WEEK 4: EMBRYOLOGY OF THE MALE REPRODUCTIVE SYSTEM Flashcards
What forms the GONADAL or urogenital ridges?
They are formed by proliferation of the epithelium and a condensation of the mesenchyme of the intermediate mesoderm
Pirmodial germ cells appear at the GONADAL ridge at Week 7 of development.
Where do they originate from?
*In the epiblast
Describe the pathway of pirmodial germ cells from the epiblast to the GONADAL ridge
Week3 : from the epiblast they migrate through the primitive streak and reside among endoderm cells in the wall of the yolk sac close to the allantois
Week 4: they migrate by the ameboid movement along the dorsal mesentery of the hindgut
Week 5: Arrive at the primitive gonads
Week 6 : invade GONADAL ridges
Which embryological layer is the male reproductive system formed from?
- Intermediate mesoderm
Name the gene on the Y chromosome which encodes the testis determing factor TDF
SRY gene (sex determining region on Y gene)
Name the structure formed when the epithelial cells penetrate the underlying mesenchyme after the proliferation of the epithelial of the GONADAL ridge
Indifferent GONAD/ primitive GONAD/ Primitive sex cords
What is the function of the Testis determing factor TDF?
Encode the primitive sex cords to continue to proliferate and penetrate deep into the medulla to form the TESTIS or MEDULLARY CORDS
Where are the Sertoli cells derived from?
From the surface epithelium of the gland
They are derived fromthe epithelial sex cords of the developing gonads
Where are the interstitial cells of Leydig derived from?
From the original mesenchyme of the GONADAL ridge
They lie between the testis cords
At what time does the Leylig cells produce testosterone?
Week 8 of gestation
The testis cords remain solid until puberty when they acquire a lumen.
What structure do they form afterwards?
Seminiferous tubules
What is the other name for the mesonephric duct?
What structure does it form?
*wolffian duct
*ductus deferens and the male duct system
What are the two pairs of genital ducts found in both male and female initially before diferentiation ?
Mesonephric duct (Wolffian duct)
Paramesonephric duct ( Mullerian ducts)
Name the master gene for testes development
SRY
Name the other gene that the SRY appears in conjunction with to induce testis differentiation
SOX9
What is produced by the SRY in conjunction with the SOX9 that acts as a chemotactic factor that causes tubules from the mesonephric duct to penetrate the GONADAL ridge?
FGF9
