Development of Reproductive Tract Flashcards
what determines gonadal development
presence of Y chromosome (SRY region and Sox9 gene)
by default would be female
XXY example
XO example
XXY - male calicos, testes
XO - turner’s syndrome, ovaries
sertoli and granulosa cells originate from…
sex cords
leydog and theca cells originate from…
mesenchyme
Wolffian (mesonephric) duct precursor to what?
male internal genitalia
- epididymis
- vas deferens
- urethra
Mullerian (paramesonephric) duct precursor to what?
female internal genitalia
- oviduct
- uterus
-cervix
development of male internal genitalia depends on the presence of what hormones
presence of testosterone
presence of anti-mullerian hormone
development of female internal genitalia depends on the absence of what hormones
absence of high testosterone
absence of anti-mullerian hormone
what cells secrete testosterone that allows development of Wolffian ducts
Leydig cells
what cells produce AMH resulting in regression of Mullerian ducts
Sertoli cells
external genitalia - precursor tissues are _____
bipotential - can develop into either male or female
what determines the masculinization of external genitalia
androgen dihydrotestosterone (DHT)
T converted to DHT via 5alpha-reductase
what does DHT direct the formation of
penis
scrotum
what determines the feminization of the external genitalia
absence of DHT = clitoris and labia
male genitalia (both internal and external) is dependent on what 3 hormones
testosterone
AMH
DHT
what has both ovarian and testicular tissue present?
what species is this most common in?
hermaphrodite
swine
what has testes + female external genitalia
male pseudohermaphrodite
what has ovaries + male external genitalia
female pseudohermaphrodite
what are characteristics of androgen resistance syndromes?
XY, bilateral testes, normal regression of mullerian ducts and normal secretion of T BUT have female external genitalia
2 forms of androgen resistance syndromes
- 5alpha-reductase deficiency
- androgen receptor dysfunction (underdeveloped Wolffian ducts)
what is freemartinism
- intersex female calf born co-twin to male
- requires anastomoses (so T and AMH go to female)
female fetus of freemartinism vs male fetus
hypoplastic ovaries
may contain seminiferous tubules
hypoplastic female external genitalia
wolffian duct derivatives present
infertile
male - minimally affected
what causes testicular descent into the scrotum
regression of gubernaculum (androgen dependent)
why are bilateral cryptorchids azoospermia (sterile)
elevated testicular temp
