Middle School Life Science: Reproductive Systems and Life Stages - Male Reproductive System — Flashcards

The male reproductive system has two main functions: producing sperm and releasing testosterone. Sperm are male gametes, or reproductive cells. Sperm form when certain cells in the male reproductive system divide by meiosis to form haploid cells. Being haploid means they have half the number of chromosomes of other cells in the body. An adult male may produce millions of sperm each day. Testosterone is the major sex hormone in males. Testosterone has two primary roles. During adolescence, testosterone causes most of the changes associated with puberty. In adulthood, testosterone is needed for the production of sperm.    
The male reproductive organs include the penis, testes, epididymis, vas deferens, and prostate gland. The penis is an external, cylinder-shaped organ that contains the urethra. The urethra is the tube that carries urine out of the body. It also carries sperm out of the body. The two testes (testis, singular) are oval organs that produce sperm and secrete testosterone. They are located inside a sac called the scrotum that hangs down outside the body. The scrotum also contains the epididymis. The epididymis is a tube that is about 6 meters (20 feet) long in adults. It is tightly coiled, so it fits inside the scrotum on top of the testes. The epididymis is where sperm mature. It also stores the sperm until they leave the body. The vas deferens is a tube that carries sperm from the epididymis to the urethra. The prostate gland secretes a fluid that mixes with sperm to help form semen. Semen is a whitish liquid that contains sperm. It passes through the urethra and out of the body.