Sertoli cell (sostenocyte): functions

The organs responsible for reproduction in men are called testicles. They produce sex cells - spermatozoa and hormones, for example, testosterone. The anatomical and histological structure of the testicles in men is complex, since these organs perform several functions at once. They carry out spermatogenesis - the formation and development of sex cells. Also, the testicles fulfill the endocrine function. They are located in a special dermal sac - the scrotum. There is maintained a special temperature, which is somewhat lower than in other parts of the body.

Eggs are ellipse-shaped, their size is about 4 cm in length and 3 in width. Normally, slight asymmetry of the sexual glands can be observed. Each testicle is divided by the membrane partitions into a number of lobules. They contain the convoluted seminal canals that form the testicular plexus. Its outflowing ducts enter the appendage of the testicle. There the main part of the sperm is formed - the head. Later - the channels enter the vas deferens, which is directed to the bladder. Further, they expand and penetrate another organ of the male reproductive system - the prostate. Before this, the canal forms into the vas deferens, which has an outlet in the urethra.

Histological structure of testicles in men

Male genital glands are composed of spermatic cord and interstitial tissue. Outdoors, they are covered with a white shell. It is represented by a dense connective tissue. The white membrane is attached to the organ. Side it thickens, forming a mediastinum of the testicle. At this point the connective tissue is divided into a number of strands. They form lobules, inside of which are convoluted tubules. They are represented by the following structural units:

1. Cage Sertoli is a sustenocyte. Together with other elements involved in the formation of the hemato-testicular barrier.
2. Cells due to which spermatogenesis is carried out.
3. Myofibroblasts. Another name for them is the peritubular cells. The main function of myofibroblasts is to ensure the advancement of seminal fluid through convoluted channels.

In addition, there is an interstitial tissue in the structure of the testicle. It is about 15%. Interstitial tissue is represented by elements such as Leydig cells, macrophages, capillaries, etc. If the convoluted channels are responsible for the formation of the sex cells, then there is the formation and production of male hormones.

Cage Sertoli: structure

Cells Sertoli have an elongated shape. Their size is about 20-40 microns. These are quite large structural units, which are called supporting cells differently. The cytoplasm of these elements contains many organelles. Among them:

1. Core. It has an irregular, sometimes pear-shaped form. Chromatin in the nucleus is distributed unevenly.
2. Smooth and rough EPS. The first - responsible for the production of steroid hormones, the second - provides protein synthesis.
3. Golgi apparatus. Thanks to this organelle, the final synthesis, storage and removal of products takes place.
4. Lysosomes - are involved in phagocytosis.
5. Microfilaments. These organelles are involved in the maturation of spermatozoa.

In addition, each Sertoli cell contains fatty inclusions. The base of the sustenocytes is located on the walls of the seminiferous tubules, and the apex - is turned into their lumen.

Sertoli cells: functions

The Sertoli cell is one of the constituent parts forming the convoluted seminiferous tubules. It is of great importance, since it participates in the process of spermatogenesis and the synthesis of male hormones. The following functions of Sertoli cells are distinguished:

1. Trophic. These elements provide immature spermatozoa with oxygen and nutrients.
2. Protective. Each cell has in the cytoplasm lysosomes - organelles involved in phagocytosis. They absorb and process degradation products, for example, dead fragments of spermatids.
3. Provision of a hemato-testicular barrier. This function is provided by tight intercellular contacts. Barrier is necessary to separate male sex cells from blood and substances contained in it. In addition, it prevents the penetration of antigens of spermatozoa into the plasma. This reduces the risk of autoimmune inflammation.
4. Endocrine function. Sertoli cells participate in the formation of sex hormones.

Sustenocytes are necessary for the formation and maintenance of a special environment in which spermatozoa develop favorably. It is known that the ion composition of Sertoli cells differs from the blood plasma. The concentration of sodium in them is lower, and the content of potassium, on the contrary, is increased. In addition, many biologically active substances are synthesized in Sertoli cells. Among them - prostaglandins, cytokines, follistatin, growth and fission factors, opioids, etc.

Functions and structure of Leydig cells

Leydig cells are part of the interstitial tissue of the testicle. Their size is about 20 μm. In the male sex glands, there are more than 200 * 10 ⁶ Leydig cells. The structural features of these elements are a large oval core and a foamy cytoplasm. It contains vacuoles containing the lipofuscin protein. It is formed during the decomposition of fats at the time of synthesis of steroid hormones. In addition, in the cytoplasm there are 1 or 2 nucleoli containing RNA and protein. The main function of Leydig cells is the production of testosterone. In addition, they are involved in the synthesis of activated. This substance stimulates the production of FSH in the brain.

What is Sertoli-cell syndrome?

One of the rare diseases of the male reproductive system is Sertoli-cell syndrome. The main manifestation of this pathology is infertility. The disease refers to congenital developmental anomalies, since it exhibits aplasia (a significant decrease or absence) of the embryonic testis tissue. As a result of this disorder, the seminiferous tubules do not develop. The only element that is not damaged is Sertoli's cage. Another name for this pathology is the del Castillo syndrome. Some of the Sertoli cells still undergo degeneration, however, most of them are normal. Despite this, the tubular epithelium is atrophied. Spermatozoa in this pathology are not formed.

Dysfunction of Leydig cells

When the cells of Leydig are damaged, their main function, the synthesis of testosterone, is disrupted. As a result, there are symptoms such as:

1. Decreased muscle mass.
2. Absence of secondary sexual characteristics (male-type haemorrhage, timbre of voice).
3. Violation of libido.
4. Decreased bone density.