Reproductive system

Sex determination

  • Dimorphic: we have to sexes that have distinct sexual organs
  • Gonads:
    • produce gametes ( sperm and eggs)
    • male gonads; testes produces sperm
    • female gonads; ovaries produce eggs
  • both have internal and external genitalia
  • Chromosomes
    • 46 chromosomes
    • 22 pairs of autosomes ( direct development on everything on body EXCEPT for sex organs)
    • 1 pair of sex chromosome ( are direly developed internal and external sex organs)
      • XX → female
      • XY → male

Sexual Differentiation

  • Bipotential tissue → before the diffretrtaio the embryonic tissue can be both developed into female or male
    • default is female
    • SRY gen( sex-determining region of the Y chromosome) inhibits female development and promotes male development
  • biopotential internal genitalia consists of 2 pairs of accery ducts
    • Wolffian duct (DER wolf) - proceed along male line
    • Müllerian duct( M- mädchen) - proceeds along feal line
  • Differentiation begins when the fetus is 6 weeks old
    • In males
    • they have the SRY gene that triggers bipotential gonads to develop testis
    • testes produce:
      • In Sertoli cells
      • anti-müllerian hormones which cuasen müllerian duct to dissapear
      • In Leydig cells
      • testosterone → DHT→ development of male external genitalia
      • testosterone coverts Wolffian duct into seminal vescöes, vas deferens and epididymis
    • In females
    • due to no inhibition, the bipotential gonads turn into ovaries
    • due to no testosterone, the Wolffian duct disappears
    • the müllerian duct natrauly development into the fallopian tube, uterus and upper part of the vagina
    • external genitatia develops into female

Gametogenesis

  • gametes in woman -→ eggs(oocytes) and we are born with them
  • games in woman-→ sperm are produced continuously over the lifetime

gamest relies on mitosis and mitosis and meiosis

  • mitosis → making an extant replica of cell with all 23 chromosome pairs
  • meiosis → splitting the pairs up to create haploid cell

Regulation of reproduction

  • In females and males
    • hypothalamus → Gonadotropin realising hormone(GnRH) to anterior Pituitary
    • Anterior pituitary → LH and FSH into circulation
    • In gonads ( testes or ovaries) LH stimulates sex hormone production
    • In gonads (testes or ovaries) FSH initiates/maintains gametogenesis
    • gonads can also porduce
      • inhibins → inhibit FSH
      • activins → stimulate FSH secretion