Biologically active substance (BAS), physiologically active substance (PAS) - a substance that in small quantities (mcg, ng) has a pronounced physiological effect on various functions of the body.

Hormone- a physiologically active substance produced by specialized endocrine cells, released into the internal environment of the body (blood, lymph) and exerting a distant effect on target cells.

Hormone - it is a signaling molecule secreted by endocrine cells that, through interaction with specific receptors on target cells, regulates their functions. Since hormones are carriers of information, they, like other signaling molecules, have high biological activity and cause responses in target cells in very low concentrations (10 -6 - 10 -12 M/l).

Target cells (target tissues, target organs) - cells, tissues or organs that contain receptors specific for a given hormone. Some hormones have a single target tissue, while others have effects throughout the body.

Table. Classification of physiologically active substances

Properties of hormones

Hormones have a number of common properties. They are usually formed by specialized endocrine cells. Hormones have selectivity of action, which is achieved by binding to specific receptors located on the surface of cells (membrane receptors) or inside them (intracellular receptors), and triggering a cascade of processes of intracellular hormonal signal transmission.

The sequence of events of hormonal signal transmission can be presented in the form of a simplified scheme “hormone (signal, ligand) -> receptor -> second (secondary) messenger -> effector structures of the cell -> physiological response of the cell.” Most hormones lack species specificity (with the exception of ) which makes it possible to study their effects on animals, as well as to use hormones obtained from animals to treat sick people.

There are three options for intercellular interaction using hormones:

• endocrine(distant), when they are delivered to target cells from the site of blood production;
• paracrine- hormones diffuse to the target cell from a nearby endocrine cell;
• autocrine - Hormones act on the producer cell, which is also its target cell.

According to their chemical structure, hormones are divided into three groups:

• peptides (number of amino acids up to 100, for example thyrotropin releasing hormone, ACTH) and proteins (insulin, growth hormone, etc.);
• derivatives of amino acids: tyrosine (thyroxine, adrenaline), tryptophan - melatonin;
• steroids, cholesterol derivatives (female and male sex hormones, aldosterone, cortisol, calcitriol) and retinoic acid.

According to their function, hormones are divided into three groups:

• effector hormones, acting directly on target cells;
• pituitary hormones, controlling the function of peripheral endocrine glands;
• hypothalamic hormones regulating the secretion of hormones by the pituitary gland.

Table. Types of hormone action

Action type	Characteristic
Hormonal (hemocrine)	The action of the hormone at a considerable distance from the place of formation
Isocrine (local)	A hormone synthesized in one cell has an effect on a cell located in close contact with the first. Its release is carried out into the interstitial fluid and blood
Neurocrine (neuroendocrine)	An action when a hormone, released from nerve endings, acts as a neurotransmitter or neuromodulator
Paracrine	A type of isocrine action, but in this case the hormone produced in one cell enters the intercellular fluid and affects a number of cells located in close proximity
Juxtacrine	A type of paracrine action, when the hormone does not enter the intercellular fluid, and the signal is transmitted through the plasma membrane of a nearby cell
Autocrine	A hormone released from a cell affects the same cell, changing its functional activity
Solicrine	The hormone released from the cell enters the lumen of the duct and thus reaches another cell, exerting a specific effect (typical of gastrointestinal hormones)

Hormones circulate in the blood in a free (active form) and bound (inactive form) state with plasma proteins or formed elements. Hormones have biological activity in a free state. Their content in the blood depends on the rate of secretion, the degree of binding, uptake and rate of metabolism in tissues (binding with specific receptors, destruction or inactivation in target cells or hepatocytes), removal in urine or bile.

Table. Physiologically active substances recently discovered

A number of hormones can undergo chemical transformations in target cells into more active forms. Thus, the hormone “thyroxine”, undergoing deiodination, is converted into a more active form - triiodothyronine. The male sex hormone testosterone in target cells can not only be converted into a more active form - dehydrotestosterone, but also into female sex hormones of the estrogen group.

The effect of a hormone on a target cell is due to binding and stimulation of a receptor specific to it, after which the hormonal signal is transmitted to the intracellular cascade of transformations. Signal transmission is accompanied by its multiple amplification, and the action of a small number of hormone molecules on a cell can be accompanied by a powerful response from target cells. Activation of the receptor by a hormone is also accompanied by the activation of intracellular mechanisms that stop the cell’s response to the action of the hormone. These may be mechanisms that reduce the sensitivity (desensitization/adaptation) of the receptor to the hormone; mechanisms that dephosphorylate intracellular enzyme systems, etc.

Receptors for hormones, as well as for other signaling molecules, are localized on the cell membrane or inside the cell. Hormones of a hydrophilic (lyiophobic) nature, for which the cell membrane is impermeable, interact with cell membrane receptors (1-TMS, 7-TMS and ligand-gated ion channels). They are catecholamines, melatonin, serotonin, hormones of protein-peptide nature.

Hormones of a hydrophobic (lipophilic) nature diffuse across the plasma membrane and bind to intracellular receptors. These receptors are divided into cytosolic (receptors of steroid hormones - gluco- and mineralocorticoids, androgens and progestins) and nuclear (receptors of thyroid iodine-containing hormones, calcitriol, estrogens, retinoic acid). Cytosolic and estrogen receptors are associated with heat shock proteins (HSPs), which prevents their entry into the nucleus. The interaction of the hormone with the receptor leads to the separation of HSP, the formation of the hormone-receptor complex and activation of the receptor. The hormone-receptor complex moves to the nucleus, where it interacts with strictly defined hormone-sensitive (recognizing) DNA regions. This is accompanied by a change in the activity (expression) of certain genes that control protein synthesis in the cell and other processes.

Based on the use of certain intracellular pathways of hormonal signal transmission, the most common hormones can be divided into a number of groups (Table 8.1).

Table 8.1. Intracellular mechanisms and pathways of hormone action

Hormones control a variety of reactions of target cells and, through them, the physiological processes of the body. The physiological effects of hormones depend on their content in the blood, the number and sensitivity of receptors, and the state of post-receptor structures in target cells. Under the influence of hormones, activation or inhibition of the energy and plastic metabolism of cells, the synthesis of various substances, including protein substances (metabolic effect of hormones); changes in the rate of cell division, its differentiation (morphogenetic effect), initiation of programmed cell death (apoptosis); triggering and regulation of contraction and relaxation of smooth myocytes, secretion, absorption (kinetic action); changing the state of ion channels, accelerating or inhibiting the generation of electrical potentials in pacemakers (corrective action), facilitating or inhibiting the influence of other hormones (reactogenic effect), etc.

Table. Distribution of the hormone in the blood

The rate of occurrence in the body and the duration of responses to the action of hormones depends on the type of stimulated receptors and the metabolic rate of the hormones themselves. Changes in physiological processes can be observed after several tens of seconds and last for a short time when stimulating plasma membrane receptors (for example, vasoconstriction and an increase in blood pressure under the influence of adrenaline) or observed after several tens of minutes and lasting for hours when stimulating nuclear receptors (for example, increased metabolism in cells and an increase in oxygen consumption by the body when thyroid receptors are stimulated by triiodothyronine).

Table. Duration of action of physiologically active substances

Since the same cell can contain receptors for different hormones, it can simultaneously be a target cell for several hormones and other signaling molecules. The effect of one hormone on a cell is often combined with the influence of other hormones, mediators, and cytokines. In this case, a number of signal transduction pathways can be launched in target cells, as a result of the interaction of which an increase or inhibition of the cell response can be observed. For example, norepinephrine and norepinephrine can simultaneously act on the smooth myocyte of the vascular wall, summing up their vasoconstrictor effect. The vasoconstrictor effect of vasopressin can be eliminated or weakened by the simultaneous action of bradykinin or nitric oxide on smooth myocytes of the vascular wall.

Regulation of hormone formation and secretion

Regulation of hormone formation and secretion is one of the most important functions and nervous systems of the body. Among the mechanisms regulating the formation and secretion of hormones, the influence of the central nervous system, “triple” hormones, the influence of the concentration of hormones in the blood through negative feedback channels, the influence of the final effects of hormones on their secretion, the influence of circadian and other rhythms are distinguished.

Nervous regulation carried out in various endocrine glands and cells. This is the regulation of the formation and secretion of hormones by neurosecretory cells of the anterior hypothalamus in response to the receipt of nerve impulses from various areas of the central nervous system. These cells have a unique ability to excite and transform excitation into the formation and secretion of hormones that stimulate (releasing hormones, liberins) or inhibit (statins) the secretion of hormones by the pituitary gland. For example, with an increase in the flow of nerve impulses to the hypothalamus under conditions of psycho-emotional arousal, hunger, pain, exposure to heat or cold, during infection and other emergency conditions, the neurosecretory cells of the hypothalamus release corticotropin-releasing hormone into the portal vessels of the pituitary gland, which enhances the secretion of adrenocorticotropic hormone (ACTH) by the pituitary gland.

The ANS has a direct effect on the formation and secretion of hormones. With an increase in the tone of the SNS, the secretion of triple hormones by the pituitary gland increases, the secretion of catecholamines by the adrenal medulla, thyroid hormones by the thyroid gland, and the secretion of insulin decreases. With an increase in the tone of the PSNS, the secretion of insulin and gastrin increases and the secretion of thyroid hormones is inhibited.

Regulation by pituitary hormones used to control the formation and secretion of hormones by peripheral endocrine glands (thyroid, adrenal cortex, gonads). The secretion of tropic hormones is under the control of the hypothalamus. Tropic hormones got their name because of their ability to bind (have affinity) to the receptors of target cells that form individual peripheral endocrine glands. The tropic hormone to thyrocytes of the thyroid gland is called thyrotropin or thyroid-stimulating hormone (TSH), to the endocrine cells of the adrenal cortex - adrenocorticotropic hormone (ACHT). Tropic hormones to the endocrine cells of the gonads are called: lutropin or luteinizing hormone (LH) - to Leydig cells, corpus luteum; follitropin or follicle-stimulating hormone (FSH) - to follicle cells and Sertoli cells.

Tropic hormones, when their level in the blood increases, repeatedly stimulate the secretion of hormones by the peripheral endocrine glands. They may also have other effects on them. For example, TSH increases blood flow in the thyroid gland, activates metabolic processes in thyrocytes, their capture of iodine from the blood, and accelerates the processes of synthesis and secretion of thyroid hormones. With an excess amount of TSH, hypertrophy of the thyroid gland is observed.

Feedback regulation used to control the secretion of hormones from the hypothalamus and pituitary gland. Its essence lies in the fact that the neurosecretory cells of the hypothalamus have receptors and are target cells for the hormones of the peripheral endocrine gland and the triple hormone of the pituitary gland, which controls the secretion of hormones by this peripheral gland. Thus, if under the influence of hypothalamic thyrotropin-releasing hormone (TRH) the secretion of TSH increases, then the latter will bind not only to the receptors of thyrsocytes, but also to the receptors of the neurosecretory cells of the hypothalamus. In the thyroid gland, TSH stimulates the formation of thyroid hormones, and in the hypothalamus, it inhibits further secretion of TRH. The relationship between the level of TSH in the blood and the processes of formation and secretion of TRH in the hypothalamus is called short loop feedback.

The secretion of TRH in the hypothalamus is also influenced by the level of thyroid hormones. If their concentration in the blood increases, they bind to the thyroid hormone receptors of the neurosecretory cells of the hypothalamus and inhibit the synthesis and secretion of TRH. The relationship between the level of thyroid hormones in the blood and the processes of formation and secretion of TRH in the hypothalamus is called long loop feedback. There is experimental evidence that hypothalamic hormones not only regulate the synthesis and release of pituitary hormones, but also inhibit their own release, which is defined by the concept ultra-short loop feedback.

The set of glandular cells of the pituitary gland, hypothalamus and peripheral endocrine glands and the mechanisms of their mutual influence on each other were called the pituitary-hypothalamus-endocrine gland systems or axes. The systems (axes) are distinguished: pituitary gland - hypothalamus - thyroid gland; pituitary gland - hypothalamus - adrenal cortex; pituitary gland - hypothalamus - gonads.

Impact of end effects hormones on their secretion takes place in the islet apparatus of the pancreas, C-cells of the thyroid gland, parathyroid glands, hypothalamus, etc. This is demonstrated by the following examples. When the blood glucose level increases, insulin secretion is stimulated, and when it decreases, glucagon secretion is stimulated. These hormones inhibit each other's secretion through a paracrine mechanism. When the level of Ca 2+ ions in the blood increases, the secretion of calcitonin is stimulated, and when it decreases, the secretion of parathyrin is stimulated. Directly influencing the concentration of substances on the secretion of hormones that control their levels is a quick and effective way to maintain the concentration of these substances in the blood.

Among the mechanisms under consideration for the regulation of hormone secretion and their final effects, one can note the regulation of the secretion of antidiuretic hormone (ADH) by cells of the posterior hypothalamus. The secretion of this hormone is stimulated by an increase in the osmotic pressure of the blood, for example, by loss of fluid. A decrease in diuresis and fluid retention in the body under the influence of ADH lead to a decrease in osmotic pressure and inhibition of ADH secretion. A similar mechanism is used to regulate the secretion of natriuretic peptide by atrial cells.

The influence of circadian and other rhythms on the secretion of hormones takes place in the hypothalamus, adrenal glands, gonads, and pineal glands. An example of the influence of the circadian rhythm is the daily dependence of the secretion of ACTH and corticosteroid hormones. Their lowest level in the blood is observed at midnight, and the highest in the morning after waking up. The highest levels of melatonin are recorded at night. The influence of the lunar cycle on the secretion of sex hormones in women is well known.

Determination of hormones

Secretion of hormones - the entry of hormones into the internal environment of the body. Polypeptide hormones accumulate in granules and are secreted by exocytosis. Steroid hormones do not accumulate in the cell and are secreted immediately after synthesis by diffusion through the cell membrane. The secretion of hormones in most cases has a cyclic, pulsating nature. The frequency of secretion is from 5-10 minutes to 24 hours or more (the common rhythm is about 1 hour).

Bound form of the hormone- formation of reversible, non-covalently bonded complexes of hormones with plasma proteins and formed elements. The degree of binding of various hormones varies greatly and is determined by their solubility in blood plasma and the presence of transport protein. For example, 90% of cortisol, 98% of testosterone and estradiol, 96% of triiodothyronine and 99% of thyroxine are bound to transport proteins. The bound form of the hormone cannot interact with receptors and forms a reserve that can be quickly mobilized to replenish the pool of free hormone.

Free form of the hormone- a physiologically active substance in the blood plasma in a state not bound to protein, capable of interacting with receptors. The bound form of the hormone is in dynamic equilibrium with a pool of free hormone, which in turn is in equilibrium with the hormone bound to receptors in target cells. Most polypeptide hormones, with the exception of somatotropin and oxytocin, circulate in low concentrations in the blood in a free state, without binding to proteins.

Metabolic transformations of the hormone - its chemical modification in target tissues or other formations, causing a decrease/increase in hormonal activity. The most important place for hormone exchange (their activation or inactivation) is the liver.

Hormone metabolism rate - the intensity of its chemical transformation, which determines the duration of circulation in the blood. The half-life of catecholamines and polypeptide hormones is several minutes, and that of thyroid and steroid hormones - from 30 minutes to several days.

Hormone receptor- a highly specialized cellular structure that is part of the plasma membranes, cytoplasm or nuclear apparatus of the cell and forms a specific complex compound with the hormone.

Organ specificity of the hormone action - responses of organs and tissues to physiologically active substances; they are strictly specific and cannot be caused by other compounds.

Feedback— the influence of the level of circulating hormone on its synthesis in endocrine cells. A long feedback chain is the interaction of the peripheral endocrine gland with the pituitary, hypothalamic centers and with the suprahypothalamic regions of the central nervous system. A short feedback loop - a change in the secretion of the pituitary tron ​​hormone, modifies the secretion and release of statins and liberins of the hypothalamus. An ultrashort feedback loop is an interaction within an endocrine gland in which the release of a hormone influences the processes of secretion and release of itself and other hormones from this gland.

Negative feedback - an increase in the level of the hormone, leading to inhibition of its secretion.

Positive Feedback- an increase in the level of the hormone, causing stimulation and the occurrence of a peak in its secretion.

Anabolic hormones - physiologically active substances that promote the formation and renewal of the structural parts of the body and the accumulation of energy in it. These substances include pituitary gonadotropic hormones (follitropin, lutropin), sex steroid hormones (androgens and estrogens), growth hormone (somatotropin), placental chorionic gonadotropin, insulin.

Insulin- a protein substance produced in the β-cells of the islets of Langerhans, consisting of two polypeptide chains (A chain - 21 amino acids, B chain - 30), which reduces blood glucose levels. The first protein whose primary structure was completely determined by F. Sanger in 1945-1954.

Catabolic hormones- physiologically active substances that promote the breakdown of various substances and structures of the body and the release of energy from it. These substances include corticotropin, glucocorticoids (cortisol), glucagon, high concentrations of thyroxine and adrenaline.

Thyroxine (tetraiodothyronine) - an iodine-containing derivative of the amino acid tyrosine, produced in the follicles of the thyroid gland, increasing the intensity of basal metabolism, heat production, affecting the growth and differentiation of tissues.

Glucagon - a polypeptide produced in the α-cells of the islets of Langerhans, consisting of 29 amino acid residues, stimulating the breakdown of glycogen and increasing blood glucose levels.

Corticosteroid hormones - compounds formed in the adrenal cortex. Depending on the number of carbon atoms in the molecule, they are divided into C 18 -steroids - female sex hormones - estrogens, C 19 -steroids - male sex hormones - androgens, C 21 -steroids - actual corticosteroid hormones that have a specific physiological effect.

Catecholamines — derivatives of pyrocatechin, actively participating in physiological processes in the body of animals and humans. Catecholamines include adrenaline, norepinephrine and dopamine.

Sympathoadrenal system - chromaffin cells of the adrenal medulla and the preganglionic fibers of the sympathetic nervous system that innervate them, in which catecholamines are synthesized. Chromaffin cells are also found in the aorta, carotid sinus, and in and around the sympathetic ganglia.

Biogenic amines- a group of nitrogen-containing organic compounds formed in the body by decarboxylation of amino acids, i.e. elimination of the carboxyl group from them - COOH. Many of the biogenic amines (histamine, serotonin, norepinephrine, adrenaline, dopamine, tyramine, etc.) have a pronounced physiological effect.

Eicosanoids - physiologically active substances, derivatives of predominantly arachidonic acid, which have a variety of physiological effects and are divided into groups: prostaglandins, prostacyclins, thromboxanes, levuglandins, leukotrienes, etc.

Regulatory peptides- high molecular weight compounds, which are a chain of amino acid residues connected by a peptide bond. Regulatory peptides with up to 10 amino acid residues are called oligopeptides, from 10 to 50 are called polypeptides, and over 50 are called proteins.

Antihormone- a protective substance produced by the body during prolonged administration of protein hormonal drugs. The formation of an antihormone is an immunological reaction to the introduction of a foreign protein from the outside. The body does not produce antihormones in relation to its own hormones. However, substances similar in structure to hormones can be synthesized, which, when introduced into the body, act as antimetabolites of hormones.

Hormone antimetabolites- physiologically active compounds that are close in structure to hormones and enter into competitive, antagonistic relationships with them. Antimetabolites of hormones are capable of taking their place in physiological processes occurring in the body or blocking hormonal receptors.

Tissue hormone (autocoid, local hormone) - a physiologically active substance produced by unspecialized cells and having a predominantly local effect.

Neurohormone- a physiologically active substance produced by nerve cells.

Effector hormone - a physiologically active substance that has a direct effect on cells and target organs.

Throne hormone- a physiologically active substance that acts on other endocrine glands and regulates their functions.

Some people try to eliminate problems in the functioning of the body on their own, without resorting to the help of doctors. However, such self-medication can negatively affect future health. After all, a disruption in the functioning of one or another organ occurs in the process of insufficient or excessive production of hormones.

However, every person has heard about these substances since childhood. Meanwhile, scientists continue to study the structure of these substances and the functions they perform. What are hormones, why do people need them, what types of hormones exist, and what effect do they have on him?

What are hormones

Hormones are biologically active substances. Their production occurs in specialized cells of the endocrine glands. Translated from ancient Greek, the word “hormones” means “to stimulate” or “to excite.”

It is this action that is their main function: when produced in some cells, these substances induce cells of other organs to act, sending them signals. That is, in the human body, hormones play the role of a unique mechanism that triggers all vital processes that cannot exist separately.

To understand their significance, it is necessary to understand where they are formed. The main sources of hormone production are the following internal glands:

• pituitary;
• thyroid and parathyroid glands;
• adrenal glands;
• pancreas;
• testes in men and ovaries in women.

Some internal organs can also participate in the formation of these substances, which include:

• liver;
• kidneys;
• placenta during pregnancy;
• the pineal gland, located in the brain;
• gastrointestinal tract;
• the thymus or thymus gland, which actively develops before puberty and decreases in size with age.

The hypothalamus is a small part of the brain that coordinates the production of hormones.

How do hormones work?

Once you understand what hormones are, you can begin to study how they work.

Each hormone affects specific organs, called target organs. Moreover, each hormone has its own chemical formula, which determines which organ will become the target. It is worth noting that the target may be not one organ, but several.

Unlike the nervous system, which transmits impulses through nerves, hormones enter the blood. They act on target organs through cells equipped with special receptors that can perceive only certain hormones. Their relationship is like a lock with a key, where the receptor cell acts as the lock, which is opened by the hormone key.

By attaching to receptors, hormones penetrate into internal organs, where, using chemical action, they force them to perform certain functions.

Active study of hormones and the glands that produce them began in 1855. During this period, the English doctor T. Addison first described bronze disease, which develops as a result of dysfunction of the adrenal glands.

Other doctors also showed interest in this science, for example, C. Bernard from France, who studied the processes of formation and release of secretion into the blood. The subject of his study was also the organs that secreted them.

And the French doctor C. Brown-Séquard managed to find a relationship between various diseases and a decrease in the function of the endocrine glands. It was he who first proved that many diseases can be cured with the help of remedies prepared from gland extracts.

In 1899, English scientists managed to discover the hormone secretin, produced by the duodenum. A little later they gave it the name hormone, which marked the beginning of modern endocrinology.

Until now, scientists have not been able to study everything about hormones, while continuing to make new discoveries.

Types of hormones

Hormones come in several types, distinguished by their chemical composition.

• Steroids. These hormones are produced in the testicles and ovaries from cholesterol. These substances perform the most important functions that allow a person to develop and acquire the necessary physical form that adorns the body, as well as to reproduce offspring. Steroids include progesterone, androgen, estradiol and dihydrotestosterone.
• Fatty acid derivatives. These substances act on cells located near those organs that are involved in their production. These hormones include leukotrienes, thromboxanes and prostaglandins.
• Amino acid derivatives. These hormones are produced by several glands, including the adrenal glands and the thyroid gland. And the basis for their production is tyrosine. Representatives of this type are adrenaline, norepinephrine, melatonin, and thyroxine.
• Peptides. These hormones are responsible for carrying out metabolic processes in the body. And the most important component for their production is protein. Peptides include insulin and glucagon, produced by the pancreas, and growth hormone, produced by the pituitary gland.

The role of hormones in the human body

The human body produces hormones throughout its entire life. They influence any processes that happen to a person.

• Thanks to these substances, each person has a certain height and weight.
• Hormones influence a person's emotional state.
• Throughout life, hormones stimulate the natural process of cell growth and breakdown.
• They participate in the formation of the immune system, stimulating or inhibiting it.
• Substances produced by the endocrine glands control metabolic processes in the body.

• Under the influence of hormones, the body can more easily tolerate physical activity and stressful situations. For these purposes, the active hormone adrenaline is produced.
• With the assistance of biologically active substances, preparation for a certain life stage occurs, including puberty and childbirth.
• Certain substances control the reproductive cycle.
• A person also experiences feelings of hunger and satiety under the influence of hormones.
• With normal production of hormones and their function, sexual desire increases, and with a decrease in their concentration in the blood, libido decreases.

The main human hormones ensure the stability of the body throughout life.

The influence of hormones on the human body

Under the influence of certain factors, the stability of the process may be disrupted. A sample list of them looks like this:

• age-related changes in the body;
• various diseases;
• stressful situations;
• changes in climatic conditions;
• unfavorable environmental situation.

In the body of men, the production of hormones is more stable than in women. In the female body, the amount of hormones secreted varies depending on various factors, including the phase of the menstrual cycle, pregnancy, childbirth and menopause.

The following signs indicate that a hormonal imbalance may have occurred:

• general weakness of the body;
• cramps in the limbs;
• headache and ringing in the ears;
• sweating;
• impaired coordination of movements and slow reaction;
• memory impairment and lapses;
• sudden changes in mood and depression;
• unreasonable decrease or increase in body weight;
• stretch marks on the skin;
• disruption of the digestive system;
• hair growth in places where it should not be;
• gigantism and nanism, as well as acromegaly;
• skin problems, including increased oily hair, acne and dandruff;
• menstrual irregularities.

How are hormone levels determined?

If any of these conditions manifest themselves systematically, you should consult an endocrinologist. Only a doctor, based on an analysis, will be able to determine which hormones are produced in insufficient or excessive quantities and prescribe adequate treatment. In this case, determining the level of all possible hormones is not required, since an experienced doctor will determine the type of research required based on the patient’s complaints.

Why is a blood test prescribed for hormone levels? It is necessary to confirm or exclude any diagnosis.

If necessary, tests are prescribed that determine the concentration in the blood of hormones secreted by the following endocrine glands:

• pituitary gland;
• thyroid gland;
• adrenal glands;
• testes in men and ovaries in women.

As an additional examination, women may be prescribed prenatal diagnostics to identify pathologies in the development of the fetus in the early stages of pregnancy.

The most popular blood test is to determine the basal level of a certain type of hormone. This examination is carried out in the morning on an empty stomach. But the level of most substances tends to change throughout the day. As an example, somatotropin is a hormone that stimulates growth. Therefore, its concentration is studied throughout the day.

If a study is carried out on the hormones of the endocrine glands that depend on the pituitary gland, an analysis is carried out to determine the level of the hormone produced by the endocrine gland and the pituitary hormone that causes this gland to produce it.

How to achieve hormonal balance

For mild hormonal imbalances, lifestyle adjustments are indicated:

• Maintaining a daily routine. Full functioning of the body's systems is possible only by creating a balance between work and rest. For example, the production of somatotropin increases 1-3 hours after falling asleep. In this case, it is recommended to go to bed no later than 23 hours, and the duration of sleep should be at least 7 hours.
• Physical activity allows you to stimulate the production of biologically active substances. Therefore, 2-3 times a week you need to do dancing, aerobics, or increase your activity in other ways.

• A balanced diet with increased protein intake and decreased fat intake.
• Compliance with drinking regime. During the day you need to drink 2-2.5 liters of water.

If more intensive treatment is required, a table of hormones is studied, and medications that contain their synthetic analogs are used. However, only a specialist has the right to prescribe them.

⚕️Melikhova Olga Aleksandrovna - endocrinologist, 2 years of experience.

Deals with issues of prevention, diagnosis and treatment of diseases of the endocrine system: thyroid gland, pancreas, adrenal glands, pituitary gland, gonads, parathyroid glands, thymus gland, etc.

All glands and cells that secrete hormones are combined into the endocrine system.

A complete list of hormones and their functions are presented in this table:

Hormone	Which gland produces	Function
Adrenocorticotropic hormone	Pituitary	Controls the secretion of hormones from the adrenal cortex
Aldosterone	Adrenal glands	Participates in the regulation of water-salt metabolism: retains sodium and water, removes potassium
Vasopressin (antidiuretic hormone)	Pituitary	Regulates the amount of urine excreted and, together with aldosterone, controls blood pressure
Glucagon	Pancreas	Increases blood glucose levels
A growth hormone	Pituitary	Manages the processes of growth and development; stimulates protein synthesis
Insulin	Pancreas	Lowers blood glucose levels; affects the metabolism of carbohydrates, proteins and fats in the body
Corticosteroids	Adrenal glands	Have an effect on the entire body; have pronounced anti-inflammatory properties; maintain blood sugar levels, blood pressure and muscle tone; participate in the regulation of water-salt metabolism
Luteinizing hormone and follicle stimulating hormone	Pituitary	Control reproductive functions, including sperm production in men, egg maturation and the menstrual cycle in women; responsible for the formation of male and female secondary sexual characteristics (distribution of areas of hair growth, volume of muscle mass, structure and thickness of skin, timbre of voice and, possibly, even personality traits)
Oxytocin	Pituitary	Causes contraction of the muscles of the uterus and mammary ducts
Parathyroid hormone	Parathyroid glands	Controls bone formation and regulates the excretion of calcium and phosphorus in urine
Progesterone	Ovaries	Prepares the inner lining of the uterus for the implantation of a fertilized egg, and the mammary glands for milk production
Prolactin	Pituitary	Induces and maintains milk production in the mammary glands
Renin and angiotensin	Kidneys	Control blood pressure
Thyroid hormones	Thyroid	Regulate the processes of growth and maturation, the speed of metabolic processes in the body
Thyroid-stimulating hormone	Pituitary	Stimulates the production and secretion of thyroid hormones
Erythropoietin	Kidneys	Stimulates the formation of red blood cells
Estrogens	Ovaries	Control the development of female genital organs and secondary sexual characteristics

Endocrine system works under the control of the central nervous system and, together with it, regulates and coordinates the functions of the body. Common to nerve and endocrine cells is the production of regulatory factors.

Through the release of hormones, the endocrine system, together with the nervous system, ensures the existence of the body as a whole. Let's consider this example. If there were no endocrine system, then the entire body would be an endlessly tangled chain of “wires” - nerve fibers. In this case, through many “wires” it would be necessary to sequentially give one single command, which can be transmitted in the form of one “command” transmitted “by radio” to many cells at once.

Endocrine cells produce hormones and release them into the blood, and cells of the nervous system ( neurons ) produce biologically active substances ( neurotransmitters - norepinephrine , acetylcholine ,serotonin and others) that stand out in synaptic clefts .

The link between the endocrine and nervous systems is the hypothalamus, which is both a nerve formation and an endocrine gland.

The hypothalamus is the highest center of the endocrine system.

It controls and combines endocrine regulatory mechanisms with nervous ones, being also the brain center autonomic nervous system . The hypothalamus contains neurons that produce special substances - neurohormones regulating the release of hormones by other endocrine glands. The central organ of the endocrine system is also the pituitary gland. The remaining endocrine glands are classified as peripheral organs of the endocrine system.

As can be seen from figure 1 , in response to information coming from the central and autonomic nervous system, the hypothalamus secretes special substances - neurohormones, which “instruct” the pituitary gland to speed up or slow down the production of stimulating hormones.

Figure 1. Hypothalamic-pituitary endocrine regulation system:
TSH - thyroid-stimulating hormone;
ACTH - adrenocorticotropic hormone;
FSH - follicle-stimulating hormone;
LH - luteinizing hormone;
STH - somatotropic hormone;
LTG - luteotropic hormone (prolactin);
ADH - antidiuretic hormone (vasopressin)

The main stimulating hormones of the pituitary gland include thyroid-stimulating, adrenocorticotropic, follicle-stimulating, luteinizing and somatotropic. In addition, the hypothalamus can send signals directly to the peripheral endocrine glands without the participation of the pituitary gland.

Thyroid-stimulating hormone acts on the thyroid and parathyroid glands. It activates the synthesis and secretion thyroid hormones (thyroxine And triiodothyronine ), as well as hormone calcitonin (which is involved in calcium metabolism and causes a decrease in calcium levels in the blood) by the thyroid gland.

The parathyroid glands produce parathyroid hormone , which is involved in the regulation of calcium and phosphorus metabolism.

Adrenocorticotropic hormone stimulates production corticosteroids (glucocorticoids And mineralocorticoids ) adrenal cortex. In addition, cells of the adrenal cortex produce androgens , estrogens And progesterone (in small quantities), responsible, along with similar hormones of the sex glands, for the development of secondary sexual characteristics. Adrenal medulla cells synthesize adrenalin , norepinephrine And dopamine .

Follicle-stimulating And luteinizing Hormones stimulate sexual function and the production of hormones by the gonads. The ovaries of women produce estrogens, progesterone, and androgens, and the testicles of men produce androgens.

Somatotropic hormone stimulates the growth of the body as a whole and its individual organs (including skeletal growth) and the production of one of the pancreatic hormones - somatotostatin , suppresses secretion by the pancreas insulin , glucagon and digestive enzymes. In the pancreas there are 2 types of specialized cells, grouped in the form of tiny islets (see islets of Langerhans figure 2, view G ).

These are alpha cells that synthesize the hormone glucagon, and beta cells that produce the hormone insulin. Insulin and glucagon regulate carbohydrate metabolism (i.e. blood glucose levels).

Stimulating hormones activate the functions of the peripheral endocrine glands, prompting them to secrete hormones involved in the regulation of the body's basic vital processes.

Interestingly, an excess of hormones produced by peripheral endocrine glands suppresses the release of the corresponding “tropic” pituitary hormone. This is a clear illustration of a universal regulatory mechanism in living organisms, referred to as negative feedback .

In addition to stimulating hormones, the pituitary gland also produces hormones that are directly involved in the control of the vital functions of the body. These hormones include: somatotropic hormone (which we already mentioned above), luteotropic hormone, antidiuretic hormone, oxytocin and others.

Luteotropic hormone (prolactin) controls milk production in the mammary glands.

Antidiuretic hormone (vasopressin) delays the removal of fluid from the body and increases blood pressure.

Oxytocin causes contraction of the uterus and stimulates the secretion of milk by the mammary glands.

The lack of pituitary hormones in the body is compensated by drugs that compensate for their deficiency or imitate their action: or have gonadotropic properties, acting like endogenous vasopressin. Medicines are also used in cases where, for some reason, it is necessary to suppress the activity of pituitary hormones - then the gonadotropic function of the pituitary gland is blocked and the release of luteinizing and follicle-stimulating hormones is suppressed.

The levels of some hormones controlled by the pituitary gland are subject to cyclic fluctuations. Thus, the menstrual cycle in women is determined by monthly fluctuations in the level of luteinizing and follicle-stimulating hormones, which are produced in the pituitary gland and affect the ovaries. Accordingly, the level of ovarian hormones - estrogen and progesterone - fluctuates in the same rhythm. How the hypothalamus and pituitary gland control these biorhythms is not entirely clear.

There are also hormones whose production changes for reasons that are not yet fully understood. Thus, for some reason, the level of corticosteroids and growth hormone fluctuates throughout the day: it reaches a maximum in the morning and a minimum at noon.

The mechanism of action of hormones. The hormone binds to receptors in target cells, and intracellular enzymes are activated, which brings the target cell into a state of functional excitation. Excessive amounts of the hormone act on the gland that produces it or through the autonomic nervous system on the hypothalamus, prompting them to reduce the production of this hormone (negative feedback again!).

The friendly and coordinated work of all organs of the endocrine system is the key to the normal functioning of our body.

On the contrary, any failure in the synthesis of hormones or dysfunction of the endocrine system leads to unpleasant health consequences. For example, with a lack of growth hormone secreted by the pituitary gland, the child remains a dwarf.

The World Health Organization has established the height of the average person as 160 cm (for women) and 170 cm (for men). A person below 140 cm or above 195 cm is already considered very short or very tall. It is known that the Roman emperor Maskimilian was 2.5 m tall, and the Egyptian dwarf Agibe was only 38 cm tall!

A lack of thyroid hormones in children leads to the development of mental retardation, and in adults - to a slowdown in metabolism, a decrease in body temperature, and the appearance of edema.

It is known that under stress, the production of corticosteroids increases and “malaise syndrome” develops. The body's ability to adapt (adapt) to stress largely depends on the ability of the endocrine system to quickly respond by reducing the production of corticosteroids.

With a lack of insulin produced by the pancreas, a serious disease occurs - diabetes.

It is worth noting that as we age (the natural decline of the body), different ratios of hormonal components in the body develop.

Thus, there is a decrease in the formation of some hormones and an increase in others. The decrease in the activity of endocrine organs occurs at different rates: by the age of 13-15, atrophy of the thymus gland occurs, concentration in blood plasma testosterone in men it gradually decreases after 18 years, estrogen secretion in women decreases after 30 years; The production of thyroid hormones is limited only by the age of 60-65.

Sex hormones. There are two types of sex hormones - male (androgens) and female (estrogens). Both types are present in the body of both men and women. The development of the genital organs and the formation of secondary sexual characteristics during adolescence (enlargement of the mammary glands in girls, the appearance of facial hair and deepening of the voice in boys, etc.) depend on their ratio. You've probably seen old women with rough voices, mustaches and even goatees on the street or in public transport. This is explained quite simply. As women age, the production of estrogens (female sex hormones) decreases, and it may happen that male sex hormones (androgens) begin to predominate over female ones. Hence the deepening of the voice and excess hair growth (hirsutism).

As men know, patients with alcoholism suffer from severe feminization (even enlargement of the mammary glands) and impotence. This is also the result of hormonal processes. Repeated intake of alcohol by men leads to suppression of testicular function and a decrease in the concentration of male sex hormone in the blood - testosterone , to which we owe our feelings of passion and sexual desire. At the same time, the adrenal glands increase the production of substances that are similar in structure to testosterone, but do not have an activating (androgenic) effect on the male reproductive system. This tricks the pituitary gland into reducing its stimulating effect on the adrenal glands. As a result, testosterone production is further reduced. At the same time, the introduction of testosterone helps little, since in the body of an alcoholic the liver converts it into the female sex hormone ( estrone ). It turns out that treatment will only worsen the result. So men have to choose what is more important to them: sex or alcohol.

It is difficult to overestimate the role of hormones. Their work can be compared to the playing of an orchestra, when any failure or false note disrupts the harmony.

In the article we will talk about the types of hormones, and we will also look at what they are and what functions they perform. After reading, you will learn to understand this issue and understand the influence of hormones on human life and health.

What is it about?

What are hormones? These are substances that are produced by certain cells of the body in the endocrine glands. They enter the blood and thus have a strong influence on physiological processes and metabolism. In fact, these substances are regulators of most phenomena occurring in the human body.

Story

Before we talk about the types of hubbub, let's talk about the history of the discovery of these important substances. The study of them and the endocrine glands was begun by the physician T. Addison in 1855. Another scientist who began the study of endocrinology is the Frenchman C. Bernard. Later, this industry was studied in detail by C. Brown-Séquard, who identified the relationship between diseases and the insufficiency of certain glands. It has been proven that various methods and types of action of hormones can indeed affect health.

Modern research confirms that too active or passive functioning of the glands negatively affects human health and causes diseases. The term “hormone” was first used in the works of physiologists E. Starling and W. Bayliss in 1902.

Operation

Any external or internal stimuli affect the body's receptors and cause impulses that are transmitted to the central nervous system, and then to the hypothalamus. It is there that active substances are produced and transported to the pituitary gland. They promote faster or slower production of tropic hormones, on which the synthesis of the necessary compounds depends. The substance is then transported to an organ or tissue of the body through the circulatory system. This causes certain chemical or physiological reactions in the body.

Types of human hormones

What types of these substances are there? Despite the fact that modern science has sufficient information about the chemical composition of each hormone, their classification is still not considered complete. You can define a hormone verbally based on its structure or chemical name, but the result is a large and difficult word to remember. This is why scientists have tacitly agreed to use simpler names.

The most popular is the anatomical classification, which relates the substance to the gland in which it is produced. According to this criterion, hormones of the adrenal glands, pituitary gland, hypothalamus, etc. are distinguished. But such a classification is not particularly reliable due to the fact that a compound can be synthesized in one gland, but released into the blood by a completely different one.

Because of this, scientists decided to develop a unified system that would be based on the chemical composition of the active substances. That is why in the modern world hormones are divided into:

• protein-peptide;
• amino acid derivatives;
• arbitrary polyunsaturated fatty acids;
• steroids.

Steroid hormones are lipid substances that have a sterane core. They are synthesized in the ovaries and testicles from cholesterol. Hormones of this type perform essential functions necessary for the normal functioning of the human body. Thus, the ability to give the body the necessary shape, as well as reproduce offspring, depends on them. This class includes androgen, progesterone, dihydrotestosterone and estradiol.

Fatty acid derivatives can affect the cells of the organs that produce them. This class includes prostaglandins, thromboxanes, etc.

Amino acid derivatives are synthesized by several glands. The basis for their creation is tyrosine. This class includes melatonin, adrenaline, thyroxine and norepinephrine.

Protein-peptide compounds are responsible for regulating metabolism in the body. The most important element for their synthesis is protein. This group includes insulin and growth hormone.

Role

We looked at the main types of human hormones, but did not pay attention to their role. And at the same time, it is impossible to imagine a person’s life without these essential substances. They are involved in every process that occurs in the body. So, thanks to hormones, each person has his own weight and height. The substances discussed have a huge impact on the emotional state, stimulate the natural processes of breakdown and cell growth.

At the same time, they take part in stimulating or suppressing the immune system. Metabolism also directly depends on the level of certain hormones in the body.

Women

There are different types of hormones in the body, but in women they are specific. An important substance for the fairer sex is estrogen, which is synthesized in the ovaries. Thanks to him, the menstrual cycle is regular. This hormone also causes the formation of secondary sexual characteristics. This substance during puberty allows the body to prepare for motherhood and future sexual life. Thanks to this substance, an adult woman maintains youth and beauty, the good condition of her skin and a positive attitude towards life. If estrogen is normal, then the woman feels good and very often looks younger than her peers who have hormonal imbalances.

The types of sex hormones are interesting because they can trigger “natural” mechanisms. So, estrogen is responsible for women’s feelings - to babysit children and protect their home. But let us note that this substance has a calming effect. That's why aggressive men in prisons take it. This hormone can also improve memory. This is why women during menopause often begin to have difficulty remembering. But the downside for many women of this hormone is that it forces the body to accumulate fat. This is necessary for women's health.

The second female hormone is progesterone. It promotes the normal onset and course of pregnancy. It is produced by the adrenal glands and ovaries. It is also called the hormone of parental instinct, since thanks to it a woman physiologically and psychologically prepares for motherhood. It is interesting that the level of this hormone in the blood increases at the time when the girl sees small children.

The next hormone we'll look at is called prolactin. It is produced in the pituitary gland and is responsible for the growth and development of the mammary glands and milk production during lactation. This hormone is also called stress, as its amount increases with overwork, physical exertion or psychological trauma.

Male hormones

The types of male hormones are few. The main one is testosterone, which is produced by the testicles and adrenal glands. It is also called the hormone of aggression, as it makes a man kill and hunt. Thanks to this substance, representatives of the stronger half of humanity have the instinct to protect and provide for their home and family. In order for this hormone to be normal, a man needs regular physical activity. During puberty, the level of this substance increases greatly. Thanks to him, men grow beards and their voices become deep.

Thyroid

What other types of hormones are there? The thyroid gland produces thyroxine, thyrecalcitonin, and triiodothyronine. The first is responsible for metabolism and excitability of the nervous system. Triiodothyronine is responsible for the same indicators as thyroxine, enhancing them. At the same time, we note that a lack of thyroid hormones in childhood threatens a delay in physical and mental development. In adults with hypofunction, lethargy, apathy and drowsiness are observed. With an excess of hormones, increased agitation and insomnia are observed. And the last hormone, thyrocalcitonin. It is responsible for calcium metabolism in the body, reducing its level in the blood and increasing it in bone tissue.

The parathyroid glands also produce parathyrin, the level of which increases when calcium levels decrease. We looked at the types of hormones and their functions. Now you understand why thyroid hormones are incredibly important for the body. It is no secret that this body is a real protector.

Pituitary

Now we will look at what types of hormones the pituitary gland produces. Growth hormone is a somatotropin that is responsible for the physical development and growth of the human body. It affects the increase in size of the entire body, stimulates muscle function and at the same time prevents fat deposition. Moreover, if there is a deficiency of this hormone, then the person suffers from dwarfism, and otherwise - gigantism. At the same time, acromegaly may occur, which is characterized by increased production of somatotropin in adulthood. Because of this, some parts of the body grow, but the bones may lose their ability to lengthen.

The next hormone we will look at is prolactin. We have already talked about it above, but we will repeat it again. It is responsible for lactation, the menstrual cycle and the mammary glands. The next pituitary hormone is thyrotropin. Its main task is to stimulate the synthesis of thyroxine. Another substance that we will look at is corticotropin, which stimulates the adrenal glands and the formation of cortisol. However, an excess of this hormone can lead to Cushing's syndrome, which is characterized by fat deposits in the upper body, general weakness, and a moon-shaped face.

Gonadotropins stimulate the maturation and development of sperm and eggs. Oxytocin is responsible for the normal course of childbirth, and also improves the overall psychological state of a person. Vasopressin protects the body from loss of moisture by absorbing it into the kidneys and storing it. If the posterior lobe of the pituitary gland is destroyed, a person develops diabetes insipidus, which is characterized by the loss of a huge amount of water.

Pancreas

We examined almost all types of human hormones, except for pancreatic substances. It produces glucagon, which increases the amount of glucose in the blood and promotes the breakdown of sugar. The pancreas also synthesizes insulin, which lowers blood sugar and moves glucose throughout the cell, making it a “building material.” If the body lacks this compound, a disease such as diabetes develops. The main symptoms are itchy skin, excessive urination and extreme thirst. If the disease is left untreated for a long time, it manifests itself as pain in the limbs, decreased appetite, blurred vision, and even coma.

Adrenal glands

There are hormones that affect certain types of metabolism. These include substances that are produced in the adrenal glands. These are cortisol, adrenaline and aldosterone. The first hormone is produced in large quantities during a stressful situation. It activates the defense process, the activity of the heart muscle and brain function. When cortisol levels rise, increased fat deposition begins in the abdomen, back, and back of the neck. At the same time, a strong decrease in the level of the hormone leads to a weakening of the immune system, and as a result the person often gets sick.

You should immediately consult a doctor in such cases, as this can lead to adrenal failure. Adrenaline is a hormone that causes a feeling of danger and fear.

In this case, a person’s blood sugar level increases, breathing quickens, and vascular tone increases. Thus, a person prepares to the maximum for physical and mental stress. However, if there is too much of this hormone, it can dull fear, which is fraught with consequences. Aldosterone regulates water-salt balance. It affects the kidneys, giving them a signal about which substances need to be left in the body and which ones to remove.

We looked at the types of male and female hormones, and now let's talk about the pineal gland hormone. This is melanin, which is responsible for body rhythms, the sleep cycle and fat storage. Also, everyone knows from school that this substance is responsible for the color of skin and hair.

Taking hormones to achieve certain results

Now let's talk about the consequences of taking hormones for beauty. Very often, women decide to take such a step in order to achieve certain results and change their appearance. But the fact is that such substances can only be taken as directed by a doctor. In the modern world, any information can be found on the Internet, so some girls decide to entrust their health and life to armchair critics. Having read different opinions, they go to the pharmacy and buy drugs that sometimes even lead to paralysis. This should not be done under any circumstances, since even a doctor cannot always objectively say whether the hormone will harm or not.

The types of action of hormones are different, which is why if hormone therapy is needed, you should only consult with a qualified specialist who has been dealing with such issues for a long time. And even so, it is difficult to say how the body will behave when exposed to certain substances. We must understand that our body is not a mechanism, but a living system that actively reacts to stimuli.

Balance

We looked at the types of female hormones. From this many realized how important they are. However, these substances play a key role in the health of absolutely all people. Therefore, you need to know how to establish hormonal balance. This can be done quite simply by adjusting your lifestyle.

Firstly, it is very important to follow a daily routine. Only under this condition will a balance between rest and work be established. For example, when a person falls asleep, somatotropin is produced. If you fall asleep at a completely different time every day, this leads to a failure in the production of this substance. This is just one example, but it makes it clear how the daily routine affects the entire system.

It is also very important to stimulate the production of active substances through physical activity. You definitely need to do fitness or dancing 2-3 times a week. But equally important is a balanced diet, which should contain a sufficient amount of protein.

A very important factor that is often forgotten is the drinking regime. For health, each person needs to drink about 2-2.5 liters of water per day. All this will help establish hormonal balance. If such methods do not help, then intensive treatment is necessary. It is prescribed by a professional who studies the hormone chart and prescribes drugs containing synthetic analogues of human hormones.

It includes organs that produce hormones that are necessary for the normal functioning of the body. Each type of hormone is responsible for a specific hormone, and their insufficient or excessive production affects the performance of all organs and tissues. It is necessary to consider in detail what hormones are and why a person needs them.

Concept and classification

What is this hormone? The scientific definition of this concept is quite complex, but if explained in a simple way, then these are active substances that are synthesized in the body, necessary for the functioning of all organs and systems. When the level of these substances in the body is disturbed, a hormonal imbalance occurs, which, first of all, affects the nervous system and psychological state of a person, and only then dysfunctions of other systems begin to occur.

What hormones are can be understood by finding out their functions and significance in the human body. They are classified according to place of formation, chemical structure and purpose.

Based on chemical characteristics, the following groups are distinguished:

• protein-peptide (insulin, glucagon, somatropin, prolactin, calcitonin);
• steroids (cortisol, testosterone, dihydrotestosterone, estradiol);
• amino acid derivatives (serotonin, aldosterone, angiothesin, erythropoietin).

A fourth group can be distinguished – eicosanoids. These substances are produced in organs other than the endocrine system and exert their effects at the local level. Therefore, they are usually called “hormone-like” substances.

• thyroid;
• epithelial body;
• pituitary;
• hypothalamus;
• adrenal glands;
• ovaries;
• testicles.

Each hormone in the human body has its own purpose. Their biological functions are shown in the following table:

Function	Purpose	Basic hormones
Regulatory	Muscle contraction and tone	Oxytocin, adrenaline
	Secretion of glands in the body	Statins, TSH, ACTH
	Control protein, carbohydrate and fat metabolism	Lipotropin, insulin, thyroid
	Responsible for behavioral processes	Thyroids, adrenaline, sex hormones
	Control body growth	Somatropin, thyroid
	Water-salt metabolism	Vasopressin, aldosterone
	Exchange of phosphates and calcium	Calcitonin, calcitriol, parathyroid hormone
Software	Puberty	Hormones of the hypothalamus, pituitary gland and gonads
Supportive	Strengthening the action of growth hormones and gonads	Thyroxine

This table shows only the main purposes of several hormones. But each of them can stimulate and be responsible for several functions at once. Here are some examples: adrenaline is not only responsible for muscle contraction, but also regulates blood pressure and is in some way involved in carbohydrate metabolism. Estrogen, which stimulates reproductive function, affects blood clotting and lipid metabolism.

The thyroid gland is located in the front of the neck and has a very small weight - about 20 grams. But this small organ plays a big role in the body - it is where hormones are produced that stimulate the functioning of all organs and tissues.

And are the main hormones of this gland. Iodine is necessary for their formation, which is why they are called iodine-containing. T3 – contains three iodine molecules. It is produced in small quantities and has the ability to quickly break down once it enters the bloodstream. T4 - consists of four molecules, has a longer viability and is therefore considered more important. Its content in the body makes up 90% of all human hormones.

Their functions:

• promote the absorption of proteins;
• stimulate energy metabolism;
• increase blood pressure;
• affect the functioning of the central nervous system;
• control cardiac performance.

If there is a deficiency of T3 and T4, then the performance of all body systems is disrupted:

• intelligence decreases;
• metabolism is disrupted;
• the production of sex hormones decreases;
• heart sounds become dull.

Serious disturbances in the psyche and nervous system may occur. Elevated levels cause irritability, sudden weight gain or loss, tachycardia, and hyperhidrosis.

There are two states in which these substances exist:

• Bound - do not affect the body as long as they are delivered by the protein albumin to the organs.
• Free – have a biologically active effect on the body.

Since everything in the body is interconnected, these types of hormones are reproduced under the influence of TSH produced in. That is why information not only about thyroid hormones, but also about the TSH hormone is important for diagnosis.

Parathyroid hormones

Behind the thyroid gland is the parathyroid gland, which is responsible for the concentration of calcium in the blood. This occurs due to PTH (parathyrin or parathyroid hormone), which stimulates metabolic processes in the body.

Functions of PTG:

• reduces the level of calcium excreted by the kidneys;
• stimulates the absorption of calcium into the blood;
• increases the level of vitamin D3 in the body;
• if there is a deficiency of calcium and phosphorus in the blood, it removes them from bone tissue;
• when there is an excess amount of phosphorus and calcium in the blood, it deposits them in the bones.

A low concentration of parathyroid hormone leads to muscle weakness, problems with intestinal motility arise, the performance of the heart is impaired and a person’s mental state changes.

Symptoms of decreased parathyroid hormone:

• tachycardia;
• convulsions;
• insomnia;
• periodic chills or feeling of heat;
• heartache.

High levels of PTH have a negative effect on bone formation and bones become more brittle.

Symptoms of increased PTH:

• growth retardation in children;
• muscle pain;
• frequent urination;
• skeletal deformity;
• loss of healthy teeth;
• constant thirst.

The resulting calcification impairs blood circulation, provokes the formation of stomach and duodenal ulcers, and the deposition of phosphate stones in the kidneys.

The pituitary gland is a brain process that produces a large number of active substances. They are formed in the anterior and posterior parts of the pituitary gland and have their own special functions. It also produces several types of hormones.

Formed in the anterior lobe:

• Luteinizing and follicle-stimulating - responsible for the reproductive system, maturation of follicles in women and sperm and men.
• Thyroid-stimulating – controls the formation and release of the hormones T3 and T4, as well as phospholipids and nucleotides.
• Somatropin – controls human growth and physical development.
• Prolactin – main function: production of breast milk. Also takes part in the formation of secondary female characteristics and plays a minor role in material metabolism.

Synthesized in the posterior lobe:

• – affects the contraction of the uterus and, to a lesser extent, other muscles of the body.
• Vasopressin – activates the kidneys, removes excess sodium from the body, and participates in water-salt metabolism.

In the middle lobe there is melanotropin, which is responsible for pigmentation of the skin. Recent evidence suggests that melanotropin may have an effect on memory.

Hormones produced in the pituitary gland are influenced by the hypothalamus, which plays the role of a regulator of the secretion of active substances in the organs. is a link connecting the nervous and endocrine systems. Hormones of the hypothalamus - melanostatin, prolactostatin, inhibit the secretion of the pituitary gland. All others, for example, luliberin, folliberin, are aimed at stimulating the secretion of the pituitary gland.

The active substances that are formed in the pancreas account for only 1–2% of the total. But, despite the small amount, they play a significant role in digestion and other body processes.

What hormones are produced in the pancreas:

• Glucagon – increases blood glucose levels and is involved in energy metabolism.
• Insulin - reduces glucose levels, suppresses its synthesis, is a conductor of amino acids and minerals into the body's cells, and prevents protein deficiency.
• Somatostatin - reduces glucagon levels, slows blood circulation in the abdominal cavity, prevents the absorption of carbohydrates.
• Pancreatic polypeptide - regulates contractions of the gallbladder muscles, controls secreted enzymes and bile.
• Gastrin – creates the necessary level of acidity for digestion of food.

Violation of the production of hormones by the pancreas primarily leads to diabetes mellitus. An abnormal amount of glucogon provokes malignant pancreatic tumors. Failures in the production of somatostatin lead to various diseases of the gastrointestinal tract.

Hormones of the adrenal cortex and gonads

The adrenal medulla produces very important hormones - adrenaline and norepinephrine. Adrenaline is formed when stressful situations occur, for example, in situations of shock, fear, severe pain. Why is it needed? When resistance to negative factors occurs, that is, it has a protective function.

People also notice that when they receive good news, a feeling of inspiration arises - the exciting function of norepinephrine is activated. This hormone gives a feeling of confidence, stimulates the nervous system, and regulates blood pressure.

Corticosteroid substances are also produced in the adrenal glands:

• Aldosterone – regulates hemodynamics and water-salt balance in the body, is responsible for the amount of sodium and calcium ions in the blood.
• Corticosterone is involved only in water-salt metabolism.
• Deoxycorticosterone – increases the body's endurance.
• – designed to stimulate carbohydrate metabolism.

The zona reticularis of the adrenal glands secretes sex hormones, which influence the development of secondary sexual characteristics. Female ones include androstenedione and, which are responsible for hair growth, the functioning of the sebaceous glands and the formation of libido. The ovaries produce estrogens (estriol, estradiol, estrone), and the reproductive function of the female body is completely dependent on them.

In men, they play virtually no role, since their main hormone is testosterone (formed from DHEA) and is produced in the testicles. The second most important male hormone, dehydrotestosterone, is responsible for potency, development of the genital organs and libido. In some cases, in men it can convert into estrogen, which leads to sexual dysfunction. Human sex hormones, wherever they are formed, depend on each other and simultaneously affect the body of men and women.