Physiology(from the Greek words: physis - nature, logos - teaching, science) the science of functions and processes, occurring in the body or its component systems, organs, tissues, cells, and the mechanisms of their regulation, ensuring the life activity of humans and animals in their interaction with environment.

Under function understand the specific activities of a system or organ. For example, the functions of the gastrointestinal tract are motor, secretory, absorption; respiratory function exchange O 2 and CO 2; the function of the circulatory system is the movement of blood through the vessels; myocardial contraction and relaxation function; the function of the neuron is excitation and inhibition, etc.

Process defined as a sequential change of phenomena or states in the development of an action or a set of sequential actions aimed at achieving a certain result.

System in physiology it means a collection of organs or tissues connected by a common function. For example, the cardiovascular system, which, with the help of the heart and blood vessels, ensures the delivery of nutrients, regulatory, protective substances and oxygen to tissues, as well as the removal of metabolic and heat exchange products. The speech motor system is a set of formations that normally ensure the implementation of a person’s speech ability in the form of reproduction of oral and vocal speech.

Reliability of biological systems– the property of cells, organs, and systems of the body to perform specific functions, maintaining their characteristic values ​​for a certain time. The main characteristic of system reliability is the probability of failure-free operation. The body increases its reliability in various ways:

1) by enhancing regenerative processes that restore dead cells,

2) pairing of organs (kidneys, lung lobes, etc.),

3) the use of cells and capillaries in operating and non-operating mode: as functions increase, previously non-functioning ones are included,

4) using protective braking,

5) achieving the same result by different behavioral actions.

Physiology studies the normal functioning of the body. Norm– these are the limits of optimal functioning of a living system, interpreted differently:

a) as an average value characterizing any set of events, phenomena, processes,

b) as an average statistical value,

c) as a generally accepted rule, example.

The physiological norm is biological optimum of life; normal body it is an optimally functioning system. The optimal functioning of a living system is understood as the most coordinated and effective combination of all its processes, the best of the realistically possible states, corresponding to certain conditions of the activity of this system.

Mechanism– a method of regulating a process or function. In physiology, it is customary to consider regulatory mechanisms; local(for example, stretching of blood vessels with increased blood pressure), humoral(influence on the functions and processes of hormones or humoral agents), nervous(strengthening or weakening of processes during excitation or inhibition of impulses in the first place), central(command messages from the central nervous system).

Under regulation understand the minimization of deviations of functions or their change in order to ensure the functioning of organs and systems. This term is used only in physiology, and in technical and interdisciplinary sciences it corresponds to the concepts of “control” and “regulation”. In this case automatic regulation is called either maintaining the constancy of some controlled quantity, or changing it according to a given law (software regulation), or in accordance with some changeable external process (tracking regulation). Automatic control refers to a broader set of actions aimed at maintaining or improving the functioning of a managed object in accordance with the purpose of management. In addition to solving regulation problems, automatic control covers self-tuning mechanisms (adaptations) control systems in accordance with changes in object parameters or external influences, automatic selection of the best modes from several possible ones. Because of this, the term "control" more accurately reflects the principles of regulation in living systems. In the case of program regulation, regulation is carried out "out of outrage" in the case of a follower - "by deviation".

Reaction call changes (increase or weakening) in the activity of the body or its components in response to irritation(internal or external). Reactions may be simple(eg muscle contraction, gland secretion) or complex(food foraging). They can be passive, arising as a result of external mechanical forces, or active in the form of a purposeful action carried out as a result of nervous or humoral influences, or under the control of consciousness and will.

Secret- a specific product of cell activity that performs a specific function and is released onto the surface of the epithelium or into the internal environment of the body. The process of producing and secreting secretions is called secretion. By nature, the secret is divided into protein(serous), slimy(mucoid), mixed And lipid.

Irritation– impact on living tissue external or internal irritants. The stronger the irritation, the stronger (up to a certain limit) the tissue response; the longer the irritation, the stronger (up to a certain limit) the tissue response.

Stimulus– factors of the external and internal environment or their changes that have an impact on organs and tissues, expressed in changes in the activity of the latter. In accordance with the physical nature of the impact, stimuli are divided into mechanical, electrical, chemical, temperature, sound, etc. The stimulus can be large threshold, those. having minimal effective impact; maximum, the presentation of which causes effects that do not change when the stimulus is strengthened; super strong, the action of which can have a damaging and painful effect, or lead to inadequate sensations.

Reflex reaction– a response action or process in the body (system, organ, tissue, cell) caused by reflex.

Reflex– the occurrence, change or cessation of the functional activity of organs, tissues or the whole organism, carried out with the participation of the central nervous system in response to irritation nerve endings(receptors).

Under the influence of various stimuli, due to the excitability properties of living protoplasm, processes of excitation and inhibition occur in the body. Excitability – the ability of living cells to perceive changes external environment and respond to these changes with an arousal reaction. The lower the threshold strength of the stimulus, the higher the excitability, and vice versa. Excitement – an active physiological process by which some living cells (nerve, muscle, glandular) respond to external influences. Excitable tissues - tissues capable of transitioning from a state of physiological rest to a state of excitation in response to a stimulus. In principle, all living cells have excitability, but in physiology these tissues are usually classified as predominantly nervous, muscular, and glandular. The result of excitation is the emergence of activity of the organism or its components; consequence braking is the suppression or inhibition of the activity of cells, tissues or organs, i.e. a process leading to a reduction or prevention of arousal. Excitation and inhibition are mutually opposite and interrelated processes. Thus, excitation can, when it intensifies, turn into inhibition, and inhibition can intensify subsequent excitation. To cause excitation, the stimulus must be of a certain strength, equal to or greater than excitation threshold, by which we mean the minimum force of irritation at which the minimum magnitude reaction of the irritated tissue occurs.

Automatic– the property of some cells, tissues and organs to be excited under the influence of impulses arising in them, without the influence of external stimuli. For example, heart automaticity is the ability of the myocardium to contract rhythmically under the influence of impulses arising within itself.

Lability– a property of living tissue that determines its functional state. Lability is understood as the speed of reactions underlying excitation, i.e. the ability of a tissue to carry out a single excitation process in a certain period of time. The limiting rhythm of impulses that excitable tissue is able to reproduce per unit time is a measure of lability, or functional mobility fabrics.

An important feature of humans and higher animals is constancy chemical composition and physicochemical properties of the internal environment of the body. To denote this constancy the concept is used homeostasis(homeostasis) is a set of physiological mechanisms that maintain the biological constants of the body at an optimal level. Such constants are: body temperature, osmotic pressure of blood and tissue fluid, the content of sodium, potassium, calcium, chlorine and phosphorus ions, as well as proteins and sugar, the concentration of hydrogen ions, etc. This is the constancy of composition, physicochemical and biological properties internal environment is not absolute, but relative and dynamic; it is constantly correlated depending on changes in the external environment and as a result of the vital activity of the organism.

Internal environment of the body– a set of fluids (blood, lymph, tissue fluid) that are directly involved in metabolic processes and maintaining homeostasis in the body.

Metabolism and energy consists of the entry into the body of various substances from the external environment, their change and assimilation, followed by the release of the decay products formed from them. Metabolism (metabolism) is a set of chemical transformations occurring in living organisms that ensure their growth, vital activity, reproduction, constant contact and exchange with the environment. Metabolic processes are divided into two groups: assimilatory and dissimilatory. Under assimilation understand the processes of assimilation of substances entering the body from the external environment; the formation of more complex chemical compounds from simple ones, as well as the synthesis of living protoplasm occurring in the body. Dissimilation – This is the destruction, disintegration, splitting of the substances that make up the protoplasm, in particular protein compounds.

Compensatory mechanisms– adaptive reactions aimed at eliminating or weakening functional changes in the body caused by inadequate environmental factors. These are dynamic, rapidly emerging physiological means of emergency support for the body. They are mobilized as soon as the body finds itself in inadequate conditions, and gradually fade as they develop adaptation process.(For example, under the influence of cold, the processes of production and conservation of thermal energy intensify, metabolism increases, and as a result of reflex narrowing of peripheral vessels (especially the skin), heat transfer decreases. Compensatory mechanisms serve integral part reserve forces of the body. Possessing high efficiency, they can maintain relatively stable homeostasis long enough for the development of stable forms of the adaptation process).

Adaptation– the process of adaptation of the body to changing environmental conditions. An important component of the body’s adaptive response is stress syndrome – the sum of nonspecific reactions that create conditions for the activation of the hypothalamic-pituitary-adrenal system, increasing the flow of adaptive hormones, corticosteroids and catecholamines into the blood and tissues, stimulating the activity of homeostatic systems. The adaptive role of nonspecific reactions lies in their ability to increase resistance(resistance) of the body to various environmental factors.

Although physiology is a unified and holistic science about the functions of animal and human organisms, it is divided into several, largely independent, but closely related areas. In this regard, general and particular physiology, comparative and evolutionary, as well as special (or applied) physiology and human physiology are usually distinguished.

General physiology explores the nature of processes common to organisms various types, as well as patterns of reactions of the body and its structures to environmental influences. In this regard, processes and properties such as contractility, excitability, irritability, inhibition, energy and metabolic processes, and general properties of biological membranes, cells, and tissues are studied.

Private physiology studies the functions of tissues (muscle, nervous, etc.), organs (brain, heart, kidneys, etc.), systems (digestion, circulation, respiration, etc.).

Comparative physiology is devoted to the study of the similarities and differences of any functions in different representatives of the animal world in order to identify the causes and general patterns changes in functions or appearance of new ones. Particular attention is paid to elucidating the mechanisms of qualitative and quantitative changes in physiological processes that appeared during the species and individual development of living beings.

Evolutionary physiology combines studies of general biological patterns and mechanisms of the appearance, development and formation of physiological functions in humans and animals in onto- and phylogenesis.

Special (applied) physiology studies the patterns of changes in the functions of the body in connection with its specific activities, practical tasks or specific living conditions. In practical terms, the physiology of farm animals is of significant importance. Problems of special physiology sometimes include some sections of human physiology (aviation, space, underwater physiology, etc.).

In terms of tasks human physiology stand out:

1) Aviation physiology – section of physiology and aviation medicine, focused on studying the reactions of the human body when exposed to aviation flights in order to develop methods and means of protecting flight personnel from adverse production factors.

2) Military physiology – section of physiology and military medicine, within the framework of which the patterns of regulation of body functions are studied in combat training and combat situations.

3) Age physiology – exploring age-related features of the formation and decline of the functions of organs, systems and the human body from the moment of inception to the cessation of its individual (ontogenetic) development.

4) Clinical Physiology – within the framework of which the role and nature of changes in physiological processes in the human body are studied during the development and establishment of pathological conditions in its organs or systems.

5) Space physiology – section of physiology and space medicine, associated with the study of the reactions of the human body to the effects of space flight factors (weightlessness, physical inactivity, etc.) in order to develop methods and means of protecting humans from their adverse effects.

6) Psychophysiology – the field of human psychology and physiology, consisting in the study of objectively recorded changes in physiological functions that accompany the mental processes of perception, memorization, thinking, emotions, etc.

7) physiology of sports – exploring the functions of the human body during training and competitive exercises.

8) Physiology of labor– studying physiological processes and features of their regulation during human labor activity with the aim of physiologically substantiating the ways and means of organization.



Functional mobility)

in physiology - the speed of elementary physiological processes in excitable tissue, defined, for example, as the maximum frequency of stimulation that it is capable of reproducing without rhythm transformation.

1. Small medical encyclopedia. - M.: Medical encyclopedia. 1991-96 2. First aid. - M.: Great Russian Encyclopedia. 1994 3. Encyclopedic Dictionary of Medical Terms. - M.: Soviet Encyclopedia. - 1982-1984.

Synonyms:

See what “Lability” is in other dictionaries:

- (from Lat. labilis sliding, unstable) in physiology, functional mobility, the speed of elementary cycles of excitation in nervous and muscle tissues. The concept of “lability” was introduced by a Russian physiologist... ... Wikipedia

lability- (from Latin labilis sliding, unstable) the maximum number of impulses that nerve cell or the functional structure can transmit per unit time without distortion. The term was proposed by N. E. Vvedensky. In differential psychology L. one thing... ... Great psychological encyclopedia

- (from Lat. labilis sliding unstable), 1) functional mobility of nervous and muscle tissue, characterized by the highest frequency with which the tissue can be excited in the rhythm of stimulation. The highest lability is in thick nerves... ... Big Encyclopedic Dictionary

Instability, mobility Dictionary of Russian synonyms. lability noun, number of synonyms: 4 variability (23) ... Synonym dictionary

LABILE, oh, oh; flax, linen (book). Mobile, unstable. Labile pressure. Labile temperature. Ozhegov's explanatory dictionary. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 … Ozhegov's Explanatory Dictionary

- (from lat. labilis sliding, unstable) (physiol.), functional mobility, the property of excitable tissue to reproduce without distortion the frequency of applied rhythmic movements. irritations. Measure L. max, the number of impulses that a given structure can transmit... ... Biological encyclopedic dictionary

- (from Latin labilis sliding, unstable), 1) functional mobility of nervous and muscle tissue, characterized by the highest frequency with which the tissue can be excited in the rhythm of stimulation. The highest lability is in thick nerves... ... encyclopedic Dictionary

- (lat. labilis mobile, unstable; synonym: functional lability, functional mobility) in physiology, the speed of elementary physiological processes in excitable tissue, defined, for example, as the maximum frequency... ... Large medical dictionary

- (from lat. labilis sliding, unstable) (physiol.), functional mobility, the speed of elementary cycles of excitation in nervous and muscle tissues. The concept of "L." introduced by the Russian physiologist N. E. Vvedensky (See Vvedensky) ... ... Great Soviet Encyclopedia

lability- labilumas statusas T sritis chemija apibrėžtis Greitas kitimas keičiantis sąlygoms. atitikmenys: engl. lability rus. lability; instability... Chemijos terminų aiškinamasis žodynas

lability- labilumas statusas T sritis fizika atitikmenys: engl. lability vok. Labilität, f rus. lability, f pranc. labilité, f … Fizikos terminų žodynas

Books

• Typology of labile verbs, Letuchy Alexander Borisovich. The book uses typological material to examine labile verbs - verbs that can be both transitive and intransitive without changing their form. Lability has not yet been studied by linguistics in...

Lability is a concept used to describe mobility. The area of ​​application may slightly change the semantic characteristics, indicating both the number of nerve impulses transmitted per unit of time by the cell, and the speed of starting and stopping mental processes.

Lability characterizes the rate of occurrence (from the onset of reaction to inhibition) of elementary processes, and is measured by the highest frequency of impulse reproduction without changes in tissue function and the time of functional recovery. This indicator is not considered a constant value, since it can change from external factors (heat, time of day, force), influences chemical substances(produced by the body or consumed) and emotional states, therefore it is possible to observe only the dynamics and predisposition of the body, the prevailing level. It is the change in lability indicators that is key in diagnosing various diseases and norms.

What is lability

In scientific applications, lability is used synonymously with mobility (normally), instability (in pathology) and variability (as a characteristic of the dynamics of a state and processes). To understand the breadth of use of this term, we can consider examples of the fact that there is lability of mood in body temperature, psyche and physiology, and accordingly applies to all processes that have speed, constancy, rhythm, amplitude and other dynamic characteristics in their indicators.

The course of any processes in the body is regulated by the nervous system, therefore, even when talking about indicators of pulse or mood lability, we are still talking about the degree of lability of the nervous system (central or autonomic, depending on the location of the instability). The autonomic nervous system regulates internal organs and the system, respectively, the general condition of the body depends on its work, the ability to maintain the rhythm and stability of processes.

Autonomic lability brings disturbances in the functioning of the heart (manifestations are in the form of arrhythmia, problems with blood pressure and quality), the functioning of the glands (problems with sweating or the production of substances necessary for the quality functioning of the body may begin). Many, it would seem, psychological problems or those associated with the central nervous system are actually resolved at the level of reducing autonomic lability, which ensures productive sleep and the absorption of beneficial microelements. At the same time, it is worth remembering that signaling about the level of stress or a critical emotional situation is primarily not the central system, but the autonomic system, by increasing its lability. Mechanisms that activate the work of all organ systems to overcome difficult or extreme situations use the internal reserves of the body, forcing the heart to speed up the rhythm, the lungs to absorb more air, the iron to remove excess adrenaline through sweat, and only then the central nervous system reactions are activated.

Lability of the nervous system or mental lability is characterized by a pathological state of mood disturbance, expressed in its swings and inconstancy. The condition may be the norm for adolescence, but is classified as a spectrum of pathological conditions for adults and requires medical care, as well as the work of a psychologist, even without prescribing medications.

Lability in psychology

Mental lability, considered in psychology, implies its mobility, and in some cases instability, while science itself studies only this aspect of lability, without going into physiology. In most sources, mental lability is considered as a negative quality that requires correction, but it does not give due credit to the fact that this is the main adaptive mechanism of the psyche. It was the speed of reaction and switching between quickly and often unexpectedly changing events in external life that helped humanity survive. The opposite is the psyche, when a person remains constant for a long time, and any changes knock him out of his normal state. Any of these characteristics in its extreme manifestation is negative, but at moderate levels it gives its advantages.

Problems with lability, when a person comes to a psychologist, are associated with frequent changes in mood, while all spectrums are experienced not superficially, but really deeply (i.e., if you feel sad, then you think about opening your veins, and if you are happy, then you want to dance on workplace and give candy to passers-by - and all this within one hour). It is precisely the difficulties in coping with one’s own and the lack of understanding of how this can be corrected that brings many not only mental suffering, but the subsequent changes in health, since the autonomic system, being subordinate to emotional states, also increases the level of its lability.

Such phenomena can be justified by the type of organization of the nervous system, so in people with the speed of reactions is already due to nature, and accordingly, increased lability to pathological condition more likely. Mood swings can also be triggered by frequent exposure to traumatic situations at an early age. But we should not exclude physiological reasons that affect a person’s psychological state: brain tumors, TBI, vascular diseases.

Correction of such unpleasant conditions begins with diagnosis and exclusion of physiological causes, then, if necessary, correction is possible with mood-stabilizing drugs (antidepressants and tranquilizers), accompanied by a course of psychotherapy. In severe cases, treatment in a hospital may be appropriate; in the mildest cases, you can cope by visiting a psychologist, without interrupting your usual life.

Lability in physiology

In physiology, lability is considered as a property of tissue that characterizes its change during prolonged excitation. Reactions to prolonged excitation can be expressed in three types of response: a response to each impulse, transformation of the original rhythm into a rarer one (for example, a response to every third impulse) or cessation of the response. For each cell of the body, this rhythm is different, and it may differ from the rhythm of the organ consisting of these cells, as well as from the rhythm of the entire organ system. The faster the tissue reacts to irritation, the higher its lability is considered, but there are few indicators of only this time; it is also necessary to take into account the time required for recovery. Thus, the reaction can be quite fast, but due to the long recovery time, the overall lability will be quite low.

Lability increases or decreases depending on the needs of the body (the normal option, without diseases, is considered), and it can increase from the metabolic rate, which forces all systems to speed up the rhythm of work. An increase in lability has been noticed, that when the body is in a working active state, i.e. The lability of your tissues is much higher if you run than if you read while lying down, and the indicators remain at an increased value for some time after the cessation of vigorous activity. Such reactions are associated with the assimilation of a rhythm that meets current environmental conditions and activity needs.

The regulation of physiological lability can also be addressed in cases of disorders of the psychological spectrum, since many conditions have as their root cause not mental disorders or emotional experiences, but physiological disorders. For example, a physiological effect can eliminate sleep problems, which will automatically increase the level of attention and reduce sleep, the treatment of which would be ineffective without taking into account physiological indicators.

Intellectual lability

Intellectual lability is one of the components of the lability of the nervous system and is responsible for the processes of switching between the processes of activation and inhibition. In life, this looks like a fairly high level of mental development and the ability to logically analyze incoming information. Since a critically huge number of information blocks requiring information are received every second, there is a need to sort them as quickly as possible (at a subconscious automatic level) into significant and insignificant.

The presence of a large knowledge base becomes irrelevant and testifies not to knowledge, but to erudition; much more significant is the ability to switch between various sources information, between different information in meaning, and also in the shortest possible time move on to solving the next (albeit opposite) problem. At this switching speed, the main thing is to maintain the ability to highlight the main thing for the task at hand. this moment time. It is precisely this process of intellectual work that ensures high intellectual lability.

Previously, they did not know about this property, then they talked about it, but rarely, and now, when the pace of life is accelerating, the amount of information consumed is growing at such a pace that a person who lived two hundred years ago would have needed a month to realize that we process within an hour , this becomes a determining factor for success. This gives the ability to respond adequately and as usefully as possible in changing conditions, promotes instant analysis of many factors, which allows minimizing the possibility of error.

In addition, rapid switching between various topics and issues provides innovative thinking, new ways to solve old problems, rapid assimilation of knowledge and skills, and this happens at a faster pace. deep level. For example, historical data on the same event, drawn from different sources (here it is impossible to do without using the capabilities modern world) provides a more objective and comprehensive understanding than quoting the textbook author’s point of view. The ability to learn quickly is due to the fact that there is no need to tune in to the arrival of material - ten minutes of reading an article in a minibus, accompanied by listening to new music, or writing a thesis with breaks to watch educational videos becomes a familiar way of functioning, providing new opportunities.

Emotional lability

Mood lability, which is the main reflection of emotional lability, is the variability of the mood pole, often without expressed reasons for this. The nervous system is responsible for our emotional state, and when it is weakened, it becomes hypersensitive, which explains the instant and strong reaction to even minor stimuli. The color can be anything - either happiness or sadness; aggressive affects and apathetic sadness arise with equal ease.

Symptoms may include spontaneity of actions, impulsiveness, lack of ability to predict the consequences of one’s own actions. The occurrence of affective outbursts and uncontrollable states for minor or absent reasons was the reason for including emotional lability in the lists of psychiatric disorders requiring stabilization under medical supervision. It may also not be a separate disease, but a symptom of more dangerous and complex ones (severe tumors, problems with blood pressure, hidden consequences of traumatic brain injuries, etc.). It is difficult to diagnose in childhood, since it has been little studied and is often confused with, therefore, a team of specialists from a psychiatrist, psychologist and neurologist is required for diagnosis.

Emotional instability manifests itself in restlessness, lack of patience and acute reaction to criticism or obstacles, difficulties in establishing logical chains, as well as mood swings. These swings are different from manic-depressive disorder and are characterized by a rapid change of states with the same deep experience of the emotional spectrum.

Any overload of the nervous system contributes to this development of the emotional sphere: emotional stress, psychotraumas or their actualization, hyper- or hypoattention from society, hormonal changes (adolescence and menopause, pregnancy). Physiological reasons: somatic diseases, deficiency of vitamins (especially group B, necessary to maintain the functioning of the nervous system), as well as difficult physical conditions.

If emotional lability is diagnosed, then a psychiatrist should correct it; if the condition is not so dire, then a course of prevention is prescribed by a psychologist. In any case, you should not treat such manifestations with disdain, explaining them as bad character.

N. E. Vvedensky developed the idea of ​​lability, or functional mobility (1892). He defined physiological lability as the speed with which a given living tissue manages to complete the full period of individual excitation in time.

A. A. Ukhtomsky believed that the measure of lability is the largest “number of individual completed periods of excitation that the substrate can accommodate per unit of time.”

Physiological lability is the main property of living tissue, which determines its functional state. It characterizes changes in the physiological state of living tissue not with a single wave of excitation, but with the interaction of a whole series of waves of excitation occurring in a certain rhythm - an ensemble of excitations. Lability determines whether living tissue will respond with a wave of excitation to each pulse of rhythmic stimulation, or whether it will transform the frequent rhythm of stimulation into a rarer one, or whether such transformation will turn into inhibition, and inhibition will again turn into excitation.

The more the frequency of irritation impulses increases, the more frequent the rhythm of excitation waves becomes. The maximum rhythm of stimulation causes the maximum rhythm of excitation, which is highly unstable. Electrophysiological studies have established that every living tissue is capable of reproducing synchronously, i.e., in accordance with the rhythm of stimulation without transformation of inhibition or fatigue, its characteristic optimal rhythm of stimulation.

The maximum rhythm of a synchronized response to stimulation for single motor nerve fibers of a frog is about 300 per 1 s, optimal - 75 (less often 50) - 150 per 1 s, for muscle fibers maximum - 150 (less often 200) per 1 s, optimal - 20-50 in 1 s.

The maximum rhythm of impulse conduction in the motor nerves of warm-blooded animals is more than 1000 per 1 s, and in the nerve centers - 200-400 per 1 s. N. E. Vvedensky established that the excitation impulses themselves are capable of changing the lability of the irritated tissue, increasing it and decreasing it.

The physiological lability of this tissue depends on the strength and frequency of excitation impulses coming to it from the H, E, Vvedensky central nervous system, and on neurohumoral influences. There is a relationship between physiological lability and excitability. Tissue excitability is highest with an average, relatively low level of physiological lability. The less time required for excitation to occur during irritation, the greater the lability of tissue. The slower the tissue reacts to irritation, the less lability there is. Lability determines not only the minimum time required for the occurrence of excitation, but also the entire time required for the excitation to occur and to restore the ability of the tissue to give new, subsequent excitation impulses. Conditions that reduce tissue viability (cold, heat, strong electricity, mechanical pressure, drugs, saline solutions, etc.), reduce the lability of the nerve section changed (altered) by these effects. This decrease in lability is due to the fact that under the influence of these influences the recovery processes slow down.

Different groups of nerve fibers have different lability. The lability of the same nerve fibers varies depending on their physiological state.

Excitability and its dynamics

The measure of excitability of a living cell is determined by two indicators: 1) by the lowest threshold strength (intensity) of stimulation that causes excitation, which is called the threshold of excitability, and 2) by the shortest time of action of a stimulus of a certain strength (intensity).

The excitability of each living tissue changes depending on the conditions and its physiological state: for example, with gradual cooling, with a shift in the blood reaction towards acidity, it decreases, and with a gradual increase in temperature to 40°C and a shift in the blood reaction towards alkalinity, it increases.

In animals with a constant body temperature, the initial level of excitability, characterizing a given living tissue, is observed in the absence of fatigue, with a normal body and normal reaction.

Mastering the Rhythm

The most frequent rhythm of threshold and suprathreshold stimulation, to which a given excitable tissue responds with the same frequent rhythm of excitation waves, reflects its functional state or its lability during activity.

A. A. Ukhtomsky created the idea of ​​mastering rhythm (1928), according to which lability changes all the time in connection with activity. Lability during stimulation can increase or decrease, which is expressed in an increase or decrease in the maximum rhythm of excitation. This change in lability is caused by. that the impulses and excitations themselves are capable of changing the functional state of the excited tissue. After the action of each irritating impulse, lability changes in two phases: first it increases and then decreases. Lability depends on the strength and frequency of impulses incident on the tissue and on the metabolism in the tissue.

Under the influence of work, lability increases, which leads to the adoption of a higher rhythm than at the beginning of work. The assimilation of rhythm is especially pronounced against the background of increased excitability. It continues for some time after the work stops.

An increase in physiological lability in connection with activity, which manifests itself in the fact that excitable tissue responds with a higher excitation rhythm compared to the initial rhythm, is called rhythm acquisition. The assimilation of rhythm depends on ongoing changes in metabolism in the tissue during its activity. After a short irritation of the muscle, its lability increases within a few minutes, which can be explained by the action of the products.

• - functional mobility, the ability of excitable tissue to reproduce without distortion the frequency of applied rhythmic movements. irritation...

  Biological encyclopedic dictionary

• - lability in physiology, functional mobility, the ability of the nervous and muscle tissues of the animal body to reproduce in 1 second the maximum number of impulses in full accordance with the rhythm of the acting...

  Veterinary encyclopedic dictionary

• - instability to changes in the external and internal environment...

  Dictionary of botanical terms

• - according to B. M. Teplov, a property of the nervous system, characterized by the speed of emergence and cessation of the nervous process...

  Trainer's Dictionary

• - 1) functional mobility of nervous and muscle tissue, characterized by the most. frequency, with which the tissue can be excited in the rhythm of stimulation...

  Natural science. encyclopedic Dictionary

• - 1) instability, variability, functional mobility of nervous and muscle tissue, characterized by the highest frequency of excitation under the influence of stimuli...

  Beginnings modern Natural Science

• - the maximum number of impulses that a nerve cell or functional structure can transmit per unit of time without distortion. The term was proposed by N. E. Vvedensky...

  Great psychological encyclopedia

• - Instability of functioning, inconstancy, significant fluctuations in the amplitude of certain manifestations...

  Explanatory dictionary of psychiatric terms

• - in physiology, the speed of elementary physiological processes in excitable tissue, defined, for example, as the maximum frequency of stimulation that it is capable of reproducing without rhythm transformation...

  Large medical dictionary

• - , functional mobility, the speed of elementary cycles of excitation in nervous and muscle tissues...

  Great Soviet Encyclopedia

• - 1) functional mobility of nervous and muscle tissue, characterized by the highest frequency with which the tissue can be excited in the rhythm of stimulation...

  Large encyclopedic dictionary

• - LABILE, -aya, -oe; - flax, - flax. Mobile, unstable. Labile pressure. Labile temperature...

  Ozhegov's Explanatory Dictionary

• - lability g. An unstable mental and physiological state of a person, one of the properties of the nervous system, characterizing the rate of emergence and cessation of nervous processes...

  Explanatory Dictionary by Efremova

• - lab "...

  Russian spelling dictionary

• - lability, instability, variability; physiol. functional mobility - the speed of elementary cycles of excitation in nervous, muscle or other excitable tissue...

  Dictionary foreign words Russian language

• - ...

  Word forms

"functional lability" in books

Functional therapy

author Panysheva Lidiya Vasilievna

Functional therapy

From the book Dog Diseases (non-contagious) author Panysheva Lidiya Vasilievna

Functional therapy The use of active movements of an animal or passive movements of individual parts for therapeutic purposes is called functional therapy. Animal movements are a physiological necessity. In the absence or insufficient movement

Functional strategy

From the book MBA in 10 days. The most important programs from the world's leading business schools author Silbiger Stephen

Functional Strategy Functional strategy is the operational methods and “value-adding” activities that management chooses for its business. The functional strategy of Philip Morris (Altria Group), for example, was to reduce costs through

4.3.6. Functional structure

From the book Strategic Management author Ansoff Igor

4.3.6. Functional structure The first modern organizational form emerged in the middle of this century as a reaction to the rapid growth and complexity of the company. This is a functional organizational structure that became widely used in industry and is still used today.

Functional structuring

From the book A Guide to the Methodology of Organization, Leadership and Management author Shchedrovitsky Georgy Petrovich

Functional structuring The following example. Imagine that there are many points in front of me. What is this - structure or organization of the material? Unclear. Now imagine that I give the task to count how many points there are. And that's because

Functional immaturity of the gastrointestinal tract

From the book Child and caring for him. From birth to 3 years author Sokolov Andrey Lvovich

Functional immaturity of the gastrointestinal tract

Functional dyspepsia

From the book From zero to primer author Anikeeva Larisa Shikovna

Functional dyspepsia in a child early age Functional digestive disorders associated with insufficient gastric juice and accelerated gastric emptying are often observed. Most often, functional dyspepsia is based on

(3) Psycho-emotional lability

From the book Thresholds of Dreaming author Ksendzyuk Alexey Petrovich

(3) Psycho-emotional lability By “psycho-emotional lability” we mean the mobility of emotional reactions that we consider to be flawed - fear, self-importance, self-pity. This effect once again confirms that the position of the assemblage point

"Functional" coloring

From the book System of Things by Baudrillard Jean

"FUNCTIONAL" TRANSCENDENCE

From the book System of Things by Baudrillard Jean

“FUNCTIONAL” TRANSCENDENCE So, the degree of perfection of a particular machine is constantly presented as directly proportional to the degree of its automation. But to automate a machine, you have to give up many of its operational capabilities. To

Functional beauty

From the book Consumer Society by Baudrillard Jean

Functional beauty In this long process of sacralization of the body as an exponential value, a functional body, that is, one that is no longer “flesh”, as in the religious vision, nor labor force, as dictated by industrial logic, but taken into its

From the book PSYCHOANALYTIC THEORIES OF DEVELOPMENT by Tyson Robert

ADOLESCENCE: AFFECT LABILITY AND PSYCHIC RESTRUCTURING Biological maturation during adolescence, accompanied by increased desire and rapid physical, cognitive and social changes, presents a test for protective and