The male reproductive system is the organ system in boys responsible for helping to maintain the reproductive cycle in humans. The scrotum is the pouch of skin on the outside of the pelvis that maintains the proper temperature for the production of sperm. The testicles, located inside the scrotum, produce sperm and male sex hormones, including testosterone.

The duct system (e.g., epididymis, vas deferens) is a series of thin tubes that transport the sperm and semen between the testicles and the urethra. The accessory glands (e.g., seminal vesicles, prostate gland) are the organs that produce most of the fluids that make up the semen. These fluids nourish the sperm and lubricate the duct system. The urethra is the tube that runs through the penis through which the semen (and urine) is expelled from the body. The penis is composed of an expandable sponge-like tissue. It includes the shaft (body), glans (head) and foreskin. The foreskin is the layer of skin that covers the glans.

Circumcision is the surgical removal of the foreskin of the penis by a physician or member of the clergy. The decision may be based on religious beliefs or social or cultural issues. It is most commonly performed on newborns but may also be done at a later age. Circumcision is not a medically necessary procedure.

After puberty, millions of sperm are produced in the seminiferous tubules of the testicles every day. They continue to develop and mature in the epididymis. During ejaculation, mature sperm are pushed from the epididymis through the vans deferens and urethra, where they mix with fluids to produce semen.

During an erection, the sponge-like tissue inside the penis fills with blood. This causes the penis to become stiff and erect, making insertion during sexual intercourse easier. When ejaculation occurs inside the vagina, the sperm travel through the cervix and uterus and into the fallopian tubes. If a sperm meets with an egg in a fallopian tube, it may fertilize the egg, producing a zygote.

There are a number of conditions that may affect the reproductive system of male children and adolescents. If a child or adolescent displays any signs or symptoms of any condition affecting his reproductive system, a visit to a pediatrician is warranted.