Functions of endocrine glands in the human body. Hormone tests and their interpretation.

January 24, 2012

The cause of many health problems is usually sought in hormonal imbalances. What are hormones and how do they work?

Hormones are special chemical messengers that regulate the functioning of the body. They are secreted by endocrine glands and travel through the bloodstream, stimulating certain cells. The term “hormone” itself comes from the Greek word “to excite.” This name accurately reflects the functions of hormones as catalysts for chemical processes.

at the cellular level.

How were hormones discovered?

The first hormone discovered was secretin
, a substance that is produced in the small intestine when food reaches it from the stomach.

Pleasure hormones

In a variety of popular texts about health you can find the mysterious phrase “pleasure hormone.” How do these hormones work and how do you get them?

Secretin was discovered by English physiologists William Bayliss and Ernest Starling in 1905.
They found that secretin is able to “travel” through the blood throughout the body and reach the pancreas, stimulating its work. And in 1920, Canadians Frederick Banting and Charles Best isolated one of the most famous hormones from the pancreas of animals - insulin
.

Female sex hormones are the culprits of a long-term hormonal storm

You could say that hormones control your entire life. Although this is a simplification of the concept, it is no different from the truth. The endocrine system is complex and is responsible for a number of functions in the human body, and overall it directly influences hormonal balance. Therefore, the endocrine system is often tested first when symptoms, both physical and mental, are present.

Women who, both at puberty and throughout their adult lives, are constantly influenced by hormonal fluctuations can tell a lot about this. After all, female sex hormones are primarily to blame for emotional breakdowns, headaches and other unpleasant situations.

Hormonal fluctuations

What do hormones do?

Hormones cause changes in the functions of various organs according to the body's requirements. Thus, they maintain the stability of the body, ensure its responses to external and internal stimuli, and also control the development and growth of tissues and reproductive functions. The control center for the overall coordination of hormone production is in the hypothalamus
, which is adjacent to the pituitary gland at the base of the brain.
Thyroid hormones
determine the rate of chemical processes in the body.
Adrenal hormones
prepare the body for stress—the “fight or flight” state.
Sex hormones
- estrogen and testosterone - regulate reproductive functions.

The role of sex hormones in the female body

The content of the article

Puberty, the menstrual cycle, pregnancy, menopause or in general: health and beauty - all these processes and conditions depend on the specific level and constant fluctuation of female sex hormones. They are responsible not only for appearance, characteristic female features or reproductive abilities, but also for many other important processes occurring in the female body.

Hormones can either improve or worsen the condition of your skin and hair; positively and negatively influence overall well-being; increase or decrease libido and finally promote or hinder pregnancy and are responsible for various diseases.

For a woman's body to function effectively, it needs a stable hormonal balance. This is why it is so important to know the functions of individual female hormones, familiarize yourself with their standards, testing forms, and options for monitoring the correct concentration in the body.

Learn what names like estrogens, progesterone, androgens, and prolactin mean, and find out what these hormones do in the body.

What hormones are there?

There are two types of hormones: steroids and peptides
.
Steroids
are produced by the adrenal glands and gonads from cholesterol.
A typical adrenal hormone is the stress hormone cortisol
, which activates all body systems in response to a potential threat.
Other steroids determine the physical development of the body from puberty to old age, as well as reproductive cycles. Peptide
hormones mainly regulate metabolism. They consist of long chains of amino acids and for their secretion the body needs a supply of protein.

Hormones and excess weight

The speed at which metabolic processes occur in the body is regulated, among other things, by hormones. How do they affect body weight? We talk in detail in the article “Hormones and excess weight.”

A typical example of peptide hormones is
growth hormone
, which helps the body burn fat and build muscle.
Another peptide hormone, insulin
, triggers the process of converting sugar into energy.

Hormones, basic concepts

Hormones are products of internal secretion that are produced by special glands or individual cells, released into the blood and distributed throughout the body, having a strictly specific and selective effect, capable of increasing or decreasing the level of vital activity of the body.

Translated from Greek, hormones mean move, excite.

Hormones are produced by special organs - endocrine glands (or endocrine glands).

“True” hormones (as opposed to local regulatory substances) are released into the blood and act on almost all organs, including those far removed from the site of hormone formation.

Hormones, in the broad sense of the word, are biologically active substances and carriers of specific information, with the help of which communication is carried out between various cells and tissues, which is necessary for the regulation of numerous functions of the body. The information contained in hormones reaches its addressee thanks to the presence of receptors that translate it into a post-receptor action (influence), accompanied by a certain biological effect.

The physiological action of hormones is aimed at:

providing humoral, i.e. carried out through the blood, regulation of biological processes;
maintaining the integrity and constancy of the internal environment, harmonious interaction between the cellular components of the body;
regulation of growth, maturation and reproduction processes.

The organ that responds to this hormone is the target organ (effector). The cells of this organ are equipped with receptors. Hormones regulate the activity of all cells of the body. They affect intelligence and physical mobility, physique and height, determine hair growth, tone of voice, sex drive and behavior. Thanks to the endocrine system, a person can adapt to strong temperature fluctuations, excess or lack of food, and physical and emotional stress.

Classification of hormones

Classification of hormones by chemical nature.

According to their chemical nature, hormones are divided into protein, steroid, amino acid derivatives and fatty acid derivatives. Protein hormones, in turn, are divided
proteid - glucoproteins: thyrotropic (TSH), follicle-stimulating (FSH), luteinizing (LH), thyroglobulin. Protein hormones are hydrophilic and can be transported in the blood both in free and partially bound to blood proteins.
steroid (lipid) hormones: corticosterone, cortisol, aldosterone, progesterone, estradiol, estriol, testosterone, which are secreted by the adrenal cortex and gonads. This group also includes vitamin D styrene - calcitriol.
Hormones are derivatives of amino acids: adrenaline and norepinephrine, synthesized in the adrenal medulla and other chromaffin cells, as well as thyroid hormones are derivatives of the amino acid tyrosine.
Hormones derived from fatty acids are prostaglandins.

According to their physiological effects, hormones are divided into:

Triggers (hormones of the pituitary gland, pineal gland, hypothalamus). Affects other endocrine glands.

Performers - influence individual processes in tissues and organs

Variants of hormone action.

Currently, the following options for the action of hormones are distinguished:

hormonal, or hemocrine, i.e. action at a considerable distance from the place of formation;
isocrine, or local, when a chemical substance synthesized in one cell has an effect on a cell located in close contact with the first, and the release of this substance is carried out into the interstitial fluid and blood;
paracrine - a type of isocrine action, but in this case the hormone produced in one cell enters the intercellular fluid and affects a number of cells located in close proximity;
juxtacrine - a type of paracrine action, when the hormone does not enter the intercellular fluid, and the signal is transmitted through the plasma membrane of another cell located nearby;
neurocrine, or neuroendocrine (synaptic and non-synaptic), action, when a hormone, released from nerve endings, performs the function of a neurotransmitter or neuromodulator, i.e. a substance that changes (usually enhances) the action of a neurotransmitter;
autocrine action, when a hormone released from a cell has an effect on the same cell, changing its functional activity;
solinocrine effect, when a hormone from one cell enters the lumen of the duct and thus reaches another cell, exerting a nonspecific effect (for example, some gastrointestinal hormones).

Properties of hormones.

Of particular interest is the body’s ability to retain hormones in an activated state.

Hormones, being specific products of the endocrine glands, do not remain stable, but change structurally and functionally in the process of metabolism. The products of hormone transformation may have new biocatalytic properties and play a certain role in the process of life: for example, the oxidation products of adrenaline - dehydroadrenaline, adrenochrome - are peculiar catalysts of internal metabolism.

The work of hormones is carried out under control and in close dependence with the nervous system. The role of the nervous system in the processes of hormone formation was first proven at the beginning of the 20th century by the Russian scientist N.A. Mislavsky, who studied the nervous regulation of the activity of the endocrine glands. They discovered a nerve that enhances the secretion of thyroid hormone; to his student M.N. Cheboksarov made a similar discovery regarding the adrenal hormone. I.P. Pavlov and his students showed the enormous regulatory significance of the cerebral cortex in hormone formation.

The specificity of the physiological action of hormones is relative and depends on the state of the organism as a whole. Of great importance is the change in the composition of the environment in which the hormone acts, in particular, an increase or decrease in the concentration of hydrogen ions, sulfhydryl groups, potassium and calcium salts, the content of amino acids and other metabolic products that affect the reactivity of nerve endings and the relationship of hormones with enzyme systems. Thus, the effect of the adrenal hormone on the kidneys and cardiovascular system is largely determined by the content of sodium chloride in the blood. The ratio between the amount of active and inactive forms of adrenaline is determined by the content of ascorbic acid in tissues. It has been proven that hormones are closely dependent on environmental conditions, the influence of which is mediated by receptors of the nervous system. Irritation of pain, temperature, visual and other receptors affects the release of hormones from the pituitary gland and thyroid gland , adrenal gland, etc. iron The components of food can serve, on the one hand, as a source of structural material for the construction of hormones (iodine, amino acids, sterols), and on the other hand, by changing the internal environment and influencing interoreceptors, influence the function of the glands that form hormones. Thus, it has been established that carbohydrates predominantly affect the secretion of insulin; proteins - on the formation of pituitary hormone, sex hormones, adrenal hormone, thyroid hormone; vitamin C – on the function of the thyroid gland and adrenal gland, etc. Some chemicals introduced into the body can specifically disrupt hormone formation.

Mechanisms of action of hormones

Hormones have different chemical structures. This results in them having different physical properties. Hormones are divided into water-soluble and fat-soluble. Belonging to one of these classes determines their mechanism of action. This is explained by the fact that fat-soluble hormones can easily penetrate the cell membrane, which consists primarily of a lipid bilayer, while water-soluble hormones cannot do this. In this regard, receptors (R) for water- and fat-soluble hormones have different localization sites (membrane and cytoplasm). Having contacted the membrane receptor, the hormone causes a cascade of reactions in the cell itself, but has no effect on the genetic material. The complex of cytoplasmic P and the hormone can act on nuclear receptors and cause changes in the genetic apparatus, which leads to the synthesis of new proteins.

Centralized city hormonal laboratory Laboratory diagnostics doctor A.A. Kovtunenko

What should be the correct estrogen concentration?

It all depends on the phase of the menstrual cycle, as well as the stage of development, age and health of the woman. In different periods, estrogen levels are different.

Estradiol values:

follicular phase: 30–120 ng/l (110–440 pmol/l),
ovulation: 130–370 ng/L (477–1358 pmol/L),
luteal phase: 70-250 ng/l (257-917 pmol/l),
postmenopausal period: <10 ng/l.

Estrone:

in the reproductive period 17-200 ng/l,
during the postmenopausal period 7–40 ng/l.

Estriol: less than 80 ng/l.

Estrogen concentrations are checked in a diagnostic laboratory. A blood sample is analyzed. You must come for the examination in the morning on an empty stomach. It should also be remembered that the values in the test results should be directly compared with the standards indicated on them, and the correct interpretation should be left to the discretion of the doctor.

Gonadotropins, that is, hormones necessary for proper childbirth

The very name of gonadotropic hormones suggests their key role in the human body. They are responsible for stimulating the activity of the human gonads, that is, the female ovaries and male testes. They are secreted by the anterior pituitary gland.

Gonadotropins primarily include:

follicle-stimulating hormone (FSH), that is, follicle-stimulating hormone,
luteinizing hormone (LH), called lutropin.

This group of hormones also includes human chorionic gonadotropin (hCG), released during pregnancy.

The FSH hormone in women is intended to stimulate the growth of ovarian follicles, control their development and regulate the functions of the corpus luteum. Stimulates the secretion of estrogens by granular cells of ovarian follicles.

Levels of stimulation of blood follicles depend on the woman’s age and the phase of the menstrual cycle. FSH norms in women are:

in the follicular phase - below 12 IU / l,
in the ovulation phase - from 20 to 90 IU / l,
in the luteal phase - below 10 IU / l,
during menopause - from 40 to 250 IU / l (after menopause, FSH concentration increases),
during pregnancy - trace concentrations.

Insufficient FSH levels are usually associated with pituitary and/or hypothalamic failure. An excess, in turn, may indicate primary or acquired ovarian failure or inhibition of ovulation stimulation.

The LH hormone in women is primarily responsible for ovulation, and its main task is to regulate and control the secretion of progesterone. After the egg enters the fallopian tube, lutropin converts granulosa cells into lutein cells (which produce progesterone), and the cells of the inner layer in the follicle shell into paralutein cells (which produce estrogens).

The role of luteinizing hormone is also to support the production of progesterone and estrogen by the corpus luteum.

As with FSH, the concentration of lutropin depends on the time of the cycle and the age of the woman. LH norms for women:

in the follicular phase - up to 5-30 IU / l,
during ovulation - from 75 to 150 IU / l,
in the luteal phase - from 3 to 40 IU / l,
after menopause - 30-300 IU / l.

Too low levels of lutropin may indicate damage to the pituitary gland or hypothalamus.

On the other hand, excess LH hormone may indicate insufficient ovarian activity or neoplastic changes in the pituitary gland.

When is a hormonal test prescribed?

Hormones take part in almost all vital processes of the human body in one way or another. Starting from birth, they regulate a person’s health, his psycho-emotional state and life in general. Due to these biologically active substances, a person adapts to changes in the environment, enters into relationships, has children, in other words, exists normally. Hormonal imbalance can have the most serious consequences.

A blood test for hormones is not just prescribed. That is, during a routine examination, no one will do an examination of the endocrine system. Such diagnostics, as a rule, are carried out exclusively on the direction of a doctor who suspects disorders of the thyroid gland, diabetes mellitus or other endocrine disease. In addition, such an analysis is often prescribed for girls and women suffering from constant irregularities in the menstrual cycle, infertility, acne, recurrent miscarriages and obesity.

For pregnant women, this is one of the mandatory studies, since a lack of one or another hormone can lead to irreversible consequences.

What to do if your estrogen levels are too low or too high?

Both excess and deficiency of these essential hormones can have negative consequences.

Excess estrogen most often occurs in women who are obese, have diabetes, have hypertension, and have certain types of cancer, such as ovarian cancer. This is also associated with taking inadequate doses of estrogen-based drugs.

The effects of excess estrogen include:

menstrual irregularities,
headaches, seizures, including migraines,
nausea and vomiting
excessive growth of the endometrium, which can lead to cancerous changes,
increased risk of blood clots and embolisms,
swelling,
breast enlargement,
weight gain,
general malaise,
mood swings.

Estrogen deficiency is physiological in women during menopause, but pathological in women of reproductive age.

This may contribute to the following disorders:

irregular menstrual cycles or their absence,
infertility,
disappearance of 2- and 3-row sexual characteristics,
vaginal dryness,
urinary tract infections,
urinary incontinence,
hot flashes and profuse sweating,
sleep disorders,
decreased sexual desire,
mood instability and depression,
loss of breast firmness,
deterioration of the quality of the skin,
calcium disorders and osteoporosis,
heart disease as a result of high cholesterol.