Download Embriology Genital Tract

Embryology of The Female
Genital Tract
Basim Abu-Rafea, MD, FRCSC, FACOG
Assistant Professor & Consultant
Obstetrics & Gynecology
Reproductive Endocrinology & Infertility
Advanced Minimally Invasive Gynecologic Surgery
Department of Obstetrics & Gynecology
King Khalid University Hospital
King Saud University
Gonads
• At approximately 5 weeks of gestation, the
gonads are structurally consolidated coelomic
prominences overlying the mesonephros,
forming the gonadal ridges.
• At this point, the gonad is morphologically
indistinguishable as a primordial testis or
ovary.
Gonads
Testes
• The factor that determines whether the indifferent
gonad will become a testis is called, the testesdetermining factor (TDF), a product of a gene located
on the Y chromosome.
• The male phenotype is dependent on the products
(antimüllerian hormone and testosterone) of the fetal
testes which are secreated from Sertoli cells & Leydig
cells.
Ovary
• Ovarian differentiation are reflected in the rapid
mitotic multiplication of germ cells, reaching 6–7
million oogonia by 16–20 weeks.
Female Genital Tract
• In the absence of AMH, the fetus will develop
fallopian tubes, uterus, and upper vagina from the
paramesonephric ducts (the müllerian ducts).
Female Genital Tract
• Canalization to create the uterine cavity, the
cervical canal, and the vagina is complete by the
22nd week of gestation.
• By the 20th week of pregnancy, the uterine
mucosa is fully differentiated into the
endometrium.
Anomalies
• Anomalies can originate in the failure of
the müllerian ducts
– to fuse in the midline
– to connect with the urogenital sinus
– to create the appropriate lumen in the upper
vagina and uterus by resorption of the central
vaginal cells and the septum between the
fused müllerian ducts.
Abnormal müllerian differentiation frequently is
associated with urologic malformations.
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