Embryology Flashcards
What stage of a developing embryo is present during implantation?
Blastocyst
What is the embryological origin of Urethra, Bladder and lower 2/3 vagina?
Urogenital Sinus
What is the embryological origin of the uterus and upper 1/3 vagina?
Paramesonephric ducts
–> fuse ventral to meso mesonephric ducts)
–> uterovaginal primordium
—–> UV primordium (projects to urogenital sinus)
—> Mullerian ubercle –> vaginal plate –> canalization
What is dominant in male versus females for embryological genital devlopment?
Male = mesonephric ducts (epididymys, ductus deferns)
Female paramesonephric ducts
Embryology: Urogenital sinus?
bladder, urethra, lower 2/3 vagina
Embryology: hymen origin?
Mullerian tubercle
Embryology: Clitoris origin?
Phallus
(same for glans, dorsum of penis for men)
Embryology: Labia Minora origin?
Labia minora = Urogenital folds
(vental penile surface in males)
Embryology: labium majora origin?
Labium majum = labioscrotal swellings
(scrotum in males)
What are examples of midline fusion defects in women pelvic embryology?
Subseptate
Septate
Arcuate
Unicollis, bicornuate
Bicollis bicornuate
Utrine dedelphys (no fusion)
Vaginal septa
Rudimentary / noncommunicating horn
Cardiac embryology: in utero…
-is pulmonary artery high or low?
High pulmonary artery pressures –> to shunt blood away from lungs to the body
Left to right shunting
What are the shunts in utero and what happens at birth?
-Ductus venosus
-Ductus arteriosis
Where do the primary oocytes for the developing gonad derive from?
the yolk sac
Where / when does meiosis I/II begin?
Meiosis I = begins in utero
Meiosis II = begins at ovulation
Where / when does meiosis I/II arrest?
Meiosis I = arrests in prophase
Meiosis II = arrests in metaphase
Where / when does meiosis I/II end?
Meiosis I = ends pre-ovulation (at his point a secondary oocyte (23 X) plus 1st polar body is surrounded by zona pellucida and corona radiata (follicular cells)
Meiosis II = ends at fertilization
In the developing oocyte, when is the haploid state accomplished?
Completion of meiosis I
What is the order of development of the zygote?
Fertilization
Zygote
Cleavage
Morula
Blastocyst
Implantation
What changes occur in the perinatal cardiovascular system at the time of birth?
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