User:DevelopingBiologist

The sex cords are embryonic structures which eventually will give rise to the adult gonads (reproductive organs). They are formed from the genital ridges in the first 2 months of gestation which depending on the sex of the embryo will give rise to male or female sex cords. If there is a Y chromosome present, testicular cords will develop via the Sry gene (on the Y chromosome): repressing the female sex cord genes and activating the male. If there is no Y chromosome present the opposite will occur, developing ovarian cords.

Male Sex Cord Stuff
Once the genital ridge has committed to becoming male sex cords, Sertoli cells develop. These cells then induce the production and organisation of cells making up the testicular cords. These cords will eventually become the testes, which in turn produce hormones, in particular testosterone. These hormones drive the formation of the other male sex characteristics, and induce testicular descent (out of the abdomen). These hormones also cause the development of the male reproductive tract. Embryos are formed with wolffian and mullerian ducts, which will either become the male or female reproductive tract, respectively. In a male embryo, the testicular cords will induce the development of the wolffian duct into the vas deferens, epididymis and the seminal vesicle and cause the repression and regression of the mullerian duct. The other male sex organs (ex. the prostate) as well as external genitalia are also formed under the influence of testosterone.