Regulation of Breathing The concept of breathing in qigong, as well as in the ancient Daoyin systems, is associated with the concept of qi. In some cases these are complete synonyms (“nourish the body with heavenly qi”), in others they are complementary factors. Various types breathing creates different circulation of qi in

Humoral physiopathology and hydrotherapy (hydrotherapy) Among the substances that form the structure of a living organism, the predominant part is represented by water, which contains minerals. Thus, in the brain, water makes up 77%, if we take into account the brain along with the brain

Humoral regulation of heart activity The work of the heart is primarily influenced by the mediators acetylcholine, released at the endings of the parasympathetic nerves, it inhibits the activity of the heart, as well as adrenaline and norepinephrine - mediators of the sympathetic nerves, which have

Humoral regulation of vascular tone Humoral regulation of the lumen of blood vessels is carried out due to chemical substances dissolved in the blood, which include general hormones, local hormones, mediators and metabolic products. They can be divided into two

Humoral regulation of lymph flow and lymph formation Adrenaline - enhances the flow of lymph through lymphatic vessels mesentery and increases pressure in the chest cavity. Histamine - enhances lymph formation by increasing the permeability of blood capillaries, stimulates

Humoral regulation of respiration The main physiological stimulus of the respiratory centers is carbon dioxide. Regulation of breathing determines the maintenance of normal CO2 content in the alveolar air and arterial blood. Increase in CO2 content in

Regulation of salivation When food enters the oral cavity irritation of mechano-, thermo- and chemoreceptors of the mucous membrane occurs. Excitation from these receptors along the sensory fibers of the lingual (branch of the trigeminal nerve) and glossopharyngeal nerves,

The act of defecation and its regulation Feces are removed through the act of defecation, which is a complex reflex process of emptying the distal colon through the anus. When the ampoule of the rectum is filled with feces and the pressure in it increases to 40 - 50 cm

Humoral The leading role in the regulation of kidney activity belongs to the humoral system. Many hormones influence kidney function, the main ones being antidiuretic hormone (ADH), or vasopressin, and aldosterone. Antidiuretic hormone (ADH), or

Humoral regulation of pain Mediators: acetylcholine, adrenaline, norepinephrine, serotonin activate chemonocyceptors. Acetylcholine causes a burning pain when administered subcutaneously or when punctured into the mucous membrane. This pain usually lasts 15 - 45 minutes and may be

Plan:

1. Humoral regulation

2. The hypothalamic-pituitary system as the main mechanism of neurohumoral regulation of hormone secretion.

3. Pituitary hormones

4. Thyroid hormones

5. Hormones parathyroid glands

6. Pancreatic hormones

7. The role of hormones in the body’s adaptation to stress factors

Humoral regulation- this is a type of biological regulation in which information is transmitted using biologically active substances that are carried throughout the body by blood, lymph, and intercellular fluid.

Humoral regulation differs from nervous regulation:

the information carrier is a chemical substance (in the case of a nervous one - a nerve impulse, PD);

transmission of information is carried out by the flow of blood, lymph, by diffusion (in the case of the nervous system - by nerve fibers);

the humoral signal travels more slowly (with blood flow in the capillaries - 0.05 mm/s) than the nervous signal (up to 120-130 m/s);

the humoral signal does not have such a precise “addressee” (the nervous signal is very specific and precise), affecting those organs that have receptors for the hormone.

Factors of humoral regulation:

"classical" hormones

Hormones of the APUD system

Classic hormones themselves- these are substances synthesized by endocrine glands. These are hormones of the pituitary gland, hypothalamus, pineal gland, adrenal glands; pancreas, thyroid, parathyroid, thymus, gonads, placenta (Fig. I).

In addition to the endocrine glands, in various organs and tissues there are specialized cells that release substances that act on target cells through diffusion, i.e., entering the body locally. These are paracrine hormones.

These include neurons of the hypothalamus, which produce some hormones and neuropeptides, as well as cells of the APUD system, or the system for capturing amine precursors and their decarboxylation. Examples include: liberins, statins, hypothalamic neuropeptides; interstinal hormones, components of the renin-angiotensin system.

2) Tissue hormones secreted by unspecialized cells of various types: prostaglandins, enkephalins, components of the kallikrein-inin system, histamine, serotonin.

3) Metabolic factors- these are nonspecific products that are formed in all cells of the body: lactic acid, pyruvic acid, CO 2, adenosine, etc., as well as decomposition products during intense metabolism: increased content of K +, Ca 2+, Na +, etc.

Functional significance of hormones:

1) ensuring growth, physical, sexual, intellectual development;

2) participation in the adaptation of the body in various changing conditions of the external and internal environment;

3) maintaining homeostasis..

Rice. 1 Endocrine glands and their hormones

Properties of hormones:

1) specificity of action;

2) distant nature of the action;

3) high biological activity.

1. The specificity of action is ensured by the fact that hormones interact with specific receptors located in certain target organs. As a result, each hormone acts only on specific physiological systems or organs.

2. Distance lies in the fact that the target organs on which hormones act are, as a rule, located far from the place of their formation in the endocrine glands. Unlike “classical” hormones, tissue hormones act paracrine, that is, locally, not far from the place of their formation.

Hormones act in very small quantities, which is where their high biological activity. Thus, the daily requirement for an adult is: thyroid hormones - 0.3 mg, insulin - 1.5 mg, androgens - 5 mg, estrogens - 0.25 mg, etc.

The mechanism of action of hormones depends on their structure

Hormones of protein structure Hormones of steroid structure

Rice. 2 Mechanism of hormonal control

Hormones of protein structure (Fig. 2) interact with receptors of the plasma membrane of the cell, which are glycoproteins, and the specificity of the receptor is determined by the carbohydrate component. The result of the interaction is the activation of protein phosphokinases, which provide

phosphorylation of regulatory proteins, transfer of phosphate groups from ATP to hydroxyl groups of serine, threonine, tyrosine, protein. The final effect of these hormones can be a reduction, enhancement of enzymatic processes, for example, glycogenolysis, increased protein synthesis, increased secretion, etc.

The signal from the receptor with which the protein hormone interacts is transmitted to the protein kinase with the participation of a specific intermediary or second messenger. Such messengers can be (Fig. 3):

1) cAMP;

2) Ca 2+ ions;

3) diacylglycerol and inositol triphosphate;

4) other factors.

Fig.Z. The mechanism of membrane reception of the hormonal signal in the cell with the participation of second messengers.

Hormones with a steroid structure (Fig. 2) easily penetrate into the cell through the plasma membrane due to their lipophilicity and interact in the cytosol with specific receptors, forming a “hormone-receptor” complex that moves into the nucleus. In the nucleus, the complex disintegrates and hormones interact with nuclear chromatin. As a result of this, interaction with DNA occurs, and then induction of messenger RNA. Due to the activation of transcription and translation 2-3 hours after exposure to the steroid, increased synthesis of induced proteins is observed. In one cell, the steroid affects the synthesis of no more than 5-7 proteins. It is also known that in the same cell, a steroid hormone can cause induction of the synthesis of one protein and repression of the synthesis of another protein (Fig. 4).

The action of thyroid hormones is carried out through receptors in the cytoplasm and nucleus, as a result of which the synthesis of 10-12 proteins is induced.

Reflation of hormone secretion is carried out by the following mechanisms:

1) direct influence of blood substrate concentrations on gland cells;

2) nervous regulation;

3) humoral regulation;

4) neurohumoral regulation (hypothalamic-pituitary system).

In the regulation of the activity of the endocrine system, the principle of self-regulation, which is carried out according to the type of feedback, plays an important role. There are positive (for example, an increase in blood sugar leads to an increase in insulin secretion) and negative feedback (with an increase in the level of thyroid hormones in the blood, the production of thyroid-stimulating hormone and thyrotropin-releasing hormone, which ensure the release of thyroid hormones, decreases).

So, the direct influence of the concentrations of blood substrates on gland cells occurs according to the principle of feedback. If the level of a substance controlled by a specific hormone changes in the blood, then “the tear responds by increasing or decreasing the secretion of this hormone.

Nervous regulation carried out due to the direct influence of the sympathetic and parasympathetic nerves on the synthesis and secretion of hormones (neurohypophysis, adrenal medulla), as well as indirectly, “changing the intensity of the blood supply to the gland. Emotional, mental influences through the structures of the limbic system, through the hypothalamus, can significantly influence the production of hormones.

Hormonal regulation It is also carried out according to the principle of feedback: if the level of a hormone in the blood increases, then the release of those hormones that control the content of this hormone decreases, which leads to a decrease in its concentration in blood.

For example, when the level of cortisone in the blood increases, the release of ACTH (a hormone that stimulates the secretion of hydrocortisone) decreases and, as a consequence,

Decrease in its level in the blood. Another example of hormonal regulation could be this: melatonin (pineal gland hormone) modulates the function of the adrenal glands, thyroid gland, gonads, i.e. a certain hormone can influence the content of other hormonal factors in the blood.

The hypothalamic-pituitary system as the main mechanism of neurohumoral regulation of hormone secretion.

The function of the thyroid, gonads, and adrenal cortex is regulated by hormones of the anterior pituitary gland - the adenohypophysis. Here they are synthesized tropic hormones: adrenocorticotropic (ACTH), thyroid-stimulating (TSH), follicle-stimulating (FS) and luteinizing (LH) (Fig. 5).

With some convention, triple hormones also include somatotropic hormone (growth hormone), which affects growth not only directly, but also indirectly through hormones - somatomedins, formed in the liver. All these tropic hormones are so named due to the fact that they ensure the secretion and synthesis of the corresponding hormones of other endocrine glands: ACTH -

glucocorticoids and mineralocorticoids: TSH - thyroid hormones; gonadotropic - sex hormones. In addition, intermedia (melanocyte-stimulating hormone, MCH) and prolactin are formed in the adenohypophysis, which have an effect on peripheral organs.

Rice. 5. Regulation of the endocrine glands of the central nervous system. TL, SL, PL, GL and CL - respectively, thyrotropin-releasing hormone, somatoliberin, prolactoliberin, gonadoliberin and corticoliberin. SS and PS - somatostatin and prolactostatin. TSH - thyroid-stimulating hormone, STH - somatotropic hormone (growth hormone), PR - prolactin, FSH - follicle-stimulating hormone, LH - luteinizing hormone, ACTH - adrenocorticotropic hormone

Thyroxine Triiodothyronine Androgen Glucocorticoids

Estrogens

In turn, the release of all 7 of these hormones of the adenohypophysis depends on the hormonal activity of neurons in the pituitary zone of the hypothalamus - mainly the paraventricular nucleus (PVN). Hormones are formed here that have a stimulating or inhibitory effect on the secretion of adenohypophysis hormones. Stimulants are called releasing hormones (liberins), inhibitors are called statins. Thyroid-releasing hormone and gonadoliberin were isolated. somatostatin, somatoliberin, prolactostatin, prolactoliberin, melanostatin, melanoliberin, corticoliberin.

Releasing hormones are released from the processes of nerve cells of the paraventricular nucleus, enter the portal venous system of the hypothalamo-pituitary gland and are transported with the blood to the adenohypophysis.

The regulation of the hormonal activity of most endocrine glands is carried out according to the principle of negative feedback: the hormone itself, its amount in the blood, regulates its formation. This effect is mediated through the formation of the corresponding releasing hormones (Fig. 6,7)

In the hypothalamus (supraoptic nucleus), in addition to releasing hormones, vasopressin (antidiuretic hormone, ADH) and oxytocin are synthesized. Which are transported in the form of granules by nerve processes in the neurohypophysis. The release of hormones into the bloodstream by neuroendocrine cells is due to reflex nerve stimulation.

Rice. 7 Direct and feedbacks in the neuroendocrine system.

1 - slowly developing and long-lasting inhibition of the secretion of hormones and neurotransmitters , as well as behavior change and memory formation;

2 - rapidly developing but long-lasting inhibition;

3 - short-term inhibition

Pituitary hormones

The posterior lobe of the pituitary gland, the neurohypophysis, contains oxytocin and vasopressin (ADH). ADH affects three types of cells:

1) cells renal tubules;

2) smooth muscle cells of blood vessels;

3) liver cells.

In the kidneys, it promotes the reabsorption of water, which means preserving it in the body, reducing diuresis (hence the name antidiuretic), in blood vessels it causes contraction of smooth muscles, narrowing their radius, and as a result, increases blood pressure (hence the name “vasopressin”), in liver - stimulates gluconeogenesis and glycogenolysis. In addition, vasopressin has an antinociceptive effect. ADH is designed to regulate the osmotic pressure of the blood. Its secretion increases under the influence of such factors: increased blood osmolarity, hypokalemia, hypocalcemia, increased decreased blood volume, decreased blood pressure, increased body temperature, activation of the sympathetic system.

If ADH secretion is insufficient, diabetes insipidus develops: the volume of urine excreted per day can reach 20 liters.

Oxytocin in women plays the role of a regulator of uterine activity and is involved in lactation processes as an activator of myoepithelial cells. An increase in oxytocin production occurs during dilation of the cervix at the end of pregnancy, ensuring its contraction during childbirth, as well as during feeding of the baby, ensuring milk secretion.

The anterior lobe of the pituitary gland, or adenohypophysis, produces thyroid-stimulating hormone (TSH), somatotropic hormone (GH) or growth hormone, gonadotropic hormones, adrenocorticotropic hormone (ACTH), prolactin, and in the middle lobe - melanocyte-stimulating hormone (MSH) or interludes.

A growth hormone stimulates protein synthesis in bones, cartilage, muscles and liver. In an immature organism, it ensures growth in length by increasing the proliferative and synthetic activity of cartilage cells, especially in the growth zone of long tubular bones, while simultaneously stimulating the growth of their heart, lungs, liver, kidneys and other organs. In adults, it controls the growth of organs and tissues. STH reduces the effects of insulin. Its release into the blood increases during deep sleep, after muscular exercise, during hypoglycemia.

The growth effect of growth hormone is mediated by the hormone’s effect on the liver, where somatomedins (A, B, C) or growth factors are formed, which cause the activation of protein synthesis in cells. The value of growth hormone is especially great during the period of growth (prepubertal, pubertal periods).

During this period, GH agonists are sex hormones, an increase in the secretion of which contributes to a sharp acceleration of bone growth. However, prolonged formation of large quantities of sex hormones leads to the opposite effect - to the cessation of growth. An insufficient amount of GH leads to dwarfism (nanism), and an excessive amount leads to gigantism. Growth of some adult bones may resume if excessive secretion STG. Then the proliferation of cells in the germ zones resumes. What causes growth

In addition, glucocorticoids inhibit all components inflammatory reaction- reduce capillary permeability, inhibit exudation, reduce the intensity of phagocytosis.

Glucocorticoids sharply reduce the production of lymphocytes, reduce the activity of T-killers, the intensity of immunological surveillance, hypersensitivity and sensitization of the body. All this allows us to consider glucocorticoids as active immunosuppressants. This property is used clinically to relieve autoimmune processes, to reduce immune defense host organism.

Glucocorticoids increase sensitivity to catecholamines and increase the secretion of hydrochloric acid and pepsin. An excess of these hormones causes bone demineralization, osteoporosis, loss of Ca 2+ in the urine, and reduces Ca 2+ absorption. Glucocorticoids affect the function of the internal nervous system - they increase the activity of information processing and improve the perception of external signals.

Mineralocorticoids(aldosgerone, deoxycorticosterone) are involved in the regulation mineral metabolism. The mechanism of action of aldosterone is associated with the activation of protein synthesis involved in the reabsorption of Na + - Na +, K h -ATPase. By increasing reabsorption and reducing it for K + in the distal tubules of the kidney, salivary and gonads, aldosterone promotes the retention of Na and SG in the body and the removal of K + and H from the body. Thus, aldosterone is a sodium-sparing and also a kaliuretic hormone. Due delay of Ia\ and, after it, water, it contributes to an increase in blood volume and, as a result, an increase in blood pressure.Unlike glucocorticoids, mineralocorticoids contribute to the development of inflammation, because they increase capillary permeability.

Sex hormones The adrenal glands perform the function of developing the genital organs and the appearance of secondary sexual characteristics during the period when the gonads are not yet developed, that is, in childhood and in old age.

The hormones of the adrenal medulla - adrenaline (80%) and norepinephrine (20%) - cause effects that are largely identical to the activation of the nervous system. Their action is realized through interaction with a- and beta-adrenergic receptors. Consequently, they are characterized by activation of the heart, constriction of skin vessels, dilation of the bronchi, etc. Adrenaline affects carbohydrate and fat metabolism, enhancing glycogenolysis and lipolysis.

Catecholamines are involved in the activation of thermogenesis, in the regulation of the secretion of many hormones - they increase the release of glucagon, renin, gastrin, parathyroid hormone, calcitonin, thyroid hormones; reduce insulin release. Under the influence of these hormones, the performance of skeletal muscles and the excitability of receptors increase.

With hyperfunction of the adrenal cortex in patients, secondary sexual characteristics noticeably change (for example, in women, male sexual characteristics may appear - a beard, mustache, timbre of voice). Obesity (especially in the neck, face, and torso), hyperglycemia, water and sodium retention in the body, etc. are observed.

Hypofunction of the adrenal cortex causes Addison's disease - a bronze tint of the skin (especially the face, neck, hands), loss of appetite, vomiting, increased sensitivity to cold and pain, high susceptibility to infections, increased diuresis (up to 10 liters of urine per day), thirst, decreased performance.

The most difficult issues in teaching the section “Man and his health”

The proposed course involves studying the most complex issues in the section “Man and His Health”, which affect the physiological mechanisms of functioning of the human body as a whole and its individual structures (cells, tissues, organs).

The purpose of the course is to give the teacher modern knowledge about the patterns of functioning of the human body, to show their role and place in the educational process in accordance with educational standards, Unified State Examination materials, and new generation biology textbooks. The content of the course is not only theoretical, but also practice-oriented, expanding the possibilities of using educational program materials to introduce new pedagogical technologies.

The main tasks solved during the study of the training course:

disclosure and deepening of the most complex anatomical and physiological concepts;
familiarization with educational standards, programs and existing textbooks on the section “Man and his health” and their analysis;
mastering the methodology of teaching complex issues of the section in class and in extracurricular activities;
application of new pedagogical technologies.

The integrated approach proposed by the authors provides wide possibilities for the use of almost all textbooks on this topic, approved by the Ministry of Education and Science of the Russian Federation. A significant role is given to the formation of pedagogical skills in designing the educational process, depending on the material and technical equipment of the classroom and the interests of schoolchildren.

The course materials can be used in class and in extracurricular activities to prepare students for the Unified State Exam and Olympiads in biology and ecology. The novelty of this training course lies in its focus on modern forms organization of the pedagogical process, examples of which are given in all lectures.

Course curriculum

Lecture 1
Regulatory systems of the body

Currently, science has formed the idea that the basic life processes of complex multicellular organisms, including humans, are supported by three regulatory systems: nervous, endocrine and immune.

Each multicellular organism develops from a single cell - a fertilized egg (zygote). First, the zygote divides and forms cells similar to itself. From a certain stage differentiation begins. As a result, trillions of cells are formed from the zygote, having different shapes and functions, but making up a single, integral organism. A multicellular organism can exist as a single whole thanks to the information contained in the genotype (a set of genes received by offspring from their parents). The genotype is the basis of hereditary characteristics and developmental programs. Throughout an individual's life, control over the genetic constancy of the body is ensured by the immune system. Coordination of the activities of various organs and systems, as well as adaptation to changing environmental conditions, are functions of the nervous and humoral systems.

Phylogenetically, humoral regulation is the most ancient. It ensures the interconnection of cells and organs in primitively organized organisms that do not have a nervous system. The main regulatory substances in this case are metabolic products - metabolites. This method of regulation is called humoral-metabolic. It, like other types of humoral regulation, is based on the “all-all-all” principle. The released substances spread throughout the body and change the activity of life support systems.

In the process of evolutionary development, a nervous system appears, and humoral regulation is increasingly subordinate to the nervous system. Nervous regulation of functions is more advanced. It is based on signaling based on the “letter with address” principle. Biologically important information reaches a specific organ along nerve fibers. The development of nervous regulation does not eliminate the more ancient one - humoral. The nervous and humoral systems are combined into the neurohumoral system for regulating functions. In highly developed living organisms, a specialized system appears - the endocrine system. The endocrine system uses special chemicals called hormones to transmit signals from one cell to another. Hormones are biologically active substances that are carried through the bloodstream to various bodies and regulate their work. The action of hormones is manifested at the cellular level. Some hormones (adrenaline, insulin, glucagon, pituitary hormones) bind to receptors on the surface of target cells, activate reactions occurring in the cell and change physiological processes. Other hormones (hormones of the adrenal cortex, sex hormones, thyroxine) penetrate into the cell nucleus and bind to a section of the DNA molecule, “turning on” certain genes. As a result, the formation of mRNA and the synthesis of proteins that change the functions of the cell are “triggered.” Hormones penetrating into the nucleus trigger the “programs” of the cells, so they are responsible for their general differentiation, the formation of sex differences, and many behavioral reactions.

The evolution of neurohumoral regulation of functions occurred as follows.

Metabolic regulation - due to the products of intracellular metabolism (protozoa, sponges).
Nervous regulation – appears in coelenterates.
Neurohumoral regulation. Some invertebrates develop neurosecretory cells - nerve cells capable of producing biologically active substances.
Endocrine regulation. In arthropods and vertebrates, in addition to nervous and simple humoral (due to metabolites) regulation, endocrine regulation of functions is added.

The following functions of regulatory systems are distinguished.

Nervous system.

Regulation and coordination of all organs and systems, maintaining a constant internal environment of the body (homeostasis), uniting the body into a single whole.
The relationship of the organism with the environment and adaptation to changing environmental conditions (adaptation).

Endocrine system.

Physical, sexual and mental development.
Maintaining body functions at a constant level (homeostasis).
Adaptation of the body to changing environmental conditions (adaptation).

The immune system.

Control over the genetic constancy of the internal environment of the body.

The immune and neuroendocrine systems form a single information complex and communicate in the same chemical language. Many biologically active substances (for example, hypothalamic substances, pituitary hormones, endorphins, etc.) are synthesized not only in the hypothalamus and pituitary gland, but also in the cells of the immune system. Thanks to a common biochemical language, regulatory systems closely interact with each other. Thus, β-endorphin, released by lymphocytes, acts on pain receptors and reduces the feeling of pain. On immune cells there are receptors that interact with peptides of the hypothalamus and pituitary gland. Some substances secreted by the immune system (in particular, interferons) interact with specific receptors on the neurons of the hypothalamus, thereby regulating the release of pituitary hormones.

At the level of physiological reactions of the body, the interaction of regulatory systems manifests itself during the development of stress. The consequences of stress are expressed in disruption of the functions of regulatory systems and the processes they control. The effect of stressors is perceived by the higher parts of the nervous system (cerebral cortex, diencephalon) and has two outputs realized through the hypothalamus:

1) in the hypothalamus there are higher autonomic nerve centers that regulate through the sympathetic and parasympathetic departments activity of all internal organs;

2) the hypothalamus controls the work of the endocrine glands, which reduce the functional activity of the immune system, including the adrenal glands, which produce stress hormones.

The role of stress in development has now been proven ulcerative lesions gastric mucosa, hypertension, atherosclerosis, dysfunction and structure of the heart, immunodeficiency states, malignant tumors and etc.

Possible outcomes of the stress reaction are presented in Diagram 1.

Scheme 1

Today, the connections between the nervous and endocrine systems, an example of which is the hypothalamic-pituitary system, have been well studied.

The pituitary gland, or lower cerebral appendage, is located under the hypothalamus in a recess of the skull bones called the sella turcica, and is connected to it through a special stalk. The mass of the human pituitary gland is small, about 500 mg, and the size is no larger than an average cherry. The pituitary gland consists of three lobes - anterior, middle and posterior. The anterior and middle lobes are combined into the adenohypophysis, and the posterior lobe is otherwise called the neurohypophysis.

The activity of the adenohypophysis is under the direct control of the hypothalamus. The hypothalamus produces biologically active substances (hypothalamic hormones, releasing factors), which travel through the bloodstream to the pituitary gland and stimulate or inhibit the formation of pituitary tropic hormones. Tropic hormones of the pituitary gland regulate the activity of other endocrine glands. These include: corticotropin, which regulates the secretory activity of the adrenal cortex; thyrotropin, which regulates the activity of the thyroid gland; lactotropin (prolactin), which stimulates milk production in the mammary glands; somatotropin, which regulates growth processes; lutropin and follitropin, which stimulate the activity of the gonads; melanotropin, which regulates the activity of pigment-containing cells of the skin and retina.

The posterior lobe of the pituitary gland is connected to the hypothalamus by axonal connections, i.e. the axons of the neurosecretory cells of the hypothalamus end on the cells of the pituitary gland. Hormones synthesized in the hypothalamus are transported along axons to the pituitary gland, and from the pituitary gland enter the blood and are delivered to target organs. The hormones of the neurohypophysis are antidiuretic hormone (ADH), or vasopressin, and oxytocin. ADH regulates kidney function by concentrating urine and increases blood pressure. Oxytocin is released in large quantities into the blood in female body at the end of pregnancy, ensuring childbirth.

As stated above, most of the neuroendocrine regulatory reactions ensure homeostasis and adaptation of the body.

Homeostasis, or homeostasis (from homoios– similar and stasis– standing) – the dynamic balance of the body, maintained by regulatory systems due to the constant renewal of structures, material-energy composition and condition.

The doctrine of homeostasis was created by C. Bernard. While studying carbohydrate metabolism in animals, C. Bernard drew attention to the fact that the concentration in the blood of glucose (the most important source of energy for the body) fluctuates very slightly, within 0.1%. With an increase in glucose content, the body begins to “suffocate in the smoke” of under-oxidized carbohydrates; with a deficiency, energy hunger occurs. In both cases, severe weakness and confusion occurs. In this particular fact, C. Bernard saw a general pattern: the constancy of the internal environment is a condition for a free independent life. The term “homeostasis” was introduced into science by W. Cannon. He understood homeostasis as the stability and consistency of all physiological processes.

Currently, the term “homeostasis” refers not only to regulated parameters, but also to regulatory mechanisms. Reactions ensuring homeostasis can be aimed at:

– maintaining a certain level of steady state of the body or its systems;
– elimination or limitation of harmful factors;
– changing the relationship between the body and changing environmental conditions.

The most tightly controlled homeostatic constants of the body include the ionic and acid-base composition of the blood plasma, the content of glucose, oxygen, carbon dioxide in arterial blood, body temperature, etc. Plastic constants include blood pressure, the number of blood elements, the volume of extracellular water .

The concept of “adaptation” (from adaptatio– adapt) has general biological and physiological significance. From a general biological point of view, adaptation is a set of morphophysiological, behavioral, population and other characteristics of a given biological species, providing the possibility of a specific lifestyle in certain environmental conditions.

How physiological concept adaptation means the process of adapting the body to changing environmental conditions (natural, industrial, social). Adaptation is all types of adaptive activities at the cellular, organ, systemic and organismal levels. There are 2 types of adaptation: genotypic and phenotypic.

As a result genotypic adaptation formed on the basis of hereditary variability, mutations and natural selection modern views animals and plants.

Phenotypic adaptation– a process that develops during an individual’s life, as a result of which the organism acquires previously absent resistance to a certain environmental factor. There are two stages of phenotypic adaptation: an urgent stage (urgent adaptation) and a long-term stage (long-term adaptation).

Urgent adaptation occurs immediately after the onset of the stimulus and is implemented on the basis of ready-made, previously formed mechanisms. Long-term adaptation occurs gradually, as a result of prolonged or repeated action on the body of one or another environmental factor. In fact, long-term adaptation develops on the basis of repeated implementation of urgent adaptation: a gradual accumulation of certain changes occurs, and the organism acquires a new quality and turns into an adapted one.

Examples of urgent and long-term adaptation

Adaptation to muscle activity. Running of an untrained person occurs with close to maximum changes in heart rate, pulmonary ventilation, and maximum mobilization of the glycogen reserve in the liver. Wherein physical labor can be neither intense enough nor long enough. With long-term adaptation to physical activity as a result of training, hypertrophy of skeletal muscles occurs and the number of mitochondria in them increases by 1.5–2 times, an increase in the power of the circulatory and respiratory systems, an increase in the activity of respiratory enzymes, hypertrophy of neurons of motor centers, etc. This can significantly increase the intensity and duration of muscle activity.

Adaptation to hypoxic conditions. The ascent of an untrained person to the mountains is accompanied by an increase in heart rate and minute blood volume, the release of blood from blood depots, due to which there is an increase in oxygen delivery to organs and tissues. At the initial stages, changes in breathing do not occur, because In high altitude conditions, the atmospheric air has a reduced content of not only oxygen, but also carbon dioxide, which is the main stimulator of the activity of the respiratory center. With long-term adaptation to a lack of oxygen, the sensitivity of the respiratory center to carbon dioxide increases and pulmonary ventilation increases. This reduces the load on the cardiovascular system. Increases hemoglobin synthesis and red blood cell formation bone marrow. The activity of tissue respiratory enzymes increases. These changes make the body adapted to high altitude conditions. In people who are well adapted to the lack of oxygen, the content of red blood cells in the blood (up to 9 million / μl), indicators of cardiovascular and respiratory systems, physical and mental performance do not differ from those of the highlanders.

The capabilities and limits of a person’s adaptive reactions are determined by the genotype and are realized subject to the action of certain environmental factors. If the factor does not have an effect, then adaptation is not implemented. For example, an animal raised among people does not adapt to its natural environment. If a person has led all his life sedentary lifestyle life, then he will not be able to adapt to physical labor.

Examples of regulation of functions

Nervous regulation. An example of nervous regulation is the regulation of blood pressure. In an adult, blood pressure is maintained at a certain level: systolic – 105–120 mm Hg, diastolic – 60–80 mm. Hg After an increase in pressure caused by various factors(For example, physical activity), y healthy person it quickly returns to normal due to signals coming from the cardiac nerve center of the medulla oblongata. The mechanism of such a reaction is presented in Scheme 2.

Scheme 2

Humoral regulation. An example of humoral regulation is maintaining blood glucose at a certain level. Carbohydrates from food are broken down into glucose, which is absorbed into the blood. The glucose content in human blood is 60–120 mg% (after a meal – 110–120 mg%, after moderate fasting – 60–70 mg%). Glucose is used as a source of energy by all cells of the body. The supply of glucose to most tissues is provided by the pancreatic hormone insulin. Nerve cells receive glucose independently of insulin due to the activity of glial cells, which regulate metabolism in neurons. If an excess amount of glucose enters the body, it is stored as liver glycogen. When there is a lack of glucose in the blood, under the influence of the pancreatic hormone glucagon and the adrenal medulla hormone adrenaline, glycogen is broken down into glucose. If glycogen reserves are depleted, then glucose can be synthesized from fats and proteins with the participation of adrenal hormones - glucocorticoids. At low concentrations glucose in the blood (below 60 mg%), the production of insulin stops and glucose does not enter the tissues (it is saved for brain cells), and fats are used as an energy source. At very high concentrations blood glucose (over 150–180 mg%), which may occur in sick people diabetes mellitus, glucose is excreted in the urine. This phenomenon is called glycosuria. The mechanism for regulating blood glucose levels is presented in Scheme 3.

Scheme 3

1 – insulin
2 – glucagon

Neurohumoral regulation. Examples of neurohumoral regulation include regulation of energy (food) intake and regulation deep temperature bodies.

Regulation of energy consumption.

Energy enters the body with food. According to the first law of thermodynamics, the amount of energy consumed = work done + heat production + stored energy (fats and glycogen), i.e. the amount of chemical energy contained in food for an adult must be such as to cover the costs of the work performed (physical and mental labor) and maintaining body temperature.

If the amount of food consumed is more than necessary, then an increase in body weight occurs, if less, it decreases. Due to the fact that the reserves of carbohydrates in the body are limited by the capacity of the liver, excess amounts of consumed carbohydrates are converted into fats and stored as reserves in the subcutaneous fatty tissue. In childhood, part of the substances and energy is spent on growth processes.

Food consumption is regulated by the nerve centers of the hypothalamus: the hunger center and the satiety center. If there is a shortage nutrients The hunger center in the blood is activated, stimulating food-seeking reactions. After eating, satiety signals are sent to the satiety center, which inhibits the activity of the hunger center (Scheme 4).

Scheme 4

Signals to the saturation center can come from different receptors. These include mechanoreceptors of the stomach wall, which become excited after eating; thermoreceptors, signals from which are received as a result of an increase in temperature caused by the specific dynamic effect of food (after eating food, especially protein, the level of metabolism and, accordingly, body temperature increase). There are theories that explain food consumption by chemical signals. In particular, the satiety center begins to send inhibitory signals to the hunger center after an increase in the level of glucose or fat-like substances in the blood.

Regulation of deep body temperature.

In warm-blooded (homeothermic) animals, the temperature of the “core” of the body is maintained at a constant level. The formation of heat in the body occurs due to exothermic reactions in every living cell. The amount of heat generated in the organ depends on the intensity of metabolism: in the liver it is the greatest, in the bones it is the least. Heat transfer occurs from the surface of the body due to physical processes: heat radiation, heat conduction and evaporation of liquid (sweat).

Through thermal radiation, the body loses heat in the form of infrared rays. However, if the ambient temperature is higher than the body temperature, then the infrared radiation from the environment will be absorbed by the body and its temperature may increase. If the body comes into contact with cold bodies that are good conductors of heat, for example cold water, damp cold earth, stones, metals, etc., then it loses heat by conduction. At the same time, the risk of hypothermia is high.

If the ambient temperature is higher than body temperature, then the only way to cool is through evaporation. High ambient temperatures and high humidity make it difficult for sweat to evaporate and increase the risk of overheating. Increased heat generation can occur due to muscle work, trembling, and increased metabolic rate.

Thermoregulation is controlled by the nervous and endocrine systems. The somatic part of the nervous system provides reactions that prevent hypothermia, such as muscle work and trembling. Sympathetic department The autonomic nervous system controls changes in the lumen of blood vessels (with increasing temperature they expand, with decreasing temperature they narrow), sweating, non-shivering thermogenesis (oxidation of free fatty acids in brown fat), contraction of smooth muscles that raise the hair.

When the ambient temperature drops, the activity of the thyroid gland and adrenal glands increases. The thyroid hormone thyroxine increases the intensity of redox reactions in cells. The adrenal medulla hormone adrenaline also increases metabolic rates.

Regulation involving the nervous, endocrine and immune systems. An example of regulation of a function involving all regulatory systems is sleep. Today, there are three groups of theories that explain the nature of sleep: nervous, humoral and immune.

Neural theories associate sleep with work nerve centers cerebral cortex, hypothalamus and reticular formation of the brain stem. The cortical theory of sleep was proposed by I.P. Pavlov, who showed in experiments on animals that during sleep, inhibition occurs in cortical neurons. Later, centers were discovered that regulate the alternation of sleep and wakefulness in the hypothalamus.

The reticular formation of the brain stem, collecting information from the receptor structures of the body, maintains tone (the awake state of the cortex), i.e. also participates in the regulation of sleep-wake processes. When the reticular formation is blocked by certain substances, a sleep-like state occurs.

Humoral factors Some hormones regulate sleep. It has been shown that when the pineal gland hormone serotonin accumulates in the blood, favorable conditions are created for REM sleep, during which the processing of information received by a person while awake occurs.

Immune theory sleep received experimental confirmation after checking long-known facts about increased sleepiness people, sick infectious diseases. It turned out that the substance muramyl peptide, which is part of the cell wall of bacteria, stimulates the production of one of the cytokines that regulate sleep by cells of the immune system. Administration of muramyl peptide to animals caused them to sleep excessively.

Methodological support of the course

Educational standards, curricula and textbooks for the section “Man and his health”

Modern educational standards were approved by order of the Ministry of Education of Russia No. 1089 dated March 5, 2004. According to the standard, the section “Man and his health” is studied in the 8th grade. However, in a number of schools the process of transition from the 1998 standard, which provides for the study of anatomical and physiological topics in the 9th grade, has not yet been fully completed.

The similarity of the two named standards is the list of the main proposed topics and issues considered: the body as a whole, the cells and tissues of the human body, the structure and functioning of organ systems, the basic physiological processes of the body, the principles of regulation of life, the relationship with the environment, the senses and higher nervous activity, issues of hygiene and disease prevention. These topics are reflected in all textbooks approved and recommended by the Ministry of Education and Science of the Russian Federation, but their names may be different.

A feature of the 2004 educational standard is the clear identification of levels of education (primary, basic 9-year, full 11-year) and levels of education for high school (basic and specialized). The standard highlights the main learning objectives for stages and levels, the mandatory minimum content of the basic educational programs, requirements for the level of training of students.

The first block of requirements includes a list of topics, concepts and problems that schoolchildren must know (understand); they are grouped under headings: basic provisions, structure biological objects, the essence of processes and phenomena, modern biological terminology and symbolism. The second block includes the skills of schoolchildren: to explain, establish relationships, solve problems, draw up diagrams, describe objects, identify, research, compare, analyze and evaluate, and independently search for information. The third block provides requirements for the use of acquired knowledge and skills in practical activities and Everyday life: recording the results, providing first aid, observing the rules of behavior in the environment, determining one’s own position and assessing the ethical aspects of biological problems.

Content educational standards implemented in educational literature. A textbook is one of the main sources of knowledge necessary for both students to obtain new educational information, and for them to consolidate the material studied in the lesson. With the help of the textbook, the main goals and objectives of education are solved: to ensure that students master various types of reproductive and creative educational activities based on the assimilation of a system of biological knowledge and skills of a theoretical and practical nature, to promote the development and education of schoolchildren.

Textbooks differ in content, as well as in structure, volume of educational information, and methodological apparatus. However, a mandatory requirement for each textbook is that its contents comply with the federal component state standard general secondary education in biology. Currently, the textbook is complex information system, around which other teaching aids are grouped (audio cassettes, computer support, Internet resources, printed notebooks, handouts, etc.), otherwise called an educational and methodological set (UMK).

Let us give a brief description of the lines of textbooks recommended (approved) for use in the educational process in general education institutions. Note that most textbooks are combined into lines, the content of which is reflected in the author’s curricula, which have substantive and methodological differences in presentation educational material. A single line of textbooks ensures continuity of biological education, common approaches to the selection of educational material, and a developed methodological system for the formation and development of knowledge and skills.

Variative textbooks on the section “Man and his health” may differ in the sequence of topics, the depth of their coverage, the style of presentation, the volume of laboratory work, questions and assignments, methodological rubrics, etc.

Almost all offered training programs have a concentric structure, i.e. The basic 9-year education ends with the study of the “General Biology” section. In each program, a leading idea is highlighted, which is consistently implemented in educational books for different sections of the biology course.

For textbooks, developed edited by N.I. Sonina, this is a functional approach, i.e. priority of knowledge about the life processes of organisms, which form the basis of the practical orientation of the content, as well as reflection modern achievements biological science (Sonin N.I., Sapin M.R."Biology. Human").

Main ideas textbook lines, developed by a team of authors edited by V.V. Papruner, we can consider biocentrism, strengthening of practical orientation and priority of the developmental function of education ( Kolesov D.V., Mash R.D.,Belyaev I.N."Biology. Human").

In line, created edited by I.N. Ponomareva, while maintaining the traditional structure of the sections, the main conceptual ideas of the educational complex are a multi-level and ecological-evolutionary approach to determining the content, and the educational material is presented according to the principle from general to specific ( Dragomilov A.G., Mash R.D."Biology. Human").

A distinctive feature of all textbook line, created under the leadership of D.I. Traitaka, is a practice-oriented orientation, implemented through textbook texts, various workshops and illustrative material ( Rokhlov V.S., Trofimov S.B.

Selection of educational material content in line, developed under the leadership of A.I. Nikishova, aimed at developing the cognitive abilities of schoolchildren. When selecting and structuring the content, a modern methodological apparatus was used, which provides for a two-level organization of the text, which makes it possible to differentiate learning ( Lyubimova Z.V., Marinova K.V."Biology. Man and his health").

In addition to the completed lines of textbooks, there are new, not yet completed lines. Educational books included in the recommended federal list comply with modern educational standards.

Questions and tasks

1. Define the concepts: adaptation, hypothalamic-pituitary system, homeostasis.

2. Compare the regulatory processes that control body functions (see table).

3. Write a short message