The endocrine system as a natural phenomenon
The endocrine system, which is also the system of neurohumoral regulation (literally “nerve-fluid control”), is extremely complex. Its structure, composition, and functioning are, apparently, at the limit of what, in principle, can be investigated and comprehended by modern science, armed with a powerful (as it seems to it) instrumental, laboratory-analytical, and computational arsenal. A whole branch of medicine, called endocrinology, deals with the study of this system, its normal operation, its various dysfunctions, and diseases, as well as methods of treating the latter. An entire sector of pharmacology is engaged in the development, synthesis, and improvement of the so-called. hormone-containing drugs; despite the chronic problem of side effects, it is no longer possible to do without this group of drugs;
Organs (glands), tissues or cells of a certain type related to the endocrine system, for example, Kulchitsky cells in the intestinal mucosa, produce special organic compounds that are usually called bioactive regulators, neurotransmitters, signaling biochemicals, but more often just hormones. This word is translated from Greek means “to excite”, “to induce” or, in more modern language, “to activate”.
The hormones go directly into the bloodstream; the slightest fluctuations in their concentration in living tissues are captured by specific receptor cells that are sensitive to one or another group of hormones and can respond to hormonal “commands” – for example, an increase in body temperature, a decrease in blood pressure in blood vessels, intense lactogenesis in the mammary glands, and many .other. In this way they start practically all physiological and mental processes in the body are forced, inhibited, or completely suppressed, in a word, controlled. Moreover, each gland, as a rule, secretes several hormones, and each hormone, in turn, affects several interrelated processes.
The synonymous term “neurohumoral regulation” does not accidentally contain the root “neuro-“. According to modern concepts, the endocrine system plays an important, exclusive role in the vital activity of the organism, but nevertheless, it is not the “supreme power” about it. Hierarchical primacy belongs to the central nervous system (CNS), i.e. the brain and spinal cord. Hormones are responsible for everything, but the secretory activity of the endocrine glands themselves are controlled by special cerebral formations and appendages, first of all, the hypothalamus-pituitary ligament in the lower region of the brain, in the so-called. diencephalon – using for this signal electrochemical impulses and a whole web of neural communication channels (in IT, such an internal network would be called an intranet). With that said,
It is difficult to say why evolving mammals developed such a complex, multistage, and multi-element neuroendocrine system. As you know, nature cares most of all about expediency, and least of all about making it convenient for a person to study it. Nature always has a lot of possible ways and options; most likely, infinitely many. It would probably be possible to regulate the vital activity of higher organisms in some other way, and preferably simpler. However, the following cannot be denied.
A modern, reasonable and technological man is still very far from creating an artificial system similar to himself – a system as compact, energetically economical and efficient, with five autonomous sensor units and two universal manipulators at once; a system that optimally combines strength, flexibility, and mobility, unconditioned and conditioned reflexes, consciousness and unconsciousness; also, the system is self-reproducing, to some extent self-learning and, most importantly, preserving homeostasis (constancy of internal conditions), i.e. self-adapting to almost any external conditions. Therefore, today we can only admire, thank nature for our amazing endocrine system – and continue to persistently explore its countless mysteries.
Major endocrine glands of ENdocrine System
You can often find the expression “the main endocrine gland”, and indifferent sources, this role is assigned to the pituitary gland, then the hypothalamus. No one knows what discoveries will be made tomorrow, so we restrict ourselves to a careful repetition of the above: as far as we know today, the activity of the neuroendocrine system (at least most of the endocrine glands) is controlled by a pair of the hypothalamus-pituitary gland. Also, the most important functions of the pituitary gland include the production of growth hormone, which regulates the processes of growth and formation of the body.
- The pineal gland (pineal gland of the brain) – one of the central neuroendocrine regulators. It is a kind of brake or limiter that blocks excessive “acceleration” of the endocrine glands. In particular, it normalizes the secretion of growth hormone and sex hormones, prevents tumor processes.
The thyroid gland is involved in the regulation of metabolism, primarily the assimilation of iodine and calcium; affects many dependent systems and processes (from general energy metabolism and intellectual productivity to tissue regeneration of the musculoskeletal system).
The parathyroid (parathyroid) glands regulate the condition of bone and muscle tissues, intraocular structures, and kidneys.
The adrenal glands produce, according to modern data, about fifty signaling substances. The most well-known and studied functions are the provision of water-salt, carbohydrate, mineral, protein metabolism, the production of male and female sex hormones (along with the gonadal glands). The famous glucocorticosteroid hormones produced by the adrenal cortex are not, of course, a panacea and can lead to numerous undesirable effects (especially when taken orally), but they often turn out to be the only “lifeline” due to their pronounced anti-inflammatory, anti-allergic, immunomodulatory, anti-shock and anti-shock and anti-shock and anti-shock effects. Such bioregulators as adrenaline and norepinephrine are no less well known. (catecholamine hormones produced by the adrenal medulla).
- Paraganglia – special clusters of cells that can rightfully be called neuroendocrine: they are responsible for sensitivity, regulate chromium metabolism, and simultaneously secrete catecholamines, like the adrenal glands.
The pancreas functionally belongs to the digestive system but contains an insignificant (1-3% of the weight of the gland) volume of endocrine cells concentrated in the so-called. islets of Langerhans and producing insulin – a hormone regulating blood glucose levels.
Testicles (in men), ovaries (in women) – secrete sex hormones (androgens and estrogens). The placenta also plays an endocrine role when carrying a pregnancy.
The thymus gland (thymus) produces mainly immune-regulating hormones.
It should be noted that far from all the functions of the endocrine glands and the hormones produced by them are known to date; only the most important and explored ones are listed here.
The most common endocrine diseases – Endocrine System Pathology
The number of independent diseases and syndromes associated with hormonal imbalance is today estimated at about six thousand. In other words, most of the diseases known to modern medicine (about ten thousand) are indeed hormonal. Some of them today threaten to become pandemic, others are sporadically rare; some are congenital and genetically determined, while others are acquired during life under the influence of numerous etiopathogenetic factors (trauma, tumor, inflammation, etc.).
The most common and well-known endocrine-metabolic disease should, apparently, be considered diabetes mellitus. Thyroid pathology is also very common, in particular, endemic iodine deficiency states, hyperthyroidism, thyroiditis, and many others. etc.
A pronounced negative effect on the entire organism, its formation, structure, appearance, functioning, – have anomalies and lesions of the glands producing sex hormones, corticoids, growth hormone. Even the famous premenstrual syndrome in women is nothing more than a transient, cyclically recurring, and transient hormonal imbalance.
In general, endocrinology has to think truly globally and systemically, dealing with a huge number of cross-linked processes, normal and pathological. However, the diseases of this group, which were once completely incomprehensible, are now being successfully diagnosed and treated. It is only important to consult a doctor on time – that is, as early as possible – until the changes become irreversible.