Damage to the nervous system in endocrine pathology. Nervous and endocrine systems The organ that unites the nervous and endocrine systems

CHAPTER 1. INTERACTION OF THE NERVOUS AND ENDOCRINE SYSTEM

The human body consists of cells that combine into tissues and systems - all this as a whole is a single supersystem of the body. Myriads of cellular elements would not be able to work as a whole, if the body did not have a complex mechanism of regulation. A special role in the regulation is played by the nervous system and the system of endocrine glands. The nature of the processes occurring in the central nervous system is largely determined by the state of endocrine regulation. So androgens and estrogens form the sexual instinct, many behavioral reactions. Obviously, neurons, just like other cells in our body, are under the control of the humoral regulatory system. The nervous system, evolutionarily later, has both control and subordinate connections with the endocrine system. These two regulatory systems complement each other, form a functionally unified mechanism, which ensures high efficiency neurohumoral regulation, puts it at the head of systems that coordinate all life processes in a multicellular organism. The regulation of the constancy of the internal environment of the body, which occurs according to the feedback principle, is very effective for maintaining homeostasis, but cannot fulfill all the tasks of adapting the body. For example, the adrenal cortex produces steroid hormones in response to hunger, illness, emotional arousal, and so on. So that the endocrine system can "respond" to light, sounds, smells, emotions, etc. there must be a connection between the endocrine glands and the nervous system.

1.1 Brief description of the system

The autonomic nervous system permeates our entire body like the thinnest web. It has two branches: excitation and inhibition. The sympathetic nervous system is the excitatory part, it puts us in a state of readiness to face challenge or danger. Nerve endings secrete neurotransmitters that stimulate the adrenal glands to release strong hormones - adrenaline and norepinephrine. They in turn increase the heart rate and respiratory rate, and act on the digestion process through the release of acid in the stomach. This creates a sucking sensation in the stomach. Parasympathetic nerve endings secrete other mediators that reduce the pulse and respiratory rate. Parasympathetic responses are relaxation and balance.

1.2 Interaction of endocrine and nervous system

The pituitary gland can receive signals about what is happening in the body, but it has no direct connection with the external environment. Meanwhile, in order for the factors of the external environment not to constantly disrupt the vital activity of the organism, the adaptation of the body to changing external conditions must be carried out. The body learns about external influences through the sense organs, which transmit the received information to the central nervous system. Being the supreme gland of the endocrine system, the pituitary gland itself obeys the central nervous system and in particular the hypothalamus. This higher vegetative center constantly coordinates and regulates the activity of various parts of the brain and all internal organs. Heart rate, tone blood vessels, body temperature, the amount of water in the blood and tissues, the accumulation or consumption of proteins, fats, carbohydrates, mineral salts - in a word, the existence of our body, the constancy of its internal environment is under the control of the hypothalamus. Most of the nervous and humoral pathways of regulation converge at the level of the hypothalamus and due to this, a single neuroendocrine regulatory system is formed in the body. Axons of neurons located in the cerebral cortex and subcortical formations approach the cells of the hypothalamus. These axons secrete various neurotransmitters that have both activating and inhibitory effects on the secretory activity of the hypothalamus. The hypothalamus “turns” the nerve impulses coming from the brain into endocrine stimuli, which can be strengthened or weakened depending on the humoral signals coming to the hypothalamus from the glands and tissues subordinate to it.

The hypothalamus controls the pituitary gland using both nerve connections and the blood vessel system. The blood that enters the anterior pituitary gland necessarily passes through the median eminence of the hypothalamus and is enriched there with hypothalamic neurohormones. Neurohormones are substances of a peptide nature, which are parts of protein molecules. To date, seven neurohormones, the so-called liberins (that is, liberators), have been discovered that stimulate the synthesis of tropic hormones in the pituitary gland. And three neurohormones - prolactostatin, melanostatin and somatostatin - on the contrary, inhibit their production. Other neurohormones include vasopressin and oxytocin. Oxytocin stimulates the contraction of the smooth muscles of the uterus during childbirth, the production of milk by the mammary glands. Vasopressin is actively involved in the regulation of the transport of water and salts through cell membranes, under its influence, the lumen of blood vessels decreases and, consequently, blood pressure rises. Due to the fact that this hormone has the ability to retain water in the body, it is often called antidiuretic hormone (ADH). The main point of application of ADH are renal tubules where it stimulates the reabsorption of water from the primary urine into the blood. Neurohormones are produced by the nerve cells of the nuclei of the hypothalamus, and then they are transported along their own axons (nerve processes) to the posterior lobe of the pituitary gland, and from here these hormones enter the bloodstream, having a complex effect on the body systems.

Tropins formed in the pituitary gland not only regulate the activity of subordinate glands, but also perform independent endocrine functions. For example, prolactin has a lactogenic effect, and also inhibits the processes of cell differentiation, increases the sensitivity of the sex glands to gonadotropins, and stimulates parental instinct. Corticotropin is not only a stimulator of sterdogenesis, but also an activator of lipolysis in adipose tissue, as well as an important participant in the transformation process in the brain short term memory in the long term. Growth hormone can stimulate the activity of the immune system, the metabolism of lipids, sugars, etc. Also, some hormones of the hypothalamus and pituitary gland can be formed not only in these tissues. For example, somatostatin (a hypothalamic hormone that inhibits the formation and secretion of growth hormone) is also found in the pancreas, where it inhibits the secretion of insulin and glucagon. Some substances act in both systems; they can be both hormones (i.e. products of the endocrine glands) and mediators (products of certain neurons). This dual role is played by norepinephrine, somatostatin, vasopressin, and oxytocin, as well as transmitters of the diffuse intestinal nervous system, such as cholecystokinin and vasoactive intestinal polypeptide.

However, one should not think that the hypothalamus and pituitary gland only give orders, lowering the "guiding" hormones along the chain. They themselves sensitively analyze the signals coming from the periphery, from the endocrine glands. The activity of the endocrine system is carried out on the basis of the universal principle of feedback. An excess of hormones of one or another endocrine gland inhibits the release of a specific pituitary hormone responsible for the work of this gland, and a deficiency induces the pituitary gland to increase the production of the corresponding triple hormone. The mechanism of interaction between the neurohormones of the hypothalamus, the triple hormones of the pituitary gland and the hormones of the peripheral endocrine glands in a healthy body has been worked out by a long evolutionary development and is very reliable. However, a failure in one link of this complex chain is enough to cause a violation of quantitative, and sometimes even qualitative, relationships in the whole system, resulting in various endocrine diseases.

CHAPTER 2. BASIC FUNCTIONS OF THE THALAMUS

2.1 Brief anatomy

The bulk of the diencephalon (20g) is the thalamus. A paired organ of an ovoid shape, the anterior part of which is pointed (anterior tubercle), and the posterior expanded (cushion) hangs over the geniculate bodies. The left and right thalamus are connected by an interthalamic commissure. The gray matter of the thalamus is divided by plates of white matter into anterior, medial, and lateral parts. Speaking of the thalamus, they also include the metathalamus (geniculate bodies), which belongs to the thalamic region. The thalamus is the most developed in humans. The thalamus (thalamus), the visual tubercle, is a nuclear complex in which the processing and integration of almost all signals going to the cortex takes place big brain from the spinal cord, midbrain, cerebellum, basal ganglia of the brain.

The nervous and endocrine systems modulate the functions of the immune system with neurotransmitters, neuropeptides, and hormones, and the immune system interacts with the neuroendocrine system with cytokines, immunopeptides, and immunotransmitters. There is a neurohormonal regulation of the immune response and functions of the immune system, mediated by the action of hormones and neuropeptides directly on immunocompetent cells or through the regulation of cytokine production (Fig. 2). Substances by axonal transport penetrate into the tissues they innervate and affect the processes of immunogenesis, and vice versa, the immune system receives signals (cytokines released by immunocompetent cells) that accelerate or slow down axonal transport, depending on the chemical nature of the influencing factor.

The nervous, endocrine and immune systems have much in common in their structure. All three systems act in concert, complementing and duplicating each other, significantly increasing the reliability of regulation of functions. They are closely interconnected and have a large number of cross paths. There is a certain parallel between lymphoid accumulations in various organs and tissues and ganglia of the autonomic nervous system.

Stress and the immune system.

Animal experiments and clinical observations indicate that the state of stress, some mental disorders lead to a sharp inhibition of almost all parts of the body's immune system.

Most of the lymphoid tissues have a direct sympathetic innervation of both the blood vessels passing through the lymphoid tissue and the lymphocytes themselves. The autonomic nervous system directly innervates the parenchymal tissues of the thymus, spleen, lymph nodes, appendix and bone marrow.

The impact of pharmacological drugs on postganglionic adrenergic systems leads to the modulation of the immune system. Stress, on the contrary, leads to desensitization of β-adrenergic receptors.

Norepinephrine and epinephrine act on adrenoreceptors - AMP - protein kinase A inhibits the production of pro-inflammatory cytokines such as IL-12, tumor necrosis factor b (TNFa), interferon g (IFNg) by antigen-presenting cells and T-helpers of the first type and stimulates the production of anti-inflammatory cytokines such as IL-10 and transforming growth factor-b (TFRb).

Rice. 2. Two mechanisms of interference of immune processes in the activity of the nervous and endocrine systems: A - glucocorticoid feedback, inhibition of the synthesis of interleukin-1 and other lymphokines, B - autoantibodies to hormones and their receptors. Tx - T-helper, MF - macrophage

However, under certain conditions, catecholamines are able to limit the local immune response by inducing the formation of IL-1, TNFa and IL-8, protecting the body from the harmful effects of pro-inflammatory cytokines and other products of activated macrophages. When the sympathetic nervous system interacts with macrophages, neuropeptide Y acts as a signal co-transmitter from norepinephrine to macrophages. By blocking a-adrenergic receptors, it maintains the stimulating effect of endogenous noradrenaline through beta-adrenergic receptors.

Opioid peptides- one of the mediators between the central nervous system and the immune system. They are able to influence almost all immunological processes. In this regard, it has been suggested that opioid peptides indirectly modulate the secretion of pituitary hormones and thus affect the immune system.

Neurotransmitters and the immune system.

However, the relationship between the nervous and immune systems is not limited to the regulatory influence of the first on the second. IN last years a sufficient amount of data on the synthesis and secretion of neurotransmitters by cells of the immune system has accumulated.

Human peripheral blood T-lymphocytes contain L-dopa and norepinephrine, while B-cells contain only L-dopa.

Lymphocytes in vitro are able to synthesize norepinephrine from both L-tyrosine and L-dopa added to the culture medium at concentrations corresponding to the content in venous blood (5-10 -5 and 10 -8 mol, respectively), while D- dopa does not affect the intracellular content of norepinephrine. Therefore, human T-lymphocytes are able to synthesize catecholamines from their normal precursors at physiological concentrations.

The ratio of noradrenaline/adrenaline in peripheral blood lymphocytes is similar to that in plasma. There is a clear correlation between the amount of norepinephrine and adrenaline in lymphocytes, on the one hand, and cyclic AMP in them, on the other, both in normal conditions and during stimulation with isoproterenol.

Thymus gland (thymus).

The thymus gland is retracted important place in the interaction of the immune system with the nervous and endocrine. There are several arguments in favor of this conclusion:

Insufficiency of the thymus not only slows down the formation of the immune system, but also leads to a violation of the embryonic development of the anterior pituitary gland;

Binding of hormones synthesized in pituitary acidophilic cells to receptors on thymus epithelial cells (TECs) increases their in vitro release of thymic peptides;

An increase in the concentration of glucocorticoids in the blood during stress causes atrophy of the thymus cortex due to the doubling of thymocytes undergoing apoptosis;

The thymus parenchyma is innervated by branches of the autonomic nervous system; the action of acetylcholine on acetylcholine receptors of thymus epithelial cells increases the protein-synthetic activity associated with the formation of thymic hormones.

Thymus proteins are a heterogeneous family of polypeptide hormones that not only have a regulatory effect on both the immune and endocrine systems, but are also under the control of the hypothalamic-pituitary-adrenal system and other endocrine glands. For example, thymulin production by the thymus regulates a number of hormones, including prolactin, growth hormone, and thyroid hormones. In turn, proteins isolated from the thymus regulate the secretion of hormones by the hypothalamic-pituitary-adrenal system and can directly affect the target glands of this system and gonadal tissues.

Regulation of the immune system.

The hypothalamic-pituitary-adrenal system is a powerful mechanism for regulating the immune system. Corticotropin-releasing factor, ACTH, β-melanocyte-stimulating hormone, β-endorphin are immunomodulators that affect both directly on lymphoid cells and through immunoregulatory hormones (glucocorticoids) and the nervous system.

The immune system sends signals to the neuroendocrine system through cytokines, the concentration of which in the blood reaches significant values during immune (inflammatory) reactions. IL-1, IL-6 and TNFa are the main cytokines causing profound neuroendocrine and metabolic changes in many organs and tissues.

Corticotropin-releasing factor acts as the main coordinator of reactions and is responsible for the activation of the ACTH-adrenal axis, temperature increase and CNS responses that determine sympathetic effects. An increase in ACTH secretion leads to an increase in the production of glucocorticoids and a-melanocyte-stimulating hormone - antagonists of cytokines and antipyretic hormones. The reaction of the sympathoadrenal system is associated with the accumulation of catecholamines in tissues.

The immune and endocrine systems cross-react using similar or identical ligands and receptors. Thus, cytokines and thymus hormones modulate the function of the hypothalamic-pituitary system.

* Interleukin (IL-l) directly regulates the production of corticotropin-releasing factor. Thymulin through adrenoglomerulotropin and the activity of hypothalamic neurons and pituitary cells increases the production of luteinizing hormone.

* Prolactin, acting on the receptors of lymphocytes, activates the synthesis and secretion of cytokines by cells. It acts on normal killer cells and induces their differentiation into prolactin-activated killer cells.

* Prolactin and growth hormone stimulate leukopoiesis (including lymphopoiesis).

Cells of the hypothalamus and pituitary gland can produce cytokines such as IL-1, IL-2, IL-6, g-interferon, b-transforming growth factor, and others. Accordingly, hormones including growth hormone, prolactin, luteinizing hormone, oxytocin, vasopressin, and somatostatin are produced in the thymus. Receptors for various cytokines and hormones have been identified both in the thymus and in the hypothalamic-pituitary axis.

The possible commonality of the regulatory mechanisms of the CNS, neuroendocrine and immunological systems put forward a new aspect of the homeostatic control of many pathological conditions (Fig. 3, 4). In maintaining homeostasis under the influence of various extreme factors on the body, all three systems act as a single whole, complementing each other. But, depending on the nature of the impact, one of them becomes the leading one in the regulation of adaptive and compensatory reactions.

Rice. 3. Interaction of the nervous, endocrine and immune systems in the regulation of the physiological functions of the body

Many functions of the immune system are provided by duplicating mechanisms, which are associated with additional reserve capabilities for protecting the body. The protective function of phagocytosis is duplicated by granulocytes and monocytes/macrophages. The ability to enhance phagocytosis is possessed by antibodies, the complement system and the cytokine g-interferon.

The cytotoxic effect against virus-infected or malignantly transformed target cells is duplicated by natural killers and cytotoxic T-lymphocytes (Fig. 5). In antiviral and antitumor immunity, either natural killer cells or cytotoxic T-lymphocytes can serve as protective effector cells.

Rice. 4. Interaction of the immune system and regulatory mechanisms with factors environment under extreme conditions

Rice. 5. Duplication of functions in the immune system provides its reserve capabilities

With the development of inflammation, several synergistic cytokines duplicate the functions of each other, which made it possible to combine them into a group of pro-inflammatory cytokines (interleukins 1, 6, 8, 12, and TNFa). Other cytokines are involved in the final stage of inflammation, duplicating each other's effects. They serve as antagonists of pro-inflammatory cytokines and are called anti-inflammatory (interleukins 4, 10, 13 and transforming growth factor-b). Cytokines produced by Th2 (interleukins 4, 10, 13, transforming growth factor-b) are antagonistic to cytokines produced by Th1 (g-interferon, TNFa).

Ontogenetic changes in the immune system.

In the processes of ontogenesis, the immune system undergoes gradual development and maturation: relatively slow in the embryonic period, it accelerates sharply after the birth of a child due to the intake of a large number of foreign antigens into the body. However, most defense mechanisms are immature throughout childhood. Neurohormonal regulation of the functions of the immune system begins to clearly manifest itself in the puberty period. In adulthood, the immune system is characterized by the greatest ability to adapt when a person enters into changed and unfavorable environmental conditions. Aging of the body is accompanied by various manifestations of acquired insufficiency of the immune system.

System Features

The endocrine system of the human body combines small in size and different in structure and functions of the endocrine glands that are part of the endocrine system. These are the pituitary gland with its independently functioning anterior and posterior lobes, the sex glands, the thyroid and parathyroid glands, the adrenal cortex and medulla, the pancreatic islet cells, and the secretory cells that line the intestinal tract. Taken together, they weigh no more than 100 grams, and the amount of hormones they produce can be calculated in billionths of a gram. The pituitary gland, which produces more than 9 hormones, regulates the activity of most other endocrine glands and is itself under the control of the hypothalamus. The thyroid gland regulates growth, development, metabolic rate in the body. Together with the parathyroid gland, it also regulates the level of calcium in the blood. The adrenal glands also influence the intensity of metabolism and help the body resist stress. The pancreas regulates blood sugar levels and at the same time acts as an external secretion gland - secretes digestive enzymes through the ducts into the intestines. The endocrine sex glands - the testes in men and the ovaries in women - combine the production of sex hormones with non-endocrine functions: germ cells also mature in them. The sphere of influence of hormones is exceptionally large. They have a direct impact on the growth and development of the body, on all types of metabolism, on puberty. There are no direct anatomical connections between the endocrine glands, but there is an interdependence of the functions of one gland from others. The endocrine system of a healthy person can be compared to a well-played orchestra, in which each gland confidently and subtly leads its part. And the main supreme endocrine gland, the pituitary gland, acts as a conductor. The anterior pituitary gland secretes six tropic hormones into the blood: somatotropic, adrenocorticotropic, thyrotropic, prolactin, follicle-stimulating and luteinizing - they direct and regulate the activity of other endocrine glands.

Hormones regulate the activity of all body cells. They affect mental acuity and physical mobility, physique and height, determine hair growth, voice tone, sexual desire and behavior. Thanks to the endocrine system, a person can adapt to strong temperature fluctuations, excess or lack of food, physical and emotional stress. The study of the physiological action of the endocrine glands made it possible to reveal the secrets of sexual function and to study in more detail the mechanism of childbirth, as well as to answer questions
the question is why some people tall, and others low, some plump, others thin, some slow, others agile, some strong, others weak.

In the normal state, there is a harmonious balance between the activity of the endocrine glands, the state of the nervous system and the response of target tissues (tissues that are affected). Any violation in each of these links quickly leads to deviations from the norm. Excessive or insufficient production of hormones causes various diseases, accompanied by profound chemical changes in the body.

Endocrinology studies the role of hormones in the life of the body and the normal and pathological physiology of the endocrine glands.

Relationship between the endocrine and nervous systems

Neuroendocrine regulation is the result of the interaction of the nervous and endocrine systems. It is carried out due to the influence of the higher vegetative center of the brain - the hypothalamus - on the gland located in the brain - the pituitary gland, figuratively referred to as the "conductor of the endocrine orchestra". Neurons of the hypothalamus secrete neurohormones (releasing factors), which, entering the pituitary gland, enhance (liberins) or inhibit (statins) the biosynthesis and release of triple pituitary hormones. The triple hormones of the pituitary gland, in turn, regulate the activity of the peripheral endocrine glands (thyroid, adrenal, genital), which, to the extent of their activity, change the state of the internal environment of the body and influence behavior.

The hypothesis of neuroendocrine regulation of the process of realization of genetic information assumes the existence at the molecular level of common mechanisms that provide both the regulation of the activity of the nervous system and the regulatory effects on the chromosome apparatus. At the same time, one of the essential functions of the nervous system is the regulation of the activity of the genetic apparatus according to the feedback principle in accordance with the current needs of the body, the influence of the environment and individual experience. In other words, the functional activity of the nervous system can play the role of a factor that changes the activity of gene systems.

The pituitary gland can receive signals about what is happening in the body, but it has no direct connection with the external environment. Meanwhile, in order for the factors of the external environment not to constantly disrupt the vital activity of the organism, the adaptation of the body to changing external conditions must be carried out. The body learns about external influences through the sense organs, which transmit the received information to the central nervous system. Being the supreme gland of the endocrine system, the pituitary gland itself obeys the central nervous system and in particular the hypothalamus. This higher vegetative center constantly coordinates and regulates the activity of various parts of the brain and all internal organs. Heart rate, blood vessel tone, body temperature, the amount of water in the blood and tissues, the accumulation or consumption of proteins, fats, carbohydrates, mineral salts - in a word, the existence of our body, the constancy of its internal environment is under the control of the hypothalamus. Most of the nervous and humoral pathways of regulation converge at the level of the hypothalamus and due to this, a single neuroendocrine regulatory system is formed in the body. Axons of neurons located in the cerebral cortex and subcortical formations approach the cells of the hypothalamus. These axons secrete various neurotransmitters that have both activating and inhibitory effects on the secretory activity of the hypothalamus. The hypothalamus “turns” the nerve impulses coming from the brain into endocrine stimuli, which can be strengthened or weakened depending on the humoral signals coming to the hypothalamus from the glands and tissues subordinate to it.

The hypothalamus controls the pituitary gland using both nerve connections and the blood vessel system. The blood that enters the anterior pituitary gland necessarily passes through the median eminence of the hypothalamus and is enriched there with hypothalamic neurohormones. Neurohormones are substances of a peptide nature, which are parts of protein molecules. To date, seven neurohormones, the so-called liberins (that is, liberators), have been discovered that stimulate the synthesis of tropic hormones in the pituitary gland. And three neurohormones - prolactostatin, melanostatin and somatostatin - on the contrary, inhibit their production. Other neurohormones include vasopressin and oxytocin. Oxytocin stimulates the contraction of the smooth muscles of the uterus during childbirth, the production of milk by the mammary glands. Vasopressin is actively involved in the regulation of the transport of water and salts through cell membranes, under its influence, the lumen of blood vessels decreases and, consequently, blood pressure rises. Due to the fact that this hormone has the ability to retain water in the body, it is often called antidiuretic hormone (ADH). The main point of application of ADH is the renal tubules, where it stimulates the reabsorption of water from the primary urine into the blood. Neurohormones are produced by the nerve cells of the nuclei of the hypothalamus, and then they are transported along their own axons (nerve processes) to the posterior lobe of the pituitary gland, and from here these hormones enter the bloodstream, having a complex effect on the body systems.

Tropins formed in the pituitary gland not only regulate the activity of subordinate glands, but also perform independent endocrine functions. For example, prolactin has a lactogenic effect, and also inhibits the processes of cell differentiation, increases the sensitivity of the sex glands to gonadotropins, and stimulates parental instinct. Corticotropin is not only a stimulator of sterdogenesis, but also an activator of lipolysis in adipose tissue, as well as an important participant in the process of converting short-term memory into long-term memory in the brain. Growth hormone can stimulate the activity of the immune system, the metabolism of lipids, sugars, etc. Also, some hormones of the hypothalamus and pituitary gland can be formed not only in these tissues. For example, somatostatin (a hypothalamic hormone that inhibits the formation and secretion of growth hormone) is also found in the pancreas, where it inhibits the secretion of insulin and glucagon. Some substances act in both systems; they can be both hormones (i.e. products of the endocrine glands) and mediators (products of certain neurons). This dual role is played by norepinephrine, somatostatin, vasopressin, and oxytocin, as well as transmitters of the diffuse intestinal nervous system, such as cholecystokinin and vasoactive intestinal polypeptide.

Our body can be compared to a metropolis. The cells that inhabit it sometimes live in “families”, forming organs, and sometimes, lost among others, they become hermits (like, for example, the cells of the immune system). Some are homebodies and never leave their haven, others are travelers and do not sit in one place. All of them are different, each with its own needs, character and regime. Between the cells are small and large transport highways - blood and lymphatic vessels. Every second, millions of events occur in our body: someone or something disrupts the peaceful life of cells, or some of them forget about their duties or, on the contrary, are too zealous. And, as in any metropolis, competent administration is required to maintain order. We know that our main manager is the nervous system. And her right hand is the endocrine system (ES).

In order

ES is one of the most complex and mysterious systems of the body. Complex because it consists of many glands, each of which can produce from one to dozens of different hormones, and regulates the work of a huge number of organs, including the endocrine glands themselves. Within the system, there is a special hierarchy that allows you to strictly control its work. The mystery of ES is associated with the complexity of the mechanisms of regulation and composition of hormones. Cutting-edge technology is required to research her work. The role of many hormones is still unclear. And we only guess about the existence of some, moreover, it is still impossible to determine their composition and the cells that secrete them. That is why endocrinology - the science that studies hormones and the organs that produce them - is considered one of the most complex among medical specialties and the most promising. Having understood the exact purpose and mechanisms of work of certain substances, we will be able to influence the processes occurring in our body. Indeed, thanks to hormones, we are born, it is they who create a feeling of attraction between future parents, determine the time of formation of germ cells and the moment of fertilization. They change our lives, affecting mood and character. Today we know that aging processes are also under the jurisdiction of the ES.

Characters...

The organs that make up the ES (thyroid gland, adrenal glands, etc.) are groups of cells located in other organs or tissues, and individual cells scattered in different places. The difference between the endocrine glands and others (they are called exocrine) is that the former secrete their products - hormones - directly into the blood or lymph. For this they are called endocrine glands. And exocrine - into the lumen of one or another organ (for example, the largest exocrine gland - the liver - secretes its secret - bile - into the lumen of the gallbladder and further into the intestine) or out (for example, the lacrimal glands). Exocrine glands are called glands of external secretion. Hormones are substances that can act on cells that are sensitive to them (they are called target cells), changing the rate of metabolic processes. The release of hormones directly into the blood gives ES a huge advantage. It takes a matter of seconds to achieve the effect. Hormones enter directly into the bloodstream, which serves as a transport and allows you to very quickly deliver the right substance to all tissues, unlike a nerve signal that propagates along nerve fibers and may not reach its goal due to their rupture or damage. In the case of hormones, this will not happen: liquid blood easily finds workarounds if one or more vessels are blocked. In order for the organs and cells to which the ES message is intended to receive it, they have receptors that perceive a particular hormone. A feature of the endocrine system is its ability to "feel" the concentration of various hormones and adjust it. And their number depends on age, gender, time of day and year, age, mental and physical state of a person, and even our habits. So ES sets the rhythm and speed for our metabolic processes.

...and performers

The pituitary gland is the main endocrine organ. It secretes hormones that stimulate or inhibit the work of others. But the pituitary gland is not the pinnacle of ES, it only plays the role of a manager. The hypothalamus is the superior authority. This is a part of the brain, consisting of clusters of cells that combine the properties of the nervous and endocrine. They secrete substances that regulate the work of the pituitary and endocrine glands. Under the guidance of the hypothalamus, the pituitary gland produces hormones that affect tissues that are sensitive to them. So, thyroid-stimulating hormone regulates the work of the thyroid gland, corticotropic - the work of the adrenal cortex. Somatotropic hormone (or growth hormone) does not affect any specific organ. Its action extends to many tissues and organs. This difference in the action of hormones is caused by the difference in their significance for the body and the number of tasks that they provide. A feature of this complex system is the principle of feedback. The EU can be called without exaggeration the most democratic. And, although it has “leading” organs (the hypothalamus and pituitary gland), the subordinate ones also affect the work of the higher glands. In the hypothalamus, the pituitary gland has receptors that respond to the concentration of various hormones in the blood. If it is high, signals from the receptors will block their production "at all levels. This is the feedback principle in action. The thyroid gland got its name from its shape. It closes the neck, surrounding the trachea. Its hormones include iodine, and its lack can Gland hormones provide a balance between the formation of adipose tissue and the use of stored fats in it. They are necessary for the development of the skeleton and the well-being of bone tissue, and also enhance the action of other hormones (for example, insulin, accelerating the metabolism of carbohydrates). These substances play a critical role in the development of the nervous system.Lack of thyroid hormones in babies leads to underdevelopment of the brain, and later - to a decrease in intelligence.Therefore, all newborns are examined for the level of these substances (such a test is included in the newborn screening program).Together with adrenaline, thyroid hormones glands affect the functioning of the heart and regulate blood pressure.

parathyroid glands

parathyroid glands- these are 4 glands located in the thickness of fatty tissue behind the thyroid, for which they got their name. The glands produce 2 hormones: parathyroid and calcitonin. Both provide the exchange of calcium and phosphorus in the body. Unlike most endocrine glands, the work of the parathyroid glands is regulated by fluctuations in the mineral composition of the blood and vitamin D. The pancreas controls the metabolism of carbohydrates in the body, and is also involved in digestion and produces enzymes that break down proteins, fats and carbohydrates. Therefore, it is located in the region of the transition of the stomach into the small intestine. The gland secretes 2 hormones: insulin and glucagon. The first lowers blood sugar levels, forcing cells to more actively absorb it and use it. The second, on the contrary, increases the amount of sugar, forcing the cells of the liver and muscle tissue to give it away. The most common disease associated with disorders in the pancreas is type 1 diabetes mellitus (or insulin-dependent). It develops due to the destruction of insulin-producing cells by cells of the immune system. In most children who are sick diabetes, there are features of the genome that probably predetermine the development of the disease. But most often it is triggered by an infection or stress. The adrenal glands get their name from their location. A person cannot live without the adrenal glands and the hormones they produce, and these organs are considered vital. The program of examination of all newborns includes a test for violations of their work - the consequences of such problems will be so dangerous. The adrenal glands produce a record number of hormones. The most famous of them is adrenaline. It helps the body prepare and cope with possible dangers. This hormone makes the heart beat faster and pump more blood to the organs of movement (if you need to flee), increases the frequency of breathing to provide the body with oxygen, reduces sensitivity to pain. It increases blood pressure, providing maximum blood flow to the brain and other important organs. Noradrenaline has a similar effect. The second most important adrenal hormone is cortisol. It is difficult to name any process in the body that it would not have an effect on. It causes tissues to release stored substances into the blood so that all cells are provided with nutrients. The role of cortisol increases with inflammation. It stimulates the production of protective substances and the work of the cells of the immune system necessary to fight inflammation, and if the latter are too active (including against their own cells), cortisol suppresses their zeal. Under stress, it blocks cell division so that the body does not waste energy on this work, and the immune system, busy restoring order, would not miss “defective” samples. The hormone aldosterone regulates the concentration in the body of the main mineral salts - sodium and potassium. The gonads are the testicles in boys and the ovaries in girls. The hormones that they produce are able to change metabolic processes. So, testosterone (the main male hormone) helps the growth of muscle tissue, the skeletal system. It increases appetite and makes boys more aggressive. And, although testosterone is considered a male hormone, it is also secreted by women, but at a lower concentration.

To the doctor!

Most often, children with excess weight, and those kids that are seriously behind their peers in growth. Parents are more likely to pay attention to the fact that the child stands out among their peers, and begin to find out the reason. Most other endocrine diseases do not have characteristic features, and parents and doctors often learn about the problem when the violation has already seriously changed the work of some organ or the whole organism. Look at the baby: physique. In young children, the head and torso will be larger relative to the total body length. From 9-10 years old, the child begins to stretch, and the proportions of his body are approaching adults.

The human body consists of cells that combine into tissues and systems - all this as a whole is a single supersystem of the body. Myriads of cellular elements would not be able to work as a whole, if the body did not have a complex mechanism of regulation. A special role in the regulation is played by the nervous system and the system of endocrine glands. The nature of the processes occurring in the central nervous system is largely determined by the state of endocrine regulation. So androgens and estrogens form the sexual instinct, many behavioral reactions. Obviously, neurons, just like other cells in our body, are under the control of the humoral regulatory system. The nervous system, evolutionarily later, has both control and subordinate connections with the endocrine system. These two regulatory systems complement each other, form a functionally unified mechanism, which ensures the high efficiency of neurohumoral regulation, puts it at the head of systems that coordinate all life processes in a multicellular organism. The regulation of the constancy of the internal environment of the body, which occurs according to the feedback principle, is very effective for maintaining homeostasis, but cannot fulfill all the tasks of adapting the body. For example, the adrenal cortex produces steroid hormones in response to hunger, illness, emotional arousal, etc. In order for the endocrine system to “respond” to light, sounds, smells, emotions, etc., there must be a connection between the endocrine glands and the nervous system .

1. 1 Brief description of the system

1.2 Interaction of the endocrine and nervous system

The pituitary gland can receive signals about what is happening in the body, but it has no direct connection with the external environment. Meanwhile, in order for the factors of the external environment not to constantly disrupt the vital activity of the organism, the adaptation of the body to changing external conditions must be carried out. The body learns about external influences through the sense organs, which transmit the received information to the central nervous system. Being the supreme gland of the endocrine system, the pituitary gland itself obeys the central nervous system and in particular the hypothalamus. This higher vegetative center constantly coordinates and regulates the activity of various parts of the brain and all internal organs. Heart rate, blood vessel tone, body temperature, the amount of water in the blood and tissues, the accumulation or consumption of proteins, fats, carbohydrates, mineral salts - in a word, the existence of our body, the constancy of its internal environment is under the control of the hypothalamus. Most of the nervous and humoral pathways of regulation converge at the level of the hypothalamus and due to this, a single neuroendocrine regulatory system is formed in the body. Axons of neurons located in the cerebral cortex and subcortical formations approach the cells of the hypothalamus. These axons secrete various neurotransmitters that have both activating and inhibitory effects on the secretory activity of the hypothalamus. The hypothalamus “turns” the nerve impulses coming from the brain into endocrine stimuli, which can be strengthened or weakened depending on the humoral signals coming to the hypothalamus from the glands and tissues subordinate to it.

and is enriched there with hypothalamic neurohormones. Neurohormones are substances of a peptide nature, which are parts of protein molecules. To date, seven neurohormones, the so-called liberins (that is, liberators), have been discovered that stimulate the synthesis of tropic hormones in the pituitary gland. And three neurohormones - prolactostatin, melanostatin and somatostatin - on the contrary, inhibit their production. Other neurohormones include vasopressin and oxytocin. Oxytocin stimulates the contraction of the smooth muscles of the uterus during childbirth, the production of milk by the mammary glands. Vasopressin is actively involved in the regulation of the transport of water and salts through cell membranes, under its influence, the lumen of blood vessels decreases and, consequently, blood pressure rises. Due to the fact that this hormone has the ability to retain water in the body, it is often called antidiuretic hormone (ADH). The main point of application of ADH is the renal tubules, where it stimulates the reabsorption of water from the primary urine into the blood. Neurohormones are produced by the nerve cells of the nuclei of the hypothalamus, and then they are transported along their own axons (nerve processes) to the posterior lobe of the pituitary gland, and from here these hormones enter the bloodstream, having a complex effect on the body systems.

processes of cell differentiation, increases the sensitivity of the sex glands to gonadotropins, stimulates the parental instinct. Corticotropin is not only a stimulator of sterdogenesis, but also an activator of lipolysis in adipose tissue, as well as an important participant in the process of converting short-term memory into long-term memory in the brain. Growth hormone can stimulate the activity of the immune system, the metabolism of lipids, sugars, etc. Also, some hormones of the hypothalamus and pituitary gland can be formed not only in these tissues. For example, somatostatin (a hypothalamic hormone that inhibits the formation and secretion of growth hormone) is also found in the pancreas, where it inhibits the secretion of insulin and glucagon. Some substances act in both systems; they can be both hormones (i.e., products of the endocrine glands) and mediators (products of certain neurons). This dual role is played by norepinephrine, somatostatin, vasopressin, and oxytocin, as well as transmitters of the diffuse intestinal nervous system, such as cholecystokinin and vasoactive intestinal polypeptide.

CHAPTER 2. BASIC FUNCTIONS OF THE THALAMUS

2.1 Brief anatomy

The bulk of the diencephalon (20g) is the thalamus. A paired organ of an ovoid shape, the anterior part of which is pointed (anterior tubercle), and the posterior expanded (cushion) hangs over the geniculate bodies. The left and right thalamus are connected by an interthalamic commissure. The gray matter of the thalamus is divided by plates of white matter into anterior, medial, and lateral parts. Speaking of the thalamus, they also include the metathalamus (geniculate bodies), which belongs to the thalamic region. The thalamus is the most developed in humans. The thalamus (thalamus), the visual tubercle, is a nuclear complex in which the processing and integration of almost all signals going to the cerebral cortex from the spinal cord, midbrain, cerebellum, and basal ganglia of the brain takes place.

ganglia of the brain. In the nuclei of the thalamus, the information coming from the extero-, proprioreceptors and interoreceptors is switched and thalamocortical pathways begin. Given that the geniculate bodies are the subcortical centers of vision and hearing, and the frenulum node and the anterior visual nucleus are involved in the analysis of olfactory signals, it can be argued that the thalamus as a whole is a subcortical "station" for all types of sensitivity. Here, the stimuli of the external and internal environment are integrated, after which they enter the cerebral cortex.

The visual hillock is the center of the organization and realization of instincts, drives, emotions. The ability to receive information about the state of many body systems allows the thalamus to participate in the regulation and determination of the functional state of the body. In general (this is confirmed by the presence of about 120 multifunctional nuclei in the thalamus).

2. 3 Functions of the nuclei of the thalamus

share of the bark. Lateral - in the parietal, temporal, occipital lobes of the cortex. The nuclei of the thalamus are functionally divided into specific, nonspecific and associative, according to the nature of the incoming and outgoing pathways.

2. 3. 1 Specific sensory and non-sensory nuclei

Specific nuclei include the anterior ventral, medial, ventrolateral, postlateral, postmedial, lateral, and medial geniculate bodies. The latter belong to the subcortical centers of vision and hearing, respectively. The basic functional unit of specific thalamic nuclei are "relay" neurons, which have few dendrites and a long axon; their function is to switch information going to the cerebral cortex from skin, muscle and other receptors.

In turn, specific (relay) nuclei are divided into sensory and non-sensory. From specific sensory nuclei, information about the nature of sensory stimuli enters strictly defined areas of III-IV layers of the cerebral cortex. Violation of the function of specific nuclei leads to the loss of specific types of sensitivity, since the nuclei of the thalamus, like the cerebral cortex, have somatotopic localization. Individual neurons of specific nuclei of the thalamus are excited by receptors of only their own type. Signals from the receptors of the skin, eyes, ear, and muscular system go to the specific nuclei of the thalamus. Signals from the interoreceptors of the projection zones of the vagus and celiac nerves, the hypothalamus also converge here. The lateral geniculate body has direct efferent connections with the occipital lobe of the cerebral cortex and afferent connections with the retina and anterior colliculi. The neurons of the lateral geniculate bodies react differently to color stimuli, turning on and off the light, i.e., they can perform a detector function. The medial geniculate body receives afferent impulses from the lateral loop and from the inferior tubercles of the quadrigeminae. Efferent paths from the medial geniculate bodies go to the temporal cortex, reaching the primary auditory cortex there.

nuclei are projected into the limbic cortex, from where the axon connections go to the hippocampus and again to the hypothalamus, resulting in the formation of a neural circle, the movement of excitation along which ensures the formation of emotions (“the emotional ring of Peipets”). In this regard, the anterior nuclei of the thalamus are considered as part of the limbic system. The ventral nuclei are involved in the regulation of movement, thus performing a motor function. In these nuclei, impulses are switched from the basal ganglia, the dentate nucleus of the cerebellum, the red nucleus of the midbrain, which is then projected into the motor and premotor cortex. Through these nuclei of the thalamus, complex motor programs formed in the cerebellum and basal ganglia are transferred to the motor cortex.

2. 3. 2 Non-specific nuclei

neurons and are functionally considered as a derivative of the reticular formation of the brain stem. The neurons of these nuclei form their connections according to the reticular type. Their axons rise to the cerebral cortex and contact with all its layers, forming diffuse connections. Nonspecific nuclei receive connections from the reticular formation of the brain stem, hypothalamus, limbic system, basal ganglia, and specific thalamic nuclei. Thanks to these connections, the nonspecific nuclei of the thalamus act as an intermediary between the brain stem and cerebellum, on the one hand, and the neocortex, limbic system, and basal ganglia, on the other hand, uniting them into a single functional complex.

2. 3. 3 Associative cores

multipolar, bipolar three-pronged neurons, i.e., neurons capable of performing polysensory functions. A number of neurons change activity only with simultaneous complex stimulation. Pillow phenomena), speech and visual functions (integration of the word with the visual image), as well as in the perception of the “body scheme”. receives impulses from the hypothalamus, amygdala, hippocampus, thalamic nuclei, central gray matter of the trunk. The projection of this nucleus extends to the associative frontal and limbic cortex. It is involved in the formation of emotional and behavioral motor activity. Lateral nuclei receive visual and auditory impulses from the geniculate bodies and somatosensory impulses from the ventral nucleus.

Motor reactions are integrated in the thalamus with autonomic processes that provide these movements.

CHAPTER 3. COMPOSITION OF THE LIMBIC SYSTEM AND ITS PURPOSE

The structures of the limbic system include 3 complexes. The first complex is the ancient bark, olfactory bulbs, olfactory tubercle, transparent septum. The second complex of structures of the limbic system is the old cortex, which includes the hippocampus, dentate gyrus, and cingulate gyrus. The third complex of the limbic system is the structures of the insular cortex, the parahippocampal gyrus. And subcortical structures: amygdala, nuclei of the transparent septum, anterior thalamic nucleus, mastoid bodies. The hippocampus and other structures of the limbic system are surrounded by the cingulate gyrus. Near it is a vault - a system of fibers running in both directions; it follows the curvature of the cingulate gyrus and connects the hippocampus to the hypothalamus. All numerous formations of the limbic cortex ring-shaped cover the base forebrain and are a kind of border between the new cortex and the brain stem.

3.2 Morphofunctional organization of the system

represents a functional association of brain structures involved in the organization of emotional and motivational behavior, such as food, sexual, defensive instincts. This system is involved in organizing the wake-sleep cycle.

circulating the same excitation in the system and thereby maintaining a single state in it and imposing this state on other brain systems. At present, connections between brain structures are well known, organizing circles that have their own functional specifics. These include the Peipets circle (hippocampus - mastoid bodies - anterior nuclei of the thalamus - cortex of the cingulate gyrus - parahippocampal gyrus - hippocampus). This circle has to do with memory and learning processes.

Another circle (almond-shaped body - mamillary bodies of the hypothalamus - limbic region of the midbrain - amygdala) regulates aggressive-defensive, food and sexual forms of behavior. It is believed that figurative (iconic) memory is formed by the cortico-limbic-thalamo-cortical circle. Circles of different functional purposes connect the limbic system with many structures of the central nervous system, which allows the latter to realize functions, the specificity of which is determined by the included additional structure. For example, the inclusion of the caudate nucleus in one of the circles of the limbic system determines its participation in the organization of the inhibitory processes of higher nervous activity.

A large number of connections in the limbic system, a kind of circular interaction of its structures create favorable conditions for the reverberation of excitation in short and long circles. This, on the one hand, ensures the functional interaction of parts of the limbic system, on the other hand, creates conditions for memorization.

3. 3 Functions of the Limbic System

The abundance of connections of the limbic system with the structures of the central nervous system makes it difficult to identify brain functions in which it would not take part. Thus, the limbic system is related to the regulation of the level of reaction of the autonomous, somatic systems during emotional and motivational activity, the regulation of the level of attention, perception, and reproduction of emotionally significant information. The limbic system determines the choice and implementation of adaptive forms of behavior, the dynamics of innate forms of behavior, the maintenance of homeostasis, and generative processes. Finally, it ensures the creation of an emotional background, the formation and implementation of the processes of higher nervous activity. It should be noted that the ancient and old cortex of the limbic system is directly related to the olfactory function. In turn, the olfactory analyzer, as the oldest of the analyzers, is a non-specific activator of all types of activity of the cerebral cortex. Some authors call the limbic system the visceral brain, that is, the structure of the central nervous system involved in the regulation of the activity of internal organs.

This function is carried out mainly through the activity of the hypothalamus, which is the diencephalic link of the limbic system. The close efferent connections of the system with the internal organs are evidenced by various changes in their functions during stimulation of the limbic structures, especially the tonsils. At the same time, the effects have a different sign in the form of activation or inhibition of visceral functions. There is an increase or decrease in heart rate, motility and secretion of the stomach and intestines, secretion of various hormones by the adenohypophysis (adenocorticotropins and gonadotropins).

3.3.2 Formation of emotions

Emotions - these are experiences that reflect the subjective attitude of a person to the objects of the external world and the results of his own activity. In turn, emotions are a subjective component of motivations - states that trigger and implement behavior aimed at satisfying the needs that have arisen. Through the mechanism of emotions, the limbic system improves the body's adaptation to changing environmental conditions. The hypothalamus is a critical area for the emergence of emotions. In the structure of emotions, there are actually emotional experiences and its peripheral (vegetative and somatic) manifestations. These components of emotions can have relative independence. Expressed subjective experiences may be accompanied by small peripheral manifestations and vice versa. The hypothalamus is a structure primarily responsible for the autonomic manifestations of emotions. In addition to the hypothalamus, the structures of the limbic system most closely associated with emotions include the cingulate gyrus and the amygdala.

with the provision of defensive behavior, vegetative, motor, emotional reactions, motivation of conditioned reflex behavior. The tonsils react with many of their nuclei to visual, auditory, interoceptive, olfactory, and skin stimuli, and all these stimuli cause a change in the activity of any of the nuclei of the amygdala, i.e., the nuclei of the amygdala are polysensory. Irritation of the nuclei of the amygdala creates a pronounced parasympathetic effect on the activity of the cardiovascular, respiratory systems. It leads to a decrease (rarely to an increase) in blood pressure, a slowing of the heart rate, a violation of the conduction of excitation through the conduction system of the heart, the occurrence of arrhythmia and extrasystole. In this case, vascular tone may not change. Irritation of the tonsil nuclei causes respiratory depression, sometimes a cough reaction. Conditions such as autism, depression, post-traumatic shock, and phobias are thought to be associated with abnormal functioning of the amygdala. The cingulate gyrus has numerous connections with the neocortex and stem centers. And plays the role of the main integrator various systems the brain that generates emotions. Its functions are providing attention, feeling pain, stating an error, transmitting signals from the respiratory and cardiovascular systems. The ventral frontal cortex has strong connections with the amygdala. Damage to the cortex causes a sharp disturbance of emotions in a person, characterized by the occurrence of emotional dullness and disinhibition of emotions associated with the satisfaction of biological needs.

3. 3. 3 Formation of memory and implementation of learning

This function is related to the main circle of Peipets. With a single training, the amygdala plays an important role due to its ability to induce strong negative emotions, contributing to the rapid and lasting formation of a temporary connection. Among the structures of the limbic system responsible for memory and learning, the hippocampus and the associated posterior frontal cortex play an important role. Their activity is absolutely necessary for the consolidation of memory - the transition of short-term memory into long-term.