Physiology of Pregnancy Flashcards
Major morphological abnormalities happen what time?
embryonic: weeks 3-8
Preg is 40 weeks from? 38 weeks from?
40 weeks from last menstrual period
38 weeks from fertilisation
signs of early preg?
morning sickness missed period increase breast size fatigue darkening areolae
biochem determiniation of preg?
blood and urine hCG
what becomes placenta?
trophoblast
what surrounds amniotic fluid?
amnion
what surrounds the amnion?
Chorion
how are the vessels setup in the placenta?
Chorionic villi are bathes in maternal blood like ‘blood lakes’
purpose of chorionic villi/blood lake structure?
prevent vasoactive substances from affecting fetal blood flow as endothelium is not intact
Umbilical vein vs. artery carries what?
Um. Vein: oxygenated blood
Um. Artery: deoxygenated blood
hPL is?
Human placental lactogen: breast development/metabolics
Monozygotic twins with the egg that splits early vs. late?
early: separate placenta likely
late: shared placenta likely
what happens to cervix in parturition?
softening
labour has rhythmic contractions of?
myometrium
labour has what kind of feedback?
positive via oxytocin
cervix dilates how much in labour?
10cm
why placenta release?
prevent maternal bleeding
what helps trigger the parturition positive feedback?
cervical stretch>uterine contractions»oxytocin»prostaglandins» more contractions
in preg what stims breast development?
estrogen, GH, cortisol stim futher gland development
what happens in late preg to breasts?
progesterone stims conversion of ducts to secretory epithelium
what structure helps with milk ejection?
myoepithelial cells in mammary gland lobules
before birth, what inhibits lactation?
- PIH (prolactin inhibiting hormone)
2. high sex steroid levels
what allow lactation post birth?
high prolactin and low estrogen
what does suckling do for lactation?
let-down reflex via inhibit PIH, oxytocin stims ejection
what does suckling do to ovarian cycle?
stops it via inhibiting GnRH
lactation pure physiological?
sound of child’s cry could release oxytocin
maternal heart reaction to preg?
increase SV by 10%, HR 10-15%
TPR in preg? How?
lower unless pre-eclampsia
caused by NO
how does haematocrit and blood volume look in preg?
plasma volume increases faster than blood volume so haematocrit falls
BV in preg by how much?
~1250ml by 30 weeks
cervix mucus plug in delivery?
expelled
why do preg women’s areola’s darken?
more melanocyte stimming hormone at 2/12
blood flow to skin in preg?
increased so warm hands
