Testicles: Basic Knowledge

This is a sensitive part of men. The testicles are an important structure. It secretes the male hormone, which determines the physiological sex of a person. In addition, it also produces sperm, a type of cell that helps humans reproduce and maintain the breed. This article will help you better understand this part, structure and function. In addition, common related diseases will also be mentioned.


1. What are testicles?

These are two oval-shaped organs in the male reproductive system. They are contained in a pouch of skin called the scrotum. The scrotum hangs outside the body in front of the pelvis, above the thigh, and just below the penis .

The structures inside the testicles are important for the production and storage of sperm until they are mature enough to ejaculate. It also produces a hormone called testosterone. This hormone is responsible for sex drive, fertility, and the development of muscle and bone mass.

2. Structure and function

Its main function is to produce and store sperm. They are also important for making the hormone testosterone and other male hormones called androgens.

The testicles are ovoid in shape from many constitutive tissues, each of which is called a lobule. The lobules are made up of coiled tubules surrounded by dense connective tissue.

>> There are many diseases that affect testicular health. Read more article: Itchy testicles: Causes, symptoms and treatment .

Testicles: Basic Knowledge

Cross-sectional structure of the testicle

Testicles consist of left and right. However, the left testicle is usually lower and smaller than the right. In most cases, it has an average length of about 4.5 cm; 2.5 cm wide; about 1.5 cm thick and about 20 g in weight. The internal structure of this division is divided into about 300-400 lobules. The function of this part is to produce sperm and guide sperm into the seminiferous tubules, then into the seminal vesicles and finally to the epididymis.

Semicircular canal (also called seminiferous tubule)

The semicircular tubes are the coiled tubes that make up most of each testicle. The cells and tissues in the seminiferous tubules are responsible for spermatogenesis, also known as spermatogenesis.

These tubes are lined with a layer of tissue called the epithelium. This layer is made up of Sertoli cells that aid in the production of the hormones that make sperm. Among the Sertoli cells, there are spermatocytes that divide and become spermatozoa.

The tissues next to the tubes are called Leydig cells. These cells produce male hormones, such as testosterone and other androgens.


After sperm are produced in the semicircular tubules, the sperm cells move toward the epididymis through the seminal vesicles. This structure helps to mix the sperm cells in the fluid secreted by the Sertoli cells. The body reabsorbs this fluid as sperm cells travel from the seminiferous tubules to the epididymis.

Before sperm can reach the epididymis, they cannot move. Millions of tiny hairs in the testicles, called microvilli, move to help move sperm to the ejaculatory ducts.

Output tubes

The ejaculatory ducts are a series of tubes connecting the testicles to the epididymis. The epididymis will store sperm cells until they are mature and ready to ejaculate.

These ducts are lined with tiny hairs called cilia. Along with a layer of muscle underneath, the cilia help move sperm into the epididymis.

The ejaculatory ducts also absorb most of the fluid that helps move the sperm cells. This results in higher sperm concentration during ejaculation.

The shells of the testicles

This part is surrounded by many layers, from outside to inside, including:

  • Peritoneal layer.
  • White shell.
  • Circuit board.

Testicles: Basic Knowledge

Structure of classes

In particular, the vascular capsule is the first thin layer of blood vessels, protecting and shielding the layers below.

Then there's the white crust. This is a thick, dense, fibrous protective layer that protects the testicles.

The peritoneum is divided into 2 smaller layers. Going from outside to inside is:

  • Wall layer: Almost completely protects testicles.
  • Visceral layer: Located just above the white crust.

3. Medical conditions related to testes

Hydrocele (hydrocele)

Hydrocele occurs when excess fluid builds up in the cavities around one of your testicles. This is sometimes seen after birth, but can also be due to trauma or inflammation.

Testicles: Basic Knowledge

Testicular effusion

Hydrocele symptoms include:

  • Swollen testicles are more noticeable during the day.
  • Dull pain in your scrotum.
  • Feeling heavy in your scrotum.

These effusions usually do not require treatment unless they are very large or painful. Most will go away on their own, but more severe cases may require surgical removal.

Testicular torsion

Testicular torsion means that your testicles have rotated in the scrotum. This can constrict blood vessels leading to cutting off blood supply, nerve function and sperm transport.

Testicles: Basic Knowledge

Twisted testicles

Symptoms include:

  • Severe scrotal pain.
  • Testicle swelling.
  • Lower abdominal pain.
  • Feeling dizzy.
  • Vomiting.
  • Urinating more than usual.

Some possible causes of testicular torsion include:

  • Scrotal injury.
  • Exercise too long or hard.
  • Exposure to cold temperatures.
  • Free movement of the testicles in the scrotum due to an inherited condition.

The doctor can treat it by manually rotating the scrotum. In some cases, surgery may be necessary to remove the torsion of the spermatic cord.


Orchitis is a condition that causes it to become swollen or inflamed. Like epididymitis, it is usually caused by an infection caused by an STI (sexually transmitted infection).

Orchitis symptoms include:

  • Pain.
  • Swollen testicles.
  • Fever.
  • Feeling dizzy.
  • Vomiting.

Both bacterial and viral infections ( mumps are common) can cause inflammation. Combining antibiotics or antivirals, along with anti-inflammatory medications or cold compresses can help relieve discomfort and pain. The disease usually disappears after 7-10 days.

Hypogonadism (Hypogonadism)

Hypogonadism occurs when your body doesn't produce enough testosterone. It could be due to a testicle problem or because your brain isn't stimulating hormone production properly.

You may be born with this condition. It can also occur due to an injury, infection, or other condition that affects testosterone production.

Symptoms of hypogonadism vary by age:

In infants

The genitals may not be clearly male, or there may be both genitals (both male and female).

In teenagers

Symptoms may include:

  • Lack of muscle development.
  • The body grows less hair.
  • No deep voice.
  • Abnormal growth of the arms and legs relative to the rest of the body.

In an adult

Symptoms may include:

  • Infertility.
  • Loss of body hair.
  • Growth of breast tissue.
  • Osteoporosis .
  • Inability to get an erection.

Hypogonadism is usually treated with hormone replacement therapy. It targets the brain or testicles, depending on the cause of low testosterone production.

Testicular cancer

Cancer occurs when cancer cells multiply in the tissue of the testicle. It usually begins in the seminiferous tubules (the site that helps produce sperm).

The cause of cancer is not always clear.

Symptoms of testicular cancer may include:

  • A tumor in your testicle.
  • Feeling heavy in your scrotum.
  • Fluid in the scrotum.
  • Scrotal pain.
  • Abdominal or back pain.

Testicles: Basic Knowledge

This disease is an obsession with men

Sometimes, your doctor may surgically remove the affected tissue. In other cases, you may have to have the entire testicle removed. Radiation therapy or chemotherapy can also help kill cancer cells.

4. Conclusion

The testicles are a very important organ. It determines the physiological sex as well as helps in the production of sperm. It is composed of many seminiferous tubules and is surrounded by several layers. There are many diseases that affect this part of the body and can sometimes lead to infertility.

Doctor Nguyen Doan Trong Nhan

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