The centers are located in the hypothalamus. Anatomy and physiology of the hypothalamus

Hypothalamus - what is it? The hypothalamus is part of the middle (intermediate) brain, the second part of this department is the thalamus. The functions of the hypothalamus and thalamus are different. The thalamus transmits all impulses from numerous receptors to the cerebral cortex. The hypothalamus, on the other hand, provides feedback; it regulates almost all functions of the human body.

This is an important vegetative center that integrates the functions of internal systems and their adjustment to the overall process of life.

Fact. Recent scientific works talk about the influence of the hypothalamus on the level and quality of memory, as well as on the emotional health of a person.

Location

The hypothalamus is located in the lower part of the brain, under the thalamus, under the hypothalamic groove. The hypothalamus is connected to the adenohypophysis by portal vessels of the latter. The blood vessels of the hypothalamus are permeable to large protein molecules.

Internal organization

The device of the hypothalamus is very complex, despite the small size of the organ. It is an intermediate part of the brain and it forms the walls and base of the lower part of the 3rd ventricle of the brain.

The hypothalamus is a region of the brain structure, it consists of nuclei and several less distinct areas. Individual cells can penetrate into nearby areas of the brain, which makes its boundary parts blurry. The anterior part is limited by the terminal plate, and the dorsolateral region is located next to the medial region of the corpus callosum, the mastoid bodies, the gray tubercle and the funnel are located below.

The central region of the funnel is called the "median eminence", it is slightly raised, and the funnel itself comes from a gray mound.

Nuclei of the hypothalamus

The hypothalamus consists of an internal complex of hypothalamic nuclei, which in turn is divided into 3 areas of groups of nerve cells:

• Front area.
• Back area.
• Middle area.

Each of the nuclei performs its strictly defined function, whether it be hunger or satiety, activity or sluggish behavior, and much more.

Fact. The structure of some nuclei depends on the gender of the person, that is, in other words, in men and women, the structure and functions of the hypothalamus are to some extent different.

What is the hypothalamus responsible for?

The property of a living organism to keep its internal environment in a certain state all the time, even in the event of small external stimuli, guarantees the survival of the organism, this ability is called homeostasis.

The hypothalamus is just involved in regulating the functioning of the autonomic nervous and endocrine systems, which are necessary to maintain homeostasis, in addition to breathing, which occurs on the machine, heart rate and blood pressure.

Important! What does the hypothalamus influence? The activity of this regulatory center seriously affects how a person behaves, his ability to survive, and also his ability to produce offspring. Its functions extend to the regulation of body systems in response to irritating factors of the surrounding world.

Together with the pituitary gland, the hypothalamus represents a single functional complex, where the hypothalamus is a regulator, and the pituitary gland performs effector functions, transmitting signals from the nervous system to organs and tissues in a humoral way.

What hormones does it produce?

The hormones of the hypothalamus are peptides, they are divided into three types:

• Releasing hormones - stimulate the formation of hormones of the anterior pituitary gland.
• Statins in the hypothalamus, if necessary, inhibit the formation of anterior lobe hormones.
• Posterior pituitary hormones - produced by the hypothalamus and deposited by the pituitary gland, then sent to the right places.

Hamartoma

Hamartoma is a benign tumor of the hypothalamus. It is known that this disease is diagnosed at the stage of intrauterine development, but, unfortunately, it has not yet been sufficiently studied.

There are only a few serious centers for the treatment of this disease around the world, one of them is located in China.

Symptoms of a hamartoma

The many symptoms of a hamartoma include: seizures (resembling fits of laughter), cognitive impairment, and early puberty. Also, with the appearance of this kind of tumor, the activity of the endocrine system is disrupted. Due to the malfunction of the hypothalamus, the patient appears overweight or, conversely, its lack.

Important. Violation of the proper functioning of this part of the brain provokes the occurrence of abnormal human behavior, psychological disorders, emotional instability, and unreasonable aggressiveness appear.

Hamartoma can be diagnosed using medical imaging tools such as tomography and MRI. It is also necessary to take a blood test for hormones.

How is hamartoma treated?

There are several ways to treat this tumor: the first method is based on drug therapy, the second is surgical, and the third is radiation treatment and radiosurgery.

Important! Drug treatment only removes the symptoms of the disease, but not its cause.

Causes of a tumor

Unfortunately, there are still no reliable causes of hamartoma, but there is an assumption that the tumor occurs due to disorders at the genetic level, for example, patients with Pallister-Hall syndrome have a predisposition to this disease.

Other diseases

Diseases of the hypothalamus can occur due to various causes, external and internal influences. The most common diseases of this part of the brain are: contusion, stroke, tumor, inflammation.

Due to pathological changes in the hypothalamus, there is a decrease in the production of important hormones, and inflammation and swelling can create pressure on nearby tissues and negatively affect their functions.

For the correct and full functioning of the hypothalamus, it is necessary to follow these recommendations:

• Sports activities and daily walks in the fresh air.
• In order for the hypothalamus to enter the usual rhythm of work, follow the daily routine.
• Eliminate alcohol and cigarettes. Avoid watching TV and working at the computer before bed.
• Proper nutrition without overeating.
• Try to eat more vegetables, raisins, dried apricots, honey, eggs, walnuts, oily fish and seaweed.

Try to take care of your health. Despite the fact that a hamartoma is a benign tumor, it is a rather serious and not fully understood disease, therefore, at the first symptoms of malaise, seek medical advice.

The hypothalamus is the highest center that regulates the function of the autonomic nervous and endocrine systems. He takes part in the coordination of the work of all organs, helps to 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 bilateral connections with other structures of the nervous system. Its cells produce biologically active substances that can affect 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 the third ventricle are also located here. The body has a complex structure and consists of several parts:

• visual tract;
• optic chiasm - chiasm;
• gray mound with a funnel;
• mastoid bodies.

The optic chiasm is formed by the fibers of the optic nerves. In this place, the nerve bundles partially pass to the opposite side. It has the form of a transverse roller, which continues into the optic tract and ends in the subcortical nerve centers. Behind the chiasm lies a gray tubercle. Its lower part forms a funnel that connects to the pituitary gland. Behind the tubercle are mastoid bodies, having the form of spheres with a diameter of about 5 mm. Outside, they are covered with white matter, and inside they contain gray matter, in which the medial and lateral nuclei are isolated.

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 various shapes and sizes:

1. 1. Front.
2. 2. Intermediate.
3. 3. Back.

In the anterior region there are neurosecretory nuclei - paraventricular and supraoptic. They produce a neurosecrete, which, through the processes of cells that form the hypothalamic-pituitary bundle, enters the posterior lobe of the pituitary gland. The intermediate zone includes the lower medial, upper medial, dorsal, serotuberous and other nuclei. The largest formations of the posterior part are the posterior hypothalamic nucleus, the medial and lateral nuclei of the mastoid body.

The main functions of the hypothalamus

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

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

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

In the cells of the hypothalamus, substances are produced 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. Thus (through the pituitary gland) the hypothalamus regulates the function of other endocrine glands. The flow of releasing factors into the blood has a certain daily rhythm.

The regulation of the hypothalamus is carried out by neuropeptides produced in the higher structures. Their production changes under the influence of environmental factors and impulses coming from the sections of the cerebral cortex. There are feedbacks 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:

Antidiuretic hormone (ADH), or vasopressin, and oxytocin are synthesized in the neurosecretory nuclei as precursors. Through 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. Also, ADH 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 of receptors, which 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 volume of circulating fluid by increasing or decreasing 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 activity, promotes the release of milk in lactating women. In the postpartum period, under its action, 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 injury;
• toxic effects - narcotic substances, alcohol, harmful working conditions;
• 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, there may be a violation of the production of certain releasing factors, vasopressin, oxytocin. In the pathology of the organ, carbohydrate and water-salt metabolism often suffer, eating and sexual behavior changes, and thermoregulation disorders occur. In the presence of volumetric education, patients are worried about headaches, and the examination reveals symptoms of compression of the chiasm - atrophy of the optic nerves, decreased acuity and narrowing of the visual fields.

Violation of the synthesis of releasing factors

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

Hormonal background with various violations of the production of releasing factors:

Some tumors are able to synthesize an excess amount of gonadotropin-releasing factor, which is manifested by precocious puberty. In rare cases, hyperproduction of somatoliberin is possible, which leads to gigantism in children and the development of acromegaly in adults.

Treatment for hormonal disorders depends on the cause. To remove tumors, surgical and radiation methods are used, sometimes medications are used. With hypopituitarism, replacement therapy is indicated. In order to normalize the level of prolactin, dopamine agonists are prescribed - cabergoline, bromocriptine.

diabetes insipidus

The most common causes of the development of the disease in children are 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 drugs - Vinblastine, Phenytoin, drug antagonists. Under the influence of damaging factors, vasopressin synthesis is suppressed, which can be temporary or permanent.

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

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

hypothalamic syndrome

Hypothalamic syndrome is a combination of autonomic, endocrine and metabolic disorders resulting from organ damage. Most often, the development of pathology is promoted by neuroinfections and injuries. The syndrome may occur due to constitutional insufficiency of the hypothalamus against the background of obesity.

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

Pathology often proceeds in the form of seizures, which can be of a different nature:

• Sympathoadrenal crises - occur suddenly, manifested by increased heart rate, cold extremities, trembling in the body, dilated pupils, fear of death. Temperature rise is possible.
• Vagoinsular crises - begin with a feeling of heat and a rush of blood to the head. Disturbed by nausea, vomiting, feeling of lack of air. The pulse slows down, pressure drops are possible. Often the condition is accompanied by frequent and profuse urination, diarrhea.

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

The human body is such a complex system, the details of which are so firmly and so closely connected with each other, that even the slightest failure in a small organ leads to a disruption in the performance of the whole organism. Moreover, there are such organs in this system, the existence of which, at best, most people simply guess, and at worst, they learn about their presence only when health problems arise (hypertensive syndrome). One of these little fighters of the invisible front, standing guard over health, is the hypothalamus.

Its weight is only a few grams, and its size is several centimeters. The hypothalamus is not so much a separate organ as an area of ​​the human brain, which is responsible for the full-fledged work of almost all vital functions of the human body due to the production of special hormones. The hypothalamus is the link between the central nervous system and the endocrine system. It helps to regulate the work inside the body, depending on the signals that enter the brain from the external environment.

Areas of responsibility of the hypothalamus

The value of the hypothalamus in human life is not just important, but systemic. After all, what the hypothalamus is responsible for concerns all systems of the human body, in particular their ability to make the body alive and healthy in conditions of the surrounding world that is not always friendly to it.

Here is what the hypothalamus controls:

1. When and how much we can consume food: feelings of hunger or satiety should work in time, and appetite should be regulated so that the body does not fall into either obesity or exhaustion.
2. Body temperature: it must adapt to all the changes that occur both inside and outside the body, so it is no coincidence that our muscles begin to tremble with external cold, and the forehead becomes hot with internal disease.
3. When and how much we should sleep: it depends on the proper functioning of the hypothalamus whether we will suffer from insomnia or, in the worst case, fall into hibernation or coma, and at best, we will be haunted by drowsiness.
4. What events will be erased from our memory, and what will be engraved into it forever, whether we meet old age in a state of apathetic dementia or active wakefulness.
5. Will we go through life as misanthropes or will we be kind to every person we meet.
6. Will we be able to adequately perceive the feeling of thirst or will we be unable to quench it.
7. Will our nervous system as a whole work without failures and overlays.

Thus, the functions of the human hypothalamus extend to his eating habits and behavior in society, memory and sleep, as well as his general physical and moral well-being. This area of ​​the brain allows the human body to live in harmony with the external and internal environments.

Why the functions of the hypothalamus are impaired

The main task of the hypothalamus is to produce the right amount of hormones, thanks to which our body will work like a beautiful, serviceable clock. But, like any organ, the hypothalamus can also fail in its work. This happens for a variety of reasons:

• due to which will put pressure on the hypothalamus;
• due to direct damage to the hypothalamus due to;
• the work of the hypothalamus can be affected by global hormonal changes in the body, in particular age-related or due to pregnancy;
• infection of the body with certain viruses and bacteria, as well as various kinds of intoxication (drugs, alcohol, chemicals at work) can play a role;
• nervous, stressful, shock loads will have a great influence on interruptions in the work of the hypothalamus;
• at risk are people who have suffered from cervical osteochondrosis or have problems with blood vessels, who also have a history of hypertension, asthma, ulcers in the gastrointestinal tract;
• the danger lies in wait for those who are overweight or delay physical development.

These and other factors can cause insufficient or excessive production of hormones by the hypothalamus, which will necessarily affect human health.

What symptoms indicate problems with the hypothalamus

Pathologies in the hypothalamus will be indicated by changes in both the appearance of a person and his behavior:

The symptoms of various hypothalamic syndromes are diverse, it all depends on which part of the hypothalamus is affected. Moreover, signals of pathology may not appear immediately, but after months and even years. Diagnosis in this regard is quite problematic: it requires complex laboratory tests (blood, urine, tests for hormone levels), as well as many hardware studies of the brain, adrenal glands, thyroid gland (, CT, ultrasound and others).

Why ? Read about the main causes of sleep disorders.

Read about and what leads to its pathological.

All about: causes, symptoms, treatment, prognosis. Why timely diagnosis and treatment of the disease is important in children.

How to treat hypothalamic syndromes

As a rule, problems with the hypothalamus become lifelong, and they will have to be solved not by one doctor, but by several. However, the symptoms can be neutralized with the help of drug therapy, provided that the primary causes of the pathology are first eliminated (the tumor is eliminated, infectious and viral diseases are cured, the nervous balance is restored).

In the long term, with adequate treatment, people with hypothalamic problems can hope for a favorable outcome, although in most cases they will have to put up with some disability. They will need to take care of their health as much as possible and avoid mental and physical stress.

The hypothalamus is a cluster of nerve cells that is about the size of the phalanx of the thumb and weighs about 4 g. It does not have a clear outline and is represented by 32 pairs of nuclei. They are associated with the thalamus, pituitary gland, diencephalon, reticular formation responsible for the level of body activity. The closest relationship is in the hypothalamus and pituitary gland. They are usually considered as a single hypothalamic-pituitary system.

Capillary permeability unusual for the brain was noted. The density of the vascular network of the hypothalamus is several times higher than in other areas of the CNS. The composition contains ordinary nerve cells - neurons and secretory.

The nuclear structure includes:

• Preoptic. The nuclei belong to the anterior hypothalamus. They receive impulses from receptors that perceive temperature, located in the skin, mucous membranes and in the brain. There are also cells that control sexual behavior.
• Supraoptic nucleus. Forms an antidiuretic hormone - vasopressin, which slows down the release of urine. It enters the back of the pituitary gland, accumulates and is stored in its cells. The hormone with blood enters the tubules of the kidneys and increases the reabsorption of water from the primary urine.

• Paraventricular. Neurons are activated during stress, infectious diseases, participate in metabolic processes, the growth of internal organs and the skeletal system, control immunity and the function of the gonads. They produce oxytocin, somatostatin and vasopressin.
• Suprachiasmatic. Its activity is subject to daily rhythms, depends on the length of daylight hours. Changes when living with artificial lighting.
• Side. The cells of this zone regulate the feeling of satiety and the digestion of food. In this area there are also neurons responsible for blood pressure, wakefulness and reducing the feeling of pain,
• Ventromedial.
• Dorsomedial. Processes signals from the lateral (lateral) nuclei and ventromedial. Maintains a normal level of indicators: blood pressure, heart rate, secretion of digestive enzymes, body temperature, sleep duration.
• Arcuate. Of all the structures of the hypothalamus, appetite is most affected. Participates in the regulation of metabolic processes and digestion, the work of the heart, provides lactation and secretion of somatostatin.
• Mammillary nucleus. Regulates memory. With a lack of vitamin B1, violations lead to disorders of consciousness, movements, paralysis of the oculomotor muscles.
• Tuberomammary. It ensures the functioning of the body when waking up after sleep, participates in the processes of learning, memorization and analysis of information, metabolism in the brain. Neurons in this zone secrete histamine.

This organ is considered the main coordinator and regulator for autonomic reactions in the body..

Disorders of the hypothalamus are manifested as follows:

• sharp fluctuations in body temperature;
• biorhythm failure, daytime sleepiness and nighttime insomnia;
• sweating;
• vegetative crises;
• obesity or sudden weight loss;
• violation of the motor activity of the stomach and intestines;

Read more in our article about the structure of the hypothalamus and its features.

The hypothalamus is a cluster of nerve cells that is about the size of the phalanx of the thumb and weighs about 4 g. It does not have a clear outline and is represented by 32 pairs of nuclei. They are associated with the thalamus, pituitary gland, diencephalon, reticular formation responsible for the level of body activity. The closest relationship (many nerve and vascular pathways) is in the hypothalamus and pituitary gland. They are usually considered as a single hypothalamic-pituitary system.

An interesting feature is capillary permeability, which is unusual for the brain. Their walls allow large molecules to pass through, which do not pass through the blood-brain barrier anywhere else. Also, the density of the vascular network of the hypothalamus is several times higher than in any other areas of the central nervous system.

The hypothalamus contains the usual nerve cells - neurons and secretory. In the latter, the formation of proteins that enter the blood and lymphatic fluid predominates. Thus, nerve signals are converted into hormonal ones.

nuclear structure

Despite the fact that the nuclear structure of the hypothalamus is well known, the purpose of many of them remains unsolved. Also controversial is their functional division into groups, since it is possible to transfer the properties of some nuclei to others in case of damage or an increased need for hormones in the body.

preoptic

They belong to the anterior hypothalamus. They receive impulses from receptors that perceive temperature, located in the skin, mucous membranes and in the brain. In this area, there are also cells that control sexual behavior.

supraoptic

Forms antidiuretic hormone - which slows down the release of urine. It enters the back of the pituitary gland, accumulates and is stored in its cells. When the concentration of sodium ions in the blood changes, the hypothalamus gives the command to remove vasopressin. This hormone enters the tubules of the kidneys with blood and increases the reabsorption of water from the primary urine.

Paraventricular

Neurons are activated during stress, infectious diseases, participate in metabolic processes, the growth of internal organs and the skeletal system, control immunity and the function of the gonads. They form somatostatin and vasopressin (together with the supraoptic nucleus).

suprachiasmatic

Its activity is subject to circadian (daily rhythms), depends on the length of daylight hours. Normally subject to 24-hour fluctuations, but changes when living with artificial lighting.

Side

The cells of this zone regulate the feeling of satiety and the digestion of food. If they are artificially stimulated (for example, by weak electrical impulses), then a feeling of hunger arises, and when they are destroyed, a person completely refuses to eat. In this area there are also neurons responsible for blood pressure, wakefulness and reducing the feeling of pain,

Ventromedial

Regulates saturation, energy formation, eating behavior, the use of carbohydrates and fatty acids in metabolic processes. When damaged, persistent obesity develops.

Dorsomedial

Processes signals from the lateral (lateral) nuclei and ventromedial. Supports the normal level of such indicators:

• blood pressure,
• heart rate,
• secretion of digestive enzymes
• body temperature,
• sleep duration.

arcuate

Of all the structures of the hypothalamus, appetite is most affected. In addition, it is involved in the regulation of:

• metabolic processes;
• digestion;
• heart work;
• release of prolactin by the pituitary gland (provides lactation);
• secretion of somatostatin, which inhibits the release of the releasing factor (liberator) of the somatotropic pituitary gland, that is, stops the growth of the body.

Mammillary

Regulates memory. With a lack of vitamin B1 (common in alcoholics), dysfunction of this part of the hypothalamus leads to disorders of consciousness, movements, paralysis of the oculomotor muscles

Tuberomammary

It ensures the functioning of the body when waking up after sleep, participates in the processes of learning, memorization and analysis of information, metabolism in the brain. The neurons of this zone secrete histamine, which is a neurotransmitter (conductor of impulses) in the brain tissue.

Watch the video about the structure and functions of the hypothalamus:

Functions and biological role

This organ is considered the main coordinator and regulator for autonomic reactions in the body. The most studied features include:

• changes in blood pressure, heart rate and respirations under the influence of external and internal factors;
• providing sensations: taste, smell, hunger, thirst;
• maintaining normal sleep duration;
• behavior management: aggression, food and sexual, motivation, emotions;
• control of the constancy of the internal environment: the composition of blood and tissue fluid, hormone levels, temperature.

These processes are carried out due to the release of two types of substances - and. The former stimulate the formation and release of pituitary hormones into the blood. Liberins, or releasing factors, are named by analogy with the hormones themselves.

For example, corticoliberin provides the secretion of adrenocorticotropic hormone, and somatoliberin - growth hormone (somatostatin), luliberin and folliberin - lutropin and pituitary follicle-stimulating hormone, thyroliberin is responsible for the production of thyroid-stimulating hormone.

• violation of sexual behavior, aggression, impotence in men, problems with ejaculation, in women - spastic condition of the vagina during sexual intercourse, frigidity;
• fear, anxiety;
• pain in the heart with normal ECG values, are not relieved by Validol or Nitroglycerin;
• feeling short of breath, headache, loss of consciousness;
• violation of the motor activity of the stomach and intestines - abdominal pain, bloating, alternating constipation and diarrhea, irritable bowel syndrome;
• attacks of unmotivated laughter or crying, impaired consciousness, convulsive muscle twitches;
• precocious puberty, polycystic ovaries, menstrual irregularities.

We recommend reading the article about. From it you will learn about the causes of pituitary adenoma, the classification of the disease, the symptoms of a brain tumor in men and women, as well as methods for diagnosing and treating pituitary adenoma.

Learn more about the causes and symptoms of acromegaly.

The hypothalamus is a cluster of 32 nuclei in the hypothalamic region of the brain. Its function is the regulation of the autonomic nervous system. Under his control are hunger, thirst, sexual behavior, emotions, temperature and digestion. It performs its functions by transmitting commands to the pituitary gland. For this, it forms liberins and statins, oxytocin and antidiuretic hormone.

In case of disruption of work, the adaptation of a person to changes in the external environment changes, mental, metabolic, and hormonal dysfunctions occur.

The hypothalamus is one of the main structures involved in the formation of the body's behavioral responses, which are necessary for the constancy of the internal environment. Stimulation of its nuclei leads to the formation of purposeful behavior - food, sexual, aggressive, etc. He also plays the main role in the emergence of the main drives (motivations) of the body.

In vertebrates, the hypothalamus is the main subcortical center for the integration of visceral processes. It governs all major homeostatic functions of the body. The integrative function of the hypothalamus is provided by autonomous, somatic and endocrine mechanisms.

Transmission of information in the hypothalamus

Sensitive information from the internal organs and the surface of the body enters the hypothalamus along the ascending spinobulbar pathways. Some of them pass through the thalamus, others through the limbic region of the midbrain, and others follow as yet not fully identified polysynaptic pathways. In addition, the hypothalamus is equipped with its own specific "inputs". It contains osmoreceptors highly sensitive to changes in the osmotic pressure of the internal environment and thermoreceptors sensitive to changes in blood temperature. The efferent pathways of the hypothalamus are polysynaptic. They associate it with the reticular formation of the brain stem, the nuclei of the spinal cord. The descending influences of the hypothalamus ensure the regulation of functions mainly through the autonomic nervous system. At the same time, an important component in the implementation of the descending influences of the hypothalamus are also pituitary hormones . In addition to afferent and efferent connections, there is a commissural pathway in the hypothalamus. Thanks to him, the medial hypothalamic nuclei of one side come into contact with the medial and lateral nuclei of the other side.

Hypothalamus connections

Numerous connections of the hypothalamus with other formations of the brain contribute to the generalization of excitations that occur in the cells of the hypothalamus. Excitation primarily spreads to the limbic structures of the brain and through the nuclei of the thalamus to the anterior sections of the cerebral cortex. The degree of distribution of the ascending activating influences of the hypothalamus depends on the magnitude of the initial excitation of the centers of the hypothalamus.

Hypothalamus and behavioral responses of the body

Hypothalamus- one of the main structures involved in the formation of the behavioral reactions of the body, which are necessary for the constancy of the internal environment. Stimulation of its nuclei leads to the formation of purposeful behavior - food, sexual, aggressive, etc. He also plays the main role in the emergence of the main drives (motivations) of the body.

Blood supply to the hypothalamus

The main source of arterial blood supply to the hypothalamic nuclei is the arterial circle of the brain. Its branches provide abundant isolated blood supply to individual groups of nuclei, the capillary network of which is several times denser than the blood supply to other parts of the nervous system. The capillary network of the hypothalamus is distinguished by high permeability for macromolecular compounds. The virtual absence of the blood-brain barrier in this area allows these blood compounds to have a direct effect on hypothalamic neurons.

Hypothalamic-pituitary system

Numerous nerve and vascular connections between the hypothalamus and the pituitary gland are the basis of a functional complex called the hypothalamic-pituitary system. The main purpose of the complex is to integrate the nervous and hormonal regulation of the visceral functions of the body. From the side of the hypothalamus, it is carried out in two ways: paraadenohypophyseal (bypassing the adenohypophysis) and transadenohypophyseal (through the adenohypophysis).

pituitary hormones

The release of hormones of the anterior pituitary gland is influenced by hormones of neurons of the hypophysiotropic zone of the medial hypothalamus. They are able to have a stimulating and inhibitory effect on the pituitary cells. In the first case, these are the so-called releasing factors (liberins), in the second - inhibitory factors (statins). The regulation of the hypothalamic-pituitary system of visceral functions is carried out according to the feedback principle. Its action is manifested even after the complete separation of the medial region of the hypothalamus from other parts of the brain. The role of the central nervous system is to adapt this regulation to the internal and external needs of the organism.

Cells of the hypothalamus

The cells of the hypothalamus are selectively sensitive to the content of certain substances in the blood and, with any change in their concentration, they enter a state of excitation. For example, hypothalamic neurons are sensitive to the slightest deviations in the pH of the blood, the voltage of O2 and CO2, and the content of ions, especially K and Na. Thus, the supraoptic nucleus contains cells that are selectively sensitive to changes in the osmotic pressure of the blood, the ventromedial nucleus - the content of glucose, and the anterior hypothalamus - sex hormones. Consequently, the cells of the hypothalamus act as receptors that perceive changes in homeostasis. They have the ability to transform humoral changes in the internal environment into a nervous process - a biologically colored excitation. However, they can be selectively activated not only by changes in certain blood constants, but also by nerve impulses from the corresponding organs associated with a given need. Receptor cells work according to the trigger type. Excitation does not arise in them immediately, as soon as any blood constant changes, but after a certain period of time, when their depolarization reaches a critical level. Consequently, the neurons of the motivational centers of the hypothalamus are distinguished by the frequency of work. In the case when the change in the blood constant is maintained for a long time, the depolarization of neurons rises to a critical level and the state of excitation is established at this level as long as there is a change in the constant that caused the development of the excitation process. The constant impulse activity of these neurons disappears only when the irritation that caused it is eliminated, i.e., the content of one or another blood factor is normalized. Excitation of some cells of the hypothalamus can occur periodically after several hours, as, for example, with a lack of glucose, others - after several days or even months, as, for example, when the content of sex hormones changes.

Removal of the hypothalamus

The destruction of the nuclei or the removal of the entire hypothalamus is accompanied by a violation of the homeostatic functions of the body. The hypothalamus plays a leading role in maintaining the optimal level of metabolism (protein, carbohydrate, fat, mineral, water) and energy, in regulating the body's temperature balance, the activity of the cardiovascular, digestive, excretory, and respiratory systems. Under its influence are the functions of the endocrine glands. When the hypothalamic structures are excited, the nervous component of complex reactions is necessarily supplemented with hormonal ones.

Posterior nuclei of the hypothalamus

Studies have shown that stimulation of the posterior nuclei of the hypothalamus is accompanied by effects similar to stimulation of the sympathetic nervous system: dilation of the pupils and palpebral fissure, an increase in heart rate, an increase in blood pressure, inhibition of the motor activity of the stomach and intestines, an increase in the concentration of adrenaline in the blood. influence on sexual development. Its damage also leads to hyperglycemia, and in some cases to the development of obesity. The destruction of the posterior nuclei of the hypothalamus is accompanied by a complete loss of thermoregulation. The body temperature of these animals cannot be maintained. The reactions that occur when the posterior hypothalamus is excited and are accompanied by the activation of the sympathetic nervous system, the mobilization of the body's energy, and an increase in the ability to exercise, are called ergotropic.

Anterior nuclei of the hypothalamus

Stimulation of the group of the anterior nuclei of the hypothalamus is characterized by reactions similar to irritation of the parasympathetic nervous system, narrowing of the pupils and palpebral fissure, slowing of the heart rate, a decrease in blood pressure, increased motor activity of the stomach and intestines, activation of the secretion of the gastric glands, an increase in insulin secretion and as a result - a decrease in blood glucose levels. The group of anterior nuclei of the hypothalamus has a stimulating effect on sexual development. It is also associated with the mechanism of heat loss. The destruction of this area leads to a violation of the heat transfer process, as a result of which the body quickly overheats.

Middle nuclei of the hypothalamus

The middle group of nuclei of the hypothalamus provides mainly the regulation of metabolism. The study of the regulation of eating behavior showed that it is carried out as a result of reciprocal interactions of the lateral and ventromedial hypothalamic nuclei. Activation of the former causes an increase in food consumption, and its bilateral destruction is accompanied by a complete refusal of food, up to exhaustion and death of the animal. On the contrary, an increase in the activity of the ventromedial nucleus reduces the level of food motivation. With the destruction of this nucleus, an increase in food intake (hyperphagia), obesity occurs. These data made it possible to regard the ventromedial nuclei as structures through which food intake is limited, i.e., associated with satiety, and the lateral nuclei as structures that increase the level of food motivation, i.e., associated with hunger. At the same time, it has not yet been possible to isolate the functional or structural accumulations of neurons responsible for this or that behavior. Consequently, the cellular formations that ensure the formation of integral behavior from individual reactions should not be considered as anatomically limited structures, known as the center of hunger and the center of satiety. Probably, groups of hypothalamic cells associated with the performance of any function differ from each other in the nature of afferent and efferent connections, synaptic organization, and mediators. It is assumed that numerous programs are embedded in the neural networks of the hypothalamus, and their activation by means of signals from other parts of the brain or interoceptors leads to the formation of the necessary behavioral and neurohumoral reactions. The study of the role of the hypothalamus by methods of irritation or destruction of its nuclei led to the conclusion that the areas responsible for the consumption of food and water, apparently, overlap each other. The most increased need for water was observed during stimulation of the paraventricular nucleus of the hypothalamus.

Interaction of the hypothalamus with other parts of the brain

With other parts of the subcortex and the cerebral cortex, the hypothalamus is in continuous cyclic interactions. Due to the fact that nervous and humoral signaling about various internal needs is addressed to the hypothalamic nuclei, they acquire the significance of a trigger mechanism for motivational excitations. The introduction of specific neurotropic substances can selectively block various hypothalamic mechanisms involved in the formation of such body states as fear, hunger, thirst, etc. The hypothalamus is under the regulatory influence of the cerebral cortex. Receiving information about the initial state of the body and the environment, cortical neurons exert a downward influence on all subcortical structures, including the hypothalamus, by regulating their level of excitation. Cortical mechanisms suppress many emotions and primary excitations that are formed with the participation of the hypothalamic nuclei. Therefore, the removal of the cortex often leads to the development of reactions of imaginary rage, expressed in dilated pupils, tachycardia, salivation, increased intracranial pressure, etc. Thus, the hypothalamus, having a well-developed and complex system of connections, occupies a leading position in the regulation of many functions of the body and, above all, in the constancy of the internal environment. Under its control is the function of the autonomic nervous system and endocrine glands. It is involved in the regulation of eating and sexual behavior, changes in sleep and wakefulness, emotional activity, maintaining body temperature, etc.