Write a brief note on hormonal regulation of spermatogenesis.

In human male reproductive system, The onset of puberty, hypothalamus begins secreting high pulses of GnRH, or gonadotropin-releasing hormone. In response, the pituitary gland releases follicle stimulating hormone (FSH) and luteinizing hormone (LH) into the male system for the first time. FSH enters the testes, stimulating the sertoli cells, which help to nourish the sperm cells that the testes produce, to begin facilitating spermatogenesis. LH also enters the testes, stimulating the interstitial cells, called leydig cells, to make and release testosterone into the testes and the blood.