which hormone stimulates leydig cells to secrete testosterone
In a man, the testes, which produce sperm and testosterone, hang well outside the pelvis, in the scrotum. The hypothalamus secretes gonadotropic-releasing hormone (GnRH). This triggers the pituitary to release luteinizing hormone (LH) and follicle stimulating hormone (FSH), which both acts on the testis. LH stimulates Leydig cells to produce testosterone, which is responsible for spermatogenesis and male secondary sexual characteristics.