Endocrine system in children

Endocrine system in children has a very complex multi-level structure and multi-loop regulation with the possibilities of both external control through mechanisms of adaptation to environmental factors and internal homeostasis through negative feedback circuits. The latter are often built on the regulation of the formation or release of the hormone due to a decrease in its content in the blood or, conversely, the growth of hormone production with its increased consumption and a decrease in concentrations. However, there are also mechanisms that change the thresholds of this reaction through a change in receptor sensitivity to circulating hormones. A classic example is the launch of puberty events with a decrease in receptor sensitivity to sex steroids.

Molecules that change the level of functional activity or the directivity of the activity of some groups of cells or tissues are very widely represented in physiology. Some of these molecules are produced by the regulated cells or tissues (autocrine regulation), some of them are produced in closely located cells, often related to the structure and function (paracrine regulation). At the same time, highly specialized regulatory bodies have emerged in evolution that form signaling molecules that propagate humorally and affect the entire aggregate of certain specialized cells or tissues, irrespective of their close or remote localization to the hormone producing cells. This is commonly called endocrine regulation, and the cells that form such molecules, and the organs that unite such cells, are referred to as endocrine glands.

The endocrine mechanisms of the regulation of physiological functions can be conditionally divided into several levels. The highest is the neurogenic or hypothalamic level and, perhaps, even higher order levels, such as thalamic, the level of the reticular formation or the rine-encephalic formations in general, the limbic-reticular complex and the new cortex, which provide integrative functions of the brain. The stimulus for these levels and formations are information signals or influences emanating from the external or internal environment of the body. The response of this level of regulation is the inclusion or non-inclusion of certain vegetative structures and apparatus, as well as groups or individual glands of internal secretion. All this is taken together to refer to superegmental levels of regulation, in which there is still no division into sympathetic and parasympathetic, vegetative and endocrine components. The division of superegmental systems, structures and levels of regulation into "ergotropic" and "trophotropic" is recognized. Each of these levels or settings of regulation is principally and comprehensively, i.e. Integratively, changes the entire orientation and structure of life processes. It is here, at the level of the rhinencephalic structures, that "decision-making" and "setting the mode of life" that are optimal for the child at the present time take place. Following the terminology of AM Vein, there is a choice between "ergotropic" and "trophotropic" forms of behavior. Simply simplifying the meaning of the most complex biological regulations, we can talk about the two "ways of life" that make up the alternative.

Ergotropic and trophotropic forms of behavior (according to AM Vein, with changes)

Indicators	Ergotropic behavior	Trophyropic behavior
Behavior itself	Adaptation to a changing environment, fear of separation, suspense and expectation, sleep disturbances, willingness and mobilization to flee or attack	Peace and comfort, relaxation, acceptance of the environment. Realization of processes of growth and development, cognitive activity, learning, memory, sleep support
The leading vegetative system	Sympathetic	Parasympathetic
Reactions of the limbic-reticular complex	Mental activation. Endocrine activation: somatostatin, ACTH, antidiuretic hormone, cortisol, catecholamines. Desynchronization of EEG, increased muscle tone	Mental relaxation. Endocrine activation: STH, IPFR, oxytocin, growth peptides, gastrin, cholecystokinin

In the case of a relatively favorable environmental environment and psychoemotional state, in the absence of external and internal stresses, central regulation mechanisms are set for "trophotropic" activity - anabolism, intensive growth and tissue differentiation, memory activation and learning mechanisms, curiosity and research behavior. This complex is triggered by the incorporation of neuroendocrine chains associated with growth hormone, other growth factors, relaxation peptides and cholecystokinin. This is the dominant set of properties of normal life and normal development of a child of any age with the leading role of parasympathetic activation.

Switching of the installation should be carried out as soon as the situation changes, if there is a stress stimulus, acute discomfort or perception of the threat. This will include the inclusion of complex emergency survival systems with the dominance of components of the "ergotropic" system with the leading participation of sympathetic activation, ACTH, catecholamines and corticosteroids. The tasks of development here recede into the background or are removed altogether, catabolism dominates the anabolic processes. Insufficiency of switching reactions, delay with switching in case of reality of a threat to the life of the child can create or repeatedly increase the risk of loss of life, even for children who are practically healthy and well-being in all respects. Experienced pediatricians know that with some acute infections, the risk of death, mainly of sudden death, is especially high in previously healthy, well-developed young children. An infection that caught such a child suddenly may not occur here with a powerful system of glucocorticoid protection and is quickly realized by hemodynamic disorders, shock and swelling-swelling of the brain. This inability to quickly include protective stressors in children with infections and its relationship to the phenomenon of "mors thymica" was described by the outstanding Russian children's pathomorphologist TE Ivanovskaya. All this has a direct relation both to the medical tactics of intensive treatment of children with a catastrophic course of acute infections, and to the practice of forming children's health. In pediatric practice, there is another form of inadequate manifestation of an ergotropic reaction in acute infections: this is a hypersecretion of an antidiuretic hormone, or a syndrome of inappropriate vasopressin release. At the same time, there are manifestations of Parkhon's disease-the termination of urination, the growing edematous syndrome with complete absence of thirst. Swelling can spread to the respiratory tract affected by viral inflammation. Hence a kind of bronchoobstructive syndrome.

Obviously, in the system of raising a healthy child, there must also be a place for some kind of training methodology for the rhinencephalic switch of the way of Life. Both anti-stress and stress-related upbringing and training are needed.

Most of the humoral factors produced at the hypothalamus level are called "liberating" or "releasing" factors, they are designated by the term "liberians". The following hormones of the hypothalamus are most studied:

• somatostatin;
• somatoliberin;
• corticoliberin;
• prolactostatin;
• gonadoliberin;
• thyreoliberin.

[1], [2]