Male Reproductive System

What is the male reproductive system?

The male reproductive system includes a group of organs that make up the reproductive system and urinary system in people assigned male at birth (AMAB).

The male reproductive system contains internal and external parts. Internal parts are inside your body, and external parts are outside your body. Together, these organs help you pee, have sexual intercourse and make biological children.

What does the male reproductive system do?

The organs that make up the male reproductive system perform the following:

• Produce, maintain and transport sperm cells and semen. Sperm cells are male reproductive cells. Semen is the protective fluid around sperm.
• Discharge sperm.
• Produce and secrete male sex hormones.

How does the male reproductive system function?

The entire male reproductive system depends on hormones. Hormones are chemicals that stimulate or regulate activity in your cells or organs. The primary hormones that help the male reproductive system function include:

• Follicle-stimulating hormone (FSH). Your pituitary gland makes FSH. FSH is necessary to produce sperm (spermatogenesis).
• Luteinizing hormone (LH). Your pituitary gland also makes LH. LH is necessary to continue the process of spermatogenesis.
• Testosterone. Testosterone is the main sex hormone in people AMAB. It helps you develop certain characteristics, including muscle mass and strength, fat distribution, bone mass and sex drive (libido).

What are the external parts of the male reproductive system?

Most of the male reproductive system is on the outside of your abdominal cavity or pelvis. The external body parts include your penis, scrotum and testicles. Other names for these parts are genitals or genitalia.

Penis

The penis is the male organ for sexual intercourse. It contains many sensitive nerve endings, and it has three parts:

• Root. The root is the base of your penis. It attaches to the wall of your abdomen.
• Body (shaft). The body has a shape like a tube or cylinder. It consists of three internal chambers: the two larger chambers are the corpora cavernosa, and the third chamber is the corpus spongiosum. The corpora cavernosa run side by side, while the corpus spongiosum surrounds your urethra. There’s a special, sponge-like erectile tissue inside these chambers. The erectile tissue contains thousands of spaces. During sexual arousal, the spaces fill with blood, and your penis becomes hard and rigid (erection). An erection allows you to have penetrative sex. The skin of your penis is loose and stretchy, which lets it change size when you have an erection.
• Glans (head). The glans is the cone-shaped tip of your penis. A loose layer of skin (foreskin) covers your glans. Healthcare providers sometimes surgically remove the foreskin (circumcision).

In most people, the opening of the urethra is at the tip of the glans. The urethra transports pee and semen out of your body. Semen contains sperm. You expel (ejaculate) semen through the end of your penis when you reach sexual climax (orgasm).

When your penis is erect, your corpora cavernosa press against the part of your urethra where pee flows. This blocks your pee flow so that only semen ejaculates when you orgasm.

What is a normal size of the penis?

Studies suggest that the average penis is about 3.5 inches (8.9 cm) when flaccid (soft) and a little more than 5 inches (13 cm) when erect.

Scrotum

Your scrotum is the loose, pouch-like sac of skin that hangs behind your penis. It holds your testicles (testes) as well as nerves and blood vessels.

Your scrotum protects your testicles and provides a sort of “climate-control system.” For normal sperm development, your testes must be at a temperature that’s slightly cooler than body temperature (between 97 and 99 degrees Fahrenheit or 36 and 37 degrees Celsius). Special muscles in the wall of your scrotum let it contract (tighten) and relax. Your scrotum contracts to move your testicles closer to your body for warmth and protection. It relaxes away from your body to cool them.

Testicles

Your testicles (testes) are oval-shaped organs that lie in your scrotum. They’re about the size of two large olives. The spermatic cord holds your testicles in place and supplies them with blood. Most people have two testicles, on the left and right side of their scrotum. Your testicles make testosterone and produce sperm. Within your testicles are coiled masses of tubes. These are the seminiferous tubules. The seminiferous tubules produce sperm cells through spermatogenesis.

Epididymis

Your epididymis is a long, coiled tube that rests on the back of each testicle. It carries and stores the sperm cells that your testicles create. Your epididymis also brings the sperm to maturity — the sperm that emerge from your testicles are immature and incapable of fertilization. During sexual arousal, muscle contractions force the sperm into your vas deferens.

What are the internal parts of the male reproductive system?

There are several internal (accessory) organs in the male reproductive system. They include:

Vas deferens

Your vas deferens is a long, muscular tube that travels from the epididymis into your pelvic cavity, just behind your urinary bladder. Your vas deferens transports mature sperm to the urethra in preparation for ejaculation.

Ejaculatory ducts

Each testicle has a vas deferens that joins with seminal vesicle ducts to form ejaculatory ducts. The ejaculatory ducts move through your prostate, where they collect fluid to add to semen. They empty into your urethra.

Urethra

The urethra is the tube that carries pee from your bladder outside of your body. If you have a penis, it also ejaculates semen when you reach orgasm.

Seminal vesicles

Your seminal vesicles are sac-like pouches that attach to your vas deferens near the base of your bladder. Seminal vesicles make up to 80% of your ejaculatory fluid, including fructose. Fructose is an energy source for sperm and helps them move (motility).

Prostate gland

Your prostate is a walnut-sized gland that rests below your bladder, in front of your rectum. Your prostate adds additional fluid to ejaculate, which helps nourish sperm. Your urethra runs through the center of your prostate gland.

Bulbourethral (Cowper) glands

Your bulbourethral glands are pea-sized structures on the sides of your urethra, just below your prostate. They create a clear, slippery fluid that empties directly into your urethra. This fluid lubricates your urethra and neutralizes any acids that may remain from your pee.

What are common conditions that affect the male reproductive system?

Common conditions that affect the male reproductive system include:

• Testicular cancer
• Penile cancer
• Prostate cancer
• Sexually transmitted infections (STIs)
• Premature ejaculation
• Male infertility
• Erectile dysfunction
• Priapism

What are common symptoms of male reproductive system conditions?

Common signs of conditions that affect the male reproductive system include:

• Lumps or sores on your external reproductive parts
• Pain or swelling
• Aching or discomfort around your groin or lower abdomen
• Blood in your semen (hematospermia)
• Blood in your pee (hematuria)
• Pain or burning when you pee (dysuria)
• Loss of bladder control (urinary incontinence)
• Inability to get and maintain an erection hard enough for sexual intercourse

What are common tests to check the health of the male reproductive system?

A healthcare provider may order the following tests to check the health of the male reproductive system:

• Physical examination
• Blood test
• Urine test
• Ultrasound
• X-ray
• Computed tomography (CT) scan
• Magnetic resonance imaging (MRI)
• Biopsy
• Digital rectal exam
• Prostate-specific antigen (PSA) test

Can a man go through menopause?

No, a man can’t go through menopause.

Menopause is when people assigned female at birth stop making reproductive hormones. One of the biggest changes after menopause is they stop menstrating and can't have biological children any more. In people AMAB, the testicles don’t lose the ability to make hormones. People AMAB may be able to make sperm well into their 80s or even longer.

However, subtle changes in how your testicles function can happen when you’re around 45. The changes can happen more dramatically after 70. Some people refer to this as “male menopause.” For many people AMAB, hormone production remains normal into their 60s and longer. Declining hormone function at an earlier age may be a side effect of another condition, like diabetes.

It’s not clear whether decreasing testicular function contributes to other symptoms, like erectile dysfunction, fatigue, weakness or depression.

Can “male menopause” be treated?

If your testosterone levels are low, hormone replacement therapy may help relieve some symptoms, including low sex drive, depression and fatigue. However, replacing male hormones can make prostate cancer worse. It can also make atherosclerosis worse.

Talk to a healthcare provider about all the pros and cons of hormone replacement therapy. Before starting, you should get a complete physical examination and laboratory tests.

How can you take care of the male reproductive system?

• Practice safe sex. Use condoms to help protect yourself against STIs.
• Perform self-examinations. Regularly examine your penis, scrotum and testicles for any changes.
• Get the human papillomavirus (HPV) vaccine. This vaccine helps protect you from HPV, which can cause penile cancer and genital warts.
• Consider circumcision. A circumcision reduces your risk of penile cancer.
• Don’t use tobacco products. Tobacco products increase your risk of developing cancers. If you smoke, ask a healthcare provider for tips to help quit smoking.
• Practice good hygiene. It’s a good idea to regularly clean your penis, scrotum and the surrounding areas with soap and warm water to help kill germs that cause infections. If you still have your foreskin, be sure to pull back your foreskin, clean the head of your penis and thoroughly dry the area.
• Get regular prostate exams. Prostate exams look for early signs of prostate cancer. You should get your first prostate exam by age 50. However, if you have a biological family history of prostate cancer, it’s a good idea to get your first prostate exam by 45.
• Maintain a weight that’s healthy for you. Ask your provider what a healthy weight means for you.
• Educate yourself about STIs. Learn about the signs and symptoms of STIs. The more you know, the better you can protect yourself and your partner(s).

Do men’s balls change with age?

As you age, your testicles (balls) may shrink, and your scrotum may hang lower.

A note from Cleveland Clinic

The male reproductive system includes many different organs. Many people think of their external organs, which include their penis, scrotum and testicles. However, the male reproductive system also includes many internal parts, including the urethra and prostate. Together, the parts that make up the male reproductive system involve sexual activity, reproduction and peeing. Your external reproductive organs might look different than someone else’s, and it’s natural for them to change slightly over time. However, if you have any symptoms or concerns about your genitals, talk to a healthcare provider.