The organs responsible for reproduction in men are called the testes. They produce sex cells - sperm and hormones, such as testosterone. The anatomical and histological structure of the testicles in men is complex, as these organs perform several functions at once. They carry out spermatogenesis - the formation and development of germ cells. The testes also have an endocrine function. They are located in a special skin sac - the scrotum. A special temperature is maintained there, which is slightly lower than in other parts of the body.
The testicles are elliptical in shape, their size is about 4 cm in length and 3 in width. Normally, slight asymmetry of the gonads may be observed. Each testicle is divided by the walls of the membrane into many lobules. They contain convoluted seminal channels forming the testicular plexus. Its efferent ducts enter the epididymis. The main part of the sperm is formed there - the head. Later - the channels enter the vas deferens, which goes to the bladder. Further, they expand and penetrate through another organ of the male reproductive system - the prostate. Before this, the channel is formed into the vas deferens, which has an outlet in the area of the urethra.
The histological structure of the testicles in men
The male sex glands are composed of spermatic cords and interstitial tissue. Outside they are covered with a protein shell. It is represented by dense connective tissue. The protein membrane is spliced with the organ. On the side, it thickens, forming a mediastinum of the testicle. At this point, the connective tissue is divided into many strands. They form lobules, inside of which there are convoluted tubules. They are represented by the following structural units:
- Sertoli Cell - Sustentocyte. Together with other elements, it is involved in the formation of a blood-testicular barrier.
- Cells due to which spermatogenesis is carried out.
- Myofibroblasts. Their other name is peritubular cells. The main function of myofibroblasts is to ensure the movement of seminal fluid along convoluted channels.
In addition, the structure of the testicle has interstitial tissue. It is about 15%. Interstitial tissue is represented by such elements as Leydig cells, macrophages, capillaries, etc. If convoluted channels are responsible for the formation of germ cells, then the formation and production of male hormones occurs.
Sertoli Cell: Building
Sertoli cells have an elongated shape. Their size is about 20-40 microns. These are quite large structural units, which are also called supporting cells. The cytoplasm of these elements contains many organelles. Among them:
- Nucleus. It has an irregular, sometimes pear-shaped. Chromatin in the nucleus is unevenly distributed.
- Smooth and rough EPS. The first - is responsible for the production of steroid hormones, the second - provides protein synthesis.
- Golgi apparatus. Thanks to this organelle, the final synthesis, storage and elimination of products takes place.
- Lysosomes - are involved in phagocytosis.
- Microfilaments. These organelles are involved in sperm maturation.
In addition, each Sertoli cell contains fatty inclusions. The base of the Sustentocytes is located on the walls of the seminiferous tubules, and the apex is turned into their lumen.
Sertoli Cells: Features
Sertoli cell is one of the constituent parts that form the convoluted seminiferous tubules. It is of great importance, since it is involved in the process of spermatogenesis and the synthesis of male hormones. The following functions of Sertoli cells are distinguished:
- Trophic. These elements provide immature sperm cells with oxygen and nutrients.
- Protective. Each cell has lysosomes in the cytoplasm - organelles involved in phagocytosis. They absorb and process decay products, for example, dead fragments of spermatids.
- Providing a hemato-testicular barrier. This function is ensured by close intercellular contacts. A barrier is needed to separate male sex cells from the blood and its substances. In addition, it prevents the penetration of sperm antigens into plasma. Due to this, the risk of developing autoimmune inflammation is reduced.
- Endocrine function. Sertoli cells are involved in the formation of sex hormones.
Sustentocytes are necessary for the formation and maintenance of a special environment in which sperm cells develop favorably. It is known that the ionic composition of Sertoli cells is different from blood plasma. The sodium concentration in them is lower, and the potassium content, on the contrary, is increased. In addition, many biologically active substances are synthesized in Sertoli cells. Among them are prostaglandins, cytokines, follistatin, growth and division factors, opioids, etc.
The functions and structure of Leydig cells
Leydig cells are part of the interstitial tissue of the testis. Their size is about 20 microns. In the male gonads, there are more than 200 * 10 6 Leydig cells. The structural features of these elements are the large oval-shaped nucleus and foamy cytoplasm. It contains vacuoles containing lipofuscin protein. It is formed during the breakdown of fats at the time of the synthesis of steroid hormones. In addition, in the cytoplasm there is 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 activin. 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 malformations, since aplasia (a significant decrease or absence) of testicular germinal tissue is observed with it. As a result of this violation, the seminiferous tubules do not develop. The only element that is not damaged is the Sertoli cell. Another name for this pathology is del Castillo syndrome. Some Sertoli cells nevertheless undergo degeneration, however, most of them are normal. Despite this, the tubule epithelium is atrophied. Sperm with this pathology are not formed.
Leydig cell dysfunction
When Leydig cells are damaged, their main function is violated - the synthesis of testosterone. As a result, symptoms such as:
- Decrease in muscle mass.
- Lack of secondary sexual characteristics (male-type hair growth, voice timbre).
- Violation of the libido.
- Decreased bone density.