Age-related features of the endocrine system of adolescent children. influence the growth and formation of organs, organ systems and the entire organism as a whole

Age-related features of the endocrine system

Endocrine system The human body is represented by endocrine glands that produce certain compounds (hormones) and secrete them directly (without ducts leading out) into the blood. In this, endocrine glands differ from other (exocrine) glands; the product of their activity is released only into the external environment through special ducts or without them. Exocrine glands are, for example, salivary, gastric, sweat glands etc. In the body there are also mixed glands, which are both exocrine and endocrine. Mixed glands include the pancreas and gonads.

Hormones of the endocrine glands They are carried throughout the body through the bloodstream and perform important regulatory functions: they influence metabolism, regulate cellular activity, growth and development of the body, cause changes in age periods, and affect the functioning of the respiratory, circulatory, digestive, excretory and reproduction organs. Under the influence and control of hormones (in optimal external conditions) the entire genetic program of human life is also implemented.

According to topography, the glands are located in different places body: in the head area there are the pituitary gland and epiphysis, in the neck and chest The thyroid, a pair of thyroid and thymus (thymus) glands are located. In the abdominal area are the adrenal glands and pancreas, in the pelvic area are the gonads. IN different parts body, mainly along large blood vessels, located small analogues of endocrine glands - paraganglia.

Features of the endocrine glands in at different ages

The functions and structure of the endocrine glands change significantly with age.

Pituitary It is considered the gland of all glands since its hormones influence the work of many of them. This gland is located at the base of the brain in the recess of the sella turcica of the sphenoid (main) bone of the skull. In a newborn, the mass of the pituitary gland is 0.1-0.2 g, at 10 years it reaches a mass of 0.3 g, and in adults - 0.7-0.9 g. During pregnancy in women, the mass of the pituitary gland can reach 1.65 g The gland is conventionally divided into three parts: anterior (adenohypophysis), posterior (non-gyrogypophysis) and intermediate. In the area of the adenohypophysis and the intermediate section of the pituitary gland, most of the hormones of the gland are synthesized, namely growth hormone(growth hormone), as well as adrenocorticotropic (ACTA), thyroid-stimulating (THG), gonadotropic (GTG), luteotropic (LTG) hormones and prolactin. In the area of the neurohypophysis they acquire active form hypothalamic hormones: oxytocin, vasopressin, melanotropin and Mizin factor.

The pituitary gland is closely connected by neural structures with the hypothalamus diencephalon, due to which the interaction and coordination of the nervous and endocrine regulatory systems is carried out. Hypothalamic-pituitary neural pathway(the cord connecting the pituitary gland to the hypothalamus) has up to 100 thousand nerve processes of hypothalamic neurons, which are capable of creating a neurosecretion (transmitter) of an excitatory or inhibitory nature. The processes of hypothalamic neurons have terminal endings (synapses) on the surface blood capillaries posterior lobe of the pituitary gland (neurohypophysis). Once in the blood, the mediator is further transported to the anterior lobe of the pituitary gland (adenohypophysis). The blood vessels at the level of the adenohypophysis again divide into capillaries, flow around the islets of secretory cells and, thus, through the blood, influence the activity of hormone formation (accelerate or slow down). According to the scheme that is described, the relationship in the work of the nervous and endocrine regulatory systems is precisely realized. In addition to communication with the hypothalamus, the pituitary gland receives neuronal processes from the gray tubercle of the anterior part cerebral hemispheres, from the cells of the thalamus, which is at the bottom of the 111th ventricle of the brainstem and from the solar plexus of the autonomic nervous system, which are also capable of influencing the activity of the formation of pituitary hormones.

The main hormone of the pituitary gland is somatotropic hormone (GH) or growth hormone, which regulates bone growth, increase in body length and weight. At insufficient quantities growth hormone (hypofunction of the gland), dwarfism is observed (body length up to 90-100 ohms, low body weight, although mental development can proceed normally). Excess of somatotropic hormones in childhood(hyperfunction of the gland) leads to pituitary gigantism (body length can reach 2.5 meters or more, mental development often suffers). The pituitary gland produces, as mentioned above, adrenocorticotropic hormone (ACTH), gonadotropic hormones (GTH), and thyroid-stimulating hormone (TSH). A greater or lesser amount of the above hormones (regulated by the nervous system), through the blood, affects the activity of the adrenal glands, gonads and thyroid glands, respectively, changing, in turn, their hormonal activity, and through this influencing the activity of those processes. which are regulated. The pituitary gland also produces melanophore hormone, which affects the color of skin, hair and other body structures, vasopressin, which regulates blood pressure and water exchange and oxytocin, which affects the processes of milk secretion, the tone of the walls of the uterus, etc.

Pituitary hormones also influence higher nervous activity in humans. During puberty, gonadotropic hormones of the pituitary gland are especially active, influencing the development of the gonads. The appearance of sex hormones in the blood, in turn, inhibits the activity of the pituitary gland (feedback). The function of the pituitary gland stabilizes in the post-pubertal period (16–18 years). If the activity of somatotropic hormones persists even after the completion of the body’s growth (after 20–24 years), then acromegaly develops, when individual parts of the body in which the ossification processes have not yet completed become disproportionately large (for example, the hands, feet, head, ears become significantly enlarged and other body parts). During the period of child growth, the pituitary gland doubles in weight (from 0.3 to 0.7 g).

Epiphysis ( weight up to OD g) functions most actively until 7 years of age, and then degenerates into an inactive form. The pineal gland is considered the gland of childhood, since this gland produces the hormone GnRH, which inhibits the development of the gonads until a certain time. In addition, the pineal gland regulates water-salt metabolism, forming substances similar to hormones: melatonin, serotonin, norepinephrine, histamine. There is a certain cyclicity in the formation of pineal gland hormones during the day: melatonin is synthesized at night, and serotonin is synthesized at night. Due to this, it is believed that the pineal gland acts as a kind of chronometer of the body, regulating changes life cycles, and also ensures the relationship between a person’s own biorhythms and the rhythms of the environment.

Thyroid(weight up to 30 grams) located in front of the larynx on the neck. The main hormones of this gland are thyroxine, tri-iodothyronine, which influence the metabolism of water and minerals, on the move oxidative processes, on the processes of fat combustion, on height, body weight, on the physical and mental development of a person. The gland functions most actively at 5-7 and 13-15 years of age. The gland also produces the hormone Thyrocalcitonin, which regulates the exchange of calcium and phosphorus in the bones (inhibits their leaching from the bones and reduces the amount of calcium in the blood). With hypofunction of the thyroid gland, children are stunted in growth, their hair falls out, their teeth suffer, their psyche and mental development are impaired (the disease myxedema develops), and they lose their minds (cretinism develops). When the thyroid gland is overactive, it occurs Graves' disease signs of which are an enlarged thyroid gland, withdrawn eyes, sudden weight loss and a number of autonomic disorders ( increased heart rate, sweating, etc.). The disease is also accompanied by increased irritability, fatigue, decreased performance, etc.

Parathyroid glands(weight up to 0.5 g) are located behind the thyroid gland. The hormone of these glands is parathyroid hormone, which maintains the amount of calcium in the blood at a constant level (even, if necessary, by washing it out of the bones), and together with vitamin D, it affects the exchange of calcium and phosphorus in the bones, namely, it promotes the accumulation of these substances in fabric. Hyperfunction of the gland leads to super-strong mineralization of bones and ossification, as well as increased excitability of the cerebral hemispheres. With hypofunction, tetany (convulsions) is observed and bones soften. The endocrine system of the human body contains many important glands and this is one of them.

Thymus gland (thymus), like the bone marrow, it is the central organ of immunogenesis. Individual red stem cells bone marrow enter the thymus through the bloodstream and undergo stages of maturation and differentiation in the gland structures, turning into T-lymphocytes (thymus-dependent lymphocytes). The latter again enter the bloodstream and spread throughout the body and create thymus-dependent zones in the peripheral organs of immunogenesis (spleen, lymph nodes etc.).. The thymus also creates a number of substances (thymosin, thymopoietin, thymic humoral factor, etc.), which most likely affect the processes of differentiation of G-lymphocytes. The processes of immunogenesis are described in detail in section 4.9.

Thymus is located in breastbone and has two fates covered with connective tissue. The stroma (body) of the thymus has a reticular retina, in the loops of which thymic lymphocytes (thymocytes) and plasma cells (leukocytes, macrophages, etc.) are located. The body of the gland is conventionally divided into a darker (cortical) and medullary part. At the border of the cortex and brain parts large cells with high division activity (lymphoblasts) are isolated, which are considered germ points, because this is where stem cells come to mature.

Thymus The endocrine system is active at 13-15 years old - at this time it has the greatest mass (37-39g). After puberty, the mass of the thymus gradually decreases: at 20 years old it averages 25 g, at 21-35 years old - 22 g (V.M. Zholobov, 1963), and at 50-90 years old - only 13 g (W. Kroeman , 1976). The complete lymphoid tissue of the thymus does not disappear until old age, but most of it is replaced by connective (fatty) tissue: if in a newborn child connective tissue makes up up to 7% of the mass of the gland, then at 20 years old this reaches up to 40%, and after 50 years - 90 %. The thymus gland is also capable of temporarily restraining the development of the gonads in children, and the hormones of the gonads themselves, in turn, can cause a reduction of the thymus.

Adrenal glands located above the kidneys and have a weight at birth of a child of 6-8 g, and in adults - up to 15 g each. These glands grow most actively during puberty, and finally mature at 20-25 years. Each adrenal gland has two layers of tissue: the outer (cortex) and the inner (medulla). These glands produce many hormones that regulate various processes in organism. Corticosteroids are formed in the cortex of the glands: mineralocorticoids and glucocorticoids, which regulate protein, carbohydrate, mineral and water-salt metabolism, affect the rate of cell reproduction, regulate the activation of metabolism during muscle activity and regulate the composition shaped elements blood (leukocytes). Gonadocorticosteroids (analogs of androgens and estrogens) are also produced, affecting the activity of sexual function and the development of secondary sexual characteristics (especially in childhood and old age). The adrenal medulla produces the hormones adrenaline and norepinephrine, which can activate the functioning of the entire body (similar to the action sympathetic division autonomic nervous system). These hormones are exclusively important to mobilize the body's physical reserves during stress, when performing physical exercise, especially during periods of hard work, intense sports training or competitions. With excessive excitement during sports performances, children can sometimes experience weakening of muscles, inhibition of reflexes to maintain body position, due to overexcitation of the sympathetic nervous system, as well as due to excessive release of adrenaline into the blood. In these circumstances, an increase in plastic muscle tone may also be observed, followed by numbness of these muscles or even numbness of spatial posture (the phenomenon of catalepsy).

The balance of the formation of GCS and mineralocorticoids is important. When insufficient glucocorticoids are produced, then hormonal balance shifts towards mineralocorticoids and this, by the way, can reduce the body’s resistance to the development of rheumatic inflammation in the heart and joints, to the development bronchial asthma. Excess glucocorticoids suppress inflammatory processes but, if this excess is significant, it can contribute to an increase in blood pressure, blood sugar levels (the development of so-called steroid diabetes) and can even contribute to the destruction of heart muscle tissue, the occurrence of ulcers of the stomach walls, etc.

Pancreas. This gland, like the gonads, is considered mixed, since it performs exogenous (production digestive enzymes) and endogenous functions. As an endogenous gland, the pancreas produces mainly the hormones glucagon and insulin, which affect carbohydrate metabolism in the body. Insulin lowers blood sugar, stimulates glycogen synthesis in the liver and muscles, promotes the absorption of glucose by muscles, retains water in tissues, activates protein synthesis and reduces the formation of carbohydrates from proteins and fats. Insulin also inhibits the formation of the hormone glucagon. The role of glucagon is opposite to the action of insulin, namely: glucagon increases blood sugar, including due to the conversion of tissue glycogen into glucose. With hypofunction of the gland, the production of insulin decreases and this can cause a dangerous disease - diabetes mellitus. The development of pancreatic function continues until approximately 12 years of age in children and thus congenital disorders in her work often appear precisely during this period. Among other pancreatic hormones, lipocaine (promotes the utilization of fats), vagotonin (activates the parasympathetic part of the autonomic nervous system, stimulates the formation of red blood cells), centropein (improves the use of oxygen by the body's cells) should be highlighted.

In the human body, in different parts of the body, individual islands of glandular cells can be found, forming analogues of the endocrine glands and are called paraganglia. These glands usually produce local hormones that influence the course of certain functional processes. For example, enteroenzyme cells of the stomach walls produce hormones (hormones) gastrin, secretin, cholecystokinin, which regulate the processes of food digestion; the endocardium of the heart produces the hormone atriopeptide, which acts to reduce blood volume and pressure. The hormones erythropoietin (stimulates the production of red blood cells) and renin (affect blood pressure and influence the exchange of water and salts) are formed in the walls of the kidneys.

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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-related features of the endocrine system

Introduction

Conclusion

Literature

Introduction

The endocrine system plays a very important role in the human body. She is responsible for growth and development mental abilities, controls the functioning of organs. Hormonal system It doesn't work the same 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. During the formation of the body, 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 highest value have a thyroid gland, pituitary gland, adrenal glands. IN puberty the role of sex hormones increases. During the period from 10-12 to 15-17 years, 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 in early age The pituitary gland does not work properly, this can lead to an excessive increase in body weight and size or, on the contrary, to small size.

The gland significantly influences the functions and role of the endocrine system, therefore, when it malfunction 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 important gland in the human body is the 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 hypothalamus is formed by female type. 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 it happens active growth, development of secondary sexual characteristics, 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

The endocrine system of the human body has a significant impact on all aspects of its 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 are formed, 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 recent 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 has also been proven - biological rhythms(for example, sexual cycles in women).

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 evolution organic world, when the nervous system has 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 have even been 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 currently 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 changes functional state nerve cells and, accordingly, to changes in activity nerve centers regulating 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 principle feedback the body always maintains a certain hormonal balance, in which the amount of hormones secreted by the glands is at a relatively constant level or changes accordingly functional activity 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 autonomic 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 of pathological processes. It is possible either an increase in the secretion of the endocrine glands - hyperfunction of the glands, or a decrease in 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 It is often observed normally as a temporary phenomenon in the process of development and growth of children and adolescents. The most noticeable endocrine changes occur in adolescence, during puberty. These hormonal changes in adolescents largely 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 the normal physical and mental development of children and adolescents.

endocrine gland hormonal mental

3. Prevention of diseases of the endocrine system

The human endocrine system, under favorable conditions of 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.

To prevent hormonal disorders, it is important to lead a healthy lifestyle. A person should get rid of bad habits(smoking, drinking alcohol and others), engage in moderate physical exercise.

Avoid violations hormonal levels The ability to cope with stress will help. Various psycho-emotional stresses cause disruptions 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 of vitamins and minerals. This allows a person to saturate his body with all the necessary elements without dieting.

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

As a result, the process of hormone production stabilizes and inflammatory processes disappear. 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).

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 Mechanism of action of hormones, Tashkent, 1976;

3. Agazhdanyan N.A. Katkov A.Yu. Our body's reserves. - M.: Knowledge, 1990

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

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Endocrine glands, or endocrine glands, have the characteristic property of producing and secreting hormones. Hormones are active substances whose main action is to regulate metabolism by stimulating or inhibiting certain enzymatic reactions and influencing the permeability of the cell membrane. Hormones are important for growth, development, morphological differentiation of tissues, and especially for maintaining the constancy of the internal environment. For normal height and the development of the child requires normal function of the endocrine glands.

The endocrine glands are located in different parts of the body and have varied structure. Endocrine organs in children have morphological and physiological characteristics, which undergo certain changes in the process of growth and development.

The endocrine glands include the pituitary gland, thyroid gland, parathyroid glands, thymus gland, adrenal glands, pancreas, male and female gonads (Fig. 15). Let's dwell on brief description endocrine glands.

Pituitary gland - small oval shape gland located at the base of the skull in the recess of the sella turcica. The pituitary gland consists of the anterior, posterior and intermediate lobes, which have different histological structure, which causes the production of various hormones. By the time of birth, the pituitary gland is quite developed. This gland has a very close connection with the hypothalamic region of the central nervous system through nerve bundles and forms a single unit with them functional system. IN Lately It has been proven that the hormones of the posterior lobe of the pituitary gland and some hormones of the anterior lobe are actually formed in the hypothalamus in the form of neurosecretions, and the pituitary gland is only the site of their deposition. In addition, the activity of the pituitary gland is regulated by circulating hormones produced by the adrenal glands, thyroid and sex glands.

The anterior lobe of the pituitary gland, as currently established, secretes the following hormones: 1) growth hormone, or somatotropic hormone (GH), which acts directly on the development and growth of all organs and tissues of the body; 2) thyroid-stimulating hormone (TSH), which stimulates the function of the thyroid gland; 3) adrenocorticotropic hormone (ACTH), which affects the function of the adrenal glands by regulation carbohydrate metabolism; 4) luteotropic hormone (LTH); 5) luteinizing hormone (LH); 6) follicle-stimulating hormone (FSH). It should be noted that LTG, LH and FSH are called gonadotropic; they influence the maturation of the gonads and stimulate the biosynthesis of sex hormones. The middle lobe of the pituitary gland secretes melanoform hormone (MFH), which stimulates the formation of pigment in the skin. The posterior lobe of the pituitary gland secretes the hormones vasopressin and oxytocin, which affect blood pressure levels, sexual development, diuresis, protein and fat metabolism, and uterine contractions.

Hormones produced by the pituitary gland enter the bloodstream, with which they are transported to certain organs. As a result of disruption of the activity of the pituitary gland (increase, decrease, loss of function) for one reason or another, various endocrine diseases can develop (acromegaly, gigantism, Itsenko-Cushing's disease, dwarfism, adiposogenital dystrophy, diabetes insipidus, etc.).

The thyroid gland, consisting of two lobules and an isthmus, is located in front and on both sides of the trachea and larynx. By the time the child is born, this gland is distinguished by its incomplete structure (smaller follicles containing less colloid).

The thyroid gland, under the influence of TSH, secretes triiodothyronine and thyroxine, which contain over 65% iodine. These hormones have a multifaceted effect on metabolism, on the activity of the nervous system, on the circulatory system, influence the processes of growth and development, and the course of infectious and allergic processes. The thyroid gland also synthesizes thyrocalcitonin, which plays a significant role in maintaining normal calcium levels in the blood and determines its deposition in the bones. Consequently, the functions of the thyroid gland are very complex.

Disorders of the thyroid gland can be caused by congenital anomalies or acquired diseases, which is expressed by the clinical picture of hypothyroidism, hyperthyroidism, and endemic goiter.

The parathyroid glands are very small glands, usually located on the posterior surface of the thyroid gland. Most people have four parathyroid glands. The parathyroid glands secrete parathyroid hormone, which has a significant effect on calcium metabolism, regulates the processes of calcification and decalcification in bones. Diseases of the parathyroid glands can be accompanied by a decrease or increase in hormone secretion (hypoparathyroidism, hyperparathyroidism) (about the goiter, or thymus gland, see “Anatomical and physiological features of the lymphatic system”).

The adrenal glands are paired endocrine glands located in the posterior superior part abdominal cavity and are adjacent to the upper ends of the kidneys. The mass of the adrenal glands in a newborn is the same as in an adult, but their development is not yet complete. Their structure and function undergo significant changes after birth. In the first years of life, the mass of the adrenal glands decreases and in the prepubertal period reaches the mass of the adrenal glands of an adult (13-14 g).

The adrenal gland consists of a cortex (outer layer) and a medulla (inner layer), which secrete hormones needed by the body. The adrenal cortex produces a large number of steroid hormones, and only some of them are physiologically active. These include: 1) glucocorticoids (corticosterone, hydrocortisone, etc.), which regulate carbohydrate metabolism, promoting the transition of proteins into carbohydrates, have a pronounced anti-inflammatory and desensitizing effect; 2) mineralocorticoids, affecting water-salt metabolism, causing the absorption and retention of sodium in the body; 3) androgens, which have an effect on the body similar to sex hormones. In addition, they have an anabolic effect on protein metabolism, affecting the synthesis of amino acids and polypeptides, increase muscle strength, body weight, accelerate growth, and improve bone structure. The adrenal cortex is under the constant influence of the pituitary gland, which secretes adrenocorticotropic hormone and other adrenopituitary products.

The adrenal medulla produces adrenaline and norepinephrine. Both hormones have the property of increasing arterial pressure, narrow blood vessels(with the exception of the coronary and pulmonary vessels, which they dilate), relax smooth muscles intestines and bronchi. When the adrenal medulla is damaged, for example due to hemorrhages, the release of adrenaline decreases, the newborn becomes pale, adynamic, and the child dies due to symptoms of motor failure. A similar picture is observed with congenital hypoplasia or absence of adrenal glands.

The diversity of adrenal gland function also determines the diversity clinical manifestations diseases, among which lesions of the adrenal cortex predominate (Addison's disease, congenital adrenogenital syndrome, adrenal tumors, etc.).

The pancreas is located behind the stomach on the back abdominal wall, approximately at the level of the II and III lumbar vertebrae. This is a relatively large gland, its weight in newborns is 4-5 g, by the period of puberty it increases 15-20 times. The pancreas has exocrine (secretes the enzymes trypsin, lipase, amylase) and intrasecretory (secretes the hormones insulin and glucagon) functions. Hormones are produced by pancreatic islets, which are cellular clusters scattered throughout the pancreatic parenchyma. Each hormone is produced by special cells and enters directly into the blood. In addition, in the small excretory ducts the glands produce a special substance - lipocaine, which inhibits the accumulation of fat in the liver.

The pancreatic hormone insulin is one of the most important anabolic hormones in the body; it has a strong influence on everything metabolic processes and above all, it is a powerful regulator of carbohydrate metabolism. In addition to insulin, the pituitary gland, adrenal glands, and thyroid gland also participate in the regulation of carbohydrate metabolism.

Due to primary damage to the pancreatic islets or a decrease in their function as a result of influence from the nervous system, as well as humoral factors diabetes mellitus develops, in which insulin deficiency is the main pathogenetic factor.

The sex glands - the testes and ovary - are paired organs. Some newborn boys have one or both testicles located not in the scrotum, but in the inguinal canal or in the abdominal cavity. They usually descend into the scrotum soon after birth. In many boys, the testicles retract inward at the slightest irritation, and this does not require any treatment. The function of the gonads is directly dependent on the secretory activity of the anterior pituitary gland. In early childhood, the gonads play a relatively small role. They begin to function intensively during puberty. The ovaries, in addition to producing eggs, produce sex hormones - estrogens, which ensure the development of the female body, its reproductive apparatus and secondary sexual characteristics.

The testicles produce male sex hormones - testosterone and androsterone. Androgens have a complex and multifaceted effect on the growing child’s body.

During puberty, the growth and development of muscles significantly increases in both sexes.

Sex hormones are the main stimulators of sexual development and are involved in the formation of secondary sexual characteristics (in boys - the growth of a mustache, beard, change in voice, etc., in girls - the development of mammary glands, pubic hair growth, armpits, changes in the shape of the pelvis, etc.). One of the signs of the onset of puberty in girls is menstruation (the result of periodic maturation of eggs in the ovary), in boys - wet dreams (throwing out of the ovary in a dream). urethra fluid containing sperm).

The process of puberty is accompanied by increased excitability of the nervous system, irritability, changes in the psyche, character, behavior, and causes new interests.

In the process of child growth and development, very complex changes in the activity of all endocrine glands, therefore the importance and role of the endocrine glands in different periods of life are not the same.

During the 1st half of extrauterine life, apparently big influence The thymus gland influences a child's growth.

In a child, after 5-6 months, the function of the thyroid gland begins to increase and the hormone of this gland has the greatest effect in the first 5 years, during the most rapid changes growth and development. The weight and size of the thyroid gland gradually increase with age, especially intensively at the age of 12-15 years. As a result, in the prepubertal and pubertal periods, especially in girls, there is a noticeable enlargement of the thyroid gland, which is usually not accompanied by a violation of its function.

Pituitary growth hormone is less important in the first 5 years of life, only around 6-7 years its influence becomes noticeable. In the prepubertal period, the functional activity of the thyroid gland and the anterior pituitary gland increases again.

During puberty, the secretion of gonadotropic hormones of the pituitary gland, androgens of the adrenal glands and especially hormones of the gonads begins, which affect the functions of the entire organism as a whole.

All endocrine glands are in a complex correlative relationship with each other and in functional interaction with the central nervous system. The mechanisms of these connections are extremely complex and currently cannot be considered fully understood.

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General characteristics of the endocrine glands in children and adolescents

The endocrine glands form the endocrine system, which, along with the nervous system, has a regulatory effect on the human body. Endocrine glands are organs in which a secretion is formed that specifically affects various functions body. The secretion of the endocrine glands is called hormones (biologically active substances). Unlike other glands, endocrine glands do not have excretory ducts and their secretions are released into the blood or lymph. Based on this principle, endocrine glands are called endocrine glands. The endocrine glands (ECGs) include:

1) pituitary gland,

2) thyroid,

3) parathyroid,

4) thymus,

5) adrenal glands,

6) pineal gland,

7) pancreas and 8) genitals.

The pituitary gland, thyroid gland, parathyroid and adrenal glands have only internal secretion. The pancreas and genitals are characterized by mixed secretion: they not only produce hormones, but also secrete substances that do not have hormonal activity.

Hormones affect all body functions. They

1) regulate metabolism (protein, carbohydrate, fat, mineral, water);

2) maintain homeostasis (self-regulation of the constancy of the internal state);

3) influence the growth and formation of organs, organ systems and the entire organism as a whole;

4) tissue differentiation occurs under the influence of hormones;

5) they can change the intensity of functioning of any organ.

All hormones are characterized by specificity of action. Phenomena that occur when one of the glands is insufficient can disappear when treated with hormones of the same gland. Thus, carbohydrate metabolism disorders can be eliminated only by the hormones of the same gland, insulin. All hormones can act on certain organs located at a great distance from the place of release. For example, the pituitary gland is located in the cranial cavity, and its hormone acts on many organs, including the gonads located in the pelvic cavity. Hormones have a very small concentrations, i.e. their biological activity very high. Thus, hormones have a number of properties:

Formed in not large quantities.

They have high biological activity.

They have strict specificity of action.

Have remote character actions.

Research in recent years has led to the creation of hypotheses regarding the mechanism of action of hormones. It is not the same for different hormones. It is believed that hormones act on target cells by changing the physical structure of enzymes, the permeability of the cell membrane and influencing the genetic apparatus of the cell. According to the first hypothesis, hormones, when joining enzymes, change their structure, which affects the rate of enzymatic reactions. Hormones can activate or inhibit the action of enzymes. This mechanism has been proven only for some of the hormones. Similarly, not all hormones have been proven to influence the permeability of the cell membrane. The effect of insulin, a pancreatic hormone, on the permeability of the cell membrane with respect to glucose has been well studied. It has now been proven that almost all hormones tend to act through the genetic apparatus.

All vital substances in the whole organism are in constant interaction. Pituitary hormones regulate the functioning of the thyroid gland, pancreas, adrenal glands, and gonads. Gonadal hormones affect the functioning of the thymus gland, and thymus hormones affect the gonads, etc. The interaction is manifested in the fact that the reaction of one or another organ is often carried out only under the sequential influence of a number of hormones. Interaction can also be carried out through the nervous system. Hormones of some glands affect the nerve centers, and impulses coming from the nerve centers change the nature of the activity of other glands.

Hormones are important in maintaining relative physico-chemical constancy the internal environment of the body, called homeostasis. The preservation of homeostasis is facilitated by humoral regulation of functions, which exhibits the ability to activate or inhibit the functional activity of organs and systems .

In the body humoral and neural regulation functions are closely interrelated. On the one hand, there are many biologically active substances that can influence the vital activity of nerve cells and the functions of the nervous system, on the other, the synthesis and release of humoral substances into the blood is regulated by the nervous system. Thus, in the body there is a single neurohumoral regulation functions that provide the ability for self-regulation of life.

For example, male sex hormones androgens influence the occurrence of sexual reflexes associated with the activity of the nervous system. Nervous system through the senses, in turn, it sends signals about the production of sex hormones at the right moments.

The hypothalamus plays an important role in the integration of the nervous and endocrine systems. This property is due to the close connection between the hypothalamus and the pituitary gland. The hypothalamus has a very significant influence on the production of pituitary hormones. Large neurons of the hypothalamus are secretory cells, the hormone of which enters the posterior lobe of the pituitary gland along the axons. The vessels surrounding the nuclei of the hypothalamus, uniting in the portal system, descend to the anterior lobe of the pituitary gland, supplying the cells of this part of the gland. From both lobes of the pituitary gland, its hormones enter the vessels through the vessels. endocrine glands, hormones of which, in turn, in addition to influencing peripheral tissues, also influence the hypothalamus and the anterior lobe of the pituitary gland, thereby regulating the need for the release of various pituitary hormones in varying quantities.

Endocrine influences change reflexively: impulses from proprioceptors, pain stimulation, emotional factors, mental and physical stress affect the secretion of hormones.

Age-related features of the endocrine glands

Weight pituitary gland a newborn child is 100 - 150 mg. In the second year of life, its increase begins, which turns out to be sharp at 4–5 years, after which a period of slow growth begins until the age of 11. By the period of puberty, the mass of the pituitary gland averages 200-350 mg, and by 18-20 years - 500-650 mg. Up to 3-5 years, the amount of growth hormone is released more than in adults. From 3-5 years of age, the rate of GH secretion is equal to that of adults. In newborns, the amount of ACTH is equal to that of adults. TSH is released sharply immediately after birth and before puberty. Vasopressin is maximally released in the first year of life. The greatest intensity of release of gonadotropic hormones is observed during puberty.

iron homeostasis internal secretion

The newborn has a mass thyroidglands ranges from 1 to 5 g. It decreases slightly by 6 months, and then a period of rapid increase begins, which lasts up to 5 years. During puberty, the increase continues and reaches the mass of the gland of an adult. Highest magnification secretion of hormones is observed during periods early childhood and puberty. Maximum activity of the thyroid gland is achieved at 21-30 years of age.

After the birth of a child, maturation occurs parathyroidglands, which is reflected in an increase in the amount of hormone released with age. The greatest activity of the parathyroid glands is observed in the first 4-7 years of life.

The newborn has a mass adrenal glands is approximately 7 years old. The growth rate of the adrenal glands is not the same at different age periods. A particularly sharp increase is observed at 6-8 months. and 2-4 g. The increase in adrenal mass continues up to 30 years. Brain matter appears later than the cortical one. After 30 years, the amount of hormones in the adrenal cortex begins to decrease.

By the end of 2 months of intrauterine development, rudiments appear in the form of outgrowths pancreasglands. The head of the pancreas in an infant is raised slightly higher than in adults and is located at approximately 10-11 thoracic vertebra. The body and tail go to the left and rise slightly upward. It weighs a little less than 100 g in an adult. At birth, iron weighs only 2-3 g in babies and is 4-5 cm long. By 3-4 months its weight doubles, by 3 years it reaches 20 g, and by 10-12 years - 30 g. Resistance to glucose load in children under 10 years of age is higher, and the absorption of dietary glucose occurs faster than in adults. This explains why children love sweets and consume them in large quantities without danger to their health. With age, the insular activity of the pancreas decreases, so diabetes most often develops after 40 years.

In early childhood thymusgland the cortex predominates. During puberty, the amount of connective tissue. IN mature age there is a strong proliferation of connective tissue.

The weight of the pineal gland at birth is 7 mg, and in an adult it is 100-200 mg. The increase in the size of the epiphysis and its mass continues until 4-7 years, after which it undergoes reverse development.

Bibliography

1. Anatomy and age physiology, Educational and methodological manual. - Komsomolsk-on-Amur, 2004.

2. Badalyan L.O., Child neurology. - M, 1994.

3. Leontyeva N.N., Marinova V.V., Anatomy and physiology child's body. - M, 1986.

4. Mamontov S.G., Biology. - M, 1991.

5. Mikheev V.V., Melnichuk P.V., Nervous diseases. - M, 1991

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