Human endocrine system and hormones. Endocrine System: Facts, Functions and Diseases

Everyone knows that every person has an endocrine system. What it is? The endocrine system is a collection of some human (or animal) organs that produce the necessary hormones for the body. An important feature of the endocrine system is that it controls the work of almost all organs, supporting and adapting the human body to changing conditions.

The endocrine system (endocrine glands) performs the following functions:

• controls the work of all human organs and systems;
• adapts the human body to changing conditions;
• regulates the development, growth of the body;
• helps to save and properly use the energy of the body;
• provides the reproductive function of the body;
• helps to differentiate sex differences;
• supports the mental and emotional organization of a person.

human endocrine system

So what is the endocrine system? Biology, which deals with the structure and functioning of animal organisms, distinguishes the glandular and diffuse apparatus in the human endocrine system. The glandular apparatus produces peptide and steroid hormones, as well as thyroid hormones. Endocrine substances of the glandular apparatus are produced within one organ, being released into the lymph or blood.

Anatomical and physiological features of the endocrine system of the glandular apparatus are represented by the following organs:

• Hypothalamus and pituitary gland. These organs are located in the human cranial region and perform storage and control functions. In particular, the pituitary gland plays the role of the main controlling organ that regulates the work of all other organs of the endocrine system.
• Thyroid. Located in the front of the human neck, the thyroid gland is responsible for the production of iodine-containing hormones, which are necessary for the regulation of metabolism and body growth. The follicles that make up the gland contain the hormones thyroxine, triiodothyronine, and calcitonin.
• Parathyroid glands. This gland, located near the thyroid gland, performs the nervous and motor functions of the body by regulating the level of calcium in the body.
• Pancreas. Located in the abdominal cavity between the duodenum and the spleen, this gland produces pancreatic juice, as well as hormones such as glucagon, insulin, and ghrelin (hunger hormone).
• Adrenals. Located on top of the kidneys, these glands regulate the synthesis of carbohydrates, the breakdown of proteins, and also produce adrenaline.
• Gonads. These are the male testicles and female ovaries, which produce male (androgynous) and female (estrogen) hormones.
• epiphysis Located in the cranium, this organ produces melatonin (affects the sequence of sleep phases) and norepinephrine (affects blood circulation and the nervous system).
• thymus. Found between the lungs, this thymus produces hormones that regulate the development and maturation of immune system cells.

Thus, it is the main endocrine system. The anatomy of the diffuse endocrine system is scattered throughout the body, as its hormones are found in virtually every tissue in the body. The main organs that will be included in the list of diffuse endocrine apparatus should be considered the liver, kidneys, stomach, intestines and spleen.

Often, patients have a pathology of the endocrine system, which is expressed in hypofunction, dysfunction or hyperfunction of the endocrine glands. These pathologies can manifest themselves in the following diseases:

• diabetes and overweight (pancreatic disease);
• hypercalcemia, parathyroid osteodystrophy (parathyroid disease);
• diseases of the immune system (thymus gland disease);
• thyrotoxicosis, hypothyroidism, thyroid cancer, cretinism (thyroid disease);
• benign and malignant tumors (apudoma, gastrinoma, glucagonoma, somatostatinoma);
• hypertension, myocardial infarction, cardiovascular disease (adrenal disease);
• myoma, infertility, mastopathy, endometriosis, cystosis, ovarian cancer (gonadal disease).

Endocrine system of children and animals

The endocrine system in children determines growth and development, and is also involved in the neurohumoral regulation of the body. Physiologically, the endocrine system in children is represented by the same organs as in an adult, but with the difference that the functioning of the glands does not work at full capacity. So the system of the gonads up to a certain point releases only a small part of the hormones, and in adolescence, on the contrary, their production is explosive. Any deviations in the functioning of the organs of the endocrine system must be investigated and treated, since the consequences can be detrimental to the whole organism as a whole and affect later life.

The endocrine system of animals is represented by a different set of endocrine glands, depending on which class of the animal world they belong to. So in insects, the endocrine glands already control metabolism, as well as puberty, growth and behavior of the body. In vertebrates, endocrine organs are involved in ion balance, metabolism, immunity, and wound healing. An important role in the life of animals is played by sex hormones, which are aimed at the production of estrogen, progesterone and testosterone, which are responsible for the reproduction of offspring.

There are many organs and systems in our body, in fact it is a unique natural mechanism. To study the human body completely, you need a lot of time. But it's not that hard to get a general idea. Especially if it is necessary to understand any of your illnesses.

internal secretion

The word "endocrine" itself comes from the Greek phrase and means "to secrete inside." This system of the human body normally provides us with all the hormones that we may need.

Thanks to the endocrine system, many processes take place in our body:

• growth, all-round development:
• metabolism;
• power generation;
• coordinated work of all internal organs and systems;
• correction of some violations in the processes of the body;
• generation of emotions, behavior control.

The importance of hormones is enormous

Already at the moment when a tiny cell begins to develop under the heart of a woman - the unborn child - it is the hormones that regulate this process.

We literally need the formation of these compounds for everything. Even to fall in love.

What is the endocrine system made of?

The main organs of the endocrine system are:

• thyroid and thymus glands;
• epiphysis and pituitary gland;
• adrenal glands;
• pancreas;
• testicles in men or ovaries in women.

All these organs (glands) are united endocrine cells. But in our body, in almost all tissues, there are individual cells that also produce hormones.

To distinguish between united and scattered secretory cells, the overall human endocrine system is divided into:

• glandular (it includes endocrine glands)
• diffuse (in this case we are talking about individual cells).

What are the functions of the organs and cells of the endocrine system?

The answer to this question is in the table below:

1. It describes the "zone of responsibility" of the main endocrine glands, that is, glandular ES organs.
2. The organs of the diffuse endocrine system perform their own functions, and along the way, the endocrine cells in them are busy producing hormones. These organs include the stomach, spleen, intestines and. In all these organs, various hormones are formed that regulate the activity of the "owners" themselves and help them interact with the human body as a whole.

It is now known that our glands and individual cells produce about thirty different types of hormones. All of them are released into the blood in different quantities and at different intervals. In fact, it is only thanks to hormones that we live.

Endocrine system and diabetes

If the activity of any endocrine gland is disturbed, then various diseases occur.

All of them affect our health and life. In some cases, improper production of hormones literally changes the appearance of a person. For example, without growth hormone, a person looks like a dwarf, and a woman without the proper development of germ cells cannot become a mother.

The pancreas is designed to produce the hormone insulin. Without it, the breakdown of glucose in the body is impossible. In the first type of the disease, insulin production is too low, and this disrupts normal metabolic processes. The second type of diabetes means that the internal organs literally refuse to take insulin.

Violation of glucose metabolism in the body triggers many dangerous processes. Example:

1. The body does not break down glucose.
2. To search for energy, the brain gives a signal to break down fats.
3. During this process, not only the necessary glycogen is formed, but also special compounds - ketones.

The endocrine system is a collection of endocrine glands that produce and secrete hormones into the circulation, do not have excretory ducts, and secrete secretions to the corresponding organs. Hormones can act as chemical messengers for a huge number of cells and tissues at the same time, and also regulate almost every metabolic activity of the body.

The endocrine glands are richly vascularized and have a dense network of blood vessels. Cells within these organs contain hormones in intracellular granules or vesicles that fuse with the plasma membrane in response to an appropriate signal and release hormones into the extracellular space.

The endocrine system, along with the nervous system, integrates signals from the internal and external environment. In addition, it produces effector molecules in the form of hormones that can cause the body to respond appropriately to maintain homeostasis. While the central nervous system reacts instantly to stimuli, the endocrine reaction is slow, but differs in the duration of action. For example, the long-term secretion of growth hormone in the body affects the development of bones, which contributes to the growth of the entire body, as well as an increase in the size of each internal organ. As another example, cortisol released during times of stress can affect appetite and metabolic processes in skeletal and smooth muscle for hours or weeks.

The endocrine system is involved in all processes occurring in the human body. Hormones can affect individual organs in many ways, from the motor activity of the digestive tract to the absorption and processing of glucose and other substances. Some affect the retention of calcium in the bones or the maintenance of muscle contraction. In addition, hormones are involved in the development and formation of adaptive immune and reproductive functions of the body. They affect overall growth and metabolism by changing the way each cell absorbs and uses essential nutrients.

Organs of the endocrine system

The endocrine system includes the pituitary and pineal glands located in the brain, the thyroid and parathyroid glands in the neck, the thymus in the thoracic region, the adrenals and pancreas in the abdominal cavity, and the gonads in the reproductive system.

Starting in the brain, the hypothalamus, pituitary and pineal glands are involved in the regulation of other endocrine organs and circadian rhythms, changing the metabolic state of the body. The pineal gland is located in the center of the brain, in an area called the epithalamus. The pituitary gland is located very close to the hypothalamus, with which direct contact is established and there are feedback loops for the production of hormones. Together, the hypothalamus and pituitary gland can regulate the work of a number of organs of the endocrine system, primarily the gonads and adrenal glands. In fact, the hypothalamus is the central link that combines two main pathways of regulation - the nervous and endocrine systems. The hypothalamus consists of groups of neurons, nerve cells that collect information from the entire body and integrate impulses into the anterior and posterior pituitary glands.

The thyroid and parathyroid glands are located in the neck. The thyroid gland consists of two symmetrical lobes connected by a narrow piece of tissue called the isthmus. Its shape is reminiscent of a butterfly. The length of each lobe is 5 cm, and the isthmus is 1.25 cm. The gland is located on the front surface of the neck behind the thyroid cartilage. Each of its lobe is usually located in front of the parathyroid glands. The parathyroid glands are approximately 6x3x1 mm in size and weigh between 30 and 35 grams, and their number varies, as some people may have more than two pairs.

The thymus or thymus gland is a pinkish-gray organ of the endocrine system, located in the sternum between the lungs and consisting of two lobes. The thymus plays an important role in the functioning of the immune system, being responsible for the production and maturation of lymphocytes (T-cells). This organ is unusual in that the peak of its activity falls on childhood. After puberty, the thymus slowly shrinks and is replaced by adipose tissue. Before puberty, the weight of the thymus is approximately 30 grams.

The adrenal glands are located above the top of the kidneys. They are yellowish in color, surrounded by a fatty layer, located under the diaphragm itself and connected with it by connective tissue. The adrenal glands consist of medulla and cortex, having external and internal secretion.

The pancreas is an organ that performs the functions of both the digestive system and the endocrine system. The glandular organ is located close to the C-bend of the duodenum behind the stomach. It consists of cells that perform both exocrine functions, producing digestive enzymes, and endocrine cells in the islets of Langerhans, producing insulin and glucagon. Hormones are involved in metabolism and maintain blood glucose levels and thus two different functions of the organ are integrated at a certain level.

Gonads (male and female gonads) perform important functions in the body. They affect the proper development of the reproductive organs during puberty, and also maintain fertility. Organs such as the heart, kidneys, and liver function as organs of the endocrine system, secreting the hormone erythropoietin, which affects the production of red blood cells.

Diseases of the endocrine system

Diseases of the endocrine system mainly occur for two reasons: a change in the level of a hormone secreted by the gland, or a change in the sensitivity of receptors in the cells of the body. For these reasons, the body does not respond appropriately to overall homeostasis. The most common disease is diabetes, which interferes with glucose metabolism. Diabetes mellitus has a huge impact on a person's quality of life, as adequate glucose levels are not only important for keeping the body functioning, but can also prevent the growth of microorganisms or cancer cells.

Imbalances in reproductive hormones are also significant, as they can affect fertility, mood, and a person's general well-being. The thyroid gland is an important component of the endocrine system with high and low levels of secretion, affecting the body's ability to function optimally. Thyroid hormone production depends on the essential micronutrient, iodine. A deficiency in this element can lead to an enlarged thyroid gland as the body attempts to compensate for low hormone levels.

Diabetes

Diabetes is a metabolic disease in which the level of glucose in the blood is higher than normal. Diabetes is caused by a deficiency of the hormone insulin, which is produced by the beta cells of the islets of Langerhans in the pancreas. The development of the disease is associated with insufficient synthesis of insulin or with a decrease in the sensitivity of body cell receptors to it.

Insulin is an anabolic hormone that stimulates the transport of glucose into muscle cells or adipose tissue, where it is stored as glycogen or converted into fat. Insulin inhibits the process of glucose synthesis in cells, interrupting gluconeogenesis and the breakdown of glycogen. Insulin is usually released when there is a spike in blood sugar after a meal. Insulin secretion protects cells from long-term damaging excess glucose, allowing for the storage and use of nutrients. Glucagon is a pancreatic hormone secreted by alpha cells, unlike insulin, it is released when blood sugar levels drop. How to prevent diabetes

Hypothyroidism

Hypothyroidism is a condition that occurs due to a lack of thyroid hormones, thyroxine (T4) and triiodothyronine (T3). The composition of these hormones includes iodine, and they are derived from one amino acid - tyrosine. Iodine deficiency is the main cause of hypothyroidism, since the gland cannot synthesize enough of the hormone.

The cause of the development of the disease may be damage to the thyroid gland due to infection or inflammation. The disease also occurs due to a deficiency of the pituitary hormone that stimulates the thyroid gland and disturbances in the functioning of hormone receptors.

Hypogonadism is a disease in which there is a decrease in the level of sex hormones. Gonads (testicles and ovaries) secrete hormones that affect the development, maturation and functioning of the genital organs, as well as the appearance of secondary sexual characteristics. Hypogonadism can be primary or secondary. Primary occurs due to the fact that the gonads produce a low level of sex hormones. The reason for the development of secondary hypogonadism may be the insensitivity of organs to signals for the production of hormones coming from the brain. Depending on the period of occurrence, hypogonadism can have various symptoms.

Female genital organs or external genital organs of an intermediate type can form in boys with embryonic hypogonadism. During puberty, the disease affects the establishment of the menstrual cycle, the development of the mammary glands and ovulation in women, the growth of the penis and testicular enlargement in boys, the development of secondary sexual characteristics, and changes in body structure. In adulthood, the disease leads to a decrease in sexual desire, infertility, chronic fatigue syndrome, or even loss of muscle and bone mass.

Hypogonadism can be diagnosed by taking a blood test. To treat the disease, long-term hormone replacement therapy will be required.

Endocrine system human is a collection of special organs (glands) and tissues located in different parts of the body.

glands produce biologically active substances - hormones(from the Greek hormáo - set in motion, encourage), which act as chemical agents.

Hormones are released into the intercellular space, where it is picked up by the blood and transferred to other parts of the body.

Hormones affect the activity of organs, changing physiological and biochemical reactions by activating or inhibiting enzymatic processes (processes of accelerating biochemical reactions and regulating metabolism).

That is, hormones have a specific effect on target organs, which, as a rule, other substances are not able to reproduce.

Hormones are involved in all processes of growth, development, reproduction and metabolism

Chemically, hormones are a heterogeneous group; the variety of substances presented by them includes

Glands that produce hormones are called endocrine glands, endocrine glands.

They secrete the products of their vital activity - hormones - directly into the blood or lymph (pituitary gland, adrenal glands, etc.).

There are also glands of another kind - exocrine glands(exocrine).

They do not release their products into the bloodstream, but release secretions onto the surface of the body, mucous membranes, or into the external environment.

it sweat, salivary, lacrimal, dairy glands and others.

The activity of the glands is regulated by the nervous system, as well as by humoral factors (factors from the liquid medium of the body).

The biological role of the endocrine system is closely related to the role of the nervous system.

These two systems mutually coordinate the function of others (often separated by a considerable distance of organs and organ systems).

The main endocrine glands are the hypothalamus, pituitary gland, thyroid gland, parathyroid glands, pancreas, adrenal glands and gonads.

The central link of the endocrine system is the hypothalamus and pituitary gland

Hypothalamus- This is an organ of the brain, which, like a control room, gives orders for the production and distribution of hormones in the right amount and at the right time.

Pituitary- a gland located at the base of the skull, which secretes a large amount of trophic hormones - those that stimulate the secretion of other endocrine glands.

The pituitary and hypothalamus are securely protected by the skeleton of the skull and made by nature in a unique for each organism, a single copy.

Human endocrine system: endocrine glands

Peripheral link of the endocrine system - thyroid gland, pancreas, adrenal glands, gonads

Thyroid- secretes three hormones; located under the skin in the anterior surface of the neck, and protected from the upper respiratory tract halves of the thyroid cartilage.

Adjacent to it are four small parathyroid glands involved in calcium metabolism.

Pancreas This organ is both exocrine and endocrine.

As an endocrine hormone, it produces two hormones - insulin and glucagon, which regulate carbohydrate metabolism.

The pancreas produces and supplies the digestive tract with enzymes to break down food proteins, fats and carbohydrates.

Adrenal glands border the kidneys, uniting the activity of two types of glands.

adrenal glands- are two small glands, located one above each kidney and consisting of two independent parts - the cortex and the medulla.

gonads(ovaries in women and testicles in men) - produce germ cells and other major hormones involved in reproductive function.

As we already know all endocrine glands and individual specialized cells synthesize and secrete hormones into the blood.

The exceptional power of the regulating effect of hormones on all body functions

Them signal molecule causes a variety of changes in metabolism:

They determine the rhythm of the processes of synthesis and decay, implement a whole system of measures to maintain water and electrolyte balance - in a word, create an individual optimal internal microclimate, characterized by stability and constancy, due to its exceptional flexibility, ability to respond quickly and specificity of regulatory mechanisms and systems controlled by them.

The loss of each of the components of hormonal regulation from the general system disrupts the single chain of regulation of body functions and leads to the development of various pathological conditions.

The demand for hormones is determined by the local conditions that arise in the tissues or organ most dependent on a particular chemical legislator.

If we imagine that we are in a mode of increased emotional stress, then metabolic processes are intensified.

It is necessary to provide the body with additional means to overcome the problems that have arisen.

Glucose and fatty acids, easily disintegrating, can provide the brain, heart and tissues of other organs with energy.

They do not need to be urgently administered with food, since there are reserves of glucose polymer in the liver and muscles - glycogen, animal starch, and adipose tissue reliably provides us with reserve fat.

This metabolic reserve is renewed, maintained in good condition by enzymes that use them when necessary and are replenished in a timely manner at the first opportunity, when the slightest excess appears.

Enzymes capable of breaking down the products of our reserves consume them only on command brought to the tissues by hormones.

Dietary supplements regulating the work of the endocrine system

The body produces many hormones

They have a different structure, they have a different mechanism of action, they alter the activity of existing enzymes and regulate the process of their biosynthesis anew, causing the growth, development of the body, the optimal level of metabolism.

A variety of intracellular services are concentrated in the cell - systems for processing nutrients, converting them into elementary simple chemical compounds that can be used at the discretion on the spot (for example, to maintain a certain temperature regime).

Our body lives at the optimal temperature regime for it - 36-37 ° C.

Normally, there are no sudden temperature changes in the tissues.

Sudden change in temperature for an organism not prepared for this - devastating destruction factor, contributing to a gross violation of the integrity of the cell, its intracellular formations.

The cell has power stations whose activities are mainly focused on energy storage.

They are represented by complex membrane formations - mitochondria.

Specificity of activity mitochondria consists in the oxidation, splitting of organic compounds, nutrients formed from proteins (carbohydrates and fats of food), but as a result of previous metabolic transformations that have already lost the signs of biopolymer molecules.

Decay in mitochondria is associated with the most important process for life.

There is a further disaggregation of molecules and the formation of an absolutely identical product, regardless of the primary source.

This is our fuel, which the body uses very carefully, in stages.

This allows not only to receive energy in the form of heat, which ensures the comfort of our existence, but also mainly to accumulate it in the form of the universal energy currency of living organisms - ATP ( adenosine triphosphate).

The high resolution of electron microscope devices made it possible to recognize the structure of mitochondria.

Fundamental research by Soviet and foreign scientists contributed to the knowledge of the mechanism of a unique process - energy accumulation, which is a manifestation of the function of the inner membrane of mitochondria.

At present, an independent branch of knowledge about the energy supply of living beings has been formed - bioenergetics, which studies the fate of energy in the cell, the ways and mechanisms of its accumulation and use.

In mitochondria, the biochemical processes of transformation of molecular material have a certain topography (location in the body).

Enzymatic systems for the oxidation of fatty acids, amino acids, as well as a complex of biocatalysts that form a single cycle for the decomposition of carboxylic acids as a result of previous reactions of the decomposition of carbohydrates, fats, proteins that have lost their resemblance to them, impersonal, unified up to a dozen of the same type of products, located in the mitochondrial matrix- make up the so-called citric acid cycle, or Krebs cycle.

The activity of these enzymes allows you to accumulate in the matrix a powerful force of energy resources.

Thereby mitochondria figuratively called cell powerhouses.

They can be used for processes of reductive synthesis, and also form a combustible material from which a set of enzymes, mounted asymmetrically across the inner membrane of mitochondria, extracts energy for the life of the cell.

Oxygen serves as an oxidizing agent in exchange reactions.

In nature, the interaction of hydrogen and oxygen is accompanied by an avalanche-like release of energy in the form of heat.

When considering the functions of any cell organelles ("organs" of protozoa), it becomes obvious how their activity and the mode of operation of the cell depend on the state of the membranes, their permeability, and the specifics of the set of enzymes that form them and serve as the building material of these formations.

An analogy is valid between texts - a set of letters that form words that form phrases, and a way to encrypt information in our body.

This refers to the sequence of alternation of nucleotides (an integral part of nucleic acids and other biologically active compounds) in a DNA molecule - a genetic code in which, as in an ancient manuscript, the necessary information about the reproduction of proteins inherent in a given organism is concentrated.

An example of encoding information in the language of organic molecules is the presence of a receptor recognized by a hormone, recognizing it among the mass of various compounds that collide with the cell.

When a compound rushes into a cell, it cannot spontaneously penetrate into it.

The biological membrane serves as a barrier.

However, a specific carrier is prudently built into it, which delivers the candidate for intracellular localization to its destination.

Is it possible for an organism to have a different "interpretation" of its molecular designations - "texts"? It is quite obvious that this is the real way to the disorganization of all processes in cells, tissues, organs.

"Foreign Diplomatic Service" allows the cell to navigate the events of extracellular life at the organ level, to constantly be aware of current events throughout the body, following the instructions of the nervous system with the help of hormonal control, receiving fuel and energy and building material.

In addition, inside the cell, its own molecular life is constantly and harmoniously going on.

Cellular memory is stored in the cell nucleus - nucleic acids, in the structure of which the program for the formation (biosynthesis) of a diverse set of proteins is encoded.

They perform a building and structural function, are biocatalysts-enzymes, can carry out the transport of certain compounds, play the role of defenders from foreign agents (microbes and viruses).

The program is contained in the nuclear material, and the work of building these large biopolymers is carried out by a whole conveyor system.

In a genetically strictly defined sequence, amino acids, building blocks of a protein molecule, are selected and fastened into a single chain.

This chain can have thousands of amino acid residues.

But in the microcosm of the cell it would be impossible to place all the necessary material if it were not for its extremely compact packaging in space.

Almost every tissue in the body contains endocrine cells.

Encyclopedic YouTube

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Subtitles

I'm at Stanford Medical School with Neil Gesundheit, one of the faculty. Hello. What do we have today? Today we will talk about endocrinology, the science of hormones. The word "hormone" comes from the Greek word meaning "stimulus". Hormones are chemical signals that are produced in certain organs and act on other organs, stimulating and controlling their activity. That is, they communicate between organs. Yes exactly. These are means of communication. Here's the right word. This is one of the types of communication in the body. For example, nerves lead to muscles. To contract a muscle, the brain sends a signal along the nerve that goes to the muscle, and it contracts. And hormones are more like Wi-Fi. No wires. Hormones are produced and carried by the bloodstream like radio waves. In this way, they act on widely located organs, without having a direct physical connection with them. Are hormones proteins or something else? What are these substances anyway? According to their chemical nature, they can be divided into two types. These are small molecules, usually derivatives of amino acids. Their molecular weight ranges from 300 to 500 daltons. And there are large proteins with hundreds of amino acids. It's clear. That is, these are any signal molecules. Yes, they are all hormones. And they can be divided into three categories. There are endocrine hormones that are released into the bloodstream and work remotely. I'll give examples in just a minute. There are also paracrine hormones that have a local effect. They act at a short distance from the place where they were synthesized. And hormones of the third, rare category - autocrine hormones. They are produced by a cell and act on the same cell or a neighboring one, that is, at a very short distance. It's clear. I would like to ask. About endocrine hormones. I know they are released somewhere in the body and bind to receptors, then they act. Paracrine hormones have a local effect. Is the action weaker? Usually, paracrine hormones enter the bloodstream, but their receptors are located very close. This arrangement of receptors determines the local nature of the action of paracrine hormones. It's the same with autocrine hormones: their receptors are located right on this cell. I have a stupid question: there are endocrinologists, but where are the paracrinologists? Good question, but they don't. Paracrine regulation was discovered later and studied within the framework of endocrinology. It's clear. Endocrinology studies all hormones, not just endocrine ones. Exactly. Well said. This figure shows the main endocrine glands, which we will talk about a lot. The first is in the head, or rather in the region of the base of the brain. This is the pituitary gland. Here he is. This is the main endocrine gland that controls the activity of other glands. For example, one of the pituitary hormones is thyroid-stimulating hormone, TSH. It is secreted by the pituitary gland into the bloodstream and acts on the thyroid gland, where there are many receptors for it, forcing the production of thyroid hormones: thyroxine (T4) and triiodothyronine (T3). These are the main thyroid hormones. What are they doing? Regulate metabolism, appetite, heat production, even muscle function. They have many different effects. Do they stimulate the overall metabolism? Exactly. These hormones speed up the metabolism. High heart rate, fast metabolism, weight loss are signs of excess of these hormones. And if there are few of them, then the picture will be completely opposite. This is a good example of the fact that hormones should be exactly as much as needed. But back to the pituitary gland. He is in charge, sending orders to everyone. Exactly. He has feedback to stop the production of TSH in time. Like a device, it monitors the level of hormones. When there are enough of them, it reduces the production of TSH. If there are few of them, it increases the production of TSH, stimulating the thyroid gland. Interesting. What else? Well, signals to the rest of the glands. In addition to thyroid-stimulating hormone, the pituitary secretes adrenocorticotropic hormone, ACTH, affecting the adrenal cortex. The adrenal gland is located at the pole of the kidney. The outer layer of the adrenal gland is the cortex, which is stimulated by ACTH. It does not apply to the kidney, they are located separately. Yes. They are related to the kidney only by a very rich blood supply due to their proximity. Well, the kidney gave the gland its name. Well, it's obvious. Yes. But the functions of the kidney and adrenal gland are different. It's clear. What is their function? They produce hormones such as cortisol, which regulate glucose metabolism, blood pressure and well-being. As well as mineralocorticoids, such as aldosterone, which regulates the water-salt balance. In addition, it releases important androgens. These are the three main hormones of the adrenal cortex. ACTH controls the production of cortisol and androgens. Let's talk about mineralocorticoids separately. What about the rest of the glands? Yes Yes. The pituitary gland also secretes luteinizing hormone and follicle-stimulating hormone, abbreviated as LH and FSH. Gotta write it down. They affect the testicles in men and the ovaries in women, respectively, stimulating the production of germ cells, as well as the production of steroid hormones: testosterone in men and estradiol in women. Is there anything else? There are two more hormones from the anterior pituitary gland. It is a growth hormone that controls the growth of long bones. The pituitary gland is very important. Yes very. Is STG abbreviated? Yes. Somatotropic hormone, aka growth hormone. And then there is prolactin, necessary for breastfeeding a newborn baby. What about insulin? A hormone, but not from the pituitary gland, but at a lower level. Like the thyroid gland, the pancreas secretes its own hormones. In the tissue of the gland there are islets of Langerhans, which produce endocrine hormones: insulin and glucagon. Without insulin, diabetes develops. Without insulin, tissues cannot take up glucose from the bloodstream. In the absence of insulin, symptoms of diabetes occur. In the figure, the pancreas and adrenal glands are located close to each other. Why? Tooting. There is a good venous outflow, which allows vital hormones to enter the blood faster. Interesting. I think that's enough for now. In the next video, we will continue this topic. OK. And we will talk about the regulation of hormone levels and pathologies. Good. Thanks a lot. And thank you.

Functions of the endocrine system

• It takes part in the humoral (chemical) regulation of body functions and coordinates the activity of all organs and systems.
• It ensures the preservation of the body's homeostasis under changing environmental conditions.
• Together with the nervous and immune systems, it regulates:
  • growth;
  • body development;
  • its sexual differentiation and reproductive function;
  • takes part in the processes of formation, use and conservation of energy.
• Together with the nervous system, hormones are involved in providing:
  • emotional reactions;
  • mental activity of a person.

glandular endocrine system

In the hypothalamus, the hypothalamic proper (vasopressin or antidiuretic hormone, oxytocin, neurotensin) and biologically active substances that inhibit or enhance the secretory function of the pituitary gland (somatostatin, thyroliberin or thyrotropin-releasing hormone, luliberin or gonadoliberin or gonadotropin-releasing hormone, corticoliberin or corticotropin-releasing hormone) are secreted. hormone and somatoliberin or somatotropin-releasing hormone). One of the most important glands of the body is the pituitary gland, which controls the work of most endocrine glands. The pituitary gland is small, weighing less than one gram, but very important for the life of iron. It is located in a depression at the base of the skull, connected to the hypothalamic region of the brain by a leg and consists of three lobes - anterior (glandular, or adenohypophysis), middle or intermediate (it is less developed than others) and posterior (neurohypophysis). In terms of the importance of the functions performed in the body, the pituitary gland can be compared with the role of the conductor of an orchestra, which shows when this or that instrument should come into play. Hypothalamic hormones (vasopressin, oxytocin, neurotensin) flow down the pituitary stalk into the posterior lobe of the pituitary gland, where they are deposited and from where, if necessary, are released into the bloodstream. The hypophysiotropic hormones of the hypothalamus, being released into the portal system of the pituitary gland, reach the cells of the anterior pituitary gland, directly affecting their secretory activity, inhibiting or stimulating the secretion of tropic pituitary hormones, which, in turn, stimulate the work of the peripheral endocrine glands.

• VIPoma;
• Carcinoid;
• Neurotensin;

Vipom's syndrome

Main article: VIPoma

VIPoma (Werner-Morrison syndrome, pancreatic cholera, watery diarrhea-hypokalemia-achlorhydria syndrome) is characterized by the presence of watery diarrhea and hypokalemia as a result of islet cell hyperplasia or a tumor, often malignant, originating from pancreatic islet cells (usually the body and tail), which secrete a vasoactive intestinal polypeptide (VIP). In rare cases, VIPoma can occur in ganglioneuroblastomas, which are localized in the retroperitoneal space, lungs, liver, small intestine and adrenal glands, occur in childhood and are usually benign. The size of pancreatic VIPomas is 1...6 cm. In 60% of cases of malignant neoplasms, there are metastases at the time of diagnosis. The incidence of VIPoma is very low (1 case per year per 10 million people) or 2% of all endocrine tumors of the gastrointestinal tract. In half of the cases, the tumor is malignant. The prognosis is often unfavorable.

gastrinoma

Glucagonoma

Glucagonoma is a tumor, often malignant, originating from the alpha cells of the pancreatic islets. It is characterized by migratory erosive dermatosis, angular apapacheilitis, stomatitis, glossitis, hyperglycemia, normochromic anemia. It grows slowly, metastasizes to the liver. It occurs in 1 case in 20 million between the ages of 48 and 70, more often in women.

Carcinoid is a malignant tumor usually originating in the gastrointestinal tract that produces several hormone-like substances

Neurotensinoma

PPoma

Distinguish:

• somatostatin from the delta cells of the pancreas and
• apudoma secreting somatostatin - duodenal tumor.

The diagnosis is based on the clinic and an increase in the level of somatostatin in the blood. Treatment is surgical, chemotherapy and symptomatic. The prognosis depends on the timeliness of treatment.