Placental Pathology Flashcards
The ____ layer of the trophectoderm remodels the endometrium to form the intervillous space.
outer syncytial layer
The ____ layer of the trophectoderm propagates to form villous structures.
inner mononuclear cytotrophoblast layer
Spontaneous abortion or miscarriage occurs due to ____
usually chromosomal anomalies or genetic mutation but also diabetes, endocrine abnormality, physical defect
Substance around fetal vessels
Wharton’s jelly
3 membranous layers of placenta
amnion, chorion, decidua
___ membrane is continuous with fetal skin
amnion –> fetal derived
the functional unit of the placenta is the _____________ of the chorionic villi which serves as the interface for nutrient and gas exchange between the fetal and maternal circulations
vasculosyncytial membrane
Blastocyst implantation has three phases:
apposition, stable adhesion and invasion
he trophectoderm penetrates through the uterine epithelium and deep into the ________________such that the entire gestational sac is implanted within the endometrium.
decidualized endometrial stroma
T/F The early intervillous space formed from the lacunae in the trophoblast shell is initially bloodless
T –> Direct connections are made but remain blocked by trophoblast plugs within the arterie
full perfusion of the intervillous space occurs around ___ weeks gestation via ___
12 weeks via uterine spiral arteries
How does dissolution of vascular mural smooth muscle facilitate implantation?
dissolution of the vascular mural smooth muscle which reduces vasomotor reactivity and resistance.
Umbilical arteries arise from ______
internal iliac arteries
This layer of the placenta is an admixture of extravillous trophoblast and decidua containing the terminal portions of the maternal arteries and veins.
maternal surface
maternal surface of placental disc is covered by ____
decidua basalis
the ___ membrane separates the fetal blood from the maternal blood; the “membrane” is composed of apposed portions of the fetal capillary and ______ that are highly attenuated with cytoplasmic organelles and nuclei pushed to the side.
vasculosyncytial // villous trophoblast
T/F a dizygous gestation will always have two chorions and amnions.
T
Chorionicity in monozygous twins depends on:
timing of the division of the zygote.
Division within the first 72 hours after fertilization results in:
two separate embryos with their own chorion and amnion.
Division between 4-8 days, after development of the chorion ,results in:
a single chorionic disc but two amnionic sacs (monochorionic diamnionic )
Division after 8 days ,following development of the chorion and amnion , results in:
a single chorionic disc and single amnionic sac (monochorionic monoamnionic)
The presence of a monochorionic placenta indicates:
monozygous twinning
The presence of two chorions indicates:
nothing –> could be fused or not but either way is dizygous
___ is the only reliable method for confirming zygosity
molecular genetic testing
Chorionicity of conjoined twins by definition is :
monochorionic monoamnionic
T/F Gestations with increasing numbers of fetuses can have any combination of disc and membrane arrangements
T
2 pathways for placental infection
ascending from birth canal and hematogenous
____ route of infection is also referred to as “transplacental” indicating that there is infection of the placental disc
hematogenous