an increased responsiveness to OT
what initiates parturition
increased estrogen
the most important estrogen of pregnancy
estriol
what levels in maternal plasma act as a placental clock for timing parturition based on fetal lung maturation
Corticotrophin-Releasing Hormone (CRH)
high = premature deliveries
low = late deliveries
where is OT made and stored
produced in the hypothalamus
stored in the posterior pituitary
who makes progesterone
weeks 6-12 : corpus luteum
after week 12 : placenta
what is the outcome of the high estrogen levels during labor that promote synthesis of connexons for gap junctions within uterine smooth muscles
cells are linked to create a coordinated contraction
when does fertilization happen
days 1-2
what are the stages of labor (parturition)
- cervical dilation- few to 24 hours (longest stage)
- delivery of baby- 30 to 90 minutes
- delivery of placenta- 15 to 30 minutes
prior to onset of labor, circulating OT levels are ___ but ___
are constant
but uterine responsiveness is 100 x greater due to increased myometrial OT receptors
what hormones promote development of mammary glands during gestation
estrogen and progesterone
what does hCG do
maintains pregnancy
stimulates the corpus luteum to secrete progesterone and estrogen
what do hCG levels look like with an ectopic pregnancy
a slower hCG level rise
what do hCG levels look like w/ a hydatidiform mole
slow, continuous rise
stages of fertilization
capacitation
acrosomal reaction
zona reaction
how is sperm activated and what is this called
capacitation
while sperm goes through reproductive tract, the cholesterol cap comes off so that it can penetrate
when is hCG detected
where does it come from
after implantation is complete (8-11 days after conception)
from the primitive placenta
what is the acrosomal reaction
sperm penetrates corona radiata
⇒
acrosin is released to allow sperm to penetrate the zona pellucida
⇒
sperm binds to the ZP3 receptors on the zona pellucida
what do hCG levels NORMALLY look like
peak at weeks 9-12
then decline
then plateau
in lactating women, how long does it take for ovulation to resume
27 weeks (7 months)
*** not to be used as a contraceptive method ***
anovulation occurs after lactation due to
GnRH inhibition ⇒ FSH and LH release
what do hCG levels look like with fetal death
levels rise normally, then fall with a half life of 24 hours
____ is needed to synthesize progesterone during pregnancy
maternal cholesterol
