Embryology Flashcards
natural screening of embryos
spontaneous abortion; likely in fetuses with cleft lip/palate, & neural tube defects
implantation of embryo outside uterus
ectopic pregnancy
where do most ectopic pregnancies implant?
ampulla (can cause abdominal pregnancy) & isthmus (early rupture from bursting of uterine/ovarian anastomoses)
mucosal adhesions & pelvic inflammatory disease cause?
tubal pregnancies—> interferes with the transport of zygote to uterus; abdominal pain
when zygotes can develop before rupture of ectopic pregnancy
intramural tubal pregnancy (uterine part of tube)
which ectopic pregnancy can go full term?
abdominal pregnancy —-> intraperitoneal bleeding/risk of maternal death
implantation of blastocyst in inferior segment of uterus & placenta blocks cervical opening
placenta previa; c-section required for complete blockage of canal
high doses of estrogen & progesterone that inhibits implantation of embryo
morning after pill
interferes with implantation by causing inflammatory reaction in the uterus
intrauterine device
what hormone is released by a cleaving zygote?
early pregnancy factor (HCG)
what produces human chorionic gonadotrophin (HCG)?
syncytiotrophoblast
leakage of blood into uterine cavity from disrupted lacunar networks in blastocyst
implantation bleeding (can be a false negative for pregnancy)
tumor that arises from remnants of primitive streak & contains tissues from 3 germ layers
sacrococcygeal teratomas; common in newborns (esp. females), benign
tumor that arises from remnants of the notochord (1/3 from cranium to nasopharynx)
chordoma; if malignant, it grows into bone
remnants of extraembryonic portion of allantois between fetal umbilical vessels
allantoic cysts —>symptomatic in childhood/adulthood when inflammed
congenital herniation of viscera into proximal umbilical cord (associated with allantoic cysts)
omphalocele
disturbance in the neuroectoderm & failure of neural folds to fuse causes?
neural tube defects
partial or complete absence of brain
meroenchephaly/anencephaly
cystic swellings formed by degenerative villi after death of embryo; high HCG
hydatidiform moles
malignant moles that develop after spontaneous abortions or normal delivery; hematogenously metastastize
choriocarcinomas
fertilization of empty oocyte by monospermic or dispermic moles
complete hydatidiform moles
fertilization of oocyte by two sperms
partial hydatidiform moles
hemolytic disease of newborn causing anemia, jaundice, hemolysis
fetal erythroblastosis; when fetus is Rh+ but mother is Rh-
what’s given to mother to prevent fetal erythroblastosis?
Rh immunoglobulin
abnormal proliferation of trophoblast
gestational trophioblastic disease (gestational choriocarcinomas)
how do you treat gestational choriocarcinomas?
chemotherapy
abnormal adherence of chorionic villi to myometrium
placenta accreta (3rd trimester bleeding)
when chorionic villi penetrate entire myometrium into perimetrium
placenta percreta (3rd trimester bleeding)
absence of umbilical artery
agenesis or degeneration of vessel in early development associated with 15-20% cardiovascular defect
low volumes of amniotic fluid —> rupture of amniochorionic membrane, placental insufficiency, reneal agenesis (no fetal urine)
oligohydraminos —> fetal abnormalities & early rupturing of fetal membrane
high volumes of amniotic fluid from fetus not swallowing enough fluid —> esophageal atresia
polyhydraminos —> an/meroencephaly
rupture of amnion, & encircling by amniotic bands —> digital constriction, major scalp, craniofacial, & visceral defects
amniotic band syndrome
anastomoses between blood vessels of fused placentas of DZ twins
erythrocyte mosaicism
shunt of twin blood through anastomoses into venous circulation of other twin; donor twin is anemic & recipient twin is polycythemic
twin transfusion syndrome (treat with lazer ablation)
50% mortality rate because umbilical cords tangle
monochorionic-monamniotic twin placenta
vascular abormalities, somatic mutations, chromosome abherrations, X chromosome inactivation
discordant MZ twins
embryonic disks don’t divide correctly
conjoined twins
fertilization of two or more oocytes at different times
superfecundation
