book- reproductive system Flashcards
(15 cards)
site of nutrient and gas exchange between fetus and mother
placenta and umbilical cord
fetal portion vs maternal portion of the placenta comes from
fetal; chorionic sac
maternal; decidua functionalis (functional layer of endometrium)
female and male reproductive tract embryonic structures “ultimate overview”
mesoderm (epithelium), mesenchyme and primordial germ cells
germ cells
develop wk 4 in yolk sac; migrate out of handout and get incorporated into primary sex cords at wk 6
into secondary sex cords into oogonia
oogonia get covered by cuboidal epithelium to become primary follicles
when do female characteristics start to develop in embryo
wk 7
paramesonephric ducts (mullerian ducts)
what do the distal and proximal ends become?
develop lateral to mesonephric kidneys from invaginations of mesothelium
distal ends fuse to form uterovaginal primordium (ultimately divide into uterus and vagina)
proximal ends form ovarian tubes
xx vs xy
xx= female
xy=male
primary sex cords in males during embyro- what happens
have outer cortex and inner medulla; cortex will regress and medulla becomes testicular tissue via the Y chromosome
when does testosterone start developing from testes in embryo to develop male genitals
wk 7
descent of testis in embryo
During embryonic development, the testes descend from the posterior abdominal wall through the inguinal canal into the scrotum, guided by the gubernaculum.
mesonephric kidneys atrophy at wk 7 and gubernaculum form (attached to developing testis)
gabernacula guide testes down through inguinal canals
fully descend into scrotum at or after birth
leydig cells and sertoli cells in embryo
leydig: devleop ot of seminiferous tubules; secrete testosterone
sertoli: produce mullein inhibiting substance to block formation of female structure
spermatogonia from primordial germ cells also develop
mesonephric ducts (wolffian ducts) in male embryo become what
proximal to distal: epididymis, vas deferens, ejactulatory duct
lateral outgrowth become seminal vesicles
many outgrowths form prostate
male vs female reproductive tract embryo
what are the 2 ducts
Both sexes start with two paired ducts: the mesonephric (Wolffian) and paramesonephric (Müllerian) ducts.
In males, testosterone promotes Wolffian duct development (into vas deferens, epididymis, seminal vesicles), while Müllerian Inhibiting Substance (MIS/AMH) causes regression of the Müllerian ducts.
In females, absence of AMH and testosterone allows Müllerian ducts to develop into the fallopian tubes, uterus, cervix, and upper vagina, while the Wolffian ducts regress.
when does gonadal ridge form
wk 5
