The testes are important male reproductive organs. Normal males have two testes, located in the scrotum on the left and right sides respectively. The testes are superficially located and consist mainly of the white membrane and the testicular lobules within them. The interstitial cells of the testis provide nutrition and play a very important role in sperm production. The interstitial cells of the testis also secrete androgens, which are important for the maintenance of male secondary sexual characteristics.