Kuehn - fetal period and developmental abnormalities Flashcards
what is the umbilical vesicle “yolk sac”
early nutrient transfer to developing embryo, formation of germinal cells, and earliest site of blood cell development
what is the amniotic membrane
contains the amniotic fluid
where does the amniotic fluid come from
placenta, amniotic membrane, embryonic urine, and guts
what is the function of the amniotic fluid
protects from injury, prevents fetal/amnion fusion, permits symmetrical growth of NBI limbs, regulates temperature and fluid exchange
what is the term for when amniotic fluids are too low
oligohydramnios
what are the consequences of oligohydramnios
poor renal function in fetus, club foot/club hands or hypolasmic lungs (too small to function after birth)
what is polyhydramnios
too much amniotic fluid
what are the consequences of polyhydramnios
esophageal atresia, cord prolapse and placental abruption
what is the chorion
space between amnion and uterus - filled with fluid early in life and will disappear
what are the chorionic villi for
increase surface area - collect nutrients from maternal blood
what separates the pleural and pericardial cavities
pleuropericardial membrane
what does the pleuropericardial membrane become after it closes as a hole
pleuropericardial canal
what does the pleruoperitoneal membrane incorporate into
the diaphragm
what happens with congenital diaphragmatic herniation
left pleuroperitoneal membrane fails to complete its attachments and structures in left upper abdomen will herniate into left pleural cavity (lung on that side will fail to grow)
at what weight is a premature birth viable
more than 500 grams (1 lb)
what are 2 ways to determine age of fetus
LMP (LNMP- last normal menstrual period) or estimated day of fertility = LMP - 2 weeks
how long is a trimester
about 13 weeks
what happens in the 1st trimester
most critical part of development
what trimester can a fetus survive outside the womb
3rd trimester
what is the difference between previable and viable
previable = the fetus’ lungs aren’t fully developed and cannot survive outside womb, viable = developed enough to survive
when can you first feel fetal movements
17-20 weeks
what is a dizygotic (fraternal) twin
2 seperate oocytes fertilized independently = 2 seperate fetus
what is a monozygotic (identical) twin
1 zygote or blastocyte divides = 2 embryos with same DNA
what is the safest procedure for testing for defects
ultrasound - high frequency sounds bounce off fetus
when would you use amniocentisis testing and what does it do
after age 35 - at 15-20 weeks (early 11-13 weeks) sample amniotic fluid and cells - keryotyping or biochemical tests
what does a chronic villus sample (CVS) do and when would you do it
collects chorionic villus cells for karyotyping - at 10-12 weeks
what is the fetoscopy test and when is it used
endoscope in amnion - used in unusual circumstances (twin-twin transfusion)
what 2 tests are hazardous to an early fetus (can be used late 3rd trimester)
X-ray and CT scan
when are defects so severe the result is death
1st 2 weeks
what time period are defects organogenesis and have serious malformations
weeks 3-8
what is a cleft
failure of fusion
what is agenisis
failure of an organ to develop
what is ectopy
abnormal location of development
what is stenosis
abnormal narrowing
what is a fistula
abnormal connection
what is a cyst
abnormal fluid-containing structure
what is atresia
a blind tube
