II: Pregnancy- Fetus Flashcards
____ twins are at highest risk for Twin-Twin Transfusion Syndrome
Monochorionic; diamniotic
____ twins are at highest risk of entanglement of umbilical cords.
Monoamniotic
____ villi: cytotrophoblast core surrounded by syncytiotrophoblasts
Primary
____ villi: cytotrophoblasts contact decidua and invade through to the inner third of the myometrium
Anchoring
____ villi: extraembryonic mesoderm growing into the cytotrophoblast layer
Secondary
____ villi: majority of placental mass, responsible for nutrient exchange
Floating
____ villi: mesenchymal cell differentiation into blood vessels to form arteriocapillary network in the villous
Tertiary
_____ are specialized basic histones with disulfide bonds that compact sperm DNA
Protamines
______ do not express MHC molecules
Syncytiotrophoblasts
______ may downregulate immune function regionally
Cytotrophoblasts
______: morphological and biochemical differentiation of uterine stromal cells
Decidualization
______: process by which blastocyst escapes the zona pellucida
Hatching
______: trophectoderm cells of the blastocyst interdigitate with the luminal epithelium of the uterus
Apposition
___-zygote: majority of spontaneous twin pregnancies (70%)
di
An activated oocyte releases ___, to prevent polyspermy.
ZP3-F
Capacitated sperm can bind to the _______ and undergo the acrosomal reaction.
zona pellucida
Dizygotic twins are __-chorionic and __-amniotic.
di; di
Fertilization occurs _____ hours following ovulation.
12 to 24
HbF has a lower affinity for ______.
2,3-BPG
How can TTTS be diganosed?
Placental Injection Studies
Hyperemesis in the context of twin pregnancies can be attributed to higher levels of ___
hCG
Implantation occurs approximately ___ days following fertilization.
6
In the placental-fetal unit, which produces 17-hydroxyprogesterone?
Fetus
In the placental-fetal unit, which produces estrogens?
Placenta
In the placental-fetal unit, which produces progesterone?
Placenta
In TTTS, the ____ twin is at risk for developmental and growth defects
Donor
In TTTS, the ____ twin is at risk for fetal hydrops.
Recipient
Monozygotic twins dividing during days 0-3 are __-chorionic and __-amniotic
di; di
Monozygotic twins dividing during days 13+ are __-chorionic and __-amniotic
mono; mono; (Conjoined)
Monozygotic twins dividing during days 4-8 are __-chorionic and __-amniotic
mono; di
Monozygotic twins dividing during days 9-12 are __-chorionic and __-amniotic
mono; mono