Age characteristics of the endocrine glands table. General characteristics of the endocrine glands in children and adolescents

Endocrine glands. The endocrine system plays an important role in regulating body functions. The organs of this system are endocrine glands– secrete special substances that have a significant and specialized effect on metabolism, structure and function of organs and tissues. Endocrine glands differ from other glands that have excretory ducts (exocrine glands) in that they secrete the substances they produce directly into the blood. That's why they are called endocrine glands (Greek endon - inside, krinein - to secrete).

The endocrine glands include the pituitary gland, pineal gland, pancreas, thyroid gland, adrenal glands, reproductive glands, parathyroid or parathyroid glands, and thymus gland.

Pancreas and gonads – mixed, since some of their cells perform an exocrine function, the other part - an intrasecretory function. The gonads produce not only sex hormones, but also germ cells (eggs and sperm). Some pancreatic cells produce the hormone insulin and glucagon, while other cells produce digestive and pancreatic juice.

Endocrine glands humans are small in size, have a very small mass (from fractions of a gram to several grams), and are richly supplied with blood vessels. Blood brings the necessary building material to them and carries away chemically active secretions.

An extensive network of nerve fibers approaches the endocrine glands; their activity is constantly controlled by the nervous system.

The endocrine glands are functionally closely related to each other, and damage to one gland causes dysfunction of other glands.

Thyroid. During ontogenesis, the mass thyroid gland increases significantly - from 1 g during the newborn period to 10 g by 10 years. With the onset of puberty, the growth of the gland is especially intense, during the same period the functional tension of the thyroid gland increases, as evidenced by a significant increase in the content of total protein, which is part of the thyroid hormone. The content of thyrotropin in the blood increases rapidly up to 7 years of age.

An increase in the content of thyroid hormones is noted by the age of 10 and at the final stages of puberty (15-16 years). At the age of 5-6 to 9-10 years, the pituitary-thyroid relationship changes qualitatively; the sensitivity of the thyroid gland to thyroid-tropic hormones decreases, the greatest sensitivity to which is noted at 5-6 years. This indicates that the thyroid gland has a particularly great importance for the development of the body in early age.

Insufficiency of thyroid function in childhood leads to cretinism. At the same time, growth is retarded and body proportions are disturbed, delayed sexual development, mental development lags behind. Early detection of thyroid hypofunction and appropriate treatment have a significant positive effect.

Adrenal glands. From the first weeks of life, the adrenal glands are characterized by rapid structural transformations. The development of adrenal measles occurs intensively in the first years of a child’s life. By the age of 7, its width reaches 881 microns, at 14 years it is 1003.6 microns. At birth, the adrenal medulla consists of immature nerve cells. During the first years of life, they quickly differentiate into mature cells called chromophilic cells, as they are distinguished by their ability to stain yellow chrome salts. These cells synthesize hormones, the action of which has much in common with the sympathetic nervous system - catecholamines(adrenaline and norepinephrine). Synthesized catecholamines are contained in the medulla in the form of granules, from which they are released under the influence of appropriate stimuli and enter the brain. venous blood, flowing from the adrenal cortex and passing through the medulla. Stimuli for the entry of catecholamines into the blood are excitement, irritation of the sympathetic nerves, physical activity, cooling, etc. The main hormone of the medulla is adrenalin, it makes up approximately 80% of the hormones synthesized in this part of the adrenal glands. Adrenaline is known as one of the fastest-acting hormones. It accelerates blood circulation, strengthens and increases heart rate; improves pulmonary respiration, expands the bronchi; increases the breakdown of glycogen in the liver, the release of sugar into the blood; enhances muscle contraction, reduces fatigue, etc. All these effects of adrenaline lead to one thing overall result– mobilization of all the body’s forces to perform hard work.

Increased secretion of adrenaline is one of the most important mechanisms of restructuring in the functioning of the body in extreme situations, during emotional stress, sudden physical exertion, and cooling.

The close connection of the chromophilic cells of the adrenal gland with the sympathetic nervous system causes the rapid release of adrenaline in all cases when circumstances arise in a person's life that require an urgent effort from him. A significant increase in the functional tension of the adrenal glands is observed by the age of 6 and during puberty. At the same time, the content of steroid hormones and catecholamines in the blood increases significantly.

Pancreas. In newborns, intrasecretory pancreatic tissue predominates over exocrine pancreatic tissue. The islets of Langerhans increase significantly in size with age. Islets of large diameter (200-240 microns), characteristic of adults, are found after 10 years. An increase in the level of insulin in the blood in the period from 10 to 11 years has also been established. The immaturity of the hormonal function of the pancreas may be one of the reasons why children diabetes is most often detected at the age of 6 to 12 years, especially after suffering acute infectious diseases (measles, chicken pox, pig). It is noted that the development of the disease contributes to overeating, especially the excess of carbohydrate-rich foods.

Development and age-related characteristics of the endocrine glands

Pituitary. In a newborn, the pituitary gland has a spherical or triangular shape with the apex directed towards the posterior surface of the sella turcica (Atl., Fig. 5, p. 21). In an adult, its dimensions are 1.5 x 2 x 0.5 cm. In newborn children, the mass of the pituitary gland is 0.1-0.15 g, weight gain begins in the 2nd year of life and by 10 years it reaches 0.3 g The mass of the pituitary gland increases especially rapidly during puberty, as a result of which by the age of 14 it becomes 0.7 g in girls and 0.66 g in boys.

During pregnancy, the mass of the pituitary gland increases to 1 g, which is associated with an increase in its functional activity. After childbirth, the mass of the pituitary gland decreases somewhat, but the pituitary gland in women still weighs more than in men of the same age.

The pituitary gland develops from two independent embryonic primordia. The adenohypophysis is formed from the primary oral recess (pocket), which, as the embryo develops, separates from the oral cavity, the cells of its walls multiply and form glandular tissue (hence the name adenohypophysis, that is, glandular pituitary gland).

The posterior lobe and stalk of the pituitary gland are formed from the floor of the third ventricle. The parenchyma of the posterior lobe consists of thin fibers of neuroglia and ependyma. Between the fibers there are cells and accumulations of neurosecretion are found, which descends into the posterior lobe of the pituitary gland along the axons of neurosecretory cells from the supraoptic and paraventricular nuclei of the hypothalamus.

Pineal gland. The rudiments of the epiphysis in the embryo appear at the 6-7th week of embryogenesis as a protrusion of the roof of the diencephalon. By the second half of pregnancy it is already formed. The first signs of the functioning of the pineal gland were detected in the 2nd month prenatal development.

In a newborn, the epiphysis has a rounded shape, flattened, without a stalk; it is located between the lobules of the midbrain and has a depression on its surface. At birth it has the following dimensions; length 2-3 mm, width 2.5 mm, thickness - 2 mm. In an adult, respectively, 5-12 mm, 3-8 mm, 3-5 mm, weight 100-200 mg. Its weight increases in the first year of life and from 3 to 6 years it acquires its final value, and then undergoes age-related involution (reverse development). The cavity of the epiphyseal ventricle may sometimes still be open.

The pineal gland of a newborn contains small embryonic undifferentiated cells that disappear at the 8th month of life, and large cells with a vesicular nucleus. The existence of these two types of marks leads to the fact that dark and lighter islands are located inside the gland. The pigment is absent, but appears later in large quantities at about 14 years of age. At the age of 2 years, the shape becomes like that of an adult.

Differentiation of the parenchyma begins in the 1st year of life, starting from the 3rd year, glia appear, and until the age of 5-7 years the differentiation of epiphysis cells ends. Connective tissue develops rapidly between 6 and 8 years of age, but maximum development occurs after 14 years of age.

During the neonatal period and early childhood, the secretory activity of the pineal gland increases and at the age of 10-40 years reaches its maximum expression, after which a decline occurs. Level melatonin in the blood is subject to significant fluctuations due to the action of factors such as sleep, light, darkness, changes in the phases of the menstrual cycle in women, time of year, etc. Melatonin is characterized by circadian rhythm fluctuations in blood levels: maximum values during the night, and minimum values during the day. Consequently, the pineal gland plays a significant role in the operation of the mechanism “ The biological clock» - periodicity of body functions in different time days.

Thyroid. During embryogenesis, the thyroid gland is formed in the form of a thickening of the endoderm lining the bottom of the pharynx in the 3rd week of intrauterine development, and its two lateral lobes and the isthmus are gradually formed (Atl., Fig. 8, p. 23).

In a newborn, it is enclosed in a thick capsule formed from two leaves. The outer leaf is rich in blood vessels and formed by short collagen fibers. The inner leaf is rich in cellular elements, formed by long collagen and elastic fibers.

Thick septa extend from the capsule and penetrate the gland; in the gland, thinner partitions extend from them, separating the lobules and nodes of the gland. In a newborn, the nodes have the form of vesicles (follicles) that contain colloid (Atl. Fig. 7, p. 22). The wall of each follicle consists of a single-layer epithelium that produces two iodine-containing hormones. The number of follicles that form the thyroid gland and their size increase with age.

Thus, in newborns the diameter of the follicle is 60-70 microns, at the age of 1 year - 100 microns, 3 years - 120-150 microns, 6 years - 200 microns, at 12-15 years - 250 microns. The follicular epithelium of the thyroid gland in newborns is cubic or cylindrical. As the body grows, it is replaced by a cubic or cylindrical one, which is characteristic of the thyroid follicles of an adult. By the age of 15, the mass and structure of the thyroid gland become the same as that of an adult.

The location of the thyroid gland in relation to other organs is almost the same as in an adult. The isthmus is attached to the cricoid cartilage by a short, strong ligament. The cranial half is located on the larynx, and the lower half is on the trachea, which does not completely cover, leaving a free area 6-9 mm high and 8 mm wide.

The cranial part can penetrate into this space thymus, entering the upper opening of the chest cavity. The lateral lobules can rise to the level of the upper edge of the thyroid cartilage near the greater cornu of the hyoid bone. They may come into contact with the neurovascular bundle of the neck. The common internal carotid artery is covered by the thyroid gland, only the internal jugular vein remains free.

The gland penetrates between the trachea and the artery, reaching the prevertebral fascia, with which it connects through free connecting bridges (Atl., Fig. 9, p. 23). Located in the groove between the trachea and esophagus laryngeal nerve, adjacent to the gland; on the left the gland is adjacent to the esophagus, to which it is attached by connective tissue fibers; on the right it is located at a distance of 1 - 2mm from the esophagus. Typically, the contact surface between the thyroid gland, trachea and esophagus is smaller than in an adult.

In a newborn, the mass of the thyroid gland ranges from 1 to 5 g. It decreases slightly by 6 months, and then begins a period of increase that lasts up to 5 years. From 6-7 years of age, the period of rapid increase in the mass of the thyroid gland is replaced by a slow one. During puberty, a rapid increase in the mass of the thyroid gland is again observed, its weight reaches 18-30 g, that is, the size of an adult.

At 11-16 years of age, the thyroid gland in girls grows faster than in boys. At 10-20 years old, her weight doubles or sometimes triples.

In an adult man, the average length of the lateral lobes is 5-6 cm, thickness 1-2 cm. In women, the size of the thyroid gland is slightly larger than in men. After 50 years, the weight and size of the thyroid gland gradually decrease.

Parathyroid glands. By the end of intrauterine development, the parathyroid glands are fully formed anatomical formations surrounded by a capsule. In a newborn they are located as in an adult: the upper ones on the posterior surface of the thyroid gland, in its upper half; the lower ones are located at the lower pole of the thyroid gland. There are 4 types parathyroid glands: compact(contains no a large number of connective tissue), reticular(has thick connective tissue crossbars), lobular, or alveolar(thin septa), and spongy. In newborns and children under 2 years of age, the first three types, and especially the compact type, are usually found. The number of glands can vary: usually there are 4, but there can be 3, 2 or even 1. The lower parathyroid glands are larger than the upper ones. In childhood, their growth is rapid and slows down after puberty.

During the aging process, the tissue of the parathyroid glands is partially replaced by fatty and connective tissue. In an adult, each gland is 6-8 mm long, 3-4 mm wide, about 2 mm thick, and weighs from 20 to 50 mg. There are two types of cells in the tissue of the parathyroid glands: main And oxyphilic. The main cells are small in size, have a large nucleus and light-colored cytoplasm. Oxyphilic cells are larger, and their cytoplasm exhibits oxyphilic (that is, stained with acidic dyes) granularity. Recent studies suggest that oxyphilic cells are senescent chief cells. Oxyphilic cells first appear after 5-7 years. Apparently, for the first time 4-7 years of life, the parathyroid glands function especially actively.

Thymus. The thymus gland is formed in the 6th week of embryonic development. In a child, the thymus gland is located in front of the trachea, pulmonary artery, aorta, superior vena cava, behind the sternum (Atl., Fig. 12, p. 24). It has the appearance of a quadrangular pyramid, located mostly in the chest cavity (base), and the bifurcated apex is in the cervical region. The thymus gland can be of three types: a) monolobar, is rare, located entirely in the chest cavity at a distance from the thyroid gland, sometimes it can have two small horns; b) form c two beats occurs in 70% of cases. The gland has two lobes separated by a midline; c) third form multilobar, which is very rare. The gland is formed from 3-4 lobes. In a newborn it has pink color, and in a small child it is white-gray; at an older age, the color becomes yellowish as a result of the process of degeneration.

The thymus gland is covered with a capsule from which interlobar septa extend. The lobes of the thymus gland have two zones: the cortical zone, formed from epithelial cells, and the medulla, containing two layers consisting of epithelial and reticular fibers. Lymphocytes are densely located in the cortical part, and Hassall's corpuscles are located in the medulla - concentrically located fusiform epithelial cells with a large light core. Hassall's bodies undergo cyclic development: they are formed, then disintegrate, and their remains are absorbed by lymphocytes and eosinophilic granulocytes. It is believed that Hassall's bodies are secretory cells of the thymus gland.

Relative to body weight, the thymus gland is heavier in boys than in girls. In a newborn, its weight is 10-15 g, in an infant - 11-24 g, in a small child - 23-27 g, in 11-14 years - on average 35-40 g, in 15-20 years - 21 g, in 20-25 years - about 19 years old Heaviest weight occurs during puberty. After 13 years, age-related involution (reverse development) of the thymus gland gradually occurs, and by the age of 66-75 its mass averages 6 g. Thus, the thymus gland reaches its greatest development in childhood.

The thymus plays an important role in the immunological defense of the body, in particular in the formation of immunocompetent cells, that is, cells capable of specifically recognizing antigen and responding to it. immune reaction (Burnet, 1961).

Children with congenital underdevelopment of the thymus gland usually die at the age of 2-5 months. It is noted that the thymus gland plays an important role in the antitumor defense of the body.

It should be noted that the thymus gland is closely related to other internal secretion organs, in particular to the adrenal glands. For example, an increase in the secretion of glucocorticoids under stress leads to a rapid decrease in the size and weight of the thymus gland. In this case, in the gland and other lymphoid organs, lymphocytes first disintegrate, and then the new formation of Hassal’s bodies occurs. On the contrary, the introduction of extracts of the thymus gland inhibits the development and function of the adrenal cortex, up to its significant atrophy. If a person has not experienced age-related involution of the thymus gland, he or she develops insufficiency in the function of the adrenal cortex and reduced resistance to stress factors.

Pancreas belongs to the glands of mixed secretion. The bulk of it carries out exocrine function- produces digestive enzymes, secreted through the duct into the cavity duodenum(Atl., Fig. 13, p. 25). Endocrine functions are inherent in the islets of Langerhans. Islet tissue makes up no more than 3% in humans. The largest amount of it is located in the caudal part of the gland: this section contains an average of 36.0 islets per 1 mm 3 of parenchyma, in the body - 22.4, in the head - 19.8 per 1 mm 3 of tissue. In general, there are up to 1800 thousand islets in the human pancreas. Their size varies - from small (diameter less than 100 microns) to large (diameter up to 500 microns). The shape of the islands is round or oval (Atl., Fig. 14, p. 25).

The human pancreas begins between the 4th and 5th weeks of embryonic development and is separated from the protrusion of the intestinal tube. The islets of Langerhans appear at the 10-11th week of embryogenesis, and by the 4-5th month they reach sizes approaching those of an adult. There are suggestions that the secretion of insulin and glucagon begins already in the early stages of embryonic development ( Falin, 1966).

The cells that make up the islet apparatus are called insulcytes and there are several types of these cells. Most of these cells are B cells, which produce insulin. The second type of cell is A cells, which are located either at the periphery of the islet or in small groups throughout the islet. They secrete glucagon.

The growth and development of the insular apparatus is especially active in the first months of life. Then, up to 45-50 years, the structure of the islands stabilizes; after 50 years, their formation is activated again ( Shevchuk, 1962). It should be noted that in at a young age large islets predominate, which include B cells, and in senile - small islets, consisting mainly of A cells. This indicates that insulin secretion predominates in childhood and young age, and glucogon secretion predominates in old age.

Adrenal glands. The adrenal glands consist of two layers: the cortex and the medulla. The medulla is located in the center of the adrenal gland and makes up about 10% of the total tissue of the gland, and the surrounding cortex makes up about 90% of the mass of this organ. The adrenal glands are covered with a thin capsule consisting of elastic fibers. The adrenal cortex consists of epithelial columns located perpendicular to the capsule. It distinguishes three zones: glomerular, fascicular and reticular (Atl., Fig. 16, p. 26).

Zona glomerulosa lies under the capsule and consists of glandular cells that form, as it were, clusters. The widest zone is fascicular, including cells arranged in the form of strands running parallel to each other from the glomerular layer to the center of the adrenal gland. Deepest, next to the medulla, is located mesh zone. It consists of a loose network of intertwined cells.

Between the cortex and the medulla there is a thin, sometimes interrupted connective tissue capsule. The medulla consists of large cells that have a rectangular or prismatic shape.

During the process of embryogenesis, the formation of the cortical part of the adrenal gland in the embryo is detected on the 22-25th day of intrauterine development. At the 6th week of embryogenesis, cells from the embryonic neural tube are introduced into the developing adrenal gland, giving rise to the adrenal medulla. Sympathetic ganglia differentiate from the same cells. Hence, brain part The adrenal gland is of nervous origin.

The adrenal glands of the fetus are very large: in an 8-week human embryo they are equal in size to the kidneys. These glands actively secrete hormones even in embryonic period development. The amount of adrenaline at 1 year is 0.4 mg, at 2 years - 1.18 mg, at 4 years - 1.96 mg, at 5 years - 2.92 mg, at 8 years - 3.96 mg, at 10-19 years - 4.29 mg.

After birth, the mass of the adrenal gland is 6.98 g, then quickly decreases, and at 6 months it is 1/4 of the original weight. After the 1st year of life, the mass of the adrenal glands increases again until 3 years, and then the growth rate decreases and remains slow until 8 years, and then increases again (Atl., Fig. 17, p. 27). At 11-13 years of age, the mass of the adrenal glands increases again, especially during puberty, and stabilizes by the age of 20.

It should be noted that there is a significant change in the growth rate of the adrenal glands at 6 months for girls, at 8 months for boys, at 2 years for boys, at 3 years for boys (during this last period, the adrenal glands in boys grow faster than in girls), at 4 years for children of both sexes.

Women have more adrenal mass than men. At the age of 60-70 years, senile atrophic changes in the adrenal cortex begin.

The location of the adrenal glands in relation to other organs differs from that of an adult. The right adrenal gland is located between the upper edge of the twelfth thoracic vertebra (can rise to the tenth) and the lower edge of the first lumbar vertebra. The left adrenal gland is located by the upper edge of the eleventh thoracic vertebra and the lower edge of the first lumbar. In a newborn, the adrenal glands are located more laterally than in an adult. As a result of the growth of the kidneys, the adrenal glands change their position, this is observed at 6 months of age.

Paraganglia - These are endocrine glands, as well as accessory organs of the endocrine system. They are the remnants adrenaline, or chromaffin, systems producing mainly cathelochomins. They originate from the sympathetic nerves or from the sympathetic branches of the cranial nerves and are located medial or dorsal to the nodes of the sympathetic trunk.

Paraganglia consist of secretory chromaffin cells, auxiliary (sheathing type neuroglia) cells and connective tissue; during embryogenesis they arise and migrate together with neuroblasts of the sympathetic nervous system. Other paraganglia are nonchromaffin (mainly at the sites of branching of the parasympathetic nervous system), including the orbital paraganglia, pulmonary paraganglia, bone marrow paraganglia, meningeal paraganglia, carotid paraganglia, and paraganglia along the vessels of the trunk and extremities.

The role of the paraganglia is to mobilize body systems during periods of stress; in addition, they regulate general and local physiological reactions.

Paraganglia usually develop in the first year of life, grow during the second year, and then undergo reverse development. Appears in the embryonic period lumbar-aortic paraganglia located on both sides of the aorta at the level of the adrenal glands. Intermittent paraganglia may appear at the level of the cervical and thoracic sympathetic chain. The paraganglia located on the aorta can be connected to each other, but after birth their connection is severed. By birth, the lumboaortic paraganglia are well developed and have lymph nodes.

Paraganglia carotid artery develop and differentiate late. In a newborn, glandular cells are found in large numbers, connective tissue is poorly developed. During the first year of life, numerous capillaries develop that surround the cells. Specific cells are still found at 23 years of age.

supracardiac paraganglia, There are two of them, the upper one is located between the aorta and the pulmonary artery. In a newborn, groups of cells of the superior suprapericardial paraganglia are surrounded by muscular-type arteries. At 8 years of age they do not contain chromaffin cells, but continue to grow until puberty and remain in adulthood.

Lesson 5.

Becoming endocrine function in ontogeny

The endocrine glands begin to function in the embryonic period. Most hormones begin to be synthesized in the 2nd month of intrauterine development, but hormones such as vasopressin and oxytocin, found in the endocrine glands of the fetus at 4-5 months. Functionality endocrine glands develop heterochronically during childhood and reach adult level period of adolescence ( 18-21 years old) and then slowly and unevenly for each gland decrease in old age. However, in old age There may be an increase in the production of certain hormones, in particular, hormones of the anterior pituitary gland ( TSH, STG, ACTH and etc.).

In general, four main parameters can change in the ontogenesis of endocrine regulation:

1) the level and quality of incretion of the endocrine glands themselves, as a consequence of their own aging;

2) correlative relationships between the functioning of individual glands;

3) regulation of endocrine glands;

4) tissue susceptibility to the action of hormones.

Pituitary

The pituitary gland is divided into three lobes: the anterior (adenohypophysis), middle and posterior (neurohypophysis).

The anterior lobe produces gonadotropic hormones, adrenocorticotropic, thyroid-stimulating, somatotropic hormones and prolactin.

Somatotropin (STH) is a growth hormone. Its main function is to enhance growth processes and physical development. With an excess of the hormone in childhood, it develops gigantism, in case of deficiency - dwarfism With an excess of the hormone in adults there is acromegaly(bone enlargement facial skull, fingers, tongue, stomach, intestines).

STG begins to develop anterior pituitary gland at 10 weeks embryonic development. In the first days and years of life, the concentration of growth hormone is highest. From 2 to 7 the content of growth hormone in the blood of children remains unchanged for years approximately at a constant level, which in 2–3 times exceeds adult level. It is significant that during this same period the most rapid growth processes are completed before puberty. Then comes a period of significant decrease in hormone levels - and growth is inhibited.

A new increase in growth hormone levels is observed after 13 years, and its maximum noted at the age of 15, i.e. just at the moment of the most intense increase in body size in adolescents.

TO 20 years old the level of growth hormone in the blood is set at a typical for adult level. With age, the secretion of growth hormone decreases, but nevertheless does not stop throughout life, since in an adult, growth processes continue, only they no longer lead to an increase in the mass and number of cells, but ensure the replacement of spent cells with new ones.

Prolactin accelerates the growth of mammary glands and enhances the processes of milk formation. Prolactin is recorded in high concentrations in a newborn. During the 1st year, its concentration in the blood decreases and remains low until adolescence. During puberty, its concentration increases again, and in girls it is stronger than in boys.

Thyroid-stimulating hormone (TSH) stimulates thyroid function. A significant increase in TSH secretion is observed immediately after birth and before puberty. First increase associated with adaptation of the newborn to new conditions existence. Second the increase corresponds hormonal changes, including strengthening the function of the gonads.

Adrenocorticotropic hormone (ACTH), regulating the function of the adrenal cortex, is contained in the blood of a newborn in the same concentrations as in an adult. Aged 10 years its concentration becomes twice as low and again reaches the size of an adult after puberty. For girls the formation of a connection between the hypothalamic-pituitary system and the adrenal glands, adapting the body to stress, occurs later than boys.

Gonadotropic hormones include follicle stimulating hormone(in women it stimulates the growth of follicles in the ovary; in men - the processes of spermatogenesis) and luteinizing hormone ( in women it stimulates the development of the corpus luteum and the synthesis of progesterone, in men it enhances testosterone production),

The concentration of gonadotropic hormones in a newborn is high. During the 1st week after birth, there is a sharp decrease in the concentration of these hormones, and up to 7–8 years old her age remains low. IN prepubertal period occurs increased secretion gonadotropins. TO 18 years old the concentration becomes the same just like adults. With age, the pituitary gland of women, and to a lesser extent of men, occurs promotion concentrations of gonadotropins, which continues after menopause.

The intermediate lobe of the pituitary gland produces melanocyte stimulating hormone (intermed), stimulating the formation of melanin and regulating skin and hair pigmentation. Its concentration in the pituitary gland is quite stable both during fetal development and after birth.

The posterior lobe of the pituitary gland is a hormone depot vosopressin (antidiuretic hormone) And oxytocin.

Vasopressin increases the reabsorption of water in the kidneys, reduces urine output, and causes vasoconstriction.

Oxytocin strengthens uterine contractions during childbirth, and also promotes milk secretion.

The content of these hormones in the blood is high at the time of birth; a few hours after birth, their concentration decreases sharply. In children, during the first months after birth, the antidiuretic function of vasopressin is insignificant, and with age its role in retaining water in the body increases. The target organs for oxytocin - the uterus and mammary glands - begin to respond to it only after puberty.

Pineal gland

The pineal gland is detected at 5–7 weeks of intrauterine development. Secretion begins in the 3rd month. Pineal gland develops up to 4 years, and then begins to atrophy, especially intense after 7–8 years.

The main hormone of the pineal gland is melatonin- inhibitor of the development and functioning of the gonads. It acts on the hypothalamic region and inhibits the formation of gonadotropic hormones in the pituitary gland, which causes inhibition of the internal secretion of the gonads. Melatonin is also involved in the regulation of pigment metabolism, circadian and seasonal rhythms, sleep and wakefulness.

IN infancy functional gland activity is high. Maximum activity observed in early childhood ( 5–7 years) and it is precisely during this period that the maximum restraining influence on the development of the gonads dates back to. Further, with age, the functional activity of the pineal gland decreases. If, for some reason, children experience early involution of the gland, this is accompanied by premature puberty. It should be noted that complete atrophy of the pineal gland does not occur even in old age.

Thyroid

The thyroid gland secretes hormones thyroxine and triiodothyronine, which enhance oxidative processes, influence protein, carbohydrate, fat metabolism, growth, development and differentiation of tissues. With hyperfunction of the thyroid gland There is an increase in nervous excitability, irritability, muscle tremors, an increase in basal metabolism, a decrease in body weight, an increase in blood pressure, and tachycardia. Underproduction of the thyroid gland development myxedema: slowing down metabolic processes, reducing basal metabolism, bradycardia, swelling of the face and limbs, drowsiness, weight gain. The absence of these hormones in early childhood leads to a significant delay in physical and mental development - cretinism up to complete mental incompetence ( idiocy).

Thyroid begins to develop on 4th week embryonic development. Thyroid hormone concentration in the blood of newborns higher, how in adults. Over the course of several days, the level of hormones in the blood decreases.

Secretory function of the thyroid gland intensifies To 7 years old. Also, a significant increase in the secretory activity of the gland occurs in puberty and in subsequent ontogenesis changes little, slightly descending to old age.

Histological changes in old and senile age are in reduction follicle diameter, atrophy of the secretory epithelium. With age, not only the amount of hormone produced changes, but also the sensitivity of tissues to its action.

It should be noted, that in adults and children thyroid hormones have different action on protein exchange: in adults at excess hormone increases split proteins, in children - increases synthesis squirrel and the growth and formation of the body is accelerated.

Hormone thyrocalcitonin synthesized by parafollicular C cells of the thyroid gland. Its main function is decreased calcium levels in the blood due to tissue enhancement of mineralization processes in bone tissue and decreased calcium reabsorption in the kidneys and intestines. Content of calcitonin increases with age, highest concentration noted after 12 years.

Parathyroid glands

The parathyroid glands produce parathyroid hormone, which, together with calcitonin and vitamin D, regulates calcium metabolism in the body. Parathormone provides increase in blood calcium levels by stimulating the function of osteoclasts and the processes of bone demineralization and increasing the reabsorption of calcium in the kidneys and intestines.

The function of the glands activated on 3–4 weeks postnatal life. The concentration of parathyroid hormone in a newborn is close to that of an adult. Most active parathyroid glands are functioning up to 4–7 years. With age, there is an increase in the number of cells of adipose and supporting tissue, which by the age of 19–20 begins to displace glandular cells. By the age of 50, the parenchyma of the glands is replaced by adipose tissue.

Adrenal hormones

The adrenal glands consist of a cortex and medulla. The cortex is divided into 3 zones - glomerular (mineralocorticoids are synthesized, regulating mineral metabolism), beam (glucocorticoids are synthesized, regulating protein, fat and carbohydrate metabolism) and mesh (sex hormones are synthesized). Hypofunction adrenal cortex leads to the development Addison's disease (bronze disease), the manifestations of which include hyperpigmentation of the skin, weakening of cardiac activity and decreased blood pressure, increased fatigue, and loss of body weight. At hypercortisolism(Itsenko-Cushing syndrome) Obesity of the trunk, moon face, osteoporosis, hypertension, hyperglycemia, and reproductive dysfunction are observed.

Incretion of corticosteroids by the adrenal cortex occurs in embryogenesis relatively early - at 7–8 weeks intrauterine development. In the first days of life in the blood of a newborn is noted low concentration hormones of the adrenal cortex.

General level the production of corticosteroids throughout childhood and adolescence increases slowly at first, and then quickly, reaching maximum V 20 years and then decreases in old age. Wherein fastest to old age production decreases mineralocorticoids , somewhat slower - sex hormones, and even slower - glucocorticoids .

The adrenal medulla produces hormones adrenaline and norepinephrine, affecting the heart, small arteries, blood pressure, basal metabolism, muscles of the bronchi and gastric tract. Adrenal medulla the newborn has developed relatively weak. However, the activity of the sympathoadrenal system appears immediately after birth. Already at birth the level of adrenaline incretion in the adrenal glands is comparable with adult level person. In children and adolescents, the hypothalamic-pituitary-adrenal system is rapidly depleted, so the ability to resist the effects unfavorable factors she is small.

Pancreas

The intrasecretory function of the pancreas is carried out by clusters of special cells (islets of Langerhans) that produce hormones insulin And glucagon, which primarily affect carbohydrate metabolism. Promotion quantities insulin leads to an increase in glucose consumption by tissue cells, reduction blood glucose concentration, as well as to stimulate the synthesis of protein, glycogen, lipids. Glucagon increases glucose concentration in the blood by mobilizing liver glycogen.

U newborns intrasecretory pancreatic tissue more exocrine . With age, the total number of islets of Langerhans increases, but when converted to a unit of mass, their number, on the contrary, decreases significantly. TO 12 years old the number of islands becomes the same as in adults, after 25 years number of islets gradually decreases.

Before 2 year old age, the concentration of insulin in the blood is about 60% from adult concentration person. Subsequently, the concentration increases, a significant increase is observed during the period of intensive growth. With aging, the blood supply to the pancreas deteriorates, the number of cells in the islets of Langerhans and the biological activity of the insulin produced in them decrease. When aging rises glucose level in blood.

It should be noted that tolerance (sustainability)) to glucose load in children under 10 years of age higher, A assimilation dietary glucose occurs significantly faster than in adults (this explains why children love sweets so much and consume them in large quantities without significant danger to their health). With old age, this process slows down even more, which indicates a decrease in the insular activity of the pancreas.

With insulin deficiency, it develops diabetes, the main symptoms of which are an increase in the concentration of glucose in the blood (hyperglycemia), excretion of glucose in the urine (glucosuria), polyuria (increased diuresis), thirst.

Diabetes mellitus is more common everything develops in people after 40 years, although cases of congenital diabetes are not uncommon, which is usually associated with a hereditary predisposition. This disease is most often observed in children from 6 to 12 years and is found almost exclusively in the form insulin dependent diabetes mellitus Are important in the development of diabetes mellitus hereditary predisposition and provoking environmental factors, infectious diseases, nervous strain and overeating.

Thymus

Thymus gland (thymus) is a lymphoid organ well developed in childhood. Hormones produced by the thymus gland - thymosins, model immune and growth processes.

Thymus is being laid on 6th week And fully formed To 3rd month intrauterine development. With age, the size and structure of the gland changes greatly. At birth, the weight of the gland is 10-15 g, maximum value she reaches by 11-13 years(35–40g). Highest relative weight(per kg body weight) observed in newborns (4,2 %).

In newborns, the thymus is characterized by functional maturity and continues to develop further. But in parallel with this, connective tissue fibers and adipose tissue begin to develop in the thymus gland already in the first year of life.

Approximately after 13 years gradually happening age-related evolution of the thymus gland- a decrease in the mass of the thymus parenchyma with age, an increase in stroma with fatty tissue, a decrease in the production of hormones and T-lymphocytes. By the age of 75, the mass of the thymus is on average only 6 g. By old age, its cortex almost completely disappears. Age-related involution of the thymus gland is one of the reasons for the decline in activity cellular immunity, increased incidence of infectious, autoimmune and oncological diseases in the elderly. But even in older people, separate islands of the thymus parenchyma are preserved, which play a large role in the immunological defense of the body.

An increase in the volume and mass of the thymus above the age limit values while maintaining the normal histoarchitecture of the organ is designated as thymomegaly(thymic hyperplasia). This condition is characterized hypofunction of the thymus and occurs under the influence of congenital or acquired dysfunction of the neuroendocrine system, accompanied immunodeficiency state predominantly T-immune systems. These children have an increased incidence of infectious diseases, atopic and autoimmune diseases. Among the etiological factors, the most important are genetic factors, intrauterine infections, and mutagenic effects during the fetal period. Thymomegaly can be persistent, but in a large number of cases it is reversible and, as the child grows, gradually disappears when the imbalance of his neuroendocrine and immune systems is leveled. Under favorable circumstances, the size of the thymus spontaneously normalizes by 3–5 years of age.

In children with congenital underdevelopment of the thymus arises lymphopenia , decreased production of thymic hormones, deficiency of cellular immunity or combined immune deficiency.

gonads

The gonads are presented in male body testes, and in women's - ovaries. Male hormones androgens(testosterone) influence the development of the genital organs, secondary sexual characteristics, and the musculoskeletal system. Female sex hormones include estrogens (produced by follicular epithelial cells) and progesterone(produced by cells of the corpus luteum). Estrogens ensure the development of the body female type. Progesterone affects the lining of the uterus, preparing it for implantation of a fertilized egg. Estrogens and androgens ensure sexual function and the development of secondary sexual characteristics. With hyperfunction of the gonads, premature puberty is observed. With hypofunction, there is underdevelopment of primary and secondary sexual characteristics, prolonged growth, and in boys a eunuchoid body structure.

Testosterone secretion begins at the 8th week of embryonic development, and during between 11th and 17th weeks reaches adult level men. This is explained by its influence on the implementation of genetically programmed sex. In order for male reproductive organs to develop, hormonal stimulation from the testes is necessary. It has been established that the female pituitary gland works cyclically, which is determined by hypothalamic influences, while in men the pituitary gland functions evenly. There are no sex differences in the pituitary gland itself; they are contained in the nervous tissue of the hypothalamus and adjacent nuclei of the brain. Androgens cause the hypothalamus to differentiate into male type . In the absence of androgens, the development of the hypothalamus occurs according to the female type.

The role of own estrogens in the development of the female fetus is not so high, since in these processes Active participation take maternal estrogens and analogues of sex hormones produced in the adrenal glands. In newborn girls, maternal hormones circulate in the blood during the first 5–7 days.

The amount of sex hormones found in the blood is very low in the first days of life, and gradually increases, accelerating the pace of development, especially in period of second childhood (8 –12 years for boys and 8–11 for girls), teenage(13-16 years old boys, 12-15 years old girls) and youthful(17-21 years old boys and 16-20 years old girls). In data age periods the activity of the gonads is important for the rate of growth, morphogenesis and metabolic rate, that is, it can act as a leading factor in development.

As the body ages, a decrease in gonadal incretion is observed. In men, with age, the secretion of testosterone decreases, the activity of spermatogenesis decreases, and the level of testicular estrogens increases. But spermatogenesis will often continue into old age. IN prostate gland connective tissue and muscle elements predominate over secretory ones, weight and tendency to hypertrophy increase. As women age, they experience menopause (cessation of menstruation). The secretion of estradiol stops. As a result, androgens secreted by the adrenal glands begin to manifest themselves, which leads to characteristic changes in appearance women after menopause.

Lesson 5.

Topic 5. AGE FEATURES OF THE ENDOCRINE SYSTEM

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Ministry of Education of the Republic of Belarus

Educational institution "Belarusian State Pedagogical University named after Maxim Tank"

Psychology faculty

Test

Age features endocrine system

Introduction

Conclusion

Literature

Introduction

Endocrine system plays a very important role in the human body. It is responsible for the growth and development of mental abilities and controls the functioning of organs. Hormonal system It works differently for adults and children. For a long time the regulatory role of the nervous system in the secretion of hormones was disputed, and the regulatory functions of the endocrine system were considered autonomous; The leading role in regulating the activity of the endocrine glands themselves was assigned to the pituitary gland. The latter was confirmed by the secretion in the pituitary gland of the so-called triple hormones that control the secretory activity of other endocrine glands. However, with the discovery of neurosecretion in the 40s of our century, the regulatory role of the nervous system was proven experimentally (E. Scharrer).

1. Formation of glands and their functioning

The formation of glands and their functioning begins during intrauterine development. The endocrine system is responsible for the growth of the embryo and fetus. In the process of body formation, connections are formed between the glands. After the birth of a child, they become stronger.

From the moment of birth until the onset of puberty, the thyroid gland, pituitary gland, and adrenal glands are of greatest importance. IN puberty the role of sex hormones increases. In the period from 10-12 to 15-17 years old, many glands are activated. In the future, their work will stabilize. Subject to the right image life and absence of disease, there are no significant disruptions in the functioning of the endocrine system. The only exception is sex hormones.

The pituitary gland plays the most important role in human development. It is responsible for the functioning of the thyroid gland, adrenal glands and other peripheral parts of the system. The mass of the pituitary gland in a newborn is 0.1-0.2 grams. At 10 years of age, its weight reaches 0.3 grams. The mass of the gland in an adult is 0.7-0.9 grams. The size of the pituitary gland may increase in women during pregnancy. While the baby is expecting, its weight can reach 1.65 grams.

The main function of the pituitary gland is considered to control body growth. It is performed through the production of growth hormone (somatotropic). If the pituitary gland does not work correctly at an early age, this can lead to an excessive increase in body weight and size or, conversely, to a small size.

The gland significantly influences the functions and role of the endocrine system, therefore, if it does not work properly, the production of hormones by the thyroid gland and adrenal glands is carried out incorrectly.

In early adolescence (16-18 years), the pituitary gland begins to work stably. If its activity is not normalized, and somatotropic hormones are produced even after the body’s growth has completed (20-24 years), this can lead to acromegaly. This disease manifests itself in excessive enlargement of body parts.

The pineal gland is a gland that functions most actively until primary school age (7 years). Its weight in a newborn is 7 mg, in an adult - 200 mg. The gland produces hormones that inhibit sexual development. By the age of 3-7 years, the activity of the pineal gland decreases. During puberty, the number of hormones produced decreases significantly. Thanks to the pineal gland, human biorhythms are maintained.

Another one important gland in the human body - thyroid. It begins to develop one of the first in the endocrine system. By the time of birth, the weight of the gland is 1-5 grams. At 15-16 years old, its weight is considered maximum. It is 14-15 grams. The greatest activity of this part of the endocrine system is observed at 5-7 and 13-14 years of age. After 21 years and up to 30 years, the activity of the thyroid gland decreases.

The parathyroid glands begin to form at 2 months of pregnancy (5-6 weeks). After the birth of a child, their weight is 5 mg. During her life, her weight increases 15-17 times. The greatest activity of the parathyroid gland is observed in the first 2 years of life. Then, until the age of 7, it is maintained at a fairly high level.

The thymus gland or thymus is most active during puberty (13-15 years). At this time, its weight is 37-39 grams. Its mass decreases with age. At 20 years old the weight is about 25 grams, at 21-35 - 22 grams. The endocrine system in older people works less intensively, which is why the thymus gland decreases in size to 13 grams. As the lymphoid tissues thymus is replaced by fat.

At birth, the adrenal glands weigh approximately 6-8 grams each. As they grow, their weight increases to 15 grams. The formation of glands occurs up to 25-30 years. The greatest activity and growth of the adrenal glands is observed in 1-3 years, as well as during puberty. Thanks to the hormones that the gland produces, a person can control stress. They also affect the process of cell restoration, regulate metabolism, sexual and other functions.

The development of the pancreas occurs before age 12. Disturbances in its functioning are detected mainly in the period before the onset of puberty.

Female and male gonads are formed during intrauterine development. However, after the birth of a child, their activity is restrained until 10-12 years, that is, until the onset of the pubertal crisis.

Male gonads - testicles. At birth, their weight is approximately 0.3 grams. From the age of 12-13, the gland begins to work more actively under the influence of gonadoliberin. In boys, growth accelerates and secondary sexual characteristics appear. At the age of 15, spermatogenesis is activated. By the age of 16-17, the process of development of the male gonads is completed, and they begin to work in the same way as in an adult.

The female reproductive glands are the ovaries. Their weight at birth is 5-6 grams. The weight of the ovaries in adult women is 6-8 grams. The development of the gonads occurs in 3 stages. From birth to 6-7 years, a neutral stage is observed.

During this period, the female-type hypothalamus is formed. The pre-pubertal period lasts from 8 years to the onset of adolescence. From the first menstruation to the onset of menopause, puberty is observed. At this stage, active growth occurs, the development of secondary sexual characteristics, and the formation of the menstrual cycle.

The endocrine system in children is more active compared to adults. The main changes in the glands occur at an early age, junior and senior school age.

In order for the formation and functioning of the glands to be carried out correctly, it is very important to prevent disruptions to their functioning. The TDI-01 “Third Wind” simulator can help with this. You can use this device from the age of 4 and throughout your life. With its help, a person masters the technique of endogenous breathing. Thanks to this, it has the ability to maintain the health of the entire body, including the endocrine system.

2. Hormones and the endocrine system

Endocrine system human body has a significant impact on all aspects of his life: from the most primitive physiological functions to multifaceted and complex mental processes and phenomena. In the organs of the endocrine system - the endocrine glands - various complex chemical physiologically active substances, called hormones (from the Greek gorman - to excite). Hormones are secreted by glands directly into the blood, which is why these glands are called endocrine glands. In contrast, exocrine glands secrete substances formed in them through special ducts into various cavities of the body or onto its surface (for example, salivary or sweat glands).

Hormones take part in the regulation of the growth and development of the body, metabolic and energy processes, and in the processes of coordinating all physiological functions of the body. IN last years The participation of hormones in the molecular mechanisms of transmission of hereditary information and in determining the periodicity of some functional processes of the body - biological rhythms (for example, sexual cycles in women) has also been proven.

Thus, hormones... component the humoral system of regulation of functions, which, together with the nervous system, provides a unified neuro-humoral regulation of the functions of the body. In evolutionary terms, the hormonal link in the system of control and regulation of functions is the youngest. It appeared in the later stages of the evolution of the organic world, when the nervous system had already won its “right to exist.”

The endocrine glands include: thyroid, parathyroid, goiter, adrenal glands, pituitary gland and pineal gland. There are also mixed glands, which are both glands of external and internal secretion: the pancreas and the sex glands - the testes and ovaries.

Currently, more than 40 hormones are known. Many of them are well studied, and some are even synthesized artificially and are widely used in medicine to treat various diseases.

It is interesting to note that many hormones act on cells every moment, but only those whose influence provides the most appropriate effect affect cellular processes. The appropriateness of the effect of hormones on cellular processes is determined by special substances - prostaglandins. They perform, figuratively speaking, the function of regulators that inhibit the effect on the cell of those hormones whose influence is this moment undesirable.

The indirect action of hormones through the nervous system is ultimately also associated with their influence on the course of cellular processes, which leads to a change in the functional state nerve cells and, accordingly, to changes in the activity of nerve centers that regulate certain functions of the body. In recent years, data have been obtained indicating the “interference” of hormones even in the activity of the hereditary apparatus of cells: they affect the synthesis of RNA and cellular proteins. For example, some hormones of the adrenal glands and sex glands have this effect.

The activity of each endocrine gland is carried out only in close connection with each other. This interaction within the endocrine system is associated both with the influence of hormones on the functional activity of the endocrine glands, and with the effect of hormones on the nerve centers, which, in turn, change the activity of the glands. As a result of such mutual influence of the endocrine glands and constant control over their activity by the nervous system according to the feedback principle, a certain hormonal balance, in which the amount of hormones secreted by the glands is at a relatively constant level or changes in accordance with the functional activity of the body.

For a long time, the regulatory role of the nervous system in the secretion of hormones was disputed, and the regulatory functions of the endocrine system were considered autonomous; The leading role in regulating the activity of the endocrine glands themselves was assigned to the pituitary gland. The latter was confirmed by the secretion in the pituitary gland of the so-called triple hormones that control the secretory activity of other endocrine glands. However, with the discovery of neurosecretion in the 40s of our century, the regulatory role of the nervous system was proven experimentally (E. Scharrer).

According to modern data, some neurons are capable, in addition to their main functions, of secreting physiologically active substances - neurosecrets. In particular, neurons of the hypothalamus, which is anatomically closely related to the pituitary gland, play a particularly important role in neurosecretion. It is the neurosecretion of the hypothalamus that determines the secretory activity of the pituitary gland, and through it of all other endocrine glands. Neurosecrets of the hypothalamus are called releasing hormones; hormones that stimulate the secretion of tropic hormones of the pituitary gland - liberins; hormones that inhibit secretion - statins.

Thus, the hypothalamus, depending on external influences and state internal environment, firstly, coordinates all vegetative processes of our body, performing the functions of the highest vegetative nerve center; secondly, it regulates the activity of the endocrine glands, transforming nerve impulses into humoral signals, which then enter the corresponding tissues and organs and change their functional activity.

Despite such perfect regulation of the activity of the endocrine glands, their functions change significantly under the influence pathological processes. It is possible either to increase the secretion of the endocrine glands - hyperfunction of the glands, or to reduce secretion - hypofunction. Disruption of the functions of the endocrine system, in turn, affects the vital processes of the body. Particularly significant disturbances in the functional activity of the body due to endocrine diseases are observed in children and adolescents. Often these diseases not only lead to physical disability of the child, but also harm his mental development. It should be noted that hormonal imbalance is often observed normally as a temporary phenomenon during the development and growth of children and adolescents. The most noticeable endocrine changes occur during adolescence, during puberty. These hormonal changes in adolescents to a large extent determine many features of their higher nervous activity and leave their mark on all aspects of behavior.

It is quite obvious that the optimal organization of educational work with children and adolescents requires knowledge not only of the characteristics of the activity of their nervous system and higher nervous activity, but also of the characteristics of the endocrine system. Below we will briefly discuss the anatomical and physiological features of the endocrine system and the specific significance of each of its components for normal physical and mental development children and teenagers.

endocrine gland hormonal mental

3. Prevention of diseases of the endocrine system

The human endocrine system favorable conditions his life functions normally - hormones responsible for certain processes in the body are produced strictly in required quantities. But sometimes even the slightest lifestyle changes can cause glands to malfunction. And they can lead to serious violations health. To avoid this, it is necessary to prevent glandular diseases. This can be done by adhering to a certain lifestyle.

The first thing that a person who decides to take up the prevention of diseases of the endocrine system should pay attention to is the diet. Quite often, disruptions to the endocrine system occur due to a lack of vitamins and minerals. Therefore, a person’s diet must be optimized. The diet should contain foods containing vitamins A, B, C, E, as well as almost all other vitamins. It is also important that the diet contains foods with sufficient mineral content, especially iodine. The need for this substance is from 50 to 120 mcg/day for a child, and 150 mcg/day for an adult. Prevention of the endocrine system should involve the consumption of lean meats, seafood (fish, seaweed and others), grains, eggs, dairy products, fruits and vegetables. In addition, there are iodized foods, such as salt, which can be an excellent source of this substance for the human body.

For prevention hormonal disorders, it is important to lead healthy image life. A person should get rid of bad habits(smoking, drinking alcohol and others), engage in moderate physical exercise.

The ability to endure stress will help to avoid hormonal imbalances. Various psycho-emotional stresses cause interruptions in the functioning of the glands. They begin to function incorrectly, causing the amount of hormones to increase or decrease.

Currently, the prevention of diseases of the endocrine system is also carried out using various dietary supplements. Dietary supplements, which contain groups of substances, provide the necessary daily dose vitamins and minerals. This allows a person to saturate his body with all necessary elements without following a diet.

Another means of preventing diseases of the glands and cells can be the use of the TDI-01 “Third Wind” breathing simulator. This small device helps normalize the functioning of the endocrine system.

As a result, the process of hormone production stabilizes and disappears inflammatory processes. Thanks to classes at TDI-01, a person reacts steadily to stress and avoids depression.

Adopting a healthy lifestyle and following a diet becomes easier.

Conclusion

From a chemical point of view, all hormones are organic compounds and can be divided into two main groups. One includes hormones that are proteins or polypeptides - peptide hormones (for example, hormones of the thyroid gland, pancreas, neurohormones, etc.); to the other - steroid hormones (hormones of the adrenal cortex and sex).

Hormones exert their influence either directly on tissues or organs, stimulating or inhibiting their work, or indirectly, through the nervous system. The mechanism of direct action of some hormones (steroids, thyroid hormones, etc.) is associated with their ability to penetrate cell membranes and interact with intracellular enzyme systems, changing the course of cellular processes. Large molecular peptide hormones cannot freely penetrate cell membranes and have a regulatory effect on cellular processes with the help of special receptors located on the surface of cell membranes. Through such hormone-receptor complexes, the synthesis of cyclic adenosine monophosphoric acid (cAMP) is then activated in the cell. The latter has an activating effect on cellular enzymes - kinases, which accordingly changes the entire course of cellular metabolic processes and energy.

Literature

1. Encyclopedia for children. Volume 18. Man. Part 1. The origin and nature of man. How the body works. The art of being healthy / Chapter. ed. V.A. Volodin. - M.: Avanta+, 2001. - 464 p.: ill.

2. Great Soviet Encyclopedia The mechanism of action of hormones, Tashkent, 1976;

3. Agazhdanyan N.A. Katkov A.Yu. reserves of our body. - M.: Knowledge, 1990

4. Etingen L.E. How are you arranged, Mr. Body? - M.: Linka - Press, 1997.

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