The male reproductive system includes both internal and external parts. Its primary functions are to:

  • produce and transport semen, which contains sperm
  • release sperm into the female reproductive tract during sex
  • make male sex hormones, such as testosterone

Have you ever wondered what the different parts of the male genitalia are and what they do? Continue reading to learn more about the individual parts of the male genitalia, their function, and more.

Let’s begin by outlining the various parts of the male genitalia. We’ll then explain their functions in a later section.


The penis is an external part of the male reproductive system and is cylindrical in shape.

Its size can vary from person to person, but on average it’s about 3.6 inches long when flaccid (not erect) and 5 to 7 inches long when erect.

The penis has three different parts:

  • Glans. Also called the head or tip of the penis, the glans is very sensitive and contains the opening of the urethra. In some men, a fold of skin that’s called the foreskin may cover the glans.
  • Shaft. This is the main body of the penis. The shaft contains layers of erectile tissue. This tissue becomes engorged with blood when a man is aroused, causing the penis to become firm and erect.
  • Root. The root is where the penis attaches to the pelvic area.


Like the penis, the scrotum is an external part of the male genitals. It’s a sac that hangs just behind the root of the penis. The scrotum contains the testicles and the ducts associated with them.


Men have two testicles, which are contained within the scrotum. Each testicle is oval in shape and is connected to the rest of the male reproductive tract via a duct called the epididymis.

Duct system

Many areas of the male reproductive system are connected via a series of ducts. These include the:

  • Epididymis. The epididymis is a coiled tube that connects the testicle to the vas deferens. One epididymis runs along the back of each testicle.
  • Vas deferens. The vas deferens is a long tube that connects to the epididymis. Each epididymis has its own vas deferens. The vas deferens in turn connects to ejaculatory ducts.
  • Ejaculatory ducts. The ejaculatory ducts connect to the vas deferens and small pouches called the seminal vesicles. Each ejaculatory duct empties into the urethra.
  • Urethra. The urethra is a long tube that has connections with both the ejaculatory ducts and the bladder. It runs through the prostate gland and penis and opens at the glans.

Prostate gland

The prostate gland is located internally just below the bladder. It’s about the size of a walnut.

Bulbourethral glands

These two small glands are found internally around the root of the penis. They’re connected to the urethra via small ducts.

Now let’s explore the functions of each part of the male genitals.


The penis has important functions for both the male reproductive tract and urinary tract:

  • Reproduction. When a man is aroused, the penis becomes erect. This allows it to enter the vagina during sex. During ejaculation, semen comes out of the tip of the penis.
  • Urinating. When the penis is flaccid, it can expel urine from the body.


The scrotum serves two functions:

  • Protection. The scrotum surrounds the testicles, helping to keep them protected from injury.
  • Temperature control. Sperm development is sensitive to temperature. Muscles around the scrotum can contract to bring the scrotum closer to the body for warmth. They can also relax to move it away from the body, reducing its temperature.


The functions of the testicles include:

  • Sperm production. Sperm, the male sex cells that fertilize the female egg, are produced in the testicles. This process is called spermatogenesis.
  • Making sex hormones. The testicles also produce the male sex hormone testosterone.

Duct system

Each duct of the male reproductive system has a specific function:

  • Epididymis. Sperm that are produced in the testicle move to the epididymis to mature, a process that takes about 12 days. Mature sperm are also stored in the epididymis until sexual arousal occurs.
  • Vas deferens. During arousal, mature sperm move through the vas deferens and to the urethra in preparation for ejaculation. (It’s the two vas deferens ducts that are cut during a vasectomy.)
  • Ejaculatory ducts. The seminal vesicles empty a viscous fluid into the ejaculatory ducts, which combines with sperm. This fluid contains components that give the sperm energy and stability. Fluid from the seminal vesicles makes up about 70 percent of semen.
  • Urethra. During ejaculation, semen exits the urethra through the tip of the penis. When the penis is flaccid, urine can exit the body via this duct.

Prostate gland

The prostate also contributes fluid to semen. This fluid is thin and milky in color. It contains components that help with sperm motility and stability.

Prostatic fluid also makes semen thinner, allowing sperm to move more efficiently.

Bulbourethral glands

The bulbourethral glands release a fluid into the urethra that provides lubrication and also neutralizes any residual urine that may be present.

Now that we’ve discussed the different parts of the male genitalia and how they function, let’s examine some of the common conditions that can affect this area of the body.

Sexually transmitted infections (STIs)

Some of the STIs that can affect the male reproductive system include:

Many times, these infections are asymptomatic, meaning there aren’t any symptoms.

When symptoms are present, they may include:

  • discharge from the penis
  • swelling or discomfort of the genitals
  • lesions in the genital area

Consult with your doctor if you’re experiencing symptoms of an STI.

Foreskin problems

Uncircumcised men can experience problems involving the foreskin. These can include phimosis and paraphimosis.

Phimosis results from the foreskin being too tight. It can cause symptoms like pain, swelling, and redness around the tip of the penis.

Paraphimosis occurs when the foreskin can’t return to its normal position after being pulled back. This is a medical emergency. Along with the symptoms of phimosis, someone with paraphimosis can have restricted blood flow to their penis.

See your doctor if you have either of these conditions.

Enlarged prostate

An enlarged prostate is a common condition in older men. It’s a benign condition, meaning that it isn’t cancerous. It’s unknown what causes an enlarged prostate, but it’s believed to happen due to factors related to aging.

Some of the symptoms of an enlarged prostate are:

  • increase in urinary urgency or frequency
  • a weak urine stream
  • pain after urination

Treatment can include:

  • lifestyle adjustments
  • medications
  • surgery


Priapism is a long-lasting, painful erection. It happens when blood becomes trapped in the penis. A variety of things can lead to priapism, including:

  • certain underlying health conditions
  • specific medications
  • injury to the penis

Priapism is a medical emergency that requires immediate attention. If it’s allowed to persist, it can lead to scarring of the penis and potentially erectile dysfunction.

Peyronie’s disease

Peyronie’s disease is a condition that results in scar tissue accumulating in the penis. This causes the penis to curve, which may be more noticeable when the penis is erect.

While it’s unknown what causes Peyronie’s disease, it’s believed to occur as a result of injury to the penis or damage from an autoimmune disease.

Treatment is typically recommended when pain is present or curvature interferes with sex or urination.

Male reproductive cancers

Cancer can develop in many parts of the male reproductive tract. Types of male reproductive cancer include:

Possible symptoms include pain, swelling, and unexplained lumps or bumps. It’s important to note that symptoms can vary based on the location of the cancer.

Some risk factors are associated with the development of male reproductive cancers. Examples include:

Talk to your doctor about any concerns you may have about male reproductive cancers.

Premature ejaculation

Premature ejaculation happens when you’re unable to delay your ejaculation. When this happens, you ejaculate earlier than either yourself or your partner would like.

It’s not known what causes premature ejaculation. However, it’s believed to happen due to a combination of physiological and psychological factors.

There are a wide variety of treatments available, such as pelvic floor exercises, medications, and counseling.

Erectile dysfunction (ED)

A person with ED can’t get or maintain an erection. A variety of things can contribute to the development of ED, including:

  • underlying health conditions
  • certain medications
  • psychological factors

ED can be treated with medications that help to increase blood flow to the penis. Some that you may be familiar with include sildenafil (Viagra) and tadalafil (Cialis).


Infertility can also affect men. Possible causes of infertility in men include:

Additionally, certain factors can increase a man’s risk of infertility. Following are a few examples:

  • smoking
  • excess weight
  • frequent exposure of the testicles to high temperatures

It’s always a good idea to talk to your doctor if you have any questions or concerns regarding your reproductive health.

Additionally, plan to make an appointment with your doctor if you notice:

  • abnormal discharge from your penis
  • pain or a burning feeling when you urinate
  • bumps, sores, or lesions in your genital area
  • unexplained pain, redness, or swelling in the area of your pelvis or genitals
  • changes in urination, such as a weak urine stream or increased frequency and urgency of urination
  • curvature of your penis that’s painful or interferes with sex
  • an erection that’s prolonged and painful
  • changes in your libido or your ability to get or maintain an erection
  • problems with or changes in ejaculation
  • problems conceiving after 1 year of trying

The male genitals have many parts. Some are external, such as the penis and scrotum. Others are inside the body, such as the testicles and prostate.

The male genitals have several functions. These include sperm production, making male sex hormones, and depositing sperm into the female reproductive tract during sex.

There are a variety of conditions that can impact the male genitals. Examples include STIs, enlarged prostate, and erectile dysfunction.

If you have questions about your reproductive health or notice concerning symptoms, make an appointment with your doctor to discuss them.