Pregnancy and birth Flashcards
ovum lifespan and viability
lifespan 72th, viability less
sperm life
5 days
what are 2 cell layers of blastocyst
- inner cell mass
2. trophoblast
how does trphoblast invade
enzymes that digest in the endometrium
what does trophoblast divide into
- syncitiotrophoblast
2. cytotrophoblast
what is the role of prostaglandins in implantation
- increase vascularization around
2. edema
what is interstitial implantation
embryo becomes fully enveloped in the endometrium
what are 2 ways that mom and fetus aren’t rejected
- trophoblast has no MHC, but HLS-G instead
2. Mother is immunosupressed - need to be aware of this
what is discoid placentation?
1-layer thick of trophoblast - allows efficient exchange of nutrients
what is source and function of hCG
source: blastocyst and early placenta
function: stim LH to maintain corpus luteum
what is source and function of estrogen
source: placenta
function: stim myometrium to grow, mammary gland, fetal dev.
what is source and function of progesterone
source: bplacenta
function: inhibs spontaneous contraction, mammry gland dev, inhibs FSH so no more follicles
what is source and function of hPL
source: placenta
function: prepares mammry gland, reduces maternal glucose use
what is source and function of relaxin
source: placenta
function: soften cervix for delivery, loosen CT between pelvic bones to facilitate delivery
what forms of est are most common in preg
estriol>estrone>estrodiol
when does hCG peak and why is this useful?
8 weeks, preg. tests
3 functions of lactogen
- lower glucose use in mom
- increase maternal lipolysis
- Na, K, Ca retention
what is DHEAS
sulfoconjugated DHEA
why is Sulfur important
prevents masculinization
where is most prenatal DHEA found
fetal cortex>adult cortex>medulla
what are the triggers of birth (5)
- E2 and OT up
- fetal cortisol up
- placental CRH up
- prostaglandins up
- progesterone down
what is birth feedback loop
baby pushed on cervix>neuroendocrine reflex>oxytocin up> contrctions
what are 2 cells responsible for milk and what hormones are they acted on by?
epithelial- milk producing - E, proeg and prolactin
myoepithelial - push milk out - oxytocin
what inhibs milk ejection reflex
stress
