Final answer:
The initiation of hormone secretion from the ovaries and testes is caused by the release of GnRH from the hypothalamus, which then stimulates the anterior pituitary to secrete FSH and LH, regulating the maturation of the gonads.
Step-by-step explanation:
The initiation of hormone secretion from the ovaries and testes is triggered by the hypothalamus releasing gonadotropin-releasing hormone (GnRH) during puberty. GnRH then stimulates the anterior pituitary gland to produce two key hormones: follitropin, commonly known as follicle-stimulating hormone (FSH), and lutropin, commonly known as luteinizing hormone (LH). FSH and LH travel through the bloodstream to the ovaries and testes where they stimulate the maturation of the gonads and the beginning of gamete production, which includes spermatogenesis in males and ovulation in females.
FSH stimulates the Sertoli cells in the testes and is involved in the maturation of ovarian follicles, while LH stimulates the Leydig cells in the testes to produce testosterone and triggers ovulation and the production of estrogen in females.