From Big Medical Encyclopedia

REACTIVITY OF THE ORGANISM — property of an organism to answer with change of life activity influences of the environment. Reactivity is the same property of an organism as growth, reproduction, food, a metabolism, etc. Reactivity forms in the course of evolutionary development of specific, hereditary qualities of an organism. Except specific properties, reactivity reflects group, standard, and also specific features of reaction of separate organisms.

The concept «reactivity of an organism» is closely connected with the concept «resistance» designating resistance of an organism to action of various disturbing factors (see. Resistance of an organism ). Reactivity represents the general designation of mechanisms of resistance of an organism, and resistance — expression of processes of reactivity as protective, adaptive act (see. Adaptation ).

The concept «reactivity» was established at the beginning of 20 century when the phenomena of an anaphylaxis and an allergy became known. Problems P. of the lake from positions of the general pathology were developed by hl. obr. in the USSR. In their development works A are of great importance. A. Bogomolts, P. K. Bulatov, M. S. Maslov, B. S. Preobrazhensky, A. D. Speransky, G. N. Speransky, M. V. Chernorutsky, etc. The general patterns of evolution primary, immunological and and l ler-gichesky forms P. the lake and the sequence of their formation in filo-and ontogenesis, the relation of reactivity and: were established to nonspecific resistance of a human body and animals to disease-producing influences by N. N. Sirotinin and his employees.

The river of the lake is an important element: a pathogeny of diseases (see. Pathogeny ). Patol. reactivity is characterized by decrease adaptive, opportunities of a human body.

With nek-ry restrictions it is possible to speak about reactivity of separate bodies, cells and even the subcellular structures making reactivity of a complete organism. Preeg it it is necessary to consider that reactivity of a complete organism is defined first of all by a condition of nervous, endocrine and immune systems. Sometimes for expression of ability: fabrics apply such concepts as reactive or areactive regeneration to regeneration or an inflammation, etc.

Reactive in the broadest sense call process phagocytosis (see), causing a resorption of this or that fabric. Reactivity call also ability of cells, e.g. an epithelium of the upper airways affected with a virus: flu to isolate and delete a virus by rejection of cells, viruliferous, with the subsequent regeneration of an epithelium.

In the course of evolution mechanisms of reactivity changed. On the basis of comparative study of reactivity of different types of animals it is established that than less shouting-ganrshovano an animal, than the nervous system is less developed at it, in simpler form its reactivity is expressed to those. So, reactivity of the elementary and many invertebrates, in essence, is defined by a metabolism, to-ry changes at adverse effects of the environment. Most often this decrease in a metabolism in various degree. Such hyporeactivity allows to transfer a considerable hypoxia, low temperatures, etc.

The most high-organized animals and the person differently react to the lowered oxygen content. Their c. N of page, and first of all the cerebral cortex, is especially sensitive to a lack of oxygen. At hypoxias (see) excitement of c is observed. the N with, is as a result activated breath, stocks of erythrocytes are thrown out a blood channel and by that respiratory function of blood increases, the minute volume of blood circulation and so forth increases. These changes are directed to strengthening of delivery of oxygen in fabrics and simplification of its utilization. The arisen reactions are the active adaptive reactions promoting existence of an organism in unfavorable conditions (see. Adaptation ).

Active changes of life activity of protective character are connected with various manifestations of processes excitement (see) and braking (see). The above the animal is organized, the it is more at it than opportunities to react actively on various, including disease-producing, influences of the environment that is carried out first of all by protective activity of a nervous system. Instinctive reflexes (see) and conditioned reflexes (see) are a basis of this activity. Such simple reflexes, as defensive — an otdergivaniye, e.g., extremities at a prick, a burn or reaction of «release» (cough, vomiting) of an organism from the harming agents (microbes, dust, poisons), and composite reactions of an organism — fever (see), inflammation (see), allergy (see) — are the mechanisms of reactivity defining its adaptive value. Guarding braking in a cerebral cortex and underlying parts of the nervous system can also have adaptive value. Thus, thanks to reactions of a nervous system in the damaged organism (an injury, an infection, poisoning, a burn) there are changes of life activity directed to maintenance of its existence in the conditions of the arisen damage. At the same time high-organized animals are less steady against influence of nek-ry bacterial toxins, napr, to dysenteric, and also against a hypoxia, action of low and high temperatures and other harmful effects of the environment.

Evolution of reactivity and resilience (resistance) on the example of infectious process is described by N. N. Sirotinin.

I. I. Showed swordsmen that infectious process at protozoa proceeds in the form of simple reproduction of microbes in protoplasm of cells (a primitive septic infection). Reaction of an organism to an infection is shown at them only in the form of intracellular digestion; they are rather steady against effect of bacterial toxins. In process of complication of the organization (a sponge, coelenterates) infection (see) is followed by the first reactive changes: phagocytes will be mobilized, there is for the first time a fabric reaction in the form of a primitive inflammation. Further complications of the organization of animals and first of all development of a nervous system cause emergence of thinner mechanisms of reactivity. So, special means of fight of an organism against contagiums, napr develop, there is an ability to develop antibodies (see), reactive changes of life activity of an organism form (fever, an inflammation, guarding braking in a cerebral cortex, a parabiosis). Similar patterns take place and at formation of reactivity at early age at high-organized animals and the person. Really, mammals at this age transfer Wednesday with the lowered oxygen content (N. N. Sirotinin) easier, are steadier against bacterial toxins (diphtheritic, etc.) that the lake, and about existence of the mechanisms adapting an organism for these conditions testifies not to low R. (e.g., smaller intensity of oxidizing processes).

Comparison of different forms of reactivity showed that at high-organized animals, at to-rykh reactivity — the most complex process managed by a nervous system, means of fight against disease-producing influences of the environment are diverse and most of all connected with reflex acts (instinctive and conditioned protective reflexes).

The complex organization of high-organized animals allows also diverse forms it «having broken», damages under the influence of influences of the environment. At the same time is available for them much more means of fight against various damages (various forms of compensatory activity). Mechanisms of reactivity, as well as mechanisms of resistance, at high-organized animals more difficult and are more diverse, than at less high-organized. So, at nek-ry vertebrata (e.g., hematocryal) inf. process proceeds differently, than at high-organized animals and the person: feverish reaction, as well as other signs inf. process (purulent, exudative inflammations, reactions of guarding braking of c. N of page, reaction of century of N of page) — at hematocryal are absent. Hematocryal have specific immunity to the majority of infections of the person.

At the animals deprived of a nervous system or having it in a primitive look, the main mechanisms of reactivity and resistance are fabric neutralization tests of poisons and mobilization of additional energy sources (naira., glycoclastic reactions at an anaerobiosis), phagocytosis, proliferative processes. These mechanisms are to a certain extent passive, but they create high and peculiar fabric reactivity and resistance.

Reactivity of the person differs from reactivity of animals first of all in the fact that functions at the person as beings social, in particular behavior, are mediated various social (production, household, family) by factors. Influence natural (geographical, climatic) factors on the person is mediated by also social factors since the person the work changes climatic (artificial reservoirs, plantings, etc.), microclimatic (the dwelling, clothes) living conditions; also character of food, etc. matters. Influence of social factors on R. of the lake of the person is implemented through nervous and endocrine systems. In a crust, time influence of various affects is intensively studied (see. Emotions ) or emotional stresses (see) on R. of the lake. The second alarm system is the most important mechanism of a social oposredovaniye of R. of the lake of the person. Suggestion (see. Hypnosis ) it is possible to change reactivity of century of N of page of the person, to cause, e.g., an attack of bronchial asthma, hypertensive crisis, and also nausea and vomiting. Suggestion, or psychotherapy (see), it is possible to remove psikhogenno the arisen diseases. Cases of death from psychogenic shock are known (see. Reactive psychoses) the people who received adverse, negative in the emotional relation, news.

The social oposredovaniye of R. of the lake of the person is the cornerstone of the principles of a deontology (see. Deontology medical ). The attentive attitude of the doctor and the looking after personnel towards the patient is the most important condition of his recovery. In many cases positive emotions, fulfillment of desires and hopes of the patient exert decisive impact on efficiency of therapeutic actions.

Various household and professional factors influencing a human body change R. to the lake. So, exhaust gases of cars reduce resistance of a human body to an influenza virus, to Friedlander's bacteria; air pollution by various chemical substances (nitric oxides, sulfurs, carbon, compound of lead, etc.) reduces natural immunity at nek-ry persons. Changes of reactivity are observed also at impact on an organism of pesticides.

Clinical aspects of reactivity

the Term «reactivity» is widely applied by clinical physicians to designation of features of development and disease at individuals. R. Ressle offered the term «pathergy» (1933) for expression first of all to the changed reactivity of the sick person. I. P. Pavlov repeatedly applied the term «reactivity» to assessment of century of N of.

The most widespread is the use of the term «reactivity» in a wedge, medicine for the general assessment of a condition of the patient. The clinic of internal and infectious diseases, e.g., distinguished reactive and not reactive forms of a course of diseases. Allocated reactive (giperergichesky) and ma-loreaktivny (anergic, gip-ergichesky) forms of pneumonia, tuberculosis, dysentery, etc. Reactive forms designated diseases with a rapid, rapid current. Understood diseases with a sluggish current as low-reactive forms, with the implicit, erased signs.

Studying of changes of R. of the lake is the basis for a research allergic diseases (see). Questions of reactivity of a children's organism are paid by pediatrics much attention. So, it is established that food and toxic dystrophies, rickets and other hypovitaminoses are followed by R.'s decrease of the lake of the child. Disturbances of reactivity at hypovitaminoses suggested to call a dizergiya. Essential changes of reactivity are found at children's infections (scarlet fever, measles, diphtheria, etc.;. Disturbances of reactivity at these infections designated as a heteroallergy.

In surgery connect various current of a wound process with change of reactivity (see. Wounds, wounds ), sepsis (see), peritonitis (see), etc. the Bystry wound repair (magnificent red granulations, the expressed epithelization) testifies to high reactivity of an organism; slow healing (small, pale granulations, weak epithelization) — about hyporesponsiveness. Distinguish the following forms of peritonitis and sepsis: giperergichesky (fulminant), normergichesky, ginergichesky (sluggish, long). The Giperergichesky form of sepsis often is followed by defeat of c. the N of page (respiratory center) and century of N of page can also end with death within a day or several hours. The main symptoms of sepsis do not manage to develop. Normergichesk I the form is followed by the expressed septic (gektichesky) fever, characteristic changes in blood (acceleration ROE, anemia, a neutrophilia, eozino-and a lymphopenia), hemorrhages in skin and serous cavities, etc. the Gipergichesky form is characterized by a sluggish current, the wrong type of a temperature curve (sometimes subfebrile temperature), minor change of ROE, a lymphocytosis and gradual development of wound (traumatic) exhaustion in the patient (see. Traumatic exhaustion).

R.'s changes by the lake of allergic type are observed at nek-ry toxicoses of pregnancy (so-called allergoses). Various forms fungus diseases of skin (see) arise against the background of R.'s changes by the lake caused by causative agents of these diseases.

At tuberculosis (see) at most of persons immunity (immunity, resistance) is followed by sharply reduced reactivity to tuberculine and to antigens of mycobacteria of tuberculosis. The lowered reactivity (anergy) to tuberculine can take place with high immunity (resistance) to mycobacteria of tuberculosis (a so-called positive anergy when antigens of mycobacteria of tuberculosis quickly collapse cells of an immune organism and do not sensibilize an organism). In other cases the lowered reactivity develops against the background of heavy weakening of an organism owing to poisoning with toxic products of the mycobacteria (a so-called negative anergy) breeding in it.

Many foreign researchers [E. Urbach, 1935; R. Ressle, 1936; The Ruble of Der, 1938] estimated a condition of reactivity only quantitatively (more — less). Condition of the increased (increased) reactivity called a hyperergy, a state reduced (weakened) — a hypergia. Similar division was the basis for many a wedge, R.'s classifications by the lake. Studying of reactivity only by quantitative indices, without qualitative, is incomplete. As it was already specified, reactivity characterizes by itself a certain form of the relation (equilibration) of an organism to the environment. A quality indicator of reactivity is resistance of an organism to action of disturbing factors. Increase in reactivity can not cause reaction, useful to an organism. E.g., at anaphylactic shock (see) reactivity it is increased, but it is followed by weakening of resistance of an organism to action of a disturbing factor. On the other hand, hibernatation (see) at nek-ry animals is followed by reduction of reactivity that is perfect adaptive reaction since promotes stability, resistance of an organism to action of harmful factors for an organism (infections, intoxications). Assessment of quality indicators of reactivity allows to characterize more fully R. by the lake for applied medicine.

Types of reactivity

there is a set of schemes and R.'s classifications by the lake [R. Ressle, 1933; A. I. Abrikosov, 1933; Urbakh, 1934; G. W. Bray, 1937; Sh. D. Moszkowski, 1947]. However they are bulky and excessively complicated.

Main types of reactivity are biological (specific), group (standard), individual, and also pathological. R.'s basis of the lake is biological, or specific, reactivity. B yole. reactivity call zashchitnoprisposobitelny changes (see. Defense reactions of an organism ), to-rye arise under the influence of usual influences (irritations) of the environment, (adequate) for each species of an animal. Sometimes such reactivity call primary. It is directed to preservation of a look and the individual. On the basis of specific reactivity reactivity of each individual — individual reactivity forms.

Example biol. reactivity the directed movement (taxis) of protozoa and compound instinctive reflexes (instincts) of invertebrates is (bees, ants, etc.); the seasonal migrations of fishes and birds connected with reproduction and seasonal changes of the environment and also seasonal changes of life activity of animals (anabiosis, hibernatation, etc.). Studying of such phenomena shows that at the same time, in addition to preservation of a look what is their basis, there are essential changes of the main properties of an animal (a metabolism, resistance to disturbing factors, etc.), and at high-organized changes of activity of nervous and endocrine systems therefore the relation of animals to influences of the environment changes are observed. E.g., excitability of nerves of a frog to electric irritation is more in the summer, than in the winter; in the spring when gonads strenuously work, the irritation of a vagus nerve causes the perverted effect (sympathetic) on action of the heart, etc.

It is convenient to show manifestations of specific reactivity on the example of hibernatation of animals, in to-ruyu under the influence of the lowered ambient temperature and deterioration in conditions of food many rodents (gophers, groundhogs, bats, sleepyheads), and also nek-ry reptiles, amphibians fall. At the same time there is a sharp oppression of life activity of an organism, all its functions are extremely lowered: in c. the N of page develops diffuse guarding braking, reflex activity of a nervous system is oppressed, the metabolism is sharply lowered; the amount of the absorbed oxygen is reduced; body temperature goes down. Hibernation sharply changes resistance of an animal to an infection and poisonings. So, the gophers, groundhogs infected with plague, tuberculosis, a malignant anthrax and other infections are not ill (microbes are late in the place of infection and remain for the period of hibernation of an animal). Awakening immediately causes a disease and death. Hibernation also increases strychnine, diphtheritic and tetanic toxins and other poisons resistance of an animal. At hibernation ability of an organism to answer with inflammatory reaction to influence of various irritants is sharply oppressed. So, healing of wounds at an animal in such state proceeds more slowly, than in a condition of wakefulness since regeneration and growth of connective tissue cells and an epithelium are sharply oppressed. Phagocytosis, antibody formation during hibernatation are lowered, the content in blood complement (see) it is reduced; it is not possible to reproduce an acute anaphylaxis and local allergic reactions.

On the basis of specific reactivity it is possible to mark out group, or standard, reactivity. At the same time consider features of reactivity of the separate individuals making group. So, on types of century of N of, immunogenetic signs of blood (see. Blood groups ), to constitutional type (see. Constitution ) develop characteristics of group reactivity.

Attempts to divide people on their behavior into groups were made during an era of Ancient Greek medicine. So, Hippocrates allocated the main types of temperaments — sanguine persons, choleric persons, melancholiacs and phlegmatic persons. He considered that each type is predisposed to certain diseases.

I. P. Pavlov on the basis of experiences on dogs allocated the main types of century of N of — strong balanced, mobile; strong balanced, inert; strong unbalanced, or impetuous, and weak. Types higher nervous activity (see) are combined with many manifestations of reactivity of animals. So, during the studying of reactivity of dogs on blood loss it was established that dogs of strong balanced type react short-term increase in the ABP, by deepening of breath, reduction in blood of quantity of erythrocytes, hemoglobin and protein, to-rye are recovered within several hours or days; dogs of weak type — falling of the ABP, increase of breath and cordial reductions and same as at dogs of strong balanced type changes in blood, to-rye are recovered in 2 — 3 weeks. After a complete starvation at dogs of strong balanced type the proteinaceous composition of blood is recovered in 2 — 3 weeks after the end of starvation, at dogs of weak type — in 5 — 9 weeks.

A. D. Ado and S. I. Weis, studying anaphylactic reactions at dogs in hron. experience, allocated reactive, moderately reactive and sluggish, low-reactive types. Under identical conditions of a sensitization and the allowing administration of antigen (horse serum) reactive dogs are sensibilized most quickly (7 — 9 days). After the postponed acute anaphylaxis they usually have no desensitization. Dogs of sluggish, low-reactive type are badly sensibilized and demand bigger time for development of an anaphylaxis. After an acute anaphylaxis they have a bystry and strong desensitization. Dogs of moderately reactive type are intermediate between two described types.

Studying various immunol. indicators of blood of the person allowed to find nek-ry correlations between a blood group and R.'s features of the lake. So, at patients with bronchial asthma the blood group of MN (MNSS system) and a blood group prevails 0 (AB0 system), also increase in a gaptoglobin is observed (Nr 2 — 2).

Impact of pathogenic factors, equal on force, on people or animals does not cause in all individuals of identical changes of their life activity. For example, diathermic current (tension 1000 — 2000 in, number of the periods 3000 in 1 sec.) causes only deep warming up of fabrics in most of people; at persons with a hyperreactivity of the nervous system increased by goitrous gland (a so-called timiko-lymphatic state) sometimes there occurs reflex delay and even a stop of cordial activity. During the testing of toxicity of bacterial drugs it is established that from the same dose one animals (e.g., mice of one weight and age) perish, others survive.

Especially brightly individual reactivity comes to light during the studying in collectives of immunity, forms of infections, efficiency of immunization and so-called reactivity of vaccines. So, at immunization of children a diphtherial anatoxin P.F. Zdrodovsky established that at 20,3% of immunizirovanny children active development of antibodies, the development of antibodies at 52% reduced, and at 27,7% — weak is observed. As conditions of immunization, age of children and antigen were identical, observed distinctions can be explained with features of individual reactivity of children. Studying of epidemics shows that people have the same infection a serious illness, easily or at all are not ill though the activator is in an organism (the masked, latent infections, a carriage of virus). During the carrying out mass inoculations (e.g., against a typhoid and paratyphus) at a part imparted (to 5%) the sharp temperature and expressed inflammatory reaction in the place of an inoculation is usually observed. If strong reactions are observed more than in 5% of cases, then such vaccines call reactive since they cause complications and in people with the reduced reactivity. Such vaccines are not suitable for the use.

Individual reactivity depends on hereditary, constitutional properties, age, sex and influences of the environment. The major factors defining individual reactivity are the type of century of N of, functional features of century of N of page, closed glands and other bodies and fabrics. Reactivity of the same organism in relation to various irritants is not identical. So, it is established that immunol. reactivity can be various to different antigens that, apparently, is caused genetically. Individual reactivity can be two types — physiological and pathological. Pathological, painfully changed, reactivity arises under the influence of impacts on an organism of disease-producing environmental factors. It is characterized by decrease in adaptive opportunities of an organism.

I. R. Petrov with sotr. it is established that the animals who transferred overheating, overcooling or a mechanical injury get patol. reactivity to blood loss (during the loss of 15 — 20% of lump of blood there can come death while intact animals transferred the loss of blood equal of 65 — 70%). At patol. reactivity separate processes can amplify, napr, immunopathological processes.

Patol. reactivity is shown by both specific, and nonspecific reactions of an organism. Specific reactions create at the patient a characteristic picture of everyone nozol. forms (e.g., formation of a tubercular hillock, defeat of an epithelium of upper respiratory tracts at flu, defeat of the hemopoietic bodies at a radial illness, a spasm of arterioles at an idiopathic hypertensia etc.). Carry fever to number of nonspecific reactions (see), adaptation syndrome (see), etc.

Patol. reactivity is observed at many patol. states (e.g., shock), at an anesthesia. So, oppression of reactivity both on offending allergen, and on various other irritants (electric, chemical, mechanical, etc.) at a Guinea pig, sensibilized to a foreign protein, after an acute anaphylaxis is observed. Shock (see) any origins the lake to an infection and other disease-producing influences sharply influences R., at the same time reactivity goes down or oppressed. As a result resistance of an organism to an infection weakens. After shock conditions for development of a wound fever are created. At traumatic and other types of shock phagocytosis is weakened, activity of leukocytes goes down, skin allergic reactions are oppressed.

Anaesthesia (see) changes R. to the lake. So, the deep anesthesia slows down development of antibodies (see) also oppresses phagocytal activity of leukocytes; weight of intoxication amplifies. Since at an anesthesia the metabolism and oxygen absorption, narkotizirovanny animals is oppressed (e.g., mice) transfer a hypoxia in comparison with nenarkotiziro-bathrooms easier. At an anesthesia the inflammation develops more slowly, accepts long character and is followed by a necrosis of the struck fabric. At the same time an impression of favorable action of an anesthesia as anti-inflammatory drug is made that is incorrect.

The role of a nervous system in reactivity of an organism

the Concept «reactivity» to some extent approaches the concepts «excitability» and «irritability», however they are not identical and are one of indicators of reactivity. So, the frog at the room temperature has hyporesponsiveness to a tetanin, to proteinaceous antigens at normal excitability of nerves and muscles to electric or chemical (acetylcholine) irritation.

In physiology the term «reactivity» is applied sometimes to designation of the size (volume) of reaction [A. S. Rosenblueth, I. S. Beritashvili, etc.]. E.g., if the muscle (or nerve-muscle preparation) answers the same electric irritation with stronger reduction, than other muscle, then it is considered more reactive.

The river of the lake and excitability of its separate fabrics not always change in one direction. So, at high reactivity of a rabbit, sensibilized to horse protein, excitability of his skeletal muscles to this protein remains low. The allowing administration of horse protein in the artery feeding a skeletal muscle (e.g., one of muscles of a shin of a rabbit), usually does not cause its reductions. States are possible, at to-rykh against the background of high reactivity excitability can increase or phase changes of excitability are observed.

R.'s changes by the lake are followed by change of functional mobility — labilities (see). N. E. Vvedensky described patol. changes of reactivity, at to-rykh were noted phase changes of lability, or functional mobility, a nervous system. Functional mobility of nervous processes at an anesthesia gradually goes down, passing certain stages of parabiotic braking (see. Parabiosis ). N. E. Vvedensky also described a condition of a so-called isteriozis of nerve centers (see. Nervous system ), at Krom reactivity and functional mobility changes. Isteriozis takes place at tetanus, rage, poisoning with strychnine, nek-ry types of electric traumas and others patol. states. Thus, functional mobility, according to N. E. Vvedensky, as well as excitability (see), is one of important fiziol. R.'s indicators of the lake.

A chronaxia (see. Hronaksimetriya ), as well as lability, represents one of expressions of R. of the lake. At epilepsy shortening of a chronaxia before and at the beginning of an attack is observed, later to-rogo there is its lengthening. In the period of an anaphylactic sensitization the chronaxia is shortened, and excitability falls. During an acute anaphylaxis excitability increases and the chronaxia is extended. However changes of a chronaxia and excitability at various changes of R. of the lake happen not always strictly in the same direction. E.g., in an incubation interval at tetanus at a rabbit increase in excitability and shortening of a subordinated chronaxia of muscles and nerves is observed, and in the subsequent the chronaxia is extended. Emergence of symptoms of local tetanus is characterized by shortening of a chronaxia, edge then again is extended. Approach of the phenomena of the general tetanus is followed by permanent shortening of a chronaxia and increase in excitability; the chronaxia is extended only before death.

At the neuroinfections striking various departments of a head and spinal cord the various changes of a chronaxia depending on the place of defeat and a stage of development of a disease are observed. So, at poliomyelitis in process of development of a disease increase in excitability and lengthening of a motive chronaxia is observed. Further the chronaxia of receptors and sensory nerves is extended. Phase changes of a chronaxia can be observed: in the beginning the chronaxia is shortened, and then it is replaced by lengthening.

In an organism after approach the wedge, death is observed progressive increase in excitability and lengthening of a chronaxia up to total loss of excitability of the dying fabrics. Sometimes in the beginning shortening of a chronaxia is observed, then it is quickly extended. Thus, the chronaxia reflects a condition of reactivity of c. N of page.

During the studying of types of century of N of at dogs I. P. Pavlov established that reactivity depends at most, mobility and steadiness of the basic nervous processes — excitement and braking — in a cerebral cortex. At rats with weak type of century of N of sharp easing of reactivity is observed. State neurosis (see) sharply changes reactivity, can cause emergence of eczema, a gastroenteritis and other diseases.

Influence of «failures» of century of N of on reactivity of an organism to toxic action of carcinogenic substances was shown to M. K. Petrova. At effect of coal tar on leather of dogs there were papillomas. At dogs with neurosis of papillomas was more and they quickly developed; dystrophic changes in a liver in the form of the centers of a necrosis, and also a pylorospasm were at the same time observed. Influence of frustration of century of N of on fabric growth is shown during the studying of healing of wounds, regeneration of nerves, etc.

Reactivity of animals to bacterial toxins, antigens and to the infecting action of microbes depends on type of century of N of. After poisoning staphylococcal, streptococcal and diphtheritic toxins, and also tetraethyllead, bulbokapniny, by Phenaminum, adrenaline at rats with weak type of century of N of observe the phenomena of diffuse cortical braking longer time, than at animals with strong, balanced and mobile century of N of.

Damages of c. N of page in an experiment significantly change R. to the lake. So, pricks to the area of a striate body and hypothalamus cause disturbance of thermoregulation, fervescence of an animal. Damage of a gray hillock (imposing of a glass ball on the Turkish saddle) causes dystrophic changes in lungs, went. - kish. path; hemorrhages in a mucous membrane develop, a submucosal layer went. - kish. path. Dystrophic changes and according to change of reactivity can arise on type patol. a reflex (see. Reflexes pathological ). I. P. Pavlov showed that damage went. - kish. a path and an abdominal wall at operations on dogs causes reflex reduction of resilience of a mucous membrane of an oral cavity, stomatitis as a result develops.

Patol. trophic reflexes at damage of various nervous trunks are studied by A. D. Speransky. Administration of croton oil in trunks of the sciatic, trigeminal or wandering nerves causes formation of ulcers in went. - kish. a path, a keratitis, hemorrhages in lungs. Damages leave in a nervous system of change in a type of trace reaction. At repeated damage of a nervous system earlier caused reaction is resumed. E.g., the rabbit repeatedly has a tetanus if to enter croton oil into a sciatic nerve. In this case nonspecific nervous irritants cause strengthening of activity of earlier created center of excitement like the phenomena dominants (see), described by A. A. Ukhtomsky.

Disturbance of functions of century of N of page significantly influences R. of the lake. Excitement of a sympathetic nervous system usually is followed by strengthening of a metabolism and R. of the lake Desimpatization (removal in an experiment of the most part of sympathetic nodes) reduces R. of the lake. So, the acute anaphylaxis at desimpatizirovanny cats does not develop.

Deprivation of fabrics of a vegetative innervation (denervation) significantly influences their reactivity to alkaloids, hormones, foreign proteins and bacterial antigens. At the same time reactivity of unstriated muscles sharply increases. The changes of a metabolism bringing fabric to a state of a parabiosis, in paradoxical phasa to-rogo excitability of substrate to many irritants, as we know, are its cornerstone increases. Special value has increase in excitability of denervated fabric to the agents playing a role of adequate irritants for this fabric (e.g., smooth muscles to adrenaline).

Role of endocrine system in reactivity of an organism. Value adrenal glands (see) in the mechanism of reactivity the hl is defined. obr. hormones of cortical substance. At action on an organism of various disturbing factors (an injury, electric current, a lack of oxygen, burns, infections and intoxications, etc.) function of cortical substance of adrenal glands amplifies and a significant amount of corticosteroids comes to blood (see). However R. of the lake raises only if intensity of a disturbing factor does not exceed certain limits and reaction of cortical substance of adrenal glands is adequate. At receipt in blood of excessive quantities of corticosteroids or at their shortcoming inadequate reaction of cortical substance of adrenal glands can become the factor determining pathological R. by the lake. Adrenalectomy (see) leads to falloff of body resistance to a mechanical injury, influence of electric current, bacterial toxins and to action of other pathogenic factors. Introduction of glucocorticoids (see. Glucocorticoid hormones ) increases body resistance to action of extraordinary irritants. However administration of hormones long time or in the doses which are not optimum causes converse effect.

Are of great importance in the mechanism P. of the lake somatotropic hormone (see) and adrenocorticotropic hormone (see), stimulating secretion of cortical substance of adrenal glands. Increase in products of adrenocorticotropic hormone (AKTG) and glucocorticoids, napr, at Itsenko's disease — Cushing (see. Itsenko — Cushing a disease ), suppresses cellular and humoral immunity (see), resistance to infections as a result goes down. At collagenoses the favorable effect from AKTG and glucocorticoids is caused by suppression of education autoantibodies (see) and activities hyaluronidases (see).

Increase in resistance of animals to infections, poisons and an anaphylaxis is caused in nek-ry cases by a thyroidectomy. The hyper thyroidism causes increase in function of cortical substance of adrenal glands, and then exhaustion in the beginning that increases sensitivity of animals to infections, poisons and an anaphylaxis. Resistance of animals to pyogenic microbes and to mycobacteria of tuberculosis decreases at reduction of an in-sulinoobrazovaniye, napr, at a diabetes mellitus.

The role of connecting fabric in reactivity of an organism

the Condition of connecting fabric is important for reactivity of the whole organism. Until recently understood ability as reactivity of cellular elements of connecting fabric macrophages (see) and elements reticuloendothelial system (see) to englobe and accumulate various substances, and also to participate in an intermediate metabolism of substances (see. Metabolism and energy ). These processes were considered as the most important expression of nonspecific reactivity of connecting fabric. Data on influence of various influences (ionizing radiation, temperature, a diet, etc.) on phagocytal function of macrophages are obtained and it is established that it is regulated by c. N page and endocrine system.

The doctrine about reactivity of connecting fabric was enriched with new data on reactivity of its separate cellular elements which are not possessing phagocytal function. So, it is established that plasmocytes (see) develop antibodies; and antibodyformation is carried out as a result of interaction of macrophages, T - and V-lymphocytes (see. Immunocompetent cells) .

In a crust, time there is a large number of data on reactivity mast cells (see). So, it is established that contain in granules of mast cells a histamine, serotonin and heparin, to-rye at allergic reactions are emitted. It matters in the mechanism of the further changes happening in bodies and fabrics.

Various changes of reactivity of connecting fabric are observed at collagenoses, napr, at a system lupus erythematosus, a dermatomyositis, a scleroderma; destruction of friable connecting fabric is described that leads to decrease in its reactivity. It is established also what one of expressions of reactive changes in connecting fabric is to the nakopleena in it neutral mukopolneakharid. Procollagen of fibrous structures of connecting fabric enters connections with bacterial antigens, with ribonucleic to-tami and forms autoantigens (see). Such form of reactivity of connecting fabric is an important factor in a pathogeny of rheumatism and various autoallergichesky diseases.

A role of food in reactivity of an organism

R.'s Condition of the lake is connected with food of an organism and its metabolism. Quantitative and high-quality disturbances of food sharply influence R. of the lake. Starvation (see) or malnutrition (nutritional dystrophy) cause falloff of reactivity; the inflammation at the same time proceeds more inertly, antibodyformation falls; the condition of an anaphylaxis is not reproduced; century of N of is sharply weakened (the developed conditioned reflexes disappear, and development of new reflexes is at a loss). Against the background of the reactivity weakened at starvation allergic reactions disappear, the wedge changes. picture of nek-ry diseases, many acute inf. diseases proceed without fervescence and the sharp inflammatory phenomena. So-called gipergicheeky forms of diseases develop.

Special value in change of reactivity has a lack of protein of a diet. At proteinaceous starvation resistance of animals to infections and intoxications decreases. So, at rats decrease in stability to paratyphoid, brucellous and to other infections is observed.

Absence in food of polyneuramins enough (see. Vitamin deficiency ) causes changes of reactivity. At a hypovitaminosis And decrease in resistance of animals to infections (a bartonellosis at rats, a dochmiasis at dogs), to experimental infection, nagtr is observed. mice stick of mouse typhus. The lack of vitamins of group B influences R. of the lake since functions of oxidizing enzymes and a decarboxylase are broken. At a lack of oryzamin stability, e.g., of rats to a malignant anthrax, monkeys to the dysentery caused by Fleksner's shigellas decreases. At a hypovitaminosis of B2 resistance of mice to mouse typhus, to microbes of a typhoid and dysentery decreases. At a hypovitaminosis of B6 the intestinal frustration caused by usual microbic flora of intestines are observed. Special value for reactivity has providing an organism with redoxon. Its shortcoming is followed by falloff of resistance of an organism to infections, oppression of antibodyformation, decrease in phagocytal activity of leukocytes, etc. At a hypovitaminosis With it is also not possible to reproduce an acute anaphylaxis and local allergic reactions. The hypervitaminosis With oppresses allergic reactivity.

Features of reactivity of an organism at children

In development and growth of the child the general and immunol. The river of the lake is exposed to changes, to-rye are connected with improvement of neuroendocrinal regulation fiziol. functions, a metabolism and immunity, and also with the regulating influence of derepression of genes, to-rye in interaction with environmental factors define formation of a phenotype of the child, and then adult.

The only type of regulation of a differentiation of fabrics and growth at early stages of an embryogenesis when the germ practically areaktiven, is gene regulation. In process of formation of neuroendocrinal system and cellular hormonal receptors humoral factors, in particular neurotransmitters begin to perform the regulating function — catecholamines (see), acetylcholine (see), serotonin (see) and, perhaps, prostaglandins (see). The first local reactions to mediators are mediated by own physiologically active agents of a fruit and to some extent the humoral factors arriving from mother through a placenta.

Development of a nervous system changes the nature of reflex reactions of a fruit; they become generalized (the irritation of any part of a body causes tonic reaction of many groups of muscles). Tendency to generalized nervnoreflektorny reactions is found in newborns in the form of reflexes of Talent, Perez, Moro and others (see. Newborn ).

According to the doctrine about to a sistemogeneza (see) P. K. Anokhin in process ontogenesis (see) those structures of an organism selectively ripen, to-rye are combined by unity of function. One of the first reflex acts of suction and swallowing, orientation of the head develop. In general development of functional systems of the child differs in a geterokhronnost that in many respects defines R.'s condition of the lake.

Crucial importance for the general R.'s formation by the lake has formation of century of N of thanks to what adaptive reactions (see. Adaptation ) gain purposeful and mobile character, reflex acts join consistently in complete activity of an organism. The general R. lakes define types of century of N of, to-rye, on Krasnogorsk, can be differentiated even at children of chest age. At the same time mobility and force of nervous processes define rates of development of functional systems and R.'s condition of the lake.

Age R.'s manifestations by the lake depend on development and sensitivity of the receptor device of cells to hormones and physiologically active agents. In early ontogenesis high sensitivity of fabric receptors to cortisol, adrenaline, a growth hormone is noted. Their sensitivity to insulin is especially high that can reflect its special role in an embryogenesis as accessory factor of growth. With age the child sensitivity of fabrics to thyroid hormone, sex hormones, a histamine increases and sensitivity to a gorkhmon of growth falls.

One of manifestations of R. of the lake is regenerator ability of bodies and fabrics, edges are varied depending on the period of ontogenesis. So, in the period of a neonatality when there are intensive processes of growth and a differentiation, regenerator ability is shown more stoutly and has qualitative features.

The most important feature of R. of the lake of the growing child is ability to stabilize growth and development. Even when dynamics of growth is broken under the influence of a disease or starvation, ability to the predetermined growth is returned. Called this property unlike a homeostasis of adults of Uoddiag-ton (S. of Waddington, 1957) go-meorezy — maintenance of constancy in the developing systems.

With age the child sensitivity of both all organism, and its separate systems to action of disturbing factors decreases (the organism is younger, the it is more sensitive to them). However at various stages of development separate systems find both falling, and increase of sensitivity, and those periods, to-rye are characterized by the highest sensitivity to external influences, it is accepted to call sensitive or critical periods.

Age features of R. of the lake are shown in the changing sensitivity of the developing organism to pharmaceuticals. E.g., to one pharmaceuticals (morphine, barbiturates, derivative curares) it is higher at early age, to others (adrenaline, aminazine, strychnine) — is reduced; to a number of drugs (Phenaminum, Hexonium, atropine) sensitivity changes wavy.

State immunol. The river of the lake is defined by reorganization of functions of immune system. In ontogenesis among immunol. the reactions caused by T lymphocytes the first shows ability to rejection of transplants. Reaction of hypersensitivity of the slowed-down type (see the Allergy) appears by the end of the pre-natal period and reaches full development only for the first year of life. At an embryo the immune response is absent, in the middle of the pre-natal period at a fruit partial tolerance is shown (humoral reactions of immunity in the absence of cellular, including phagocytosis), at the end of this period the immune response includes reactions of humoral and cellular type.

For the period of a neonatality when the organism meets diverse natural antigens, hypersensitivity to conditional a pathogen - nym to bacterial infections is characteristic; reaction of blast transformation to antigens is reduced, skin tests are poorly expressed in reactions of hypersensitivity slowed down ooze, killerny is lowered and suppressor function of T lymphocytes is increased. Formation of limfotokein and the factor oppressing migration of macrophages is not enough. However, despite active suppression of humoral reactions of immunity, newborns are capable to antibodyformation at development of infectious and inflammatory diseases.

It is established that phagocytosis at a fruit is not active, it joins in the first days of life. Dynamics of level of opsonins, properdin and a complement, in particular its SZ-component is similar at them. Mills (V. of J. Mills) et al. (1979) established that the classical mechanism of complement activation is carried out at newborns as well as at adults, and alternative, or properdino-vy, is not developed. Exposure of newborns to septic states is explained by it.

Increase in activity of factors of nonspecific protection in the first months of life is connected with the beginning of breastfeeding, emergence of microbic flora in intestines, influence of specific and nonspecific antigenic incentives. Due to R.'s features of the lake many inf. diseases (measles, whooping cough, dysentery, flu, typhoid, etc.) at newborns and children of early age proceed atypically at absence or at extremely weak expressiveness of characteristic symptoms of a disease, it is frequent with the expressed displays of toxicosis, bacteremia and a septicaemia.

Due to R.'s features of the lake the general pathology of children's age is characterized by special pattern: the child is younger, the specific characters of a disease whereas nonspecific manifestations act into the forefront are less expressed. Dominance of the general a wedge, symptoms over local is typical for all pathology of early children's age. Besides, practically any disease of the child is followed by considerable disbolism and energy (see. the Metabolism and energy at children ). Due to the features immunol. reactivity at children of early age such diseases of the autoimmune nature, as rheumatism (see), system lupus erythematosus (see), diffusion glomerulonephritis (see) and others, arise seldom.

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A. D. Ado; BB. E. Veltishchev (ped.).