Aug29 M1-Female_Urogenital_System_Gonadal_and_Duct_Embryogenesis Flashcards
most imp structure for dev in female pelvis
PMD
consequence of SRY and Sox-9 prod by the testis (after PGCs went from allantois to the bipotential gonad and then testis formed with Sertoli cells)
- testes become an endocrine organ
- produce testo
- produce AMH
- affects ducts + external genitalia*
(IMPORTANT) how embryo testis differs from puberty, adult testis
produces testo without pituitary hormones influence
fct of AMH from Sertoli cells
regression of PMD (Sertoli cells also make SRY which allows testis formation and make Sox-9 also)
fct of testo of Leydig cells
-form mesonephric duct which will form the male system (vas deferens, etc.)
5 alpha reductase is present where in the embryo
only in external genitalia. converts testo from blood into DHT (4x more potent). get male external genitalia
(IMPORTANT) what happens if embryo has no testo and no AMH
- MD regresses
- PMD persists and gets a female type (uterus)
- external genitalia stays in bipotential state
what happens if Sertoli cells don’t make SRY
you form ovaries rather than testes
architecture of testes in embryo
- seminiferous cords with PGCs
- separated by coelomic epith by tunica alb.
- within the cord mesenchyme, Leydig cells form
PGCs fct in female
- PGCs reach the primary sex cords with the coelomic epith cells
- PGCs proliferate to make 7M cells, stop meiosis at prophase 1
coelomic epith fct in the female gonad
forms sex cord (rete ovary) with granular and theca follicular cells
Leydig cells do what other than making testo
develop LH-CG Rs
first time that LH-CG Rs of Leydig cells are used
- trophoblast of placenta at implantation produces HCG
- HCG similar to LH. binds LH-CG R of Leydig cells to make them produce testo (HCG also maintains the pregnancy)
(imp) important cellular association in the embryonic ovaries
in the outer cortical region, PGCs are surrounded by follicular cells and proliferate there
- stop at prophase 1
- 7M cells produced (primary oocytes arrested in prophase 1)
what happens to the rete ovary in the female gonad
becomes a remnant
ovaries position in embryo
high up at L1. and the ovarian a supplies it
(IMPORTANT) name of the functional unit of the follicular cells associated to a primary oocyte in the embryo
primary follicle
analog of follicular cells and primary oocyte assoc in the male
PGS assoc with Sertoli cells
(important) how the PMD is formed and maintained
EPITHELIAL MESENCHYMAL INTERACTION
- induced by the mesonephric duct. this mesenchyme produces hox genes which control that.
- the coelomic epithelium invaginates to produce the PMD. the coelomic epith expresses Lim-1, a TF
why is the PMD not made in the male (why does it regress)
- Sertoli cells make AMH (which is in the TGF, transforming growth factor, family)
- AMH interacts with Rs on the coelomic epith (which surrounds the mesonephric duct = mesenchyme)
- because of this mesenchyme (PMD) - epithelium (coelomic) interaction, the PMD regresses
why PMD maintained in the female
- Rs for AMH are still there in the mesenchyme
- no AMH
- epithelial-mesenchyme interaction (is not EM transition, that’s a diff thing) to maintain PMD