15-30% have infertility resulting in 1% of live births
Fusion of pronuclei
Division of blastomeres forming morula and new
tight junctions to allow for fluid buildup around inner
cell mass = embryo and outer cell mass =
trophoblast (placenta)
hCG secreted if pregnancy
occurs (secreted by
syncitiotrophoblast)
Ectopic pregnancy common in
ampullary region of uterine tube or
in Rectouterine (Douglas') pouch
No pregnancy ->
corpus luteum
regresses, eliminating
progesterone and
beginning menstration
Basal layer regenerates for next cycle
Blastocyst (consisting of
inner, outer, and fluid)
Trophoblast
Cytotrophoblast (makes
cells)
Form extraembryonic mesoderm which form
tertiary villi and surround amnion and yolk
sacs
Somatic Mesoderm
Splanchnic Mesoderm
Chorionic Cavity between
but coninuous at the
umbilical region
Syncytiotrophoblast
(forms syncytium)
Responsible for
invasion of
blastocys in uterine
endometrium and
hormone production
Attach to tertiary villi resulting in
maternal-embryonic blood flow
(connection to mother can lead to
bleeding, often mistaken for menstruation)
Forms villi for placenta
Primary villi = core of
cytotrophoblast coverred by
syncytiotrophoblast
Secondary villi = core of
extraembryonic mesoderm,
covered by cytotrophoblast,
covered y with each other and to
umbilical vessels to form the fetal
circulation