Embryology Flashcards
Origin of upper 2/3 vagina
Paramesonephric ducts
Origin of lower 1/3 vagina
Urogenital sinus
The intraembryonic coelom forms within which structure?
Lateral plate mesoderm
Gonads and urogenital system develop from which cell layer?
Intermediate mesoderm
Skeletal muscles, the skeleton, the dermis and connective tissue develop from which cell layer?
Paraxial mesoderm
At what gestational age do fetal breathing movements commence?
12 weeks
Meconium is found in the fetal gut from what gestational age?
14 weeks (but passage of meconium is rare before 34 weeks)
How many turns does the midgut go through in its embryological formation?
Three 90 degree turns
What proportion of primordial follicles undergo atresia?
99%
When in embryological development should the neural tube be closing?
4-5 weeks
By which day of embryonic development does the primitive streak usually appear?
Day 15
“incomplete closure of the lateral folds leaving a defect through which abdominal viscera protrude”
Gastroschisis
What is the seminal colliculus equivalent to
Hymen
What condition is associated with a single umbilical artery?
Cardiovascular anomalies (15-20%)
Which aortic arches disappear?
Second and fifth
