The upper surface is the important pituitary gland. The role and functions of the pituitary gland

What pituitary and where is it located? The pituitary gland is a small pineal gland hanging from the middle of the brain in the lower middle part of it. The pituitary gland is located in the area of \u200b\u200bthe "Turkish saddle" - a bone notch, also called the pituitary fossa, this fossa is formed sphenoid bone skulls. The pituitary gland is located below the bottom of the third cerebral ventricle, connecting with the funnel of the hypothalamus.

It can be said that pituitary - main body controlling other endocrine centers (centers of internal secretion, or hormonal regulation). Under the control of the pituitary gland - the functions of growth and development, reproductive functions. It provides well-coordinated work several endocrine glands: thyroid, adrenal and gonads. Thus, in general, the pituitary gland is in charge of the chemical, endocrine and mental self-regulation of the whole organism.

The size of the pituitary gland of an adult is from 6 to 15 mm. In a newborn, the weight of the pituitary gland is approximately 0.15 g, by the age of 10 it reaches 0.3 g, and in an adult it is 0.5-0.7 g. The main period of growth of the pituitary gland is during puberty.

The pituitary gland consists of 2 parts. One of them is presented nerve cells- this part is called neurohypophysis, and is located in posterior region, it is 2 times smaller than the other part - adenohypophysis- which consists of glandular cells, and is located in front. Between these two parts there is also an intermediate part, which is a narrow plate, which is considered a rudimentary formation, and presumably!, the pituitary gland is of much greater importance for animals.

The functions of the pituitary gland are not fully understood. Sometimes it is called a brain appendage. Until the end of the nineteenth century. it was widely believed that the pituitary gland determines appearance man, which served as the idea of writing such a work as "The Heart of a Dog" for M. Bulgakov.

The blood supply to the adenohypophysis occurs with the help of the lower pituitary arteries, the neurohypophysis supplies blood to the upper pituitary arteries. The capillary network between the lobes unites them circulatory system. The outflow of blood occurs with the help of venous collectors or sinuses of the dura mater.

In embryogenesis, the pituitary gland is formed - on the one hand - from the downward protrusion of the bottom of the 3rd ventricle of the brain (neurohypophysis); and on the other hand, the primary oral recess rises upward (adenohypophysis), then this tissue outgrowth completely separates and attaches to the neurohypophysis. Then both shares develop in parallel.

From sympathetic trunk from the spinal cord to the pituitary gland are postganglionic fibers. nerve impulses, coming along these fibers, cause the secretion of hormones in the glandular cells of the pituitary gland and regulate the work of blood vessels.

in the adenohypophysis the following hormones:

Somatotropin - a growth hormone. The maximum concentration of somatotropic hormone is observed in early age in children, as well as in the prenatal period - 4-6 months. In the elderly, its concentration is minimal.
Thyroid-stimulating hormone (TTG) - regulates the work thyroid gland, is responsible for the synthesis of proteins, phospholipids, nucleic acids, hormones - thyroxine (T4) and triiodothyronine (T3).
Corticotropin - activates the adrenal cortex, regulates the synthesis of glucocorticosteroids: cortisol, cortisone, corticosterone.
Prolactin - regulates the process of milk production during lactation and breastfeeding.
luteinizing hormone - promotes the synthesis of testosterone in men, and in women affects the production corpus luteum, regulates the process of ovulation, stimulates the secretion of progesterone and estrogen.
Follicle stimulating hormone - thanks to him, follicles are produced and develop in female ovaries, and spermatozoa are produced in the testicles of men.

neurohypophysis responsible for regulating hormones how:

With violations of the functions of the pituitary gland, the following negative consequences are possible:

The lack of somatotropin and sex hormone at an early age causes dwarfism or short stature.
Excessive production of neurohypophysis hormones leads to the development of adenoma.
With insufficient production of vasopressin, the development of diabetes insipidus, later on to coma, is possible.
Total lack of hormones or pituitary failure causes the inability of the gland to give signals to other endocrine glands, and is also fraught with serious consequences. Usually similar phenomenon occurs as a result of difficult childbirth, injuries and infections of the brain, with vascular disorders.
Various degrees of calcification of the pituitary gland also adversely affect the work of all dependent regulated glands.

Thus, both hyperfunction and hypofunction of the pituitary gland are undesirable. Like all other organs, balance is important for stable operation of the pituitary gland. Just as the entire body depends on the pituitary gland, the pituitary gland itself is dependent on general condition organism, not only physical, but also mental.

One of the directions, mostly aimed at working with the skull and brain, helps to restore the internal balance of the body, allows you to find the root causes of disorders even in difficult cases and eliminate them, restoring health.

The pituitary gland is the master gland human body. This gland has an amazing effect, releasing hormones, and also influencing other glands, already regulating their work on secreting the right hormones.

Location of the pituitary gland

The pituitary gland is located in the brain and is connected by a stalk. This compound allows the two glands to control many aspects of the body's metabolic processes. In other words, they ensure the proper functioning of the entire body.

The dimensions of the pituitary gland are approximately 10x13x6 mm. The average weight is 0.5 g. At the same time, both the mass and the dimensions change due to functional state glands.

The pituitary gland has two main lobes - anterior and posterior. The front is ¾ of the total mass.

What is the pituitary gland for? Hormones secreted by the pituitary gland

As mentioned above, the role of the pituitary gland is to secrete a certain type of hormone and influence other glands that also secrete their own hormones. All this allows us to speak of this organ as the most metabolic processes.

Hormones secreted by the posterior lobe

The posterior lobe of the pituitary gland secretes two main hormones - antidiuretic hormone. As for the first hormone, it is designed to control the amount of water in the human body. With its help, the work of the kidneys is controlled. If the hormone affects them, then they begin to secrete or retain fluid.

Oxytocin is not yet fully understood. It is believed that under its influence generic activity. During childbirth, there is a large release of this hormone into the uterus, which begins to contract faster. In addition, oxytocin affects the amount breast milk. As for directly, the hormone affects their development.

Hormones secreted by the anterior lobe

The anterior pituitary gland secretes six hormones. At the same time, four hormones affect other organs:

Thyroid;
- adrenal glands;
- sex glands.

Thyretropic hormone acts on, and adrenocorticotropic hormone - on the adrenal glands.
The anterior pituitary secretes prolan A and prolan B. They have the greatest effect on the sex glands.

The hormone prolactip directly affects the function of reproduction, the growth hormone - on the ability to develop normally in the human body.

In many meditation practices Special attention given exactly. It is believed that its proper operation is a guarantee of health and longevity. Without the pituitary gland, we could not experience feelings of euphoria, cravings for the opposite sex, control water balance, and much more. Until now, scientists have not been able to fully study. It may well be that the pituitary gland has a wider range of action in the human body.

The pituitary gland is a small organ responsible for the secretion of many hormones in the human body. It regulates most of the processes of the whole organism - growth and development, reproductive and sexual functions, psycho-emotional state, etc.

The structure of the pituitary gland

The pituitary gland is located in the "Turkish saddle" (a bone pocket in the human skull). closes it hard shell brain, which has a hole for connection with the hypothalamus. The hypothalamus is a link between the nervous and endocrine systems, it synthesizes hormones, the activity of which is regulated by the pituitary gland. The pituitary gland is connected with the hypothalamus, because. they are part of one system that controls the work of other glands in the body.

This gland has a small size - on average, about 10 mm in length and 12 in width, and the mass is about 0.5 grams. The pituitary gland is responsible for the proper functioning of many processes in the human body. It consists of two main lobes, one of which occupies 80% of the volume of the entire gland. The anterior (largest) lobe is called the adenohypophysis, and the posterior lobe is the neurohypophysis. There is also a third, intermediate share. She has smallest value among all shares. Responsible for the production of melanocyte-stimulating hormone.

The functions of the pituitary gland are vital for the body and therefore this gland develops quite early - it is present in the fetus already at 4-5 weeks of gestation, but its development continues until full puberty. The average proportion in newborns is much smaller than in adults, but over time, its size decreases.

Blood supply to the pituitary gland

blood supply this body carried out for the most part along the anterior pituitary artery, which, in turn, is a branch of the internal carotid artery. This artery produces capillary network, passing into the venous trunks and braiding the pituitary stalk. This is how the adenohypophysis and the anterior pituitary stalk are supplied with blood. The blood supply of the latter is additionally carried out at the expense of other arterial branches. From the adenohypophysis, veins divided into sinusoids depart from the pituitary gland, supplying blood enriched with hormones. The posterior lobe is supplied with blood flow by the posterior pituitary artery.

Note: Both lobes have different blood supply. This may be due to the fact that the pituitary gland develops from different primordia, which is why it has several parts.

Hormones of the adenohypophysis and their functions

Somatotropin (STG)

One of the most important hormones, which are produced in the pituitary gland, is growth hormone. Controls protein, lipid, mineral and carbohydrate metabolism. Promotes the breakdown of fat cells, increased blood glucose, protein biosynthesis. A lack of growth hormone leads to slow growth and development, and an excess stimulates the manifestation of gigantism.

Fact: You can stimulate the production of somatotropin by exercise and intake of certain amino acids.

STG is produced throughout a person's life in varying amounts. Its greatest amount is produced before full puberty, then its level decreases by 15% every 10 years of life. The main functions of growth hormone:

cardiovascular system - maintaining cholesterol levels. With a lack of growth hormone, there is a risk of vascular atherosclerosis, stroke, heart attack, etc.;
body weight - during sleep, somatotropin stimulates the breakdown of fat cells, if this process is disturbed, obesity occurs;
skin - the production of collagen, with a small amount of which accelerates the aging process;
muscle tissue - an increase in muscle elasticity, overall muscle strength;
tone - maintaining normal growth hormone provides a boost of energy, improves sleep quality.
bones - STH is responsible for timely growth and strength bone tissue by participating in the synthesis of vitamin D

Prolactin

AT female body considered the most necessary, at the same time plays an important role in the sexual function of men. The main task in the female body is to control the process of lactation, in both sexes it reflects the level of stress. A feature of this pituitary hormone is the ability a wide range actions.

An interesting fact: even minor disturbances immediately before the test for the level of prolactin can show an overestimated result.

The main functions of prolactin:

strengthens the immune system;
accelerates wound healing;
regulates the work of the adrenal glands;
participates in the rejection of transplanted organs, which helps to prevent the consequences of unsuccessful transplantation.

Prolactin in the female body:

stimulation of the growth of the mammary glands and the appearance of milk before breastfeeding;
maintaining the functions of the corpus luteum of the ovary, which maintains the level of progesterone;
development of maternal instinct.

Prolactin in men:

regulation of sexual function;
maintenance of testosterone levels;
regulation of spermatogenesis;
stimulation of the secretion of the prostate gland.

Gonadotropins

The two main gonadotropic hormones are follicle-stimulating and luteinizing. Both are responsible for sexual and reproductive function.

In women, FSH stimulates the synthesis of estrogens and the growth of follicles on the ovaries, converts testosterone into estrogens, and LH controls the development of the genital organs. Their level varies significantly depending on the phase of the cycle, and also changes significantly during pregnancy and lactation.

Fact: before puberty, gonadotropins are secreted in equal amounts in women, after the first year of menstruation, LH is secreted 1.5 times more FSH, and for the rest of life until menopause, the ratio of FSH and LH approaches 1: 2.

At men FSH responsible for the growth of the testes and seminiferous tubules, protein synthesis in the genitals, spermatogenesis. LH is involved in the regulation of cells in the testes that produce testosterone and dihydrotestosterone, which generally affects the quantity and quality of spermatozoa. Quite a few importance LH has while maintaining sexual function and controlling sexual behavior.

TSH

Thyroid-stimulating hormone is closely related to the work of peripheral endocrine glands. With their weak activity, TSH increases, and with a high concentration of tropins decreases.

maintenance of heat exchange and metabolism;
glucose production;
synthesis of protein, phospholipids, nucleic acids;
control of sexual, nervous, cardiovascular systems and digestive organs;
body growth in childhood;
regulation of erythrocyte synthesis;
is responsible for the absorption of iodine, does not allow its excess.

Fact: A change in TSH is often associated with diseases of the thyroid gland, less often with diseases of the pituitary gland and hypothalamus. If a deviation from the norm is detected, additional tests and ultrasound of the thyroid gland are prescribed.

ACTH

Adrenocorticoid hormone controls the activity of the adrenal glands. It is very important in adapting the body to new conditions. Covers a small range of activities.

Functions of ACTH:

control of the activity of the adrenal glands;
responsible for the production of steroid hormones;
enhances skin pigmentation;
accelerates the breakdown of fats;
affects muscle development.

Functions of neurohypophysis hormones

The two main posterior hormones are vasopressin and oxytocin.

Vasopressin is mainly needed to maintain water balance. Its increase occurs with blood loss, a high amount of sodium in the blood, pain stress. It is indispensable for supplying muscle and other tissues with water, increasing the volume of blood in the vessels, and is able to regulate the reabsorption of water.

The pituitary hormone oxytocin stimulates the appearance of maternal instinct and regulates the process of lactation, enhances the secretion of estrogens (in women), and is responsible for sexual arousal. Oxytocin significantly affects the psycho-emotional state of a person. In combination with vasopressin improves brain activity.

An interesting fact: during childbirth, the level of oxytocin in the mother rises sharply, which is manifested by love and tolerance for the child. At caesarean section this does not happen, which is why postpartum depression often occurs.

Diseases of the pituitary gland

Since the pituitary gland is an organ of the brain, the cause of its diseases is often diseases or defects of the latter, such as injuries, surgical operations, congenital underdevelopment, meningitis, encephalitis.

An excess of pituitary hormones often occurs in connection with the appearance of an adenoma. An adenoma is a tumor that, as it grows, more and more inhibits the work of this gland. Its diagnosis is an MRI examination of the pituitary gland.

A low level of hormones provokes the development of:

secondary lack of hormones of other endocrine glands;
physical disorders (developmental disorders individual bodies or the whole organism as a whole).
diabetes insipidus;
hypopituitarism ( low level all pituitary hormones).

Diseases with an excess of hormones:

hyperprolactinemia;
physical disorders;
Itsenko-Cushing's disease.

Important: the type of disease depends on the specific hormone, as well as on its level. Since the pituitary gland is responsible for many vital important processes, the list of diseases can be huge.

In the course of these diseases, the most commonly prescribed hormone therapy. Most often serious illness treated with lifelong medication. With adenoma, therapy is carried out according to a different scheme; in especially severe cases, surgical intervention is necessary.

Conclusion

The pituitary gland is very complex organ, even a slight disruption of which can have serious consequences for the body. Timely diagnosis and treatment of such diseases have a positive prognosis.

The pituitary gland (pituitary gland or lower cerebral appendage) is an endocrine organ that is located at the base of the brain. To be more specific, on bottom surface it, in a bone pocket, which is called This gland in a person of a very small size, about the size of a pea, is a rounded formation weighing only 0.5 g. But despite such a small size, the role of hormones produced by the pituitary gland is enormous.

This little gland is the main organ of our entire endocrine system. The hormones it produces affect following features body:

reproductive;
metabolic processes;
growth.

The functions and which it produces are closely interconnected. In order to understand this issue in more detail, let us first consider the structure of this endocrine gland.

It consists of three main lobes: anterior, posterior and intermediate, which differ in their origin and structure. The pituitary gland begins to form in the embryo at 4-5 weeks of intrauterine development. Its anterior lobe is formed from the epithelial surface of the posterior wall oral cavity, the so-called Rathke pocket, in the form of a small oblong outgrowth. In the process embryonic development it grows towards diencephalon.

The posterior lobe is formed a little later than the anterior from the nervous tissue of the diencephalon, where these lobes are connected. Even later, an intermediate lobe of the pituitary gland is formed. It consists of a thin layer of cells. All three lobes of the pituitary gland are essentially separate secretory glands, and each produces its own hormones. The pituitary gland (hormones and its functions) takes a huge part in the work of the entire human endocrine system.

Anterior pituitary gland

This share is called the adenohypophysis and makes up the bulk of the gland (70%). It consists of various kinds endocrine glandular cells. Each type of cell in this lobe produces its own hormone. These endocrine cells are called adenocytes. There are two types of adenocytes: chromophilic and chromophobic, both synthesize hormones:

Thyroid-stimulating hormone (TSH) - is responsible for the secretory activity of the thyroid gland.
Adrenocorticotropic (ACTH) - stimulates the adrenal cortex.
Gonadotropic hormones, which include follicle-stimulating and luteinizing hormones (FSH, LH), which are responsible for reproductive function.
Somatotropic hormone (GH) - responsible for growth, stimulates the breakdown of fats, protein synthesis in cells and the formation of glucose.
Luteotropic hormone, or prolactin, which regulates instinctive care for offspring, lactation, metabolic and growth processes.

The pituitary hormones are physiological role in the human body is huge.

Somatotropin

Somatotropin (or is not produced constantly, it is released only 3-4 times a day. Its secretion increases markedly during periods of sleep, with severe physical activity and during fasting. The production of this hormone persists throughout a person's life, but with age it is greatly reduced. Under the influence of growth hormone in the cells, the breakdown of fats and carbohydrates occurs. As a result, under the influence of somatomedins produced in the liver, cell division and protein synthesis are enhanced, thus, bone growth occurs.

If the synthesis of somatotropin is insufficient for some reason, then dwarfism develops. At the same time, all proportions of the body are preserved, the physique is usually normal. Thus, the insufficiency of the function of the pituitary gland directly affects the growth of a person.

Excess secretion of growth hormone causes gigantism. If hypersecretion occurs in childhood, then all proportions of the body are preserved, and in adulthood, increased production of it leads to acromegaly. This is manifested by a disproportionate elongation of the limbs, the nose and chin are enlarged, as well as the tongue and all digestive organs.

Thyroid Stimulating Hormone (TSH)

This hormone regulates the activity of the thyroid gland. Under its influence, the secretion of triiodothyronine and thyroxine occurs. It activates the enzyme adenylate cyclase, which affects the uptake of iodine by thyroid cells. In addition, under the influence of TSH, protein metabolism: increases the production of nucleic acids and protein synthesis, increases the growth and size of thyroid cells.

Synthesis of TSH is able to increase under the influence of cold. The cold reaction increases the production of thyroid hormones, this leads to more education body heat. Glucocorticoids are able to inhibit the production of TSH, the same thing happens under the influence of anesthesia, pain reaction or trauma.

Excessive secretion of thyroid-stimulating hormone is manifested clinically (hyperfunction of the thyroid gland).

adenocorticotropic hormone

ACTH is synthesized unevenly throughout the day. The highest concentration is observed in morning time from 6.00 to 8.00 hours, the minimum - in the evening from 18.00 to 23.00. ACTH regulates the synthesis of corticosteroids, which are secreted by the cells of the adrenal cortex. Secretion of corticosteroids increases with severe emotional states such as fear, anger, chronic stress. Thus, ACTH has a direct impact on the emotional balance of a person. In the same way, the synthesis of ACTH is enhanced by strong cold and pain reactions, severe physical exertion. Hypoglycemia also stimulates the production of ACTH.

Excessive secretion of this hormone can be observed with pituitary adenoma, this disease is called its manifestations: hypertension, obesity, and body fat accumulate on the trunk and face, and the limbs remain normal, increased blood sugar concentration, reduced immune defense.

Insufficient production of ACTH leads to a decrease in the synthesis of glucocorticoids, and this, in turn, is expressed by a metabolic disorder and a decrease in the body's endurance to environmental influences.

Gonadotropic hormones

They control the work of the sex glands of both women and men. So, folliculotropin in women stimulates the formation of follicles in the ovaries. In the male half, this secret affects the development of the prostate and spermatogenesis (the formation of spermatozoa).

Luteoptropin regulates the formation of androgens - male hormones(testosterone, androstenedione, etc.) and estrogens - female hormones (estriol, estradiol, etc.).

Thus, the pituitary gland and its hormones are involved in the work of almost all organs.

Posterior pituitary gland

The posterior lobe of the pituitary gland is called the neurohypophysis and is made up of epidermal cells called pituitocytes. The neurohypophysis, like the adenohypophysis, produces hormones. Posterior pituitary hormones:

oxytocin;
vasopressin;
asparotocin;
vasotocin;
glumitocin;
valitocin;
isotocin;
mesotocin.

All these hormones perform their specific functions in the human body. Let's talk about some of them separately.

Oxytocin

So, the hormone oxytocin affects the contraction of the muscles of the uterus during childbirth. On a surface cell membranes there are special receptors sensitive to oxytocin. During pregnancy, this hormone does not rise to a level that can cause contractile activity uterus. Only immediately before the birth itself, under the influence of the female hormones estrogen, sensitivity to oxytocin increases and childbirth occurs. It also leads to contraction of myoepithelial cells located in the mammary glands, which stimulates milk production.

The effect of oxytocin on the male body is not well understood. It is believed that it is able to influence the functioning of the walls of the intestines, gallbladder and bladder.

Vasopressin (ADH)

Vasopressin (also called ADH) performs two functions in the body. It has an antidiuretic effect, ie. enhances water reabsorption in the collecting ducts of the kidneys and, in addition, it affects the smooth muscles of arterioles (small blood vessels, extending from the arteries), i.e. able to narrow their gap. In physiological concentration, this action does not cause a significant effect on the body, but in pharmacological doses with the artificial introduction of ADH in its pure form, the arterioles are significantly narrowed, which causes an increase in pressure.

Thus, the hormones of the posterior pituitary gland, if not produced enough, can cause diabetes insipidus (antidiuretic effect), in which up to 15 liters of fluid can be lost per day (excreted with urine). This loss must be constantly replenished. People with diabetes insipidus are constantly thirsty.

Intermediate pituitary gland

The intermediate lobe also produces a number of hormones, such as melanostimulating hormone, which is responsible for skin and hair color. Under its influence, the pigment melanin is formed, which plays a significant role in the race of people.

Importance of pituitary hormones

The pituitary gland (hormones and its functions are described above) works together with the hypothalamus (diencephalon), more precisely, its neurosecretory nuclei. Together they form the hypothalamic-pituitary system. It controls the work of all peripheral endocrine glands. Pituitary dysfunction ( hormonal disorders) leads to serious consequences. Endocrinologists deal with such problems.

The pituitary gland and its functions in the body are very important. The proper functioning of all organs and systems depends on them.

Diseases and pathologies

When problems arise in such a small endocrine gland, like the pituitary gland, its hormones and functions do not work correctly, and serious pathologies can develop in the human body:

acromegaly;
gigantism;
diabetes insipidus;
pituitary hypothyroidism or hyperthyroidism;
pituitary hypogonadism;
hyperprolactinemia;
pituitary dwarfism;
Itsenko-Cushing's disease;
Sheehan syndrome.

Such diseases can be observed if one or several hormones are not synthesized by the pituitary gland, or, conversely, too many of them enter the bloodstream. The functions and hormones of the pituitary gland are important for the body. Their violations can cause a number of pathologies that require a serious approach and often require hormone therapy.

This article will reveal the question of what the pituitary gland of the brain is. The greatest role in the formation and formation is played by the neuroendocrine center of the brain - the pituitary gland. Thanks to developed structure and numerical connections, the pituitary gland, with its hormonal systems, has the strongest influence on human form. pituitary gland has messages with the adrenal and thyroid glands, affects the activity of female sex hormones, contacts with the hypothalamus, interacts directly with the kidneys.

Structure

The pituitary gland is part of the hypothalamic-pituitary system of the brain. This association is a decisive component in the activity of the human nervous and endocrine systems. In addition to anatomical proximity, the pituitary gland and the hypothalamus are tightly connected functionally. In hormonal regulation, there is a hierarchy of glands, where the main regulator of endocrine activity, the hypothalamus, is located at the height of the vertical. It secretes two types of hormones - liberins and statins(releasing factors). The first group increases the synthesis of pituitary hormones, and the second - inhibits. Thus, the hypothalamus completely controls the work of the pituitary gland. The latter, receiving a dose of liberins or statins, synthesizes necessary for the body substances or vice versa - suspends their production.

The pituitary gland is located on one of the structures of the base of the skull, namely the Turkish saddle. This is a small bone pocket located on the body of the sphenoid bone. In the center of this pocket is the pituitary fossa, protected behind by the back, in front by the tubercle of the saddle. At the bottom of the back of the saddle there are grooves containing internal carotid arteries, a branch of which - the lower pituitary artery - nourishes the lower cerebral appendage with substances.

Adenohypophysis

The pituitary gland is made up of three small parts: the adenohypophysis (anterior), the intermediate lobe, and the neurohypophysis ( rear end). The middle lobe is similar in origin to the anterior one and appears as a thin septum separating the two lobes of the pituitary gland. However, the specific endocrine activity of the layer forced experts to single it out as a separate part of the lower cerebral appendage.

The adenohypophysis is made up of separate types of endocrine cells, each of which releases its own hormone. In endocrinology, there is the concept of target organs - a set of organs that are targets for the directed activity of individual hormones. So, the anterior lobe produces tropic hormones, that is, those that affect the glands that are lower in the hierarchy vertical system endocrine activity. The secret secreted by the adenohypophysis initiates the work of a certain gland. Also, according to the principle of feedback, the anterior part of the pituitary gland, receiving with blood increased amount hormones of a certain gland, suspends its activity.

neurohypophysis

This section of the pituitary gland is located in its posterior part. Unlike the anterior part, the adenohypophysis, the neurohypophysis performs not only a secretory function, but also acts as a "container": nerve fibers Hormones from the hypothalamus descend to the neurohypophysis and are stored there. The posterior lobe of the pituitary gland consists of neuroglia and neurosecretory bodies. Hormones stored in the neurohypophysis affect water metabolism (water-salt balance) and partially regulate the tone of small arteries. In addition, the secret of the back of the pituitary gland is actively involved in the birth processes of women.

Intermediate share

This structure is represented by a thin ribbon with protrusions. Back and front middle department the pituitary gland is limited to thin balls of the connective layer containing small capillaries. The actual structure of the intermediate lobe consists of colloidal follicles. The secret of the middle part of the pituitary gland determines the color of a person, but is not decisive in the difference in skin color of different races.

Location and size

The pituitary gland is located at the base of the brain, namely on its lower surface in the fossa of the Turkish saddle, but is not part of the brain proper. The size of the pituitary gland is not the same for all people and its dimensions vary individually: the average length reaches 10 mm, height - up to 8-9 mm, width - no more than 5 mm. In size, the pituitary gland resembles an average pea. The mass of the lower appendage of the brain averages up to 0.5 g. During pregnancy and after it, the size of the pituitary gland undergoes changes: the gland increases and after childbirth does not return to the reverse size. These morphological changes are associated with vigorous activity pituitary during childbirth.

Functions of the pituitary gland

The pituitary gland has many important functions in human body. Pituitary hormones and their functions provide the most important single phenomenon in any living developed organism - homeostasis. Thanks to its systems, the pituitary gland regulates the work of the thyroid, parathyroid, adrenal glands, controls the state of the water-salt balance and the state of the arterioles by special interaction with internal systems and the external environment - feedback.

The anterior pituitary gland regulates the synthesis of the following hormones:

Corticotropin(ACTG). These hormones are stimulants of the adrenal cortex. First of all, adrenocorticotropic hormone affects the formation of cortisol, the main stress hormone. In addition, ACTH stimulates the synthesis of aldosterone and deoxycorticosterone. These hormones play an important role in the formation blood pressure due to the amount of circulating water in the bloodstream. Corticotropin also has little effect on the synthesis of catecholamines (epinephrine, norepinephrine and dopamine).

growth hormone(somatotropin, growth hormone) - a hormone that affects human growth. The hormone has such a specific structure, due to which it affects the growth of almost all types of cells in the body. The growth process of somatotropin is provided by protein anabolism and increased RNA synthesis. Also, this hormone takes part in the transport of substances. The most pronounced effect of growth hormone has on bone and cartilage tissue.

Thyrotropin(TTG, thyroid-stimulating hormone) has a direct relationship with the thyroid gland. This secret initiates metabolic reactions with the help of cellular messengers (in biochemistry - secondary intermediaries). Influencing the structures of the thyroid gland, TSH carries out all types of metabolism. Thyrotropin plays a special role in iodine metabolism. Main function- Synthesis of all thyroid hormones.

Gonadotropin(gonadotropin) carries out the synthesis of human sex hormones. In men, testosterone in the testicles, in women, the formation of ovulation. Also, gonadotropin stimulates spermatogenesis, plays the role of an amplifier in the formation of primary and secondary sexual characteristics.

Hormones of the neurohypophysis:

Vasopressin (antidiuretic hormone, ADH) regulates two phenomena in the body: control of water levels, due to its reabsorption in the distal nephron, and spasm of arterioles. However, the second function is carried out due to a large amount of secretion in the blood and is compensatory: with a large loss of water (bleeding, prolonged stay without fluid), vasopressin spasms the vessels, which in turn reduces their penetration, and less water enters the filtration departments of the kidneys. Antidiuretic hormone is very sensitive to the osmotic pressure of the blood, lowering blood pressure and fluctuations in the volume of cellular and extracellular fluid.
Oxytocin. Influences activity smooth muscle uterus.

In men and women, the same hormones can act differently, so the question of what the pituitary gland of the brain in women is responsible for is rational. Except listed hormones posterior lobe, the adenohypophysis secretes prolactin. The main target of this hormone is the mammary gland. In it, prolactin stimulates the formation of specific tissue and the synthesis of milk after childbirth. Also, the secret of the adenohypophysis affects the activation of the maternal instinct.

Oxytocin can also be called the female hormone. On the surfaces of the smooth muscles of the uterus are oxytocin receptors. Directly during pregnancy, this hormone has no effect, but it manifests itself during childbirth: estrogen increases the sensitivity of receptors to oxytocin, and those, acting on the muscles of the uterus, increase their contractile function. In after birth period Oxytocin is involved in the production of milk for the baby. However, it cannot be said with certainty that oxytocin is female hormone: his role in male body not studied enough.

The question of how the brain regulates the work of the pituitary gland, neurophysiologists have always paid special attention.

Firstly, direct and direct regulation of the activity of the pituitary gland is carried out by releasing hormones of the hypothalamus. It also takes place biological rhythms that affect the synthesis of certain hormones, in particular corticotropic hormone. AT in large numbers ACTH is secreted between 6-8 am, and its lowest amount in the blood is observed in the evening.

Secondly, feedback control. Feedback can be positive or negative. The essence of the first type of connection is to increase the production of pituitary hormones when its secretion in the blood is not enough. The second type, that is, the negative Feedback, consists in the opposite action - stopping hormonal activity. Monitoring of the activity of organs, the amount of secretion and condition internal systems It is carried out thanks to the blood supply of the pituitary gland: dozens of arteries and thousands of arterioles pierce the parenchyma of the secretory center.

Diseases and pathologies

Deviations of the pituitary gland of the brain are studied by several sciences: in theoretical aspect– neurophysiology (structural disturbance, experiments and research) and pathophysiology (especially about the course of pathology), in medical field- endocrinology. Clinical manifestations It is the clinical science of endocrinology that deals with the causes and treatment of diseases of the lower appendage of the brain.

Hypotrophy the pituitary gland of the brain or the syndrome of an empty Turkish saddle is a disease associated with a decrease in the volume of the pituitary gland and a decrease in its function. It is often congenital, but there is also an acquired syndrome due to any brain disease. Pathology is mainly manifested in complete or partial absence functions of the pituitary gland.

Dysfunction pituitary gland is a violation of the functional activity of the gland. However, the function can be disturbed in both directions: both to a greater extent (hyperfunction) and to a lesser extent (hypofunction). An excess of pituitary hormones includes hypothyroidism, dwarfism, diabetes insipidus, and hypopituitarism. To reverse side(hyperfunction) - hyperprolactinemia, gigantism and Itsenko-Cushing's disease.

Pituitary disease in women has a number of consequences that can be both severe and favorable in terms of prognosis:

Hyperprolactinemia is an excess of the hormone prolactin in the blood. The disease is characterized by defective milk production outside of pregnancy;
The inability to conceive a child;
Qualitative and quantitative pathologies of menstruation (the amount of blood released or cycle failure).

Diseases of the pituitary gland in women very often occur against the background of conditions associated with the female sex, that is, pregnancy. During this process, a serious hormonal changes organism, where part of the work of the lower appendage of the brain is aimed at the development of the fetus. The pituitary gland is a very sensitive structure, and its ability to withstand stress is largely determined by individual characteristics woman and her fetus.

Lymphocytic inflammation of the pituitary gland - autoimmune pathology. It appears in most cases in women. Symptoms of inflammation of the pituitary gland are nonspecific, and making this diagnosis is often difficult, but the disease still has its own manifestations:

spontaneous and inadequate jumps in health: good condition can change dramatically to the bad, and vice versa;
frequent unobvious headache;
manifestations of hypopituitarism, that is, partially the functions of the pituitary gland are temporarily reduced.

The pituitary gland is supplied with blood from many vessels suitable for it, so the causes of an increase in the pituitary gland of the brain can be varied. A change in the shape of the gland in a big direction can be caused:

infection: inflammatory processes cause tissue swelling;
birth processes in women;
benign and malignant tumors;
congenital parameters of the structure of the gland;
hemorrhages in the pituitary gland due to direct trauma (TBI).

Symptoms of diseases of the pituitary gland can be different:

delayed sexual development of children, lack of sexual desire (decrease in libido);
in children: delay mental development due to the inability of the pituitary gland to regulate the metabolism of iodine in the thyroid gland;
in patients with diabetes insipidus daily diuresis can be up to 20 liters of water per day - excessive urination;
excessive tall stature, huge facial features (acromegaly), thickening of the limbs, fingers, joints;
violation of the dynamics of blood pressure;
weight loss, obesity;
osteoporosis.

According to one of these symptoms, the inability to conclude a diagnosis of the pathology of the pituitary gland. To confirm this, you must full examination organism.

Adenoma

A pituitary adenoma is a benign formation that forms from the gland cells themselves. This pathology is very common: pituitary adenoma accounts for 10% of all brain tumors. One of common causes defective regulation of the pituitary gland by hypothalamic hormones. The disease is manifested by neurological, endocrinological symptoms. The essence of the disease lies in the excessive secretion hormonal substances tumor cells pituitary gland, which leads to the corresponding symptoms.

More information about the causes, course and symptoms of pathology can be found in the article pituitary adenoma.

Tumor in the pituitary gland

Any pathological neoplasm in the structures of the lower cerebral appendage is called a tumor in the pituitary gland. Defective tissues of the pituitary gland grossly affect the normal functioning of the body. Fortunately, based on histological structure and topographic location, pituitary tumors are not aggressive, and for the most part are benign.

You can learn more about the specifics of pathological neoplasms of the lower brain appendage from the article tumor in the pituitary gland.

pituitary cyst

Unlike a classic tumor, a cyst involves a neoplasm with liquid contents inside and a strong shell. The cause of the cyst is heredity, brain injury and various infections. A clear manifestation of the pathology is a constant headache and blurred vision.

You can learn more about how a pituitary cyst manifests itself by going to the pituitary cyst article.

Other diseases

Panhypopituitarism (Shien's syndrome) is a pathology characterized by a decrease in the function of all parts of the pituitary gland (adenohypophysis, middle lobe and neurohypophysis). Is very serious illness, which is accompanied by hypothyroidism, hypocorticism and hypogonadism. The course of the disease can lead the patient into a coma. The treatment is radical removal of the pituitary gland followed by lifelong hormonal therapy.

Diagnostics

People who have noticed symptoms of a pituitary gland disease in themselves are wondering: “how to check the pituitary gland of the brain?”. To do this, you need to go through several simple procedures:

donate blood;
pass the test;
external examination of the thyroid gland and ultrasound;
craniogram;

Perhaps one of the most informative methods studying the structure of the pituitary gland is magnetic resonance imaging. Read about what MRI is and how it can be used to examine the pituitary gland in this article MRI of the pituitary gland

Many people are interested in how to improve the performance of the pituitary and hypothalamus. However, the problem is that these are subcortical structures, and their regulation is carried out at the highest autonomous level. Despite changes in external environment and various options adaptation disorders, these two structures will always work normally. Their activities will be aimed at supporting stability internal environment organism, because the human genetic apparatus is programmed that way. Like instincts uncontrolled by human consciousness, the pituitary and hypothalamus will invariably obey their assigned tasks, which are aimed at ensuring the integrity and survival of the body.