Hormone testosterone and its functions in the human body

In the human body, there are two main mechanisms for the regulation of organs and systems: the nervous and humoral. The first of these is due to abundant innervation of all internal organs, glands, vessels and musculoskeletal apparatus.

The second mechanism operates due to the distant action of hormones, in which they are produced in the endocrine gland, and then transferred to the tissue or target organ with blood flow. Thus, the hormone testosterone, the main androgen, is produced in a small amount in the adrenal cortex, and at the onset of puberty in boys begins to be actively developed in the testes, then it extends through the excretory ducts from the glands into the blood and then exerts an effect on the musculoskeletal system, and Also on the metabolism in the liver. On the principle of feedback, testosterone is able to regulate the production of other sex hormones (both in the female and in the male body).

Functions of testosterone

Of course, testosterone levels in men far exceed its level in women, because in the male body it performs more functions: in the pubertal period, under the influence of boys , the so-called. Secondary sexual characteristics, namely: "breaking" of the voice, widening of the shoulder belt in comparison with the pelvis, increasing the muscle mass and compaction of bones, maturing of the gametes in the genital glands.

In adult men, it also helps maintain sexual function, that is, sexual desire, potency and forms psychophysiological sexual behavior. The hormone testosterone is also produced in women: in the adrenal cortex, in the ovaries and in the transformation of estrogens. It has an inhibitory effect on the maturation of follicles in the ovaries and regulates the production of estradiol and estrone through the hypothalamic-pituitary-adrenal system. When it is hypersecretion in women or the artificial intake of drugs containing this hormone (many anabolic steroids), women develop masculinization, manifested in the coarsening of the voice, increased hairiness, muscle development and aggressive behavior.

Regulation of testosterone secretion

There are several mechanisms that affect testosterone levels. Its rate in men is 11-33 nmol / liter, and in women - only 0,24-2,7. In this case, the hormone testosterone is in the blood in two fractions: free albumin bound and transport proteins and a specific globulin capable of binding sex hormones (SHGG). However, only free (2% of total) and albumin-bound testosterone show only biological activity. After 30-35 years in men, the hormone testosterone, both its bioavailable and total fractions, tends to decrease with an average rate of 2-3% / year, and in the old age the level of active testosterone is reduced by 5 times (compared to adolescence) , And the total - 2.5 times. According to some information, this is due not only to a gradual decrease in its secretion, but also to increased binding to SHBG, as a result of which the bioavailable fraction is deactivated.