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
Hox genes fct in the female
- are TFs
- are important for segmentation of the reprod system
PMD goes where
all the way to the urogenital sinus
origin of the Fallopain tube
PMD
origin of the uterus
PMD
origin the upper third of the vagina
PMD
(imp) what happens in Lim1 double negative mutants
Fall tube, uterus, upper third of vagina all absent
period of dev of PMD and consequence
weeks 10 to 17. so vulnerable for a long time
what surrounds the PMD
mesenchyme with a segmental hox gene expression influencing the segmental division of the PMD
(important) example of substance that can influence the female reprod system formation
DES (diethylstilbesterol. synthetic estrogen given in the 1900s)
reason is hox genes are influenced by estrogen
hox genes influence in vertebral column dev
retinoic acid
hox genes influence in repro system dev
estrogens (for uteus and fallopian tubes)
what hox genes help form what female repro system structures
- hox9 = fall tubes
- hox10 = body of uterus
- hox11 = cervix
- hox13 = upper portion of the vagina
what step is necessary for the formation of the body of the uterus
fusion of the two PMDs (coming from both sides forming each one fallopian tube)
long period of fusion so vulnerable
(IMPORTANT) bicornuate uterus def
improper fusion of PMD
(IMPORTANT) unicornuate uterus def
one PMD formed and other one regressed
what happens if DES (synthetic estrogen) is introduced during the period of uterus formation
get an abnormal shape uterus, T shaped and smaller
how does estrogen regulate hox genes of uterus formation
- Hox10 gene for uterus body formation has 2 regulatory elements: estrogen response element 1 and 2.
- mediate estrogen responsive transcription
other problem related to DES use than abnormal uterus
children of mothers exposed to DES have adenoCA of the vagina
when is hox10 produced in life
- in embryogenesis
- in postnatal life during every menstrual cycle, it rises between day 14 and day 26 and goes back down after that
why is hox10 gene present expressed in menstrual cycle after ovulation
because it is important for normal implantation
hox genes are related to what disease
endometriosis (bc are important in endometrial development)
relations of the PMD in the embryo
- vertically oriented at L1,L2 then displaced horizontally during vertical growth of the pelvis
- rectum posterior
- attached to gonads (ovaries) by mesentery
- the MD is nearby, connected to the UGS
- ovarian artery enters the sex cords through the mesentery
- gubernaculum goes all the way to the labio-scrotal fold. passes BEHIND the PMD. and behind L5 fold.
where will the PMDs fuse (landmark)
at the point where the gubernaculums pass behind them
when does the meso duct regress
as the PMDs are fusing
name of the mesentery where the ovarian a runs
infundibular-pelvic ligament (or cranial suspensory ligament of the ovary). also contains ovarian v and lymphatics
the gubernaculum leads to what two structures
- ligament of the ovary (ovarian ligament)
2. round ligament of the uterus
location of the degenerating mesonephros and mesonephric tubules in the female
within the mesovarium (mesentery of the ovary between ovary and fallopian tube)
anomaly assoc to incomplete degeneration of mesonephros and meso tubules
cysts can form because of that, in the ovarian ligament and the mesovarium
ovary in the ovarian (inguinal) canal explanation
- very rare anomaly
- associate to the presence of defective portions of the PMD (as in a unicornuate uterus)
- the gubernaculum pulls the ovary all the way in the inguinal canal with it
- can do that bc ovary not attached to fallopian tube and uterine body (bc parts are missing)
name of the mesentery attaching to the fallopian tube (for Dr Daniels)
mesovarium
anomalies assoc with incomplete degen of the mesonephric duct in the female
a lot of cysts can form on the side of the ovaries, beside the UGS, inside the uterus.
Gartner cysts**
where would you find cysts from incomplete degeneration of PMD in the male
in the testis
name of the two possible remnants of the PMD from its incomplete degeneration in the male
- appendix epididymis
- appendix testis
- found in the testis close the apex = top*
