PLACENTA Flashcards
how is placenta form
when maternal blood supply. has been accessed
what happens when synctiotrophoblastts invade maternal blood vessels
lacunae form
chorionic villi form
- proliferation of cytotrophoblast
- growth of chorionic mesoderm
- ## blood vessel development
what happens to primary chorionic villi around day 13 post fertilisation
cords or asses of cytotrophoblasts growing into lacunae within synctiotrophoblass
what day is secondary chorionic villi
- days 16
when is teritary chorionic villi
end of third week development
nam
tertiary villi early
name
tertiary villi mature
maternal component of placenta - decidualisatin
after implanation of blastocyst
stroma cells become large round decidual cells
regions of decidua
- decidua basalis
- decidua capsularis
- decidua parietalis
what happens by the end of 3 month for placenta decidualisation
gestation
decidua capsularises fuses with decidua parietalis of opposite wall
which layers of the endometrium form decidua
all but the deepest layer
what does decidua shed with
placenta at birth
what is a cytotrophoblastic shell
complete shell around synctiotrophoblast - attaches to endometrium
what do maternal blood vessels communicate with
through shell
what happens to the villi during pregnancy
mature - smaller in diameter
what happens to the cytotrophoblast during pregnancy
discontinues
plates in mature placenta
basal plate
chorionic plate
what does basal form from in mature placenta
decidual basalis
what does chorionic plate form from in mature placenta
embryological origin
what is the blood supply to the placenta
spiral arteries
what is the placental barrier
seperation of maternal and fetal blood
describe the diameter of the placental barrier
very thin by 4 months > allow exchange of products across placenta
functions of placenta
- metabolism
- transport
- barrier function
- immunological function
- endocrine function
when does placenta take over from
corpus leutrum 8 weeks gestation
what does adrenal cortex provide
androgens
when is human chorionc gonadotropins produced from
6 days post fertilisatin
maintains corpus leutrum < maintains endometrium > and pregnancy
placental problems
- placenta previa
- placenta abruption
what is placenta previa
covers internal os of cervix
what is placenta abruption
comes away from uterine wall
what is pre-eclampsia
pregnancy induced hypertension + protenuria
what is the treatment of pre-eclampsia
delivery of placenta