Testosterone is a steroidal sex hormone produced in the testes (Leydig cells) in men, in women in small amounts in the ovaries and in the adrenal glands in both sexes. The functions performed by the hormone can be divided into 2 groups:
1. anabolic - growth of muscle mass, increase in bone density;
2. androgenic - formation of the genitals of the fetus (penis, scrotum, prostate, seminal vesicles).
Adequate testosterone levels are especially important during puberty and adulthood. In adolescents, testosterone prepares the body for childbearing. During this period the hormone has the following effects:
- Enlargement of the sebaceous glands (which sometimes leads to the appearance of adolescent acne);
- An increase in the size of the external genitals;
- Increase in libido and frequency of erections;
- Growth of pubic hair, spreading to the thighs and up to the navel;
- Growing facial hair (beard, moustache, sideburns);
- Hair growth on legs, breasts, nipples (periareolar) and anus (perianal), armpits;
- Reduction of subcutaneous fat on the face;
- Increase in muscle mass and strength;
- Coarsening of the voice, growth of the Adam's apple;
- Activation of sperm production (spermatogenesis) in the testes;
- Growth of jaw, forehead, chin, nose.
- Cessation of growth, completion of bone maturation.
Testosterone is present in both sexes: in both men and women, but the effect of the hormone is much more pronounced in men:
- Activation of Sertoli cells in the testicles, which are necessary for the normal development of sperm;
- Maintaining physical and mental performance;
- Involvement in the nourishment (trophism) of muscle tissue;
- Involvement in the blood coagulation-anti-coagulation system through regulation of thromboxane A2;
Testosterone in medicine is used (under control of blood concentrations) to treat infertility, erectile dysfunction, decreased libido, osteoporosis.
Read also: "Male menopause: myths and reality", Men's health profile