Urogenital Development Flashcards
what gives rise to the permanent kidney
metanephros
where does the ureter derive from
mesonephric duct
where does the kidney derive form
caudal end of the urogenital plates
where does the collecting system of the kidney derive from
ureteric bud
where does the excretory system derive from
metanephric blastema
what does the cloaca divide to form? what derives from that structure?
divides to form the primitive urogenital sinus
bladder and pelvic urethra derives from it
what induces the development of the vesical trigone
kidneys ascent
what does the differentiation of the bladder produce?
the absorption of the mesonephric ducts into the bladder
what does the genital system derive from?
mesonephros and adjacent ducts
what does the mesonephros give rise to
a) mesonephric/wolffian duct
b) genital ridge
what is the mesonephric/wolffian duct
gives rise to the male genital ducts, requires androgens to develop, degenerates in females in response to low androgens levels
what is the genital ridge
gives rise to the testes or ovaries (the source of androgens and estrogens)
what does the mesodermal coelomic epithelium give rise to?
paramesonephric/mullerian duct
what is the paramesonephric/mullerian duct
gives rise to the female genital ducts, DOES NOT REQUIRE HORMONES TO DEVELOP, degenerates in males in response to mullerian inhibiting substance (MIS)
what happens in male embryos
indifferent gonads differentiate into testes under the influence of the SRY gene of the Y chromosome
what happens in female embryos
absence of a SRY gene results in dissociation of the primitive sex cords and differentiation of the gonad into ovaries
what do the efferent ducts derive from
mesonephric tubules
what do the epididymis, ductus deferens, ampullas and vesiculary glands derive from
mesonephric duct
what do the uterine tubes, uterus, and cranial region of the vagina derive from
paramesonephric duct
what do the caudal region of the vagina and vestibule derive from
urogenital sinus
what do the external genitalia derive from
mesenchymal cells that proliferate and surround the cloacal membrane
in males, induced by androgens, what do the genital tubercle and urogenital folds give rise to?
genital tubercle –> rise to erectile tissue and tunica albuginea of the penis
urogenital folds –> rise to the caudal region of the penile urethra
what does the cranial region of the urethra derive from
ectodermal cells at the tip of the penis
what do the genital swelling in the male give rise to
the scrotum
in females, induced by estrogens, what does the genital tubercle and the urogenital folds and genital swellings give rise to
genital tubercle –> clitoris
urogenital folds/genital swellings –> vulva
what does the female vestibule give derive from
urogenital sinus
what phases does the testis descent occur in and what is it caused by
1) intrabdominal
2) extraabdominal
caused by the gubernaculum
what is a gubernaculum
a band of mesenchymal tissue, extends from the caudal pole to the testes to the genital swellings
what occurs in the intrabdominal phase
depends more on INSL3
reduction of size/length of the gubernaculum
what occurs in the extra abdominal phase
depends more on androgens
2) increase in size/thickness of the gubernaculum
3) reduction of size/length of the gubernaculum
