Releasing hormones are produced in. The role of steroid hormones, thyroid and parathyroid hormones

The hypothalamus is one of the most important organs in the human endocrine system. It is located near the base of the brain. It is responsible for the correct functioning of the pituitary gland and normal metabolism. Hormones produced in the hypothalamus are very important for the body. They are peptides that are responsible for various processes occurring in the body.

What hormones does the hypothalamus produce?

The hypothalamus contains nerve cells that are responsible for the production of all vital hormones. They are called neurosecretory cells. At a certain moment, they receive afferent nerve impulses supplied by different parts nervous system. The axons of neurosecretory cells end on blood vessels, where they form axo-vasal synapses. The hormones produced are released through the latter.

The hypothalamus produces liberins and statins - the so-called releasing hormones. These substances are needed to regulate the hormonal activity of the pituitary gland. Statins are responsible for reducing the synthesis of independent elements, and liberins are responsible for increasing it.

To date, the best studied hormones of the hypothalamus are:

1. Gonadoliberins. These hormones are responsible for increasing the amount of sex hormones produced. They also take part in supporting normal menstrual cycle and the formation of sexual desire. Under the influence of a large amount of luliberin, one of the types of gonadoliberins, a mature egg is released. If these hormones are lacking, a woman may develop.
2. Somatoliberin. These hormones, produced by the hypothalamus, are needed to release growth substances. They should be most actively produced in childhood and youth. If there is a lack of the hormone, dwarfism may develop.
3. Corticoliberin. Responsible for more intense production of adrenocorticotropic hormones in the pituitary gland. If the hormone is not produced in the required quantity, adrenal insufficiency develops in most cases.
4. Prolactoliberin. This substance should develop especially actively during pregnancy and throughout the entire period of lactation. This releasing factor increases the amount of prolactin produced and promotes the development of ducts in the mammary gland.
5. Dopamine, melanostatin and somatostatin. They suppress tropic hormones produced in the pituitary gland.
6. Melanoliberin. Takes part in the production of melanin and the proliferation of pigment cells.
7. Thiroliberin. Necessary for the release of thyroid-stimulating hormones and increase in the blood.

Regulation of the secretion of hypothalamic hormones

The nervous system is responsible for regulating the secretion of hormones. The more hormones produced by the target gland, the less secretion of tropic hormones. This connection can act not only depressingly. In some cases, it changes the effect of hypothalamic hormones on cells located in the pituitary gland.

The hypothalamus is the highest center that regulates the function of the autonomic nervous and endocrine systems. It takes part in coordinating the work of all organs and helps maintain the constancy of the internal environment of the body.

The hypothalamus is located at the base of the brain and has a large number of two-way connections with other structures of the nervous system. Its cells produce biologically active substances that can influence the functioning of the endocrine glands, internal organs and human behavior.

Location and structure of the organ

Anatomy of the hypothalamus

The hypothalamus is located in the diencephalon. The thalamus and third ventricle are also located here. The organ has a complex structure and consists of several parts:

• optic tract;
• optic chiasm;
• gray bump with funnel;
• mastoid bodies.

The optic chiasm is formed by fibers of the optic nerves. At this point, the nerve bundles partially move to the opposite side. It has the shape of a transverse ridge that continues into the optic tract and ends in the subcortical nerve centers. Posterior to the chiasm lies a gray tubercle. His Bottom part forms a funnel that connects to the pituitary gland. Behind the tubercle there are mastoid bodies, which look like spheres with a diameter of about 5 mm. Outside they are covered with white matter, and inside they contain gray matter, in which medial and lateral nuclei are distinguished.

The cells of the hypothalamus form more than 30 nuclei, connected to each other by nerve pathways. There are three main hypothalamic regions, which, according to the anatomy of the organ, are clusters of cells of different shapes and sizes:

1. 1. Front.
2. 2. Intermediate.
3. 3. Rear.

In the anterior region there are neurosecretory nuclei - paraventricular and supraoptic. They produce neurosecretion, which enters the posterior lobe of the pituitary gland along the processes of the cells that form the hypothalamic-pituitary bundle. The intermediate zone includes the inferior medial, superior medial, dorsal, gray tuberous and other nuclei. The largest formations of the posterior part are the posterior hypothalamic nucleus, the medial and lateral nuclei of the mastoid body.

Main functions of the hypothalamus

Scheme of the influence of releasing factors on the functioning of the pituitary gland and endocrine glands

Hypothalamusresponsible for numerous autonomic and endocrine functions. Its role in the human body is as follows:

• regulation of carbohydrate metabolism;
• maintaining water-salt balance;
• formation of eating and sexual behavior;
• coordination of biological rhythms;
• control of body temperature constancy.

The cells of the hypothalamus produce substances that affect the functioning of the pituitary gland. These include releasing factors - statins and liberins. The former contribute to a decrease in the production of tropic hormones, and the latter - to an increase. In this way (via the pituitary gland) the hypothalamus regulates the function of other endocrine glands. The release of releasing factors into the blood has a certain daily rhythm.

The functioning of the hypothalamus is regulated by neuropeptides produced in higher structures. Their products change due to factors external environment and impulses coming from parts of the cerebral cortex. There are feedback connections between the hypothalamus, pituitary gland and other glands of the endocrine system. With an increase in the concentration of tropic and other hormones in the blood, the production of liberins decreases, and the production of statins increases.

The main types and spheres of influence of releasing factors are presented in the table:

In the neurosecretory nuclei, they are synthesized as precursors. antidiuretic hormone(ADH), or vasopressin, and oxytocin. Along the processes of nerve cells (neurohypophyseal tract), they enter the posterior lobe of the pituitary gland. During the movement of substances, their active forms are formed. ADH also partially enters the adenohypophysis, where it regulates the secretion of corticoliberin.

The main role of vasopressin is to control the excretion and retention of water and sodium by the kidneys. The hormone interacts with different types receptors that are located in the muscular wall of blood vessels, liver, kidneys, adrenal glands, uterus, pituitary gland. The hypothalamus contains osmoreceptors that respond to changes in osmolarity and circulating fluid volume by increasing or decreasing the secretion of ADH. There is also a connection between the synthesis of vasopressin and the activity of the thirst center.

Oxytocin initiates and enhances labor and promotes milk secretion in nursing women. In the postpartum period, under its influence, the uterus contracts. The hormone has a great influence on the emotional sphere; it is associated with the formation of feelings of affection, sympathy, trust and peace.

Organ diseases

Various factors can lead to organ dysfunction:

• head injuries;
• toxic effects - narcotic substances, alcohol, harmful conditions labor;
• infections - influenza, viral parotitis, meningitis, chicken pox, focal lesions of the nasopharynx;
• tumors - craniopharyngioma, hamartoma, meningioma;
• vascular pathologies;
• autoimmune processes;
• surgical interventions or radiation in the hypothalamic-pituitary zone;
• systemic infiltrative diseases - histiocytosis, tuberculosis, sarcoidosis.

Depending on the location of the damage, the production of certain releasing factors, vasopressin, and oxytocin may be impaired. With organ pathology, carbohydrate and water-salt metabolism often suffer, eating and sexual behavior changes, and thermoregulation disorders occur. In the presence of a space-occupying lesion, patients are bothered by headaches, and upon examination, symptoms of compression of the chiasm are revealed - atrophy of the optic nerves, decreased acuity and narrowing of the visual fields.

Impaired synthesis of releasing factors

Tumors most often lead to disruption of the production of tropic hormones. surgical interventions and system processes. Depending on the type of releasing factor, the synthesis of which suffers, insufficiency of secretion of a certain substance develops - hypopituitarism.

Hormonal levels in various disorders of the production of releasing factors:

Some tumors are capable of synthesizing excessive amounts of gonadotropin-releasing factor, which is manifested by premature puberty. In rare cases, overproduction of somatoliberin is possible, which leads to gigantism in children and the development of acromegaly in adults.

Treatment tactics hormonal disorders depends on the reason. Surgical and radiation methods, Sometimes - medications. For hypopituitarism, replacement therapy is indicated. In order to normalize prolactin levels, dopamine agonists are prescribed - cabergoline, bromocriptine.

Diabetes insipidus

Most common reasons The development of the disease in children is caused by infections, and in adults - tumors and metastatic lesions of the hypothalamus, surgical interventions, an autoimmune process - the formation of antibodies to organ cells, injuries and the use of medications - Vinblastine, Phenytoin, drug antagonists. Under the influence of damaging factors, the synthesis of vasopressin is suppressed, which can be temporary or permanent.

The pathology is manifested by severe thirst and an increase in urine volume to 5–6 liters per day or more. There is a decrease in sweating and salivation, bedwetting, pulse instability with a tendency to increase, emotional imbalance, and insomnia. With severe dehydration, blood thickening occurs, pressure drops, body weight decreases, mental disorders develop, and temperature rises.

To diagnose a disease, look general analysis urine, determine the electrolyte composition of the blood, perform a Zimnitsky test, tests with a dry diet and the administration of desmopressin - an analogue of ADH, and perform an MRI of the brain. Treatment consists of eliminating the cause of the pathology, using replacement doses of desmopressin drugs - Nativa, Minirin, Vazomirin.

Hypothalamic syndrome

Hypothalamic syndrome is a set of autonomic, endocrine and metabolic disorders resulting from organ damage. Most often, the development of pathology is facilitated by neuroinfection and trauma. The syndrome may occur due to constitutional insufficiency of the hypothalamus due to obesity.

The disease is manifested by vegetative-vascular, endocrine-metabolic symptoms, as well as impaired thermoregulation. Characterized by weakness, fatigue, weight gain, headaches, excessive anxiety and mood swings. A number of patients exhibit high blood pressure, signs of functional hypercortisolism (increased production of adrenal hormones), and impaired glucose tolerance. In women, the syndrome leads to dysmenorrhea, polycystic ovary syndrome, and early menopause.

The pathology often occurs in the form of attacks, which can be of different nature:

• Sympathoadrenal crises - occur suddenly, manifested by increased heart rate, cold extremities, trembling in the body, dilated pupils, fear of death. Possible increase in temperature.
• Vagoinsular crises begin with a feeling of heat and a rush of blood to the head. I am worried about nausea, vomiting, and a feeling of lack of air. The pulse slows down, and blood pressure may drop. The condition is often accompanied by frequent and profuse urination and diarrhea.

Diagnosis of the syndrome is based on finding out the patient’s life history, his complaints and external examination. They conduct general clinical and biochemical blood tests, assess the hormonal profile, and a number of instrumental examinations - ECG, MRI of the brain, EEG, ultrasound of the thyroid gland and others (as indicated). Treatment of the pathology is complex. It is necessary to correct all identified disorders, normalize the work and rest regime, and exercise therapy.

The pituitary gland and hypothalamus are important components of the human endocrine system, producing various. Almost everyone knows these complex names and understands their connection with the brain, but what do the hypothalamus and pituitary gland actually do and what is their role in human life and health?

The pituitary gland is a cerebral appendage located under the cerebral cortex. It is tiny in size but performs very important functions. This endocrine gland regulates processes such as growth and development, sexual function and reproductive ability, and metabolism.

The tiny pituitary gland is divided according to its structure into lobes, each of which has its own functions. Each of the lobes (anterior, posterior and intermediate) has its own groups of cells that produce certain regulating various systems and body functions.

The concepts of gigantism and dwarfism are associated with underdevelopment or excessive action of the pituitary gland.The pituitary gland is connected to the hypothalamus, part of the intermediate. This small area acts as a coordinator. It produces hormones by communicating with the pituitary gland. Hormones affect the pituitary gland and provoke the production of other hormones that control almost the entire endocrine system of the body. Conditions of the body such as hunger or thirst, as well as sleep, depend on the work of the hypothalamus.

Hormones of the pituitary gland and hypothalamus play an important role - this is a complex process of coordinating the work of the entire organism as a whole.

The posterior lobe of the pituitary gland is the receiver of signals sent by the hypothalamus. The intermediate lobe of the pituitary gland in humans is only a thin layer. In some animals it is very well developed.

More information about the hypothalamic-pituitary system can be found in the video.

Various malfunctions in the functioning of the hypothalamic-pituitary system lead to serious and irreversible disorders.

For example, a tumor of the pituitary gland leads to serious visual impairment, and the hypothalamus plays the role of an indicator of hunger or satiety.

There is a theory according to which obesity can be treated by directly influencing the hypothalamus. If the functioning of the hypothalamus was disrupted in childhood, the child's growth will be slowed down, and there will also be problems with the formation of sexual characteristics.

Functions of hormones

Each section of the pituitary gland and the hypothalamus itself produce their own individual hormones (releasing hormones), which are vital for the body to function normally.

Let's look at some of them:

• Somatoliberin. This is a hormone of the hypothalamus that affects the pituitary gland. It is also called growth hormone. Its deficiency leads to short stature, and its excess leads to tall stature or even gigantism. This hormone enhances protein production and fat breakdown. During the day, the hormone level is not too high, but it increases during eating and sleeping.
• Prolactin. Prolactin is produced by the pituitary gland. It is of direct importance for reproduction and lactation. First of all, it affects their growth, the production of colostrum and its transformation into breast milk. Immediately after childbirth, this hormone begins to be actively produced, provoking lactation. Around the third day, colostrum and milk begin to be released.
• Gonadotropic hormones of the pituitary gland. There are 3 such hormones that are responsible for the sexual functions of the body: follicle-stimulating (formation of follicles and formation of the corpus luteum), luteinizing (transformation of the follicle into the corpus luteum) and luteotropic (the already known prolactin).
• Thiroliberin. It is produced by the hypothalamus and affects the pituitary gland, which provokes the production of a similar hormone in it. The effect of this hormone on the nervous system and the reduction of depression at sufficient levels has been proven. An excess of this hormone can lead to sexual dysfunction.
• Corticotropin. Produced by the pituitary gland and controls the functioning of the adrenal glands, and is also responsible for the production of steroid hormones. It promotes the breakdown of adipose tissue. An excess of this hormone leads to disruptions in the functioning of almost all internal organs; muscles and bones undergo changes. Adipose tissue develops unevenly: in some areas of the body it is in excess, in others it is absent.

Diseases related to hormones

Gigantism - malfunctions of the hormonal system

Hormones of the hypothalamic-pituitary system must be in constant balance. This system is complex and has many different connections with other systems and organs. Any failure leads to serious consequences.

There are a lot of diseases caused by dysfunction of the pituitary gland and hypothalamus.

They have complex system symptoms and are quite difficult to diagnose and treat:

1. Gigantism. This is rare and is associated with excessive production of growth hormone by the pituitary gland. In addition to their incredibly tall stature, these people also suffer from other complications such as severe pain in joints, headaches, fatigue, infertility, heart failure, etc. This disease is treated with the hormone somatostatin, which controls growth. Unfortunately, most patients with this disease do not live to old age due to the large number.
2. Acromegaly. A disease similar to gigantism, expressed in enlargement of the bones of the skull, especially the facial bones, as well as the feet and hands. This disease does not develop immediately, but only after growth has completed. It can proceed slowly, changing a person’s appearance from year to year. Facial features become rough and large, and hands and feet become disproportionately large. In addition, hypertension, sleep apnea, and high blood pressure are observed.
3. Itsenko-Cushing's disease. This is a serious disease caused by malfunctions in the hypothalamic-pituitary system. It is associated with excessive release of corticotropin. As a result, metabolic processes in the body are disrupted, fat is actively and unevenly deposited, stretch marks appear, hair on the body and face actively grows, bones become brittle, immunity drops, and the entire sexual sphere is disrupted. With a mild form of the disease, the prognosis is quite favorable. However, in severe cases, even after recovery, irreversible problems remain, for example, renal failure.

Failures in the hypothalamic-pituitary system often lead to severe complications and are difficult to treat. A large number of diseases are associated with tumors of the pituitary gland, which determines the excess or deficiency of hormones secreted by it.

Hypothalamic hormones are the most important regulatory hormones produced by the hypothalamus. All hypothalamic hormones have a peptide structure and are divided into 3 subclasses: releasing hormones stimulate the secretion of hormones of the anterior lobe of the pituitary gland, statins inhibit the secretion of hormones of the anterior lobe of the pituitary gland, and hormones of the posterior lobe of the pituitary gland are traditionally called hormones of the posterior lobe of the pituitary gland according to the place of their storage and release, although are actually produced by the hypothalamus.

Hormones of the hypothalamus play one of the leading roles in the activities of the entire human body. These hormones are produced in a part of the brain called the hypothalamus. Without exception, all of these substances are peptides. Moreover, all these hormones are divided into three types: releasing hormones, statins and hormones of the posterior pituitary gland.

In the nuclei of the hypothalamus, in response to nerve or chemical impulses, biologically active peptides are secreted and transported to the adenohypophysis, which regulate the production of pituitary hormones. The names of these regulatory hormones reflect their biological significance.

All hypothalamic hormones are oligopeptides. The function of liberins is activation, and statins are inhibition of the production of corresponding hormones in their main target organ - the adenohypophysis. The exception is somatostatin - its target is also the pancreas, where this hormone is produced and inhibits the secretion of insulin and glucagon.

Hypothalamic hormone A pituitary hormone whose production is regulated

Corticoliberin Adrenocorticotropic

Thyroliberin Thyrotropic

Folliberin follicle stimulating

Luliberin Luteinizing

Somatotropic somatotropic (growth hormone)

Somatostatin Growth hormone secretion inhibitor

Prolactoliberin Prolactin

Prolactostatin Prolactin secretion inhibitor

Melanoliberin Melanocyte-stimulating

Melanostatin Inhibitor of melanocyte-stimulating hormone secretion

Pituitary hormones

The pituitary gland together with the hypothalamus, where neurohormones are produced that regulate the formation and release of pituitary hormones, ensure neurohumoral integration of metabolism and adaptation of the body to changes in the external and internal environment.

The anterior lobe of the pituitary gland synthesizes 6 hormones that control the development and functions of other endocrine glands. These hormones exert their effect on the functions of peripheral glands or directly on peripheral tissues after binding to their membrane receptors and activating adenylate cyclase. The formation of cAMP affects hormone formation or metabolism in target cells.

Thyroid-stimulating hormone (TSH) is a complex glycoprotein. The production of hubbub is activated by thyrotropin-releasing hormone, and thyroid hormones are inhibited according to the principle feedback. TSH controls thyroid function. It promotes the absorption of iodine by thyroid cells, stimulates the synthesis of thyroid hormones and promotes the release of thyroxine. Along with thyroid cells, the targets of the hormone are adipose tissue cells, where the hormone accelerates lipolysis. TSH is used in the treatment of thyroid diseases associated with impaired thyroid function.

Adrenocorticotropic hormone (ACTH) is a polypeptide consisting of 39 amino acid residues. ACTH production is activated by corticoliberin. The concentration of the hormone in the blood is determined by the level of adrenal hormones in it - with an increase in their content, the release of ACTH decreases, and with a decrease, it increases (negative feedback). The target organ of ACTH is the adrenal glands. ACTH activates initial stages biosynthesis of glucocorticoids by the zona fasciculata of the adrenal cortex, increasing the concentration of cholesterol in it. The hormone stimulates the penetration of glucose into the cells of the adrenal cortex, enhances the reactions of the pentose phosphate pathway, the use ascorbic acid adrenal tissues. ACTH activates the function of lipases and phosphorylases, exhibits fat-mobilizing and melanocyte-activating properties. The activity of the hormone is associated with the mobilization of the body's defenses during stress, injury, infection, and toxicosis. ACTH is used as a hormonal drug for insufficient activity of the adrenal cortex, treatment of rheumatism, polyarthritis, gout, allergies.

Follicle-stimulating hormone (FSH) is a glycoprotein by chemical nature.

Hormone secretion is activated by folliberin. Inhibitor of folliberin formation - estrogens (negative feedback). The target organs in females are the ovaries, in males - the testes.

FSH stimulates the growth of follicles in the ovary in females and promotes spermatogenesis in males. In clinical practice, a hormone analogue is used - serum gonadotropin in the blood of pregnant mares to stimulate ovulation.

Luteinizing hormone (LH) is also a glycoprotein.

Its production is controlled by luliberin (activation) and progesterone (by feedback principle). It activates the secretion of estrogen and progesterone by the ovaries, and androgens by the testes. Used together with FSH to stimulate sexual function in infantile females and males.

Lactotropic hormone (LTH) or prolactin is a protein.

Hormone synthesis is accelerated by prolactoliberin and limited by prolactostatin and progesterone (negative feedback).

In females, it supports the activity of the corpus luteum and the secretion of progesterone. The main function of the hormone is to stimulate milk production in the mammary glands (the target of prolactin). Here the synthesis of caseinogen, lactose, lipids and other components of milk increases. Prolactin complements the action of the gonads, together with thyroid hormones and corticosteroids ensures normal lactation, and is involved in the regulation of water-salt metabolism.

Prolactin inhibits the effect of luteinizing hormone - ovulation and luteinization. In adipose tissue, the hormone activates lipogenesis. LTG is used for decreased secretion of the mammary gland during the postpartum period.

Somatotropic hormone (GH) or growth hormone is a protein by chemical nature. It promotes RNA synthesis, cell permeability to amino acids, protein synthesis, glycogen synthesis, mobilization of fats from fat depots, and deposition of calcium and phosphorus in bones. Thanks to this, the growth of the body is stimulated. With a lack of the hormone, dwarf growth is observed, with excessive formation - gigantism. With high levels of the hormone in adulthood, acromegaly develops - disproportionate development individual parts bodies. The hormone is used as a diabetogenic agent.

Melanocyte-stimulating hormone (MSH) is synthesized in the middle lobe of the pituitary gland. There are 2 types of it - -, consisting of 13 amino acid residues and -, including 18 amino acid residues. The targets of the hormone are melanophore cells. The effect is the dispersion of black pigment (melanin). MSH stimulates the synthesis of melanin, which affects the color of skin, fur, feathers, and affects the biosynthesis of rhodopsin in the retina. Depigmented areas of the skin do not respond to the introduction of the hormone.

The posterior pituitary hormones vasopressin and oxytocin are synthesized in the hypothalamus and then transported along nerve fibers to the neurohypophysis.

Vasopressin or antidiuretic hormone (ADH) is a cyclic nanopeptide.

The targets of vasopressin are arterioles and capillaries of the pulmonary and coronary vessels. The hormone causes their narrowing, which is accompanied by an increase blood pressure and associated dilation of cerebral and renal vessels (secondary dilation). Another target is the distal convoluted tubule and collecting duct of the nephron. The effect is realized through the adenylate cyclase system. This is manifested by activation of hyaluronidase, increased breakdown hyaluronic acid and the associated increase in the permeability of the tubular epithelium. As a result of increased permeability, water reabsorption is accelerated, which leads to a decrease in final urine volume. When vasopressin is administered, its effect is manifested by a decrease in diuresis. This determined the second name of the hormone – antidiuretic. Hormone deficiency is manifested by increased diuresis (polyuria), accompanied by increased thirst (polydipsia). Vasopressin drugs are used to normalize blood pressure and in the treatment of diabetes insipidus.

Oxytocin is also a cyclic nanopeptide. Target organs are the smooth muscles of the intestines, gallbladder, ureters and myometrium. The hormone increases the tone of smooth muscles, especially the uterus, and stimulates its contraction during childbirth. During pregnancy, the activity of the hormone decreases as a result of enzymatic breakdown. During lactation, oxytocin activates prolactin, thereby increasing milk secretion. The hormone drug is used for weak efforts during childbirth, to stimulate the muscles of the uterus.

Regulation of carbohydrate metabolism in the body. The role of insulin and counterinsular hormones (glucagon, adrenaline, thyroxine, glucocorticosteroids) in the regulation of carbohydrate metabolism. Hypo- and hyperglycemia.

In regulating the constancy of blood sugar concentrations main role performed by the liver. When there is an excess intake of carbohydrates in the body, glycogen accumulates in the liver, and when there is insufficient intake, on the contrary, glycogen breaks down into glucose. This way the normal amount of sugar is maintained.

The constancy of glucose in the blood and glycogen in the liver is regulated by the nervous system. The metabolism of carbohydrates is influenced by the cerebral cortex. Proof of this is the increase in sugar in the urine of students after a difficult exam. The center of carbohydrate metabolism is located in the hypothalamus and medulla oblongata.

The influence of the hypothalamus and cerebral cortex on carbohydrate metabolism is carried out primarily through the sympathetic nervous system, which causes increased secretion of adrenaline by the adrenal glands.

Great importance In carbohydrate metabolism, they have endocrine glands - pancreas, thyroid, adrenal glands, pituitary gland, etc., which, under the influence of the central nervous system, regulate the assimilation and dissimilation of carbohydrates.

The pancreatic hormone insulin converts glucose into glycogen and thereby reduces the amount of sugar in the blood.

Adrenaline and glycogen increase the breakdown of glycogen in the liver and muscles, resulting in an increase in blood sugar.

Therefore, insulin is a sugar-lowering hormone, while glycon is a sugar-increasing hormone.

When the concentration of sugar in the blood decreases, the center of carbohydrate metabolism in the hypothalamus is excited, which gives impulses to the pancreas, and it increases the production of glucagon until the glucose content due to the breakdown of glycogen increases to normal levels.

The group of contrainsular hormones also includes glycocorticoids, which, by inducing the synthesis of messenger RNA responsible for the formation of proteins - enzymes of glyconeogenesis, contribute to an increase in glycemia levels. In contrast to insulin, hydrocortisone reduces permeability cell membranes and slows down the rate of the hexokinase reaction. Glycocorticoids are involved in the mechanism of hyperglycemia in diabetes mellitus and Itsenko-Cushing's disease.

Corticotropin acts similarly to glycocorticoids, since, by stimulating their secretion, it enhances gluconeogenesis and inhibits the activity of hexokinase.

Increased production of the adenohypophysis hormone - somatotropin (growth hormone), for example in acromegaly, is accompanied by reduced tolerance to carbohydrates and hyperglycemia. There is an idea that somatotropin causes hyperplasia of α-cells of pancreatic islets and increases the secretion of glucagon. Along with glycocorticoids, somatotropin reduces the activity of hexokinase and, therefore, the consumption of glucose by tissues, i.e., it is also a counter-insular hormone. In addition, somatotropin stimulates the activity of liver insulinase. Its administration to animals increases the function of β-cells of the pancreatic islets, which can lead to their depletion and the occurrence of metapituitary diabetes.

Thyroid hormones are also involved in the regulation of carbohydrate metabolism. It is known that hyperfunction of the thyroid gland is characterized by a decrease in the body's resistance to carbohydrates. Thyroxine stimulates the absorption of glucose in the intestines and also increases the activity of liver phosphorylase.

Disorders of carbohydrate metabolism. The following main disorders of carbohydrate metabolism are distinguished:

1.hyper-and hypoglycemia.

2. glycogen storage diseases.

3.glycosuria.

4.galactosymia.

5.lactosuria.

6. maltosuria.

7.fructosuria - the cause may be:

b) fructokinase deficiency (inability to consume fructose);

c) deficiency or partial inactivity of fructose diphosphate aldolase in the liver; the consequence is the accumulation of fructose-1-phosphate, which blocks glucose consumption.

Normal blood glucose concentration is 3.3-6 mmol/l. Hyperglycemia can be caused by excess glucose in food or diabetes. Diabetes can be primary or secondary.

1. Primary (idiopathic) subdivided into:

a) potential (family predisposition);

b) latent (hidden) - manifests itself. during treatment with cartisone, acute infections, pregnancy; the diabetic type of sugar load curve is characteristic;

c) asymptomatic (chemical)

d) clinical - divided into: “type 1” insulin-dependent (juvenile) - manifests itself in the first 40 years of life and is characterized by a sharp decrease in insulin secretion due to beta-cell atrophy. “type two” insulin-independent. It affects people over 40 years of age and is characterized by a slight decrease in insulin secretion.

2. Secondary. Causes: a) damage to the pancreas during chronic pancreatitis, tumors and other obvious diseases;

b) the presence of insulin antagonists: excessive secretion of growth hormone or glucocarticoids;

c) inhibition of insulin secretion: insulin secretion by beta cells can be suppressed by excess norepinephrine products, which leads to the mobilization of glycogen in the liver. Epinephrine and norepinephrine block insulin secretion.

Other causes of diabetes: 1. partial disruption of the normal structure of insulin; 2. increased level of insulinase secretion; 3. partial disruption of the normal structure of insulin receptors.

Hypoglycemia is divided into:

a) hypoglycemia due to fasting.

Insulin-secreting tumors (pancreas),

Insufficiency of the pituitary and adrenal glands,

Liver diseases and glycogen storage diseases.

B) reactive hypoglycemia.

Insulin overdose

Reception medicines,

Alcohol intake, partial stomach reaction.

This condition can be caused by sulfonylurea.

Glucosuria is divided into:

1. nutritional (excess glucose in food);

2.emarganal (stress).

Other reasons: 1. the effect of chemicals (morphine, chloroform);

3.low threshold of renal reabsorption;

4. acute infection, concussion.

What are the hormones of the hypothalamus?

Corticoliberin is a hormone produced by the hypothalamus. This substance is responsible for the manifestation of anxiety.

Gonadotropin-releasing hormone is a natural hormone, under the influence of which the production of gonadotropins is enhanced.

The hypothalamus is one of the most important means of the endocrine system, responsible for the production of hormones.

The elements synthesized by the hypothalamus are extremely necessary for the body because they are peptides involved in various metabolic processes in the systems.

Nerve cells, present in the hypothalamus, ensure the release of all necessary substances to ensure the normal functioning of the body.

Such elements are called neurosecretory cells. They perceive impulses transmitted by various parts of the nervous system. Elements are released through certain axovasal synapses.

The hypothalamus produces releasing hormones, so-called statins and liberins. These substances are essential to ensure the normal functioning of the pituitary gland.

Liberins are responsible for increasing the concentration of independent substances, and statins, on the contrary, are responsible for decreasing them.

Nowadays, only some substances secreted by the hypothalamus are the most studied by medicine.

Gonadotropin-releasing hormone

GnRH is involved in the production of sex substances. IN female body It is these components that take part in the formation of the natural course of menstruation.

Responsible for libido. GnRH is responsible for the process of releasing a mature egg.

GnRH is extremely necessary for a woman, because with its deficiency, the development of infertility cannot be ruled out.

Somatoliberin

The substance is clearly produced in childhood and adolescence and is responsible for normalizing the growth process of all organs and systems of the body.

This hormone must be released in normal quantities, because the full development and formation of the child depends on it.

As a result of a lack of this hormone, the hypothalamus can form nanism.

Corticotropin releasing hormone

Corticoliberin is responsible for the production of adrenocorticotropic substances by the pituitary gland. If the component is not produced in the required volume, adrenal insufficiency occurs.

Corticorelin- a substance responsible for the severity of feelings of anxiety; at its high concentrations, a person becomes overly excited.

Prolactoliberin

It is actively produced during gestation and is contained in the body of a nursing mother throughout the entire period of lactation.

This releasing factor affects the process of normal prolactin production, which contributes to the formation of a sufficient number of ducts in the mammary gland.

Prolactostatin

This subclass of statins is produced by the hypothalamus and inhibits the production of prolactin. Prolactostatins:

• dopamine;
• somatostatin;
• melanostatin.

Each of them has a suppressive effect on the tropic hormones of the pituitary gland and hypothalamus.

Melanotropin releasing hormone

Participates in the process of melanin production and the division of pigment cells melanoliberin. It influences the elements of the PRD of the pituitary gland.

Plays a great influence on human behavior in neurophysiological terms. Used for therapy depressive states and parkinsonism.

Thyrotropin-releasing hormone (TRH)

Thyroliberin– releasing hormone of the hypothalamus. Thyroliberin affects the production of thyroid-stimulating hormones of the adenohypophysis.

It has a lesser effect on the process of prolactin production. Thyroliberin is necessary to increase the concentration of thyroxine in the blood.

The central nervous system is largely responsible for the normal process of producing elements. Neurohormones are produced in neurosecretory cells of the regulatory system.

The development of an individual’s protective and adaptive characteristics largely depends on these components.

Liberins and statins are releasing hormones. The functioning of the pituitary gland largely depends on their content in the body.

They participate in the process of performing certain actions of the peripheral endocrine glands:

• thyroid gland;
• ovaries in women;
• testicles in representatives of the stronger sex.

Currently, the following statins and liberins are isolated:

• gonadoliberin (lyuliberin, folliberin);
• melonostatin;
• thyrotropin-releasing hormone;
• somatostatin;

The summary table shows releasing factors and peripheral hormones that correspond to them.

Releasing hormones are neurosecrets of the hypothalamus, their action is aimed at accelerating the production of tropic substances of the pituitary gland.

Releasing hormones are responsible for connecting the endocrine system with parts of the central nervous system.

By their nature, releasing factors are peptides. Currently, 3 releasing hormones have been identified that inhibit the secretory action of the pituitary gland. Such substances include the following elements:

• melanostatin;
• somatostatin;
• prolactostatin.

The list of substances that stimulate secretory functions includes the following elements:

• corticoliberin;
• melanotropin hormone;
• luliberin;
• thyrotropin-releasing hormone;
• somatoliberin;
• prolactoliberin;
• folliberin.

Some of these substances are produced not only by the hypothalamus, but also by other organs, for example, the pancreas.

Releasing hormone – how does it work?

GnRH stimulate the secretion of luteinizing and follicle-stimulating hormone in the pituitary gland.

GnRH in men is responsible for the activity of androgens, which determine the activity of sperm and libido levels.

Neurohormones in women are responsible for the adequate passage of menstruation; it is noteworthy that the concentration of substances varies depending on the phases of the menstrual cycle.

A lack of releasing hormones leads to infertility and often causes impotence.

Substances produced by the hypothalamus have not been identified for pituitary tropic elements. The type of their influence is final indefined.

The nature and main functions of liberins

Hormones from the hypothalamus and pituitary gland are responsible for regulatory functions. Regarding releasing factors, gonadoliberins are responsible for normal functioning in relation to the genital area in men and women.

Such components are responsible for the production and affect the functioning of the testicles and ovaries.

Luliberin has the greatest impact on women's health. This component separates ovulation and creates the possibility of conceiving a fetus.

Luliberin and folliberin are produced in small quantities in women who are indifferent to intimacy.

Corticoliberin is an equally important releasing factor that interacts with pituitary hormones. This element affects the functioning of the adrenal glands.

This point is extremely important because people with a lack of corticoliberin in the body are often susceptible to hypertension and adrenal insufficiency.

Inhibitory factors correlate with the following pituitary tropic hormones:

• melanotropin;
• prolactin;
• somatotropin.

The remaining releasing factors belong to the medial lobe of the pituitary and adenohypophysis with the hypothalamus, and their connection with elements of the pituitary gland has not been studied.

Other hypothalamic hormones

Releasing factors depend on pituitary functions, but in addition, the hypothalamus is responsible for the production of hormones such as oxytocin and vasopressin.

Similar elements have a similar structure, but in the human body they perform completely different functions, independent of each other.

In the first case, there is a decrease in the production of substances, in the second - an increase. There can be many reasons for the development of pathologies of this nature:

• tumor formations;
• inflammation of areas of the brain;
• strokes;
• serious head injuries.

In most cases, both hyperfunction and hypofunction of the hypothalamus require cardinal treatment. Therapeutic intervention involves taking medications.

The course of therapy may take several years.

During therapy, it is important to constantly monitor hormonal background patient.