Explain Human-male reproductive system. With diagram.

The primary male reproductive organ is a pair of testes. The testes lies in small sac like muscular structure outside the abdominal cavity called *******. ******* provides an optimal temperature for formation of sperm. This temperature is 1-3oC lower than the temperature of the body. The function of testes is to produce sperms and the male hormone (testosterone). Testes form sperms throughout the reproductive life (puberty stage onwards) of man. From each of the testis arises a long tube called vas deferens. It unites with a duct coming from the urinary bladder to form a common tube called urethra. The urethra is enclosed within a thick muscular organ, called *****, and opens to the outside through a male genital pore. There is only one opening for the urine and sperms.