Placental Histo Flashcards
Difference between cytotrophoblasts and syncytiotrophoblasts
cytotrophoblasts directly encircle developing cell mass
syncytiotrophoblasts invade the endometrial layer
Where do syncytiotrophoblasts come from
cytotrophoblasts
syncytiotrophoblasts do not undergo mitosis, they only come from cytotrophoblasts
Syncytiotrophoblasts do this when they invade the endometrium
destroy capillaries and glands
1˚villi composed of
trophoblast only
- cytotrophoblast inside
- syncytiotrophoblast outside
2˚ villi composed of
trophoblast + mesoderm
mesodermal ingrowths into 1˚ villis core
branching begins
3˚ villi composed of
trophoblast + mesoderm + blood vessels
anastamosis of villi blood vessels w/ fetal circulation
Anchoring and free villi
both 3˚ villi
- anchoring: invade to shell
- free: not connected to shell
Decidual reaction
transformation of endometrial stromal cells
swell due to glycogen and lipid accumulation
occurs each menstrual cycle and enhanced after conception
Decidua basalis
maternal portion of placenta
between conceptus and myometrium
Decidua capsularis
from baby
between baby and uterine cavity
Decidua parietalis
from baby
remainder of endometrium along uterine wall
part that is not connected to the baby
Decidua
- basalis
- capsularis
- parietalis
basalis: placenta from mom that connects to baby
capsularis: placenta surrounding baby
parietalis: endometrium not contracting baby
Cotyledons
location
function
adjacent to basalis, lobules of 3˚ villi
divides placenta via lobule formation
hCG
where is it produced
by syncytiotrophoblast
acts on LH receptors on corpus luteum
secretion of estrogen and progesterone before placenta starts doing that
How does the baby get estrogens?
baby’s adrenals make androgens
androgens made into estrogens by syncytiotrophoblasts
