Hormones of the female reproductive glands. The structure and functions of the male gonads. How is testosterone produced?

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Male gonads

The gonads (sometimes called gonads) are the ovaries in women and the testes in men. The two testicles are located inside the scrotum on the anterior pelvis. Their main function is the production of sperm, which are released through the penis.

Male reproductive tract

Location and structure

The testicles are the primary male reproductive organs, located in the testes.

Functions

The testicles are responsible for producing sperm and semen, but they also contain special cells with endocrine function. They produce male sex hormones called androgens, of which the main hormone is testosterone.

Testosterone is responsible for:
. growth and development of male genital organs and maintenance of their adult sizes;

. enlargement of the larynx (and, as a result, changes in voice);
. increased bone and muscle growth;
. male sexual arousal.

How is testosterone produced?

Testosterone is produced by the action of hormones from the hypothalamus and the anterior pituitary gland. Testosterone levels are regulated by negative feedback.

Female gonads

The ovaries are the primary female reproductive organs, located in the lower abdominal cavity on the sides of the uterus. They produce eggs for reproduction, but also other systems - ovarian follicles and the corpus luteum - which have endocrine functions related to the body's reproductive activities.

Functions

Ovarian follicles secrete the hormone estrogen, which at the beginning of puberty is responsible for:
. maturation of female genital (reproductive) organs, such as the uterus and vagina;
. breast development;
. growth and distribution of body hair;
. distribution of fat on the hips, legs and chest.

The corpus luteum also secretes some estrogen, but its main hormone is progesterone, which causes the lining of the uterus to thicken to prepare the body for pregnancy. Both estrogen and progesterone are responsible for the changes that occur during the menstrual cycle.

How estrogen and progesterone are produced

Like testosterone, estrogen and progesterone are released as a result of the actions of hormones from the hypothalamus and pituitary gland. Estrogen and progesterone levels are regulated by negative feedback.

Female reproductive tract

Pituitary gland control of the ovulation cycle

The ovaries are under the control of the anterior pituitary gland. Under the influence of estrogen produced by the ovarian follicle, the pituitary gland produces follicle-stimulating hormone (Prolan A, FSH) and luteinizing hormone (Prolan B, LH). These hormones cause the follicle to mature and release an egg during ovulation. The remainder of the follicle forms the corpus luteum, which produces progesterone. If the egg is not fertilized, progesterone levels drop and menstruation occurs.

Before the onset of puberty, the amounts of male and female hormones in boys and girls are approximately the same. With the onset of puberty, the ovaries produce several times more female sex hormones, and the testes produce several times more male sex hormones.

Male sex hormones - androgens (androsterone, testosterone, etc.) are produced in the tissues of the testes. Testosterone regulates the process of spermatogenesis, the development of secondary sexual characteristics, and affects the level of protein and carbohydrate metabolism.

Female sex hormones - estrogens (estrol, estriol, estradiol) are produced in the ovaries. They participate in the regulation of puberty and the development of secondary sexual characteristics in girls, regulate the menstrual cycle, and when pregnancy occurs, regulate its normal course. In the ovaries, at the site of the burst follicle (Graafian vesicle), a corpus luteum is formed. The corpus luteum produces the hormone progesterone, which prepares the uterine mucosa for implantation of a fertilized egg, stimulates the development of the mammary glands and the muscular layer of the uterus, and regulates the normal course of pregnancy in its initial stages. During pregnancy, the placenta also produces female sex hormones that regulate the course of pregnancy and childbirth.

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See what “sex glands” are in other dictionaries:

Modern encyclopedia

- (gonads) organs that form sex cells (eggs and sperm) in animals and humans, as well as producing sex hormones. Male gonads testes, female ovaries; mixed sex glands are hermaphroditic (in some worms, ... ... Big Encyclopedic Dictionary

Sex glands- (gonads), organs that form reproductive cells (eggs and sperm) in animals and humans, as well as producing sex hormones. Male gonads testes, female ovaries; mixed sex glands are hermaphroditic (in some worms, ... ... Illustrated Encyclopedic Dictionary

GENITAL GLANDS- GENITAL GLANDS, or gonads, glands that produce germ cells (generative function of the pancreas) and sex hormones (endocrine function of the pancreas). (Comparative anatomy and embryology of the pancreas, see Genitourinary organs.) The male reproductive glands are called... ... Great Medical Encyclopedia

- (synonym - gonads), organs that form sex cells (see Gametes) and sex hormones. They are an integral part of the genital organs. They perform mixed functions, since they produce products not only external (potential... ... Sexological encyclopedia

- (gonads), organs that form reproductive cells (eggs and sperm) in animals and humans, as well as producing sex hormones. Male gonads testes, female ovaries; mixed sex glands are hermaphroditic (in some worms, ... ... encyclopedic Dictionary

Human organs that form sex cells (gametes) and produce sex hormones. They form the sex of the individual, sexual instincts and behavior, etc. The male gonads (testes) produce sperm and hormones that stimulate development and function... ... Biological encyclopedic dictionary

Gonads, organs that form reproductive cells (eggs and sperm) in animals and humans. P.J. Higher animals secrete sex hormones into the blood. Intrasecretory function of pancreas. regulated by gonadotropic hormones (See Gonadotropic... ... Great Soviet Encyclopedia

- (gonads), organs that form reproductive cells (eggs and sperm) in animals and humans, as well as producing sex hormones. Husband. P.J. testes, female ovaries; mixed P. f. hermaphroditic (in some worms, mollusks, etc.) ... Natural science. encyclopedic Dictionary

GENITAL GLANDS- organs in which sex cells are formed (in women these are the ovaries, which produce eggs, and in men, these are the testes, which produce sperm), as well as sex hormones... Encyclopedic Dictionary of Psychology and Pedagogy

Books

Textbook of physiology, Bykov K. M., Vladimirov G. E., Delov V. E., The publication is a textbook for students of medical institutes, which determines its composition and selection of material. As the authors write in the Preface, this edition of the textbook is more... Category: Human Anatomy and Physiology Publisher: State Publishing House of Medical Literature,
A Work in Black (audiobook MP3 on 2 CDs), Gustav Meyrink, “Even though from the point of view of intelligence and high spirituality, the later novels of Gustav Meyrink are more significant, opening up such abysses that are breathtaking, but these stories, ... Category: Classic and modern prose Publisher: Bibliophonika, audiobook

Most circulating testosterone (60%) is tightly bound in the blood to sex hormone binding globulin (SHBG). Free and albumin-bound testosterone can enter the body's cells, in light of which this part of testosterone is called biologically available. Despite binding to SHBG, testosterone has a short half-life of 10 minutes. Testosterone is metabolized primarily by the liver. However, testosterone metabolites account for only 20-30% of urinary 17-ketosteroids.

SHBG is a large glycoprotein produced by the liver. The production of SHBG by the liver depends on many metabolic factors:

sex steroids actively modulate the synthesis of SHBG - estrogens stimulate it, while androgens suppress it, which accounts for the higher concentration of SHBG in women;
in patients with liver cirrhosis, the level of estrogen in the blood remains normal, but testosterone decreases, which leads to an increase in the level of SHBG in such patients;
reduced concentration of T4 or T, reduces the level of SHBG, while against the background of thyrotoxicosis the level of SHBG increases;
SHBG concentration is reduced in obesity and acromegaly, which is due to the influence of hyperinsulinemia.

Factors influencing the concentration of sex hormone binding globulin

Conversion of testosterone to 17β-estradiol and dihydrotestosterone (DHT). Daily testosterone synthesis is 5-7 mg, or 5000-7000 mcg. In healthy men, up to 40 mcg of 17β-estradiol is formed, with 3/4 of this amount formed in peripheral tissues by aromatization of testosterone by the enzyme aromatase, and the remaining 10 mcg are secreted directly by the testicles (Leydig cells). The largest amount of aromatase is found in adipose tissue, so the higher the degree of obesity, the more intense the synthesis of estradiol.

Metabolism of estradiol in men:

daily production 35-45 mcg;
2-3% of estradiol is biologically active, the rest is associated with SHBG;
sources of circulating estradiol:

formation from testosterone through its aromatization on the periphery - 60%;
secretion by testicles - 20%;
peripheral conversion from estrone is 20%.

The main part of DHT (up to 350 mcg) is formed by direct transformation of testosterone under the action of 5α-reductase. In humans, two isoenzymes of 5-reductase have been isolated. Type 1 is localized primarily in the skin, liver, and testicles, while type II is localized primarily in the reproductive tissues, genital skin, and epididymis.

Androgen receptor binding. The androgen receptor is a polypeptide (910 amino acids), like other steroid and thyroid receptors, a DNA-binding protein. The same receptors bind testosterone and DHT.

Regulation of the function of the male reproductive glands

Testicular function is regulated by closed feedback systems, which have six main components:

extrahypothalamic parts of the central nervous system;
hypothalamus;
adenohypophysis;
testicles;
target organs regulated by male sex hormones;
transport system for male sex hormones and their metabolism.

Extrahypothalamic regulation of the central nervous system. Extrahypothalamic parts of the brain have both stimulating and suppressive effects on reproductive function. In the midbrain, cells contain biogenic amines, norepinephrine (NA) and serotonin (5-hydroxytryptamine; 5-HT), as well as neurotransmitters that are closely associated with many parts of the hypothalamus, including the preoptic, anterior and mediobasal zones, where GnRH-producing neurons are located .

Hypothalamic regulation

Pulsatile secretion of GnRH. The hypothalamus serves as an integrating center for GnRH regulation. GnRH is a decapeptide that is secreted into the portal system of the pituitary gland at a certain frequency - peak secretion every 90-120 minutes. The half-life of GnRH is 5-10 minutes, and it practically does not enter the systemic circulation, so its content in the blood is not studied. The selectivity of stimulating the secretion of gonadotropins LH and FSH depends on the frequency of pulsatile secretion of GnRH. The secretion of GnRH is regulated by the “hypothalamic biorhythm generator”, localized in the arcuate nucleus. At the same time, each individual neuron secretes GnRH not constantly, but periodically, which probably ensures the overall pulsating nature of GnRH secretion under the synchronizing influence of the “hypothalamic biorhythm generator.” The pulsating secretion of GnRH also determines the pulsating rhythm of the secretion of hormones from the glands it regulates (LH, FSH, androgens, inhibin). It was previously assumed that there are releasing hormones for both LH and FSH, but now the majority shares the view that only GnRH regulates the secretion of both LH and FSH, and the degree of influence on LH and FSH depends on the rhythm of GnRH secretion: high frequency reduces the secretion of both LH and FSH; low frequency stimulates the secretion of FSH to a greater extent than LH; administration of GnRH at a constant rate suppresses the secretion of both pituitary gonadotropins.
Regulation of GnRH. The synthesis and secretion of GnRH is regulated by the extrahypothalamic parts of the central nervous system, the concentration in the blood of androgens, peptide hormones such as prolactin, activin, inhibin and leptin. Local modulation of GnRH secretion is carried out by neuropeptides, catecholamines, indolamines, NO, dopamine, neuropeptide Y, VIN and CRH.

The hypothalamic peptide kisspeptin in men stimulates a rapid increase in LH secretion. More recently, hypothalamic GnRH secretion has been shown to be mediated by kissneurons producing kisspeptin, which stimulates the kiss1 receptor. Kisspeptin neurons also mediate sex hormone feedback to the hypothalamus.

Administration of lepitin increases the content of kiss1 in the messenger RNA of hypothalamic cells, as well as the secretion of LH and testosterone. Kisspeptin may therefore be an intermediate link in leptin's stimulation of GnRH secretion.

Prolactin suppresses GnRH secretion, which results in hypogonadism in patients with hyperprolactinemia.

Pituitary regulation. The gonadotropins LH and FSH are synthesized by gonadotrophs of the adenohypophysis and secreted in a spike manner, in response to the spike-shaped secretion of GnRH. However, since the rate of elimination of gonadotropins is slower than GnRH, the peaks in gonadotropin secretion are less pronounced. LH and FSH are large glycoproteins.

LH binds to specific membrane receptors of Leydig cells, which triggers a chain of reactions mediated by G protein and leading to stimulation of testosterone synthesis in the testicles.

FSH binds to receptors on Sertoli cells, stimulating the formation of a number of specific proteins in them, including androgen binding protein, inhibin, activin, plasminogen activator, γ-glutamyl transpeptidase and protein kinase inhibitor. FSH, in collaboration with testosterone produced by Leydig cells, and activin synergistically stimulate spermatogenesis and suppress apoptosis of germ cells.

Regulation of gonadotropin secretion. As stated above, the secretion of gonadotropins is regulated by the pulsatile secretion of GnRH.

Regulatory influence of inflammatory cytokines.

Biological effects of testosterone and its metabolites

Testosterone has a direct effect on the body or indirectly through its two main metabolites - DHT and 17β-estradiol.

There are three stages of life in which testosterone has different, and key, effects on the body. Lack of testosterone or 5a-reductase, which converts testosterone into DHT, leads to the development of ambivalent genitals.

In the absence of the enzyme 5α-reductase, a symptom such as micropenis appears. DHT is necessary for the growth and development of the prostate gland, where its concentration is 10 times higher than testosterone. In principle, the actions of testosterone and DHT are topographically dependent: beard growth is influenced by testosterone, and armpit and pubic hair is DHT-dependent. DHT suppresses hair growth on the scalp, causing the characteristic pattern of baldness in some men. Testosterone stimulates erythropoiesis through two mechanisms:

stimulating renal and extrarenal formation of erythropoietin;
having a direct effect on the bone marrow.

With a deficiency of the aromatase enzyme, osteoporosis develops as the content of estradiol decreases. Estradiol is also necessary for the closure of epiphyseal growth zones.

Recently, data have emerged regarding the effect of testosterone on metabolism:

increases sensitivity to insulin and, accordingly, glucose tolerance, stimulates mitochondrial oxidative phosphorylation genes;
increases the expression of regulatory enzymes of glycolysis and the glucose transporter GLUT4;
the effect of testosterone on lipids appears after puberty: the concentration of high-density lipoproteins decreases, and the concentration of triglycerides and low-density lipoproteins increases;
in the prepubertal period there are no sex differences in lipid metabolism.

Testosterone has a vasodilatory effect, and it is endothelial-independent, having a direct effect on vascular smooth muscle. Estradiol also has a vasodilatory effect, which is realized through nitric oxide (II).

Testosterone has important psychotropic effects on the brain, increasing mood (drive), motivation, aggressiveness and libido. It also affects cognitive functions, in particular improves spatial orientation and mathematical abilities. However, testosterone levels are negatively correlated with ease of verbal function.

Biological effects of testosterone and dihydrotestosterone

Testosterone	DHT
Stimulates beard growth. Deficiency leads to erectile dysfunction	Provides intrauterine development of male genital organs
Increases libido. Ensures normal architecture of the penis	Causes hair loss
Stimulates the development of muscle tissue and its strength	Stimulates the growth and development of the prostate gland
Stimulates erythropoiesis
Increases insulin sensitivity
Improves glucose tolerance
Increases the expression of regulatory enzymes of glycolysis
Increases expression of the glucose transporter GLUT4
Has a vasodilating effect
Improves mood (drive)
Improves brain function, particularly short-term memory, and increases math skills
Testosterone levels are negatively correlated with verbal functioning

During puberty, testosterone and DHT influence the growth of the scrotum and penis and ensure the functional unity of these structures, and they also stimulate:

ambisexual hair growth;
sexual hair growth (beard, mustache, chest, stomach and back);
activity of the sebaceous glands (acne).

Testosterone and DHT stimulate the growth of skeletal muscles and the larynx, which in the latter case is manifested in a deep voice in men.

Testosterone and its metabolites (DHT and estradiol) stimulate the growth of epiphyseal cartilaginous plates, cause rapid growth during puberty, promote the closure of epiphyseal growth zones, increase bone mass, stimulate hematopoiesis, prostate growth, libido, characteristically change social behavior, and increase aggressiveness.

Estradiol:

ensures pubertal growth;
maintains bone mass density;
regulates the secretion of gonadotropins.

Phases of the functional development of the hypothalamic-pituitary-gonadal system

In a male fetus, the concentrations of gonadotropins and testosterone in the blood begin to increase towards the end of the 2nd month of gestation, quickly rising to a maximum, which is maintained until late pregnancy; Testosterone concentrations in newborn boys are only slightly higher than those observed in girls.

Soon after birth in boys, the concentrations of LH, FSH and testosterone increase again and remain at the achieved level for about 3 months, but then gradually decrease to very low levels by the end of the first year of life. These low levels of gonadotropins and testosterone persist until puberty.

During the prepubertal period, GnRH secretion increases in amplitude and frequency in the morning hours before awakening, which is accompanied by an increase in the secretion of LH, FSH and testosterone in the morning hours. As puberty progresses, the duration of peak secretion of gonadotropins and testosterone increases until, at the end of puberty, secretion peaks become regular throughout the day.

During puberty, the sensitivity of gonadotropins to the stimulating effect of GnRH is also restored.

After puberty, the concentrations of gonadotropins and testosterone increase, reaching the values of an adult male by 17 years of age.

Stages of puberty in boys (according to Tanner)

Stages of development of the genital organs	Stages of pubic hair growth
Stage 1. Prepubertal. Testicles, scrotum and penis are approximately the same size and proportions, characteristic of early childhood	Stage 1. Prepubertal. Only vellus hair growth is noticeable, which is no more pronounced than on the anterior wall of the abdomen, i.e. no pubic hair
Stage 2. The scrotum and testicles enlarge, the texture of the skin of the scrotum changes, it acquires a reddish tint	Stage 2. Growth of long, lightly pigmented, sparse, vellus, straight or slightly curly hair around the base of the penis
Stage 3. The penis grows, initially mainly in length and to a lesser extent in diameter. There is also further growth of the scrotum and testicles	Stage 3. The hair becomes much darker, coarser, and more crimped. Sparse hair grows at the suprapubic joint
Stage 4. The penis increases in length and diameter even more, and the head of the penis develops. The testicles and scrotum become enlarged, the skin of the scrotum darkens	Stage 4. Full pubic hair is similar to that of an adult, but the surface area covered is noticeably smaller than that of most adults.
Stage 5. Full development of the genital organs in both size and shape. After reaching the 5th stage of development, further growth of the genital organs does not occur	Stage 5. Pubic hair, both in quality and type, corresponds to the adult period, distributed in the form of a triangle turned upside down. Hair growth is also noted on the inner surface of the legs, but not along the linea alba and does not extend above the base of the pubic hair growth triangle. Most men experience further growth of pubic hair as they age.

During the pre-pubertal period, the level of gonadotropins and gonadal steroids is low. At the same time, under the influence of ACTH, the secretion of adrenal androgens begins to increase in boys from 7-8 years of age, i.e. This phenomenon is called adrenarche. The growth spurt observed before puberty and sometimes the appearance of axillary and pubic hair are associated with the action of adrenal androgens.

Pubic hair growth is caused by androgens from the testicles and adrenal glands. Hair growth on the face also increases: growth spreads to the middle of the lower lip, to the sides and lower surface of the chin. The first stage of facial hair growth coincides with the 3rd stage of pubic hair growth (average age 14.5 years), and the last stage coincides with the completion of the 5th stage of pubic hair growth and the 5th stage of genital development. Hair in the perianal area appears a little earlier than in the armpits. At the end and after puberty, the hair growth zone extends from the pubic area upward, taking on a diamond-shaped shape.

The first sign of the onset of puberty is usually an increase in the maximum diameter of the testicles (excluding the epididymis) by more than 2.5 cm. In maturing Sertoli cells, mitoses stop and they differentiate into mature cells. Under the influence of LH, the number of Leydig cells in the testicles also increases.

Spermatozoa in morning urine (spermarche) appear at the chronological age of 13.5 years or at the corresponding bone age at the 3-4 stages of development of the genital organs and pubic hair at stages 2-4. When puberty develops earlier or later, the age at which spermarche occurs changes accordingly. Thus, the reproductive function in boys develops before the onset of physical and, naturally, psychological maturity.

Pubertal acceleration (leap) growth occurs under multilateral endocrine control, in which the leading role is given to growth hormone and sex hormones; if one or both are deficient, the pubertal growth spurt is reduced or does not occur at all. By enhancing the secretion of growth hormone, sex hormones indirectly stimulate the synthesis of IGF-1 and, in addition, directly activate the formation of IGF-1 in cartilage. From the beginning of puberty, the growth rate of the legs is faster than the growth rate of the body, but during the growth spurt these rates level out. The distal parts of the limbs (feet and hands) begin to grow before the proximal parts begin to grow, so a rapid increase in shoe size is the first harbinger of the pubertal growth spurt. On average, during the puberty period, boys grow by 28 cm, and the later the puberty period begins, the higher the final height is (due to the longer period of puberty).

During puberty, the larynx enlarges, the vocal cords thicken and lengthen, which is accompanied at approximately 13 years of age by a brittle voice and a decrease in its timbre; the formation of a male timbre is completed by the age of 15. Due to the anabolic effect of androgens, muscle mass increases (especially androgen-sensitive muscles of the chest and shoulder girdle), connective tissue, bones, and bone density increases. Lymphoid tissue reaches its maximum mass by the age of 12, and after that the mass decreases with the progression of puberty.

Gonads are organs that take part in the formation of germ cells. They are part of both the female and male reproductive systems and belong to the mixed secretion glands. These secretory organs produce hormones. When they enter the bloodstream, they ensure the normal functioning of the body and genital organs in particular. They also produce cells without which conception is impossible: sperm and eggs.

When are the genitals formed?

The development of the reproductive system of the unborn child occurs around the 4th or 5th week of pregnancy. At the same time, the sex glands are formed. At first, the embryo is bisexual, that is, the organs develop in the same way in boys and girls. Belonging to a specific gender emerges closer to 12 weeks. The process depends entirely on the Y chromosome. Male gonads begin to develop from the mesoderm. Seminiferous tubules and excretory ducts of the glands are formed. At 8 months, the testicles descend into the scrotum. After 32 weeks, little hormonal activity is observed in the ovaries in girls. It persists until the end of pregnancy and is the norm. Further organ development ends during puberty.

These organs in women include the ovaries. Their weight is about 8 grams.

These paired sex glands are located in the small pelvis and have a bluish color. The structure of the organ is heterogeneous; the surface consists of cubic epithelium. The cortex is located deeper. You can see spherical sacs in it. This is the follicle in which the egg develops. After the process of its maturation, the membrane bursts, the female reproductive cell enters the uterine cavity through the fallopian tubes. This is how the ovulation process occurs. In place of the follicle that burst, a corpus luteum forms. If fertilization does not occur, it turns whitish and then disappears altogether. The female sex glands secrete the following hormones: estrogens, progesterone.

Hormone estrogen: functions

Estrogen refers to a group of hormones: estradiol, estriol, estrone. They all play an important role in the body. First of all, they are responsible for the normal course of the menstrual cycle. In addition, they directly contribute to fertilization, the release of the egg into the uterus. Estrogen hormones, which are produced by the sex glands, affect the condition of the skin, the type of hair growth (female), the functioning of the sebaceous secretion organs, and also take part in water-salt metabolism. Stimulating bone tissue formation is another function they perform. It is the insufficient production of estrogen during menopause that contributes to frequent fractures and the development of osteoporosis. If there is a small amount of the hormone during puberty, a cycle failure and slow development of the mammary glands and other genital organs may occur. Its increased content is characterized by irritability, weight gain, problems with skin and hair.

Progesterone, its meaning

The second hormone produced by the female reproductive glands, namely the corpus luteum, is progesterone. It directly affects the process of conception, and also helps to preserve and bear a child. With its help, the egg is able to implant itself in the uterus. Progesterone also stops the menstrual cycle during pregnancy. If its quantity is insufficient, vaginal bleeding, irregularities in the course of menstruation, sudden mood swings, and inflammatory processes in the organs of the reproductive system can be observed. It is also important that one of the causes of infertility is a low level of this hormone. Excess progesterone indicates the presence of neoplasms (although increased levels during pregnancy are normal). With increased production of this hormone, frequent depression can be observed (as it directly affects a woman’s emotionality), sexual desire decreases, and headaches and weight gain are common.

The testicles in men are the organ for secreting sex hormones. It is in them that sperm are formed and specific substances are produced.

The male gonads perform the following functions: preparation for the process of conception, manifestation of sexual desire, development of secondary sexual characteristics. Intensive growth of the testicles is observed up to 15 years. On the outside they are covered with a shell, inside of which there are up to 300 lobules. They house the seminal canals and connective tissue. Through the vas deferens, the sex cells enter the ejaculatory ducts, which open into the urethra. The sperm itself consists of a head, neck, and tail. Such cells begin to be produced during puberty. The process continues until old age. Their number in sperm, which is ejected at a time, can reach 200 million. The male gonads produce the following hormones: androgens (testosterone), a small amount of estrogens.

Testosterone as a masculinity hormone

This hormone is synthesized from cholesterol by special Leydig cells. Its main function is to maintain sexual desire and ensure normal potency.

Its influence on the formation of skeletal muscles and bone growth has been established. Testosterone is directly involved in body hair growth (male principle); due to its action, the vocal cords thicken (as a result, the voice becomes rougher). Well, and, of course, the growth of the testicles, penis and prostate gland also depend on its production. Any decrease in the amount of this hormone can result in infertility. If a deficiency occurs during puberty, then in young men the development of the genital organs slows down, the muscles weaken, and there is little hair on the body. A lack of testosterone after this period can lead to impotence. Poor functioning of the testicles significantly affects a man’s weight. Moreover, you can observe both its growth and decrease in body weight. A natural decrease in testosterone occurs after 60 years of age.