$A-$Testosterone, $B-$Sertoli cell, $C-$Inhibin. Hormonal Control of Spermatogenesis Spermatogenesis is initiated due to the increase in Gonadotropin Releasing Hormone $(GnRH)$ by hypothalamus. $GnRH$ acts on the anterior lobe of the pituitary gland to secrete Luteinising Hormone $(LH)$ and Follicle Stimulating Hormone $(FSH)$. LH acts on the Leydig cells of the testis to secreted testosterone.$FSH$ acts on the sertoli cells of the seminiferous tubules of the testis to secrete an androgen binding protein $(ABP)$ and inhibin. $ABP$ concentrates testosterone in the seminiferous tubules. Inhibin suppresses $FSH$ synthesis. $FSH$ act on spermatogonia to stimulate sperm production