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.
About the male reproductive system
The reproductive systems are the unique organ systems in each gender that allow humans to create further generations. The male reproductive system is responsible for the production, nourishment and transport of sperm. Male reproductive structures are located both inside and outside the pelvis.
The scrotum is the pouch of skin located outside the pelvis that houses many structures of the male reproductive system. The purpose of the scrotum is to maintain the proper temperature for the production of sperm, which must be kept lower than regular body temperature. The scrotum regulates temperature by changing in size. It gets smaller and tighter when it is cold, in order to retain body heat. It gets larger and looser when it is warm, to release excess body heat.
The testicles, or testes, are the two oval-shaped organs located inside the scrotum. In an adult man, these gonads are around 2 inches (about 5 centimeters) long and about 1 inch (around 3 centimeters) wide. They normally descend from the pelvic cavity into the scrotum before birth. Structures inside the testicles called the seminiferous tubules produce sperm. The testicles are also part of the endocrine system, because they produce male sex hormones (androgens), such as testosterone.
The duct system is a series of ducts that the sperm and semen pass along between the testicles and the urethra. The epididymis is a coiled tube that connects the testicles and the vas deferens. There are two of these – one for each testicle. This is where sperm mature and are stored. The vas deferens is the tube that transports sperm-filled semen to the urethra.
The accessory glands 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 seminal vesicles connect to the vas deferens, near the bladder. The prostate gland surrounds the part of the urethra below the bladder. The urethra is also part of the urinary system. It runs through the length of the penis and is the passage through which urine and semen are expelled from the body at different times.
The penis is composed of an expandable sponge-like tissue. It may vary in size and appearance greatly from one body to another, and in different developmental stages. Despite numerous advertising claims, no special exercises, diets or dietary supplements can alter the size of the penis.
The penis is composed of the shaft, glans and foreskin. The shaft is the long, cylindrical body of the penis. The glans, which is also called the head, is the cone-shaped tip of the penis. The opening of the urethra is normally located at the tip of the glans. The foreskin (prepuce) is the fold of skin that covers the glans.
About circumcision
Circumcision is the removal of the foreskin of the penis by a physician or member of the clergy. It is the parents’ decision to circumcise or not to circumcise their child. The decision may be based on reasons of religious beliefs, social or cultural issues. It is most commonly performed on newborns but may also be done at a later age. However, a newborn needs to be healthy to be circumcised. For this reason, premature infants are frequently not circumcised or are circumcised at a later age. Circumcision is not a medically necessary procedure.
According to the American Academy of Pediatrics (AAP), the practice of circumcision is uncommon in Asia, Latin America and most of Europe. It is also uncommon in Canada. It is much more common in the United States. The AAP reports that, within America, circumcision is more common among whites than among blacks or Hispanics.
Circumcision does cause pain. However, local anesthesia is safe for infants and effective in reducing the pain associated with the procedure. Older boys require general anesthesia during circumcision. The procedure is associated with some complications, and the risk of complications is unknown. According to the AAP, excessive bleeding is the most common complication. Other potential complications include infection, problems with the urethra and scarring.
Function of the male reproductive system
The primary role of the reproductive system – whether male or female – is to create a new generation and further propagate human life. The male reproductive system is required to produce and supply the sperm to fertilize the egg (ova). The sperm and egg contain the genetic material of the parents, which combine to form the genetic blueprint of the fetus.
The male reproductive system, along with the pituitary gland in the brain, is responsible for the production of male sex hormones (androgens), including testosterone. These hormones are a crucial part of puberty. It is not until after puberty that reproduction is possible. Though the age that puberty begins varies widely between individuals, it generally starts at some point between the ages of 10 and 14 years. However, some children experience puberty earlier than their peers (precocious puberty). During puberty, the reproductive organs mature and increase in size and pubic hair begins to grow in the groin region.
It takes about 72 days for a sperm cell to develop into sperm. After puberty, millions of sperm are produced in the seminiferous tubules every day. They continue to develop and mature in the epididymis, in a process that takes about 15 to 25 days. Sperm are about 1/600 of an inch (about 0.05 millimeters) long. They are composed of a spherical head, which contains genetic information, and a slender tail used to move the sperm through the male and female reproductive systems. If enough time passes and the sperm are not ejaculated, they die and are reabsorbed by the body.
Most of the time, the penis is flaccid (limp). However, 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. Erections go away after ejaculation or on their own. They are frequently caused by sexual arousal but may occur for no particular reason, especially during puberty. They may occur many times during REM (rapid eye movement) sleep. Sometimes, ejaculation may also occur during sleep. This is called nocturnal emissions, or “wet dreams.”
During ejaculation, mature sperm are pushed from the epididymis through the vas deferens and urethra. At the same time, the accessory glands secrete the fluids that make up the bulk of semen. These fluids and the sperm mix and are expelled from the body through the penis. Between 0.05 and 0.2 fluid ounces (1.5 to 6.0 milliliters) of semen, including between 75 million and 900 million sperm, are released from the penis during ejaculation.
When ejaculation occurs inside the vagina, the sperm travel through the cervix and uterus and into the fallopian tubes. If intercourse is not protected using contraception, then when a sperm encounters an egg in a fallopian tube it may fertilize the egg, producing a zygote. A sperm can survive in the uterus for up to two days while waiting for an egg.
Conditions of the male reproductive system
There are a number of conditions that may affect the male reproductive system of children and adolescents. If a child or adolescent displays any signs of symptoms of any condition affecting his reproductive system, a visit to a pediatrician is warranted. Adolescent boys also benefit from regular testicular exams and self-exams.
Testicular self-examinations are a useful way to check for testicular cancer and other abnormalities. These are generally recommended once every month for adolescent males who are near or have entered puberty. Regular exams help the adolescent recognize what is normal, so that he can more easily detect abnormalities. During a testicular self-exam, the testicles are gently rolled between the fingers, one at a time. A physician can instruct an adolescent in how to perform a testicular examination. Any lumps, swellings, or changes in color or size, as well as any groin pain, need to be reported to a physician.
Although testicular cancer is rare in adolescents, it is the most common form of cancer affecting males between 15 and 35 years of age, according to the American Academy of Family Physicians(AAFP). Testicular cancer can also develop in younger boys and in older men. It can nearly always be cured when caught and treated early.
The testicles are very sensitive. Even minor trauma can result in severe pain, as well as bruising and/or swelling. Examples of testicular trauma include striking, hitting, kicking or crushing the testicles, as may occur due to sports injuries. Testicular torsion occurs when a testicle twists around. This can cut off the blood supply to the testicle and generally requires surgery. Irreversible damage can occur without treatment within 12 hours.
Sexually transmitted diseases (STDs) are infectious diseases that are typically spread through sexual contact. The United States has high rates of STDs, which can often be prevented by the use of male condoms during sexual intercourse. There are a large number of STDs, including:
Gonorrhea
Chlamydia
Genital herpes
Human papilloma virus (HPV), which may cause genital warts
Trichomoniasis
Human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS)
Syphilis
Other conditions that may affect the male reproductive system include:
Cryptorchidism (undescended testicle). Failure of one or both testicles to lower from the pelvic cavity into the scrotum before birth. This condition is more common in boys born prematurely. Hormonal injections or surgery may be needed if the testicles have not descended by age 1. Cryptorchidism increases the risk of infertility and testicular cancer.
Inguinal hernia. Occurs when a portion of the intestines pushes through an abnormal opening or weakening of the abdominal wall and into the groin or scrotum. The hernia may look like a bulge or swelling in the groin area. The condition is more common in boys with birth defects (e.g., cystic fibrosis, cryptorchidism) or those born prematurely. It requires surgical intervention.
Varicocele. A swollen (varicose) vein near the testicle. Common during puberty, varicoceles generally cause no problems but may reduce sperm production or damage a testicle in some males.
Hydrocele. The collection of fluid around the testicles. Though usually painless, it may cause swelling. The condition may require surgical intervention.
Epididymitis. Inflammation of the epididymis due typically to an infection, such as by the STD chlamydia. Symptoms include pain and swelling.
Urethritis. Inflammation of the urethra, often caused by an STD. Symptoms include painful urination.
Prostatitis. Inflammation of the prostate gland, often because of an STD or other bacterial infection. Symptoms include painful urination. The other common prostate conditions (prostate cancer and prostate enlargement) are associated with middle and old age.
Orchitis. Inflammation of one or both testicles, often caused by an STD.
Penile inflammation. Inflammation of the penis. Symptoms include redness, itching, swelling and pain. A few types of penile inflammation include inflammation of the glans (balanitis) and inflammation of the foreskin (posthitis). A combination of the two types of penile inflammation, known as balanoposthitis, often occurs in uncircumcised males.
Phimosis. Occurs when the foreskin is too tight. It does not generally require treatment, but if it causes complications it may be treated with medications or circumcision surgery.
Paraphimosis. Occurs when the foreskin is retracted behind the sulcus (the groove behind the glans) and cannot be pulled back over the glans. Paraphimosis can be corrected by lubricating the glans and foreskin and then gently trying to push the tight foreskin over the sulcus. The condition rarely requires surgery.
Priapism (painful erection lasting four hours or more). Causes include spinal cord disorders, sickle cell anemia and STDs.
Birth defects. Structural defects present at birth. Examples include hypospadias (urethral opening located on the underside of the penis), ambiguous genitalia (genitalia that are not obviously male or female), and micropenis (significantly below average penis size).
Questions for your doctor on the male system
Preparing questions in advance can help patients and parents have more meaningful discussions with their physicians regarding their or their child’s treatment options. The following questions related to the male reproductive system may be helpful:
Is my son healthy enough to be circumcised?
What risks and benefits of circumcision should I be aware of?
I’ve heard that circumcision reduces the risk of penile cancer. How common is this cancer?
Does my/my son’s reproductive system appear to be developing normally?
Is it normal for me/my son to begin puberty at my/his age?
How are my/my son’s hormones affecting me/him at this stage of development?
What can I/my son do to keep my/his reproductive system healthy?
Do you recommend testicular self-exams for me/my son?
How often should I/my son have a physical examination from a doctor?
Can you recommend ways I can discuss sexual intercourse, sexually transmitted diseases and pregnancy with my son?
Can you recommend any local resources that may help me discuss sexuality with my son?
Is it normal for me/my son to get frequent erections and have frequent wet dreams?
Can you recommend any local resources or support groups that deal with adolescent pregnancy?
