The hypothalamus and pituitary gland secrete hormones that control the male and female reproductive systems. In males, luteinizing hormone causes the testes to secrete testosterone, which stimulates sperm production and the development of male sex characteristics. In females, luteinizing hormone and follicle-stimulating hormone stimulate the ovaries to secrete estrogen and progesterone, which regulate the menstrual cycle and development of female sex characteristics. Hormones also prepare the uterus for pregnancy and control its growth. Overall, hormones have important roles in regulating the development and functioning of both the male and female reproductive systems.