A hormone is a biologically active substance produced by the human endocrine system , which includes the pituitary, thyroid, adrenal glands and a number of special cells. Hormones regulate all physiological processes in the body, while not directly contacting the cells, but working with them through special receptors tuned to the corresponding hormone. What organs are involved in hormonal regulation, and how it affects the body - this is the main question.
Classification by origin
The mechanism of hormonal regulation includes a variety of functions. This is possible due to the fact that hormones are composed of a variety of substances. They can be conditionally divided into several groups according to their composition:
- Hormones, consisting mainly of protein, are called polypoids and are produced mainly in the hypothalamus, pituitary and thyroid glands. Also, this type of hormone is produced in the pancreas.
- Another group of hormones is mainly composed of amino acids. This type of trace elements is produced in the adrenal glands and the thyroid gland, that part of it, which is called iodine-containing.
- Steroid type of hormones. It is produced by the human reproductive system - in the female body by the ovaries, and in the male - by the testes. Also, a small proportion of steroid hormones are produced in the adrenal cortex.
Function Classification
These trace elements are involved in the hormonal regulation of various processes in the body. For example, lipid, carbohydrate and amino acid metabolism is regulated by insulin, glucagon, adrenaline, cortisol, thyroxine and growth hormone.
The exchange of salt and water in the human body is supported by aldosterone and vasopressin.
Calcium and phosphates are absorbed by the body's cells with the help of parathyroid hormone, calcitonin and calcitriol. In the reproductive system, hormones such as estrogen, androgen, and gonadotropic hormones work.
There are trace elements that regulate the production of other hormones - these are the tropic hormones of the pituitary gland, liberin and statin in the hypothalamus. But hormonal regulation involves the use of the same trace elements in various processes, for example, testosterone regulates the functioning of the reproductive system in the body of a man, while he is also responsible for the growth of bones and muscle mass. And without adrenaline, the cardiovascular system and the regulation of the quality of carbohydrate and lipid absorption by the body are impossible.
The mechanism of action of hormones on the body
The mechanism of hormonal regulation involves several types of effects of the hormone on the cell. The first method is the effect on the activity of enzymes in the cell through the membrane receptor. At the same time, the hormone itself does not penetrate into the cell, but acts on it through special intermediaries - receptors. This type of effect includes peptides, protein hormones and adrenaline.
In the second method of exposure, hormones pass through the membrane into the cell and directly affect their respective receptors. These are steroids and thyroid hormones.
In the third group of hormones are insulin and thyroid hormones, they act on the membrane receptors, taking advantage of the change in ions in the membrane channels.
What is the uniqueness of hormonal effects?
Hormonal regulation is unique in that it is carried out almost instantly and at the same time uses a very small amount of active substance. The level of hormones in the blood is determined by micromoles.
Another feature is the distance: the homon can be produced only in one gland, while falling into the organ of influence located in another part of the body.
And the last, very rare and convenient function of hormonal regulation is the rapid inhibition of the process. The body does not wait until the active element removes the natural metabolism from the body; it produces a hormone inactivator. He ceases the action of the active hormone almost instantly.
What is a receptor and signal transmission through a membrane?
Hormonal regulation of metabolism is carried out by the action of hormones on receptors sensitive to them, located inside the cells or on their surface - on the membrane. A receptor sensitive to a specific hormone makes the target cell a target.
The receptor in its structure is similar to the hormone of action, and it consists of complex proteins of glycoproteins. This element, as a rule, consists of 3 domains. The first is the hormone recognition domain. The second is the domain that passes through the membrane. And the third creates a connection with the hormone with cellular substances.
The hormonal regulation system is divided into several stages:
- The connection of the receptor with the corresponding hormone.
- The receptor-hormone bond reacts with the G-protein, changing its structure.
- The resulting protein binding of the hormone receptor induces an adenylate cyclase reaction in the cell.
- In the next step, adenylate cyclase causes a protein kinase reaction, which accordingly leads to the activation of protein enzymes.
This hormonal regulation of functions is called the adenylate cyclase system.
There is another system - guanylate cyclase. According to the principle of regulation of the hormonal cycle, it is similar to the adenylate cyclase system, but when it works, the signal from the sequence of exposure to proteins in the cell can be amplified tens of times. There are still similar signaling methods - Ca 2+ messenger system and inositol triphosphate system. Each individual type of protein has its own system.
Intracellular receptors
There are a number of hormones, most of them steroids, which can act on the target cell, coming into contact with receptors located in the cytoplasm, that is, inside the cell. In this case, the hormone immediately penetrates the cell nucleus and, having entered into a relationship with the prescription, triggers the mechanism of action on the DNA enhancer or silencer. This ultimately leads to a change in the amount of proteins and enzymes that affect the metabolism inside the cell and change its state.
Hormones of the central nervous system
It is known that part of the hormones is produced by the central normal system, namely the hypothalamus - these are tropic hormones. Hormonal regulation accumulates them in the anterior and posterior parts of the hypothalamus, from where they enter the thyroid gland with blood flow.
Hormones such as thyrotropin, corticotropin, growth hormone, lutropin, prolactin and several others have a very wide range of effects on the human body. At the same time, hormones that inhibit their action are produced in the thyroid gland in response to a nervous reaction by the periphery of organs. But even if this did not happen, this type of hormone has the shortest period of life - no more than 4 minutes.
Thyroid Homons
Hormonal regulation of the body is not complete without the thyroid gland. It produces hormones that are responsible for the absorption of oxygen by the cells of the body, synthesize a number of proteins, secrete cholesterol and bile, and also break down fatty acids and fats themselves. These are triiodothyronine and tetraiodothyronine.
With an increase in the level of these hormones in the blood, the breakdown of proteins, fats and carbohydrates is accelerated, the heart rate is accelerated, the work of the entire nervous system is loosened, and goiter formation is possible.
With a low production of triiodothyronine and tetraiodothyronine in the body, failures of a different nature occur - the person's face takes a rounded shape, the mental and physical development of the child is delayed, the metabolism slows down.
Algorithm for the regulation of hormones by the central nervous system
All functions in the body are controlled by the human brain. Moreover, this always happens unconsciously, that is, without the participation of the personal "I" of a person.
Even hormonal regulation of glucose or other substances in the blood of a person is a signal that passes from an external stimulus or internal organ to the central nervous system.
When a signal is received, the hypothalamus, located in the diencephalon, enters the process. The hormones produced by him enter the pituitary gland, where the pituitary hormones, i.e. tropic hormones, are already synthesized. From the anterior lobe in the pituitary gland, the thyroid hormone enters the thyroid gland or other organs of the endocrine system. There they start the synthesis of hormones appropriate to the situation.
This chain of hormonal regulation levels can be considered using adrenaline as an example.
With a strong fright, that is, exposure from the outside, the whole chain instantly begins to work, the hypothalamus - the pituitary gland - the adrenal glands - the muscles. Once in the blood, adrenaline causes an increased contraction of the heart muscle, which means increased blood flow to the muscles. This makes them stronger and more durable. This explains the fact that a person against a background of severe fright can run a distance faster than a trained athlete or overcome a rather high obstacle with one jump.
What affects the amount of hormones in the blood?
Hormones in the blood are constantly present, but at some periods there are fewer, and at some times more. It depends on many factors. For example, chronic nervous tension, stress, fatigue, lack of sleep. Also affects the level of hormones, the quality and quantity of food eaten, alcohol consumed or cigarettes smoked. It is known that in the daytime the level of hormones is the lowest in comparison with the night. Especially its peak is reached in the early morning. By the way, that’s why men have a morning erection, and that’s why all tests for the level of a hormone are taken in the morning and on an empty stomach.
In the case of female hormones, their blood level is affected by the day of the menstrual cycle.
Types of hormones by their effects on the body
Hormones and hormonal regulation depend on the type of trace element. After all, there are hormones whose life lasts less than 4 minutes, and there are those that affect the body for 30 minutes and even several hours. Then a new stimulation is needed to produce them.
- Anabolic hormones. These are trace elements that allow the body to receive and accumulate energy in cells. They are produced by the pituitary gland, and they are represented by follitropin, lutropin, androgens, estrogens, somatotropin and chorionic gonadotropin of the placenta.
- Insulin. This hormone is produced by the beta cells of the pancreas. Insulin controls the absorption of glucose by the body’s cells. In case of disruption of the work of this body and the cessation of insulin production, a person develops diabetes. The disease is incurable, and if untreated, even fatal. Fortunately, it is easily diagnosed by primary symptoms and an elementary blood test. So if a person began to drink a lot, he was constantly tormented by thirst, and urination became multiple, then, most likely, his blood sugar level was impaired, which means there is diabetes. Insulin-dependent diabetes is most often a congenital pathology, and type 2 diabetes, respectively, is an acquired disease. Treatment includes insulin injections and a strict diet.
- Catabolic hormones are represented by corticotropin, cortisol, glucagon, thyroxine and adrenaline. These microelements participate and control the breakdown of fats, amino acids and carbohydrates that enter the body with food, and the production of energy from them.
- Thyroxine. This hormone is produced in the thyroid gland - in that part of it that synthesizes iodine cells. The hormone controls the production of a variety of hormones, mainly sex, and regulate the growth of tissues in the body.
- The glucagon polypeptide stimulates the decomposition of glycogen, which increases blood sugar.
- Corticosteroid. This type of hormone is produced mainly in the adrenal glands and is presented in the form of the female hormone - estrogen and the male hormone - androgen. In addition, corticosteroids perform a number of functions in the metabolism that affect its growth and feedback from the central nervous system.
- Adrenaline, norepinephrine and dopamine represent a group of so-called catecholamines. It is difficult to overestimate the influence of these microelements on the body as a whole and in particular on its cardiovascular system. After all, it is adrenaline that helps the heart to pump blood smoothly and smoothly through the vessels.
Hormones are produced not only by certain organs of the endocrine system, there are also specific cells that can synthesize these trace elements. For example, there is a neurohormone produced by nerve cells, or the so-called tissue hormone that is born in the skin cells and has a purely local effect.
Conclusion
Hormonal regulation depends on many factors, and the absence or low level of just one hormone can lead to a dangerous condition in the body. Diabetes was examined using insulin as an example, and if a man has almost no testosterone in his body, he will never be able to become a father, and he will be short and weak. Just like a woman without the necessary amount of estrogen, she will not have external sexual characteristics and will lose the ability to give birth to children.
Thus, the question arises - how to maintain the necessary level of the necessary hormones in the body?
First of all, one should not let the appearance of alarming signs in the body work - incomprehensible thirst, sore throat, sleep and appetite disturbances, dry flaky skin, faded hair and an apathetic state. If these symptoms appear, consult a doctor immediately. And children should be shown to the pediatrician at least every 6 months. Indeed, many dangerous pathologies manifest themselves precisely in childhood, when it is still possible to cope with the disease with the help of substitution therapy. An example of such a deviation is gigantism or dwarfism.
Adults need to pay attention to their lifestyle. You can not accumulate fatigue and stress - this necessarily leads to hormonal failure. In order for the central nervous system to work without interruptions, you need to learn not to respond to stimuli, go to bed on time. Sleep should be given at least 8 hours a day. And you need to sleep at night, as part of the hormones are produced only in the dark.
Do not forget about the dangers of overeating and addictions. Alcohol can destroy the pancreas, and this is a direct road to diabetes and early death.
Throughout life, you need to follow a certain diet - do not eat fatty and sweet foods, reduce the consumption of preservatives, and diversify your menu with fresh vegetables and fruits. But most importantly, you need to eat fractionally - 5-6 times a day in small portions.