Downing: Placental Histology Flashcards
On what day does the trophoblast meet the prepared secretory phase of the endometrium?
Day 6, ‘it tacks 6 days to stick’
Day 7: What to cytotrophoblast give rise to? Are they mitotically active?
syncytiotrophoblast, a true mass of cells with no boundaries that are highly aggressive and erosive into the endometrial surface
What contains maternal and glandular secretions around Day 9?
Lacunar networks! syncytium keeps expanding into the glands and arteries.
Day 13: what does ‘forming the villi of the placenta’ consist of?
movement of cytotrophoblasts towards the interface between somatic mesoderm and the syncytiotrophoblast
T or F: primary villi consist only of trophoblast (syncytiotrophoblast and cytotrophoblast)
T. no extraembryonic mesoderm yet!
What are the three layers of the secondary villi?
syncytiotrophoblast (outer), cytotrophoblast (middle), mesodermal core (inner)
What kind of villi have a cytotrophoblastic shell formation?
ANCHORING. invasion of cytotrophoblast through syncytiotrophoblast and it makes direct contact with decidual cells
what does the tertiary villi consist of?
differentiation of blood vessels in the mesodermal core of secondary villus.
in which villi stage do you get anastomosis of villar blood vessels with fetal circulation?
tertiary villi!
what villi starts to have a CORE OF MESODERM?
secondary villi
______ is the transformation of endometrial stromal cells
Decidual reaction. Swell due to glycogen and lipid accumulation. transformation spreads throughout superficial layers of endometrium
what is the decidua basalis?
maternal portion of placenta, site of decidual reaction and most extensive villar invasion
where is the decidua capsularis located?
between conceptus and uterine lumen
_____ is the remainder of the endometrium?
decidua parietalis
what is the fetal placental circulation?
umbilical arteries -> chorionic arteries -> villar caps -> chorionic veins -> umbilical vein
What is the maternal circulation of the placenta?
spiral arteries -> intervillous space -> endometrial veins
after how many weeks does the cytotrophoblast progressively disappears and connective tissue thins? what does the barrier then become?
20 wks. syncytial trophoblast, basal laminae, fetal capillaries.
What organisms are in TORCH?
Toxoplasmosis, other infections (hep B, cox, syphillis, VZV, HIV, parvovirus b19), rubella, CMV, HSV-2
what hormone maintains corpus luteum and its production of progesterone and estrogen in the first trimester?
Human chorionic gonadotropin (hCG)
what can be measured within 6 days of fertilization in a urine test?
hCG
what is produced by the decidua cells and helps to SOFTEN the cervix just prior to parturition?
RELAXIN
