Age physiology. Age-related anatomy and physiology (manual for OZO)

(PHYSIOLOGY OF CHILD DEVELOPMENT)

Tutorial

For students of higher pedagogical educational institutions

M.M.Bezrukikh I (1, 2), III (15), IV (18-23),

V.D.Sonkin I (1, 3), II (4-10), III (17), IV (18-22),

D.A. Farber I (2), III (11-14, 16), IV (18-23)

Reviewers:

Doctor of Biological Sciences, Head. Department of Higher Nervous Activity and Psychophysiology of St. Petersburg University, Academician of the Russian Academy of Education,

Professor A. S. Batuev; Doctor of Biological Sciences, Professor I.A. Kornienko

Bezrukikh M. M. and etc.

Developmental physiology: (Physiology of child development): Proc. aid for students higher ped. schools, institutions / M. M. Bezrukikh, V. D. Sonkin, D. A. Farber. - M.: Publishing center "Academy", 2002. - 416 p. ISBN 5-7695-0581-8

The textbook presents modern concepts of human ontogenesis, taking into account the latest achievements of anthropology, anatomy, physiology, biochemistry, neuro- and psychophysiology, etc. The morphofunctional characteristics of the child at the main stages are considered age development, their connection with the processes of socialization, including training and education. The book is illustrated with a large number of diagrams, tables, drawings that facilitate the assimilation of the material, and questions for self-test are offered.

AGE PHYSIOLOGY 1

Tutorial 1

PREFACE 3

Section I INTRODUCTION TO AGE PHYSIOLOGY 7

Chapter 1. SUBJECT OF AGE PHYSIOLOGY (DEVELOPMENTAL PHYSIOLOGY) 7

Chapter 2. THEORETICAL FOUNDATIONS OF AGE PHYSIOLOGY 18

(DEVELOPMENTAL PHYSIOLOGY) 18

Chapter 3. GENERAL PLAN OF THE STRUCTURE OF THE ORGANISM 28

Section II ORGANISM AND ENVIRONMENT 39

Chapter 4. GROWTH AND DEVELOPMENT 39

Chapter 5. ORGANISM AND ITS ENVIRONMENT 67

Chapter 6. INTERNAL ENVIRONMENT OF THE ORGANISM 82

Chapter 7. METABOLISM (METABOLISM) 96

Chapter 8. OXYGEN SUPPLY SYSTEM 132

Chapter 9. PHYSIOLOGY OF ACTIVITY AND ADAPTATION 162

Chapter 10. MUSCULAR ACTIVITY AND PHYSICAL CAPABILITIES OF A CHILD 184

Section III ORGANISM AS A WHOLE 199

Chapter 11. NERVOUS SYSTEM: MEANING AND STRUCTURAL-FUNCTIONAL ORGANIZATION 199

Chapter 12. STRUCTURE, DEVELOPMENT AND FUNCTIONAL IMPORTANCE OF VARIOUS DEPARTMENTS OF THE CENTRAL NERVOUS SYSTEM 203

Chapter 13. REGULATION OF THE FUNCTIONAL STATE OF THE BRAIN 219

Chapter 14. INTEGRATIVE ACTIVITY OF THE BRAIN 225

Chapter 15. CENTRAL MECHANISMS OF MOVEMENT REGULATION 248

Chapter 16. AUTONOMIC NERVOUS SYSTEM AND REGULATION OF THE INTERNAL ENVIRONMENT OF THE ORGANISM 262

Chapter 17. HUMORAL REGULATION OF BODY FUNCTIONS 266

Section IV STAGES OF CHILD DEVELOPMENT 297

Chapter 18. INFANTRY (from 0 to 1 year) 297

Chapter 19. EARLY AGE 316

(FROM 1 YEAR TO 3 YEARS) 316

Chapter 20. PRESCHOOL AGE 324

(FROM 3 TO 6-7 YEARS) 324

Chapter 21. JUNIOR SCHOOL AGE (FROM 7 TO 11-12 YEARS OLD) 338

Chapter 22. ADOLESCENCE AND YOUTH AGE 353

Chapter 23. SOCIAL FACTORS OF DEVELOPMENT AT DIFFERENT STAGES OF ONTOGENESIS 369

LITERATURE 382

PREFACE

Clarification of the patterns of child development, the specifics of the functioning of physiological systems at different stages of ontogenesis and the mechanisms that determine this specificity is a necessary condition for ensuring the normal physical and mental development of the younger generation.

The main questions that should arise for parents, teachers and psychologists in the process of raising and educating a child at home, in kindergarten or at school, at a consultation or individual lessons are what kind of child is he, what are his characteristics, what option of training with him will be the most effective. Answering these questions is not at all easy, because this requires deep knowledge about the child, the patterns of his development, age and individual characteristics. This knowledge is extremely important for the development of the psychophysiological foundations of the organization academic work, development of adaptation mechanisms in the child, determining the influence on him innovative technologies and so on.

Perhaps for the first time, the importance of a comprehensive knowledge of physiology and psychology for a teacher and educator was highlighted by the famous Russian teacher K.D. Ushinsky in his work “Man as a Subject of Education” (1876). “The art of education,” wrote K.D. Ushinsky, “has the peculiarity that it seems familiar and understandable to almost everyone, and even easy for others, and the more understandable and easier it seems, the less a person is theoretically familiar with it and practically. Almost everyone admits that parenting requires patience; some think that it requires innate ability and skill, i.e. skill; but very few have come to the conviction that, in addition to patience, innate ability and skill, special knowledge is also necessary, although our numerous wanderings could convince everyone of this.” It was K.D. Ushinsky who showed that physiology is one of those sciences in which “the facts and those correlations of facts are presented, compared and grouped in which the properties of the subject of education, i.e., man, are revealed.” Analyzing the physiological knowledge that was known, and this was the time of the formation of age-related physiology, K.D. Ushinsky emphasized: “Education has hardly yet drawn from this source, which is just opening.” Unfortunately, even now we cannot talk about the widespread use of age-related physiology data in pedagogical science. The uniformity of programs, methods, and textbooks is a thing of the past, but the teacher still takes little into account the age and individual characteristics of the child in the learning process.

At the same time, the pedagogical effectiveness of the learning process largely depends on the extent to which the forms and methods of pedagogical influence are adequate to the age-related physiological and psychophysiological characteristics of schoolchildren, whether the conditions for organizing the educational process correspond to the capabilities of children and adolescents, whether the psychophysiological patterns of the formation of basic school skills - writing and reading, as well as basic motor skills during classes.

The physiology and psychophysiology of a child is a necessary component of the knowledge of any specialist working with children - a psychologist, educator, teacher, social worker. “Upbringing and teaching deals with the whole child, with his holistic activity,” said the famous Russian psychologist and teacher V.V. Davydov. - This activity, considered as a special object of study, contains in its unity many aspects, including... physiological (V.V. Davydov “Problems of developmental training.” - M., 1986. - P. 167).

Age-related physiology is the science of the peculiarities of the life of the body, the functions of its individual systems, the processes occurring in them, and the mechanisms of their regulation at different stages of individual development. Part of it is the study of the physiology of a child at different age periods.

A textbook on developmental physiology for students of pedagogical universities contains knowledge about human development at those stages when the influence of one of the leading factors of development - learning - is most significant.

The subject of developmental physiology (physiology of child development) as academic discipline are the features of the development of physiological functions, their formation and regulation, the vital activity of the organism and the mechanisms of its adaptation to the external environment at different stages of ontogenesis.

Basic concepts of age-related physiology:

An organism is a complex, hierarchically (subordinately) organized system of organs and structures that ensure vital activity and interaction with the environment. The elementary unit of an organism is the cell. A collection of cells similar in origin, structure and function forms tissue. Tissues form organs that perform specific functions. Function is the specific activity of an organ or system.

A physiological system is a collection of organs and tissues connected by a common function.

A functional system is a dynamic combination of various organs or their elements, the activities of which are aimed at achieving a specific goal (useful result).

As for the structure of the proposed textbook, it is structured so that students develop a clear idea of the patterns of development of the body in the process of ontogenesis, of the characteristics of each age stage.

We tried not to overload the presentation with anatomical data and at the same time considered it necessary to give basic ideas about the structure of organs and systems at different stages of age-related development, which is necessary for understanding the physiological patterns of organization and regulation of physiological functions.

The book consists of four sections. Section I - “Introduction to developmental physiology” - reveals the subject of developmental physiology as an integral part of age-related physiology, gives an idea of the most important modern physiological theories of ontogenesis, and introduces basic concepts without which it is impossible to understand the main content of the textbook. This section gives the most general idea of the structure of the human body and its functions.

Section II - “Organism and Environment” - gives an idea of the main stages and patterns of growth and development, the most important functions of the organism that ensure the interaction of the organism with the environment and its adaptation to changing conditions, the age-related development of the organism and characteristic features stages of individual development.

Section III - “The Organism as a Whole” - contains a description of the activities of systems that integrate the organism into a single whole. First of all, this is the central nervous system, as well as the autonomic nervous system and the system of humoral regulation of functions. The main patterns of age-related development of the brain and its integrative activity are a key aspect of the content of this section.

Section IV - “Stages of child development” - contains a morpho-physiological description of the main stages of child development from birth to adolescence. This section is most important for practitioners working directly with a child, for whom it is important to know and understand the basic morphofunctional age-related characteristics of the child’s body at each stage of its development. To understand the content of this section, you must master all the material presented in the previous three. This section concludes with a chapter that examines the influence of social factors on child development.

At the end of each chapter there are questions for students’ independent work, which allow them to refresh their memory of the main provisions of the material being studied that require special attention.

Section I INTRODUCTION TO AGE PHYSIOLOGY

Chapter 1. SUBJECT OF AGE PHYSIOLOGY (DEVELOPMENTAL PHYSIOLOGY)

The relationship of age-related physiology with other sciences

By the time of birth, the child’s body is still very far from a mature state. A human baby is born small, helpless, and cannot survive without the care and attention of adults. It takes a lot of time for it to grow and become a full-fledged mature organism.

The branch of physiological science that studies biological patterns and mechanisms of growth and development is called age-related physiology. The development of a multicellular organism (and the human body consists of several billion cells) begins at the moment of fertilization. The entire life cycle of an organism - from conception to death - is called individual development, or ontogenesis.

Regularities and features of the vital activity of an organism in the early stages of ontogenesis are traditionally the subject of research age physiology (physiology of child development).

The physiology of child development concentrates its interest on those stages that are of greatest interest to educators, educators, and school psychologists: from birth to morphofunctional and psychosocial maturation. Earlier stages related to intrauterine development are being explored by science embryology. Later stages, from maturity to old age, are studied normal physiology And gerontology.

A person in his development obeys all the basic laws established by Nature for any developing multicellular organism, and therefore developmental physiology is one of the sections of a much broader field of knowledge - developmental biology. At the same time, in the dynamics of human growth, development and maturation there are many specific, special features inherent only to the species Homo sapience (Homo sapiens). In this plane, developmental physiology is closely intertwined with science anthropology , whose tasks include a comprehensive study of man.

A person always lives in the specific conditions of the environment with which he interacts. Continuous interaction and adaptation to the environment is the general law of the existence of living things. Man has learned not only to adapt to the environment, but also to change the world around him in the necessary direction. However, this did not save him from the influence of environmental factors, and at different stages of age development, the set, strength of action and result of the influence of these factors may be different. This determines the connection between physiology and ecological physiology, which studies the impact of various factors on a living organism. external environment and ways of adapting the body to the action of these factors.

During periods of intensive development, it is especially important to know how environmental factors affect a person and how various risk factors influence them. This has traditionally received increased attention. And here the physiology of development closely interacts with hygiene, since it is physiological patterns that most often act as the theoretical foundations of hygienic requirements and recommendations.

The role of living conditions, not only “physical”, but also social and psychological, in the formation of a healthy person adapted to life is very great. A child should be aware of the value of his health from early childhood and possess the necessary skills to preserve it.

Formation of the value of health and a healthy lifestyle - the tasks of pedagogical valeology, which draws factual material and basic theoretical principles from developmental physiology.

Finally, developmental physiology provides a natural scientific basis pedagogy. At the same time, the physiology of development is inextricably linked with the psychology of development, since for each person his biological and personal make up a single whole. It is not without reason that any biological damage (disease, injury, genetic disorders, etc.) inevitably affects the development of the individual. The teacher must be equally well versed in problems developmental psychology and developmental physiology: only in this case will his activities bring real benefit to his students.

MM. Bezrukikh, V.D. Sonkin, D.A. Farber

Age physiology: (Physiology of child development)

Tutorial

For students of higher pedagogical educational institutions

Reviewers:

Doctor of Biological Sciences, Head. department of higher nervous activity and psychophysiology of St. Petersburg University, academician of the Russian Academy of Education, professor A.S. Batuev;

Doctor of Biological Sciences, Professor I.A. Kornienko

PREFACE

The main questions that should arise for parents, teachers and psychologists in the process of raising and educating a child at home, in kindergarten or at school, at a consultation or individual lessons are what kind of child is he, what are his characteristics, what option of training with him will be the most effective. Answering these questions is not at all easy, because this requires deep knowledge about the child, the patterns of his development, age and individual characteristics. This knowledge is extremely important for developing the psychophysiological foundations for organizing educational work, developing adaptation mechanisms in a child, determining the impact of innovative technologies on him, etc.

Perhaps for the first time, the importance of comprehensive knowledge of physiology and psychology for teachers and educators was highlighted by the famous Russian teacher K.D. Ushinsky in his work “Man as a Subject of Education” (1876). “The art of education,” wrote K.D. Ushinsky, - has the peculiarity that it seems familiar and understandable to almost everyone, and even to others - an easy matter - and the more understandable and easier it seems, the less a person is familiar with it theoretically and practically. Almost everyone admits that parenting requires patience; some think that it requires an innate ability and skill, that is, a skill; but very few have come to the conviction that, in addition to patience, innate ability and skill, special knowledge is also necessary, although our numerous wanderings could convince everyone of this.” It was K.D. Ushinsky showed that physiology is one of those sciences in which “the facts and those correlations of facts are presented, compared and grouped in which the properties of the subject of education, i.e., man, are revealed.” Analyzing the physiological knowledge that was known, and this was the time of the formation of age-related physiology, K.D. Ushinsky emphasized: “Education has hardly yet drawn from this source, which is just opening.” Unfortunately, even now we cannot talk about the widespread use of age-related physiology data in pedagogical science. The uniformity of programs, methods, textbooks is a thing of the past, but the teacher still takes little into account age and individual characteristics child in the learning process.

Physiology and psychophysiology of a child is a necessary component of the knowledge of any specialist working with children - psychologist, educator, teacher, social teacher. “Upbringing and teaching deals with the whole child, with his holistic activity,” said the famous Russian psychologist and teacher V.V. Davydov. “This activity, considered as a special object of study, contains in its unity many aspects, including ... physiological” (V.V. Davydov “Problems of developmental training.” - M., 1986. - P. 167).

Age physiology- the science of the peculiarities of the body’s vital functions, the functions of its individual systems, the processes occurring in them, and the mechanisms of their regulation at different stages of individual development. Part of it is the study of the physiology of a child at different age periods.

The subject of developmental physiology (physiology of child development) as an academic discipline is the features of the development of physiological functions, their formation and regulation, the vital activity of the body and the mechanisms of its adaptation to the external environment at different stages of ontogenesis.

Send your good work in the knowledge base is simple. Use the form below

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

Posted on http://www.allbest.ru/

ABSTRACT

AGE PHYSIOLOGY

Age physiology is a science that studies the features of the life processes of an organism at different stages of ontogenesis.

It is an independent branch of human and animal physiology, the subject of which includes the study of the patterns of formation and development of the physiological functions of the body throughout its life. life path from fertilization to the end of life.

Depending on the age period, age-related physiology is studied: age-related neurophysiology, age-related endocrinology, age-related physiology of muscle activity and motor function; age-related physiology of metabolic processes, cardiovascular and respiratory systems, digestive and excretory systems, physiology of embryonic development, physiology of infants, physiology of children and adolescents, physiology of adulthood, gerontology (the science of aging).

The main objectives of studying age-related physiology are the following:

studying the characteristics of the functioning of various organs, systems and the body as a whole;

identification of exogenous and endogenous factors that determine the functioning of the body at different age periods;

determination of objective age criteria (age standards);

establishing patterns of individual development.

Age-related physiology is closely related to many branches of physiological science and widely uses data from many other biological sciences. Thus, to understand the patterns of formation of functions in the process of individual human development, data from such physiological sciences as cell physiology, comparative and evolutionary physiology, physiology of individual organs and systems: heart, liver, kidneys, blood, respiration, nervous system, etc. are needed.

At the same time, the patterns and laws discovered by age-related physiology are based on data from various biological sciences: embryology, genetics, anatomy, cytology, histology, biophysics, biochemistry, etc. Finally, age-related physiology data, in turn, can be used for the development of various scientific disciplines. For example, age-related physiology is important for the development of pediatrics, pediatric traumatology and surgery, anthropology and gerontology, hygiene, developmental psychology and pedagogy.

History and main stages in the development of age-related physiology

The scientific study of the age-related characteristics of the child’s body began relatively recently - in the second half of the 19th century. Soon after the discovery of the law of conservation of energy, physiologists discovered that a child consumes slightly less energy during the day than an adult, although the child’s body size is much smaller. This fact required a rational explanation. In search of this explanation, the German physiologist Max Rubner conducted a study of the rate of energy metabolism in dogs of different sizes and found that larger animals, per 1 kg of body weight, expend significantly less energy than small ones. Having calculated the surface area of the body, Rubner became convinced that the ratio of the amount of energy consumed is proportional to the size of the body surface - and this is not surprising: after all, all the energy consumed by the body must be released into the environment in the form of heat, i.e. the energy flow depends on the heat transfer surface. It was by differences in the ratio of mass and body surface that Rubner explained the difference in the intensity of energy metabolism between large and small animals, and at the same time between adults and children. Rubner's “surface rule” became one of the first fundamental generalizations in developmental and ecological physiology. This rule explained not only differences in the amount of heat production, but also in the frequency of heart contractions and respiratory cycles, pulmonary ventilation and blood flow volume, as well as in other indicators of autonomic functions. In all these cases the intensity physiological processes in a child’s body is significantly higher than in an adult’s body. This purely quantitative approach is characteristic of the German physiological school of the 19th century, consecrated by the names of outstanding physiologists E.F. Pfluger, G.L. Helmholtz and others. Through their works, physiology was raised to the level of natural sciences, on a par with physics and chemistry. However, the Russian physiological school, although rooted in the German one, has always been distinguished by an increased interest in qualitative features and patterns. An outstanding representative of the Russian pediatric school, Dr. Nikolai Petrovich Gundobin back at the very beginning of the 20th century. argued that a child is not just small, he is also in many ways different from an adult. His body is structured and works differently, and at each stage of its development, the child’s body is perfectly adapted to the specific conditions that he has to face in real life. and the ideas were shared and developed by the remarkable Russian physiologist, teacher and hygienist Pyotr Frantsevich Lesgaft, laid the foundations for school hygiene and physical education of children and adolescents. He considered it necessary to deeply study the child’s body and its physiological capabilities.

The central problem of developmental physiology was formulated most clearly in the 20s of the 20th century. German physician and physiologist E. Helmreich. He argued that the differences between an adult and a child are on two levels, which must be considered as independently as possible, as two independent aspects: the child as small body and child developing organism. In this sense, Rubner's “surface rule” considers the child in only one aspect - namely, as a small organism. Much more interesting are those characteristics of the child that characterize him as a developing organism. One of these fundamental features is the discovery in the late 30s Ilya Arkadyevich Arshavsky uneven development of sympathetic and parasympathetic influences of the nervous system on all the most important functions of the child’s body. I.A. Arshavsky proved that sympathotonic mechanisms mature much earlier, and this creates an important qualitative uniqueness of the functional state of the child’s body. The sympathetic department of the autonomic nervous system stimulates the activity of the cardiovascular and respiratory systems, as well as metabolic processes in the body. Such stimulation is quite adequate for an early age, when the body needs an increased intensity of metabolic processes necessary to ensure the processes of growth and development. As the child’s body matures, parasympathetic and inhibitory influences intensify. As a result, the heart rate, breathing rate, and relative intensity of energy production decrease. The problem of uneven heterochrony (multiple times) of development of organs and systems has become the central object of study by the outstanding physiologist academician Peter Kuzmich Anokhin and his scientific school. In the 40s he formulated the concept systemogenesis, according to which the sequence of events unfolding in the body is arranged in such a way as to satisfy the needs of the body that change during development. At the same time, P.K. Anokhin for the first time moved from considering anatomically integral systems to the study and analysis of functional connections in the body. Another prominent physiologist Nikolai Alexandrovich Bernshtein showed how algorithms for controlling voluntary movements gradually form and become more complex during ontogenesis, how mechanisms of higher control of movements spread with age from the most evolutionarily ancient subcortical structures of the brain to newer ones, reaching an increasingly higher level of “construction of movements.” In the works of N.A. Bernstein, it was first shown that the direction of ontogenetic progress in the control of physiological functions clearly coincides with the direction of phylogenetic progress. Thus, the concept of E. Haeckel and A. N. Severtsov that individual development (ontogenesis) is an accelerated evolutionary development (phylogeny) was confirmed using physiological material.

Leading expert in the field of evolution theory, academician Ivan Ivanovich Shmalhausen For many years he also worked on issues of ontogenesis. The material on which I.I. Shmalgauzen made his conclusions was rarely directly related to the physiology of development, but the conclusions from his works on the alternation of stages of growth and differentiation, as well as methodological work in the field of studying the dynamics of growth processes, carried out in the 30s , and are still of great importance for understanding the most important patterns age development. In the 60s, a physiologist Hakob Artashesovich Markosyan put forward the concept of biological reliability as one of the factors of ontogenesis. She relied on numerous facts that showed that the reliability of functional systems increases significantly as the body matures. This was confirmed by data on the development of the blood coagulation system, immunity, and the functional organization of brain activity. In recent decades, many new facts have accumulated that confirm the main provisions of the concept of biological reliability of A.A. Markosyan. On modern stage development of medical and biological science, research in the field of age-related physiology is also ongoing using modern research methods. Thus, physiological science currently has significant multilateral information concerning the functional activity of any physiological system of the child’s body and its activity as a whole.

Basic patterns of growth in the development of children and adolescents.

The main feature of childhood and adolescence-- a constantly ongoing process of growth and development, during which the gradual formation of an adult takes place. During this process, the quantitative indicators of the body increase (the size of individual organs and the whole body), and the functioning of organs and physiological systems is improved, ensuring the possibility of normal life of a mature person, the main points of which are work activity and the birth of healthy offspring. His future largely depends on how a child and adolescent grows and develops and, therefore, this process from the moment the child is born until the completion of the processes of growth and development should be under the constant control of doctors, parents and teachers. And although every child is completely individual, some patterns of growth and development of children are common to everyone. Child development is a non-stop process in which all stages of slow quantitative changes gradually lead to dramatic transformations in the structures and functions of the child’s body. Often such changes take a sharp, spasmodic form. The normal course of growth and development of a child and adolescent indicates a favorable state of his body, the absence of pronounced harmful influences and, therefore, physical development at this age is one of the leading signs of health, on which its other indicators depend. The level of achieved physical development is necessarily assessed by a doctor during a medical examination and is a necessary criterion for the general assessment of the health status of a child and adolescent. The number of indicators that determine a person’s physical development is quite large. For the purposes of medical and pedagogical practice, relatively easy to measure indicators called somatometric are most often used: body length, body weight, chest circumference. An external examination of the body reveals somatoscopic indicators: shape of the chest, back, feet, posture, muscle condition, fat deposition, skin elasticity, signs of puberty. To assess the functional capabilities of the body, physiometric indicators are used - vital capacity (VC), hand grip strength (dynamometry). All these indicators are taken into account when assessing physical development of children and adolescents, which should be carried out comprehensively, using all of the indicated indicators. To correctly assess the physical development of a child, it is necessary to know the basic patterns of development of children and adolescents and the age-related characteristics of this process, which allows us to understand and explain the activities of individual organs and systems, their relationships, and functioning. whole organism child at different age periods and his unity with the external environment.

The human life cycle is conventionally divided into three stages: maturation, adulthood and aging. It is possible to draw a chronological boundary for the transition of an organism from one stage to another based on studying the characteristics of its growth and development, interaction with the environment (including the social) environment. The maturation stage is characterized, first of all, by the achievement of sexual maturity, the body's ability and the ability to perform reproductive functions, which ensures the preservation of the species. The preservation of the species is the biological meaning of the individual growth and development of any living creature, including humans. However, it would be a mistake to judge a person's maturity only by the degree of sexual development. An equally important feature is the individual’s readiness to carry out social functions, labor and creative activities, and this is the social and public meaning of his development. Puberty occurs at 13-15 years of age. Labor maturity occurs much later, usually at the end of school or college, i.e. at 17-18 years of age. It comes only with the approaching completion of physical development and the acquisition of experience in social activity. Currently, there is a discrepancy in the timing of puberty and labor maturity. If puberty in modern conditions is observed somewhat earlier, then labor maturity in conditions modern production, requiring a fairly high level of training, on the contrary, later. Therefore, the chronological limit of complete maturation of the body and the onset of maturity should be considered 20-21 years. Namely, by this age, not only the process of full maturation and growth is completed, but also the necessary knowledge is accumulated, moral foundations are formed, i.e., opportunities are created for a person to perform both biological and social functions. At the entire stage of maturation (from birth to full maturity), the growth and development of the body proceeds in accordance with objectively existing laws, the main of which are:

uneven growth and development rates,

non-simultaneous growth and development of individual organs and systems (heterochrony),

Determination of growth and development by sex (sexual dimorphism),

genetic determination of growth and development,

conditioning of growth and development by factors habitat children,

historical development trends (acceleration, deceleration).

Uneven rates of growth and development. The processes of growth and development occur continuously and are progressive in nature, but their pace has a nonlinear dependence on age. The younger the organism, the more intense the processes of growth and development. This is most clearly reflected by the indicators of daily energy consumption. The child is 1-3 months old. daily energy consumption per 1 kg of body weight per day is 110-120 kcal, for a one-year-old - 90-100 kcal. In subsequent periods of the child's life, the decrease in relative daily energy expenditure continues. Uneven growth and development is evidenced by changes in body length in children and adolescents. During the first year of life, the body length of a newborn increases by 47%, during the second - by 13%, and in the third - by 9%. At the age of 4-7 years, body length increases annually by 5-7%, and at the age of 8-10 years - only by 3%.

During puberty, there is a growth spurt; at the age of 16-17 years, a decrease in the rate of growth is observed, and at 18-20 years, the increase in body length practically stops. Changes in body weight, chest circumference, as well as the development of individual organs and systems as a whole occur unevenly. The uneven rate of growth and development of the organism at the stage of maturation is a general pattern. However, during this period some individual characteristics also appear. There are individuals whose rate of development is accelerated, and in terms of maturity they are ahead of their chronological (calendar) age. The opposite relationship is also possible. In this regard, the term “child’s age” must be specified: chronological or biological. The difference between chronological and biological age can reach 5 years. Children with a slow rate of biological development may account for 10-20%. Such children are most often identified before entering school or during training. The lag in biological age in children is manifested by a decrease in most indicators of physical development compared to the average age and is combined with more frequent deviations in the musculoskeletal system, nervous and cardiovascular systems. Students with a slower rate of biological development are less active in class. They experience increased distractibility and an unfavorable type of change in performance. During the educational process, more pronounced tension in the visual, motor analyzer and of cardio-vascular system. The most pronounced changes in performance and health status are observed in children with a sharp lag in biological age (a difference of 3 years or more). Fast pace individual child development leads to an advance of biological age compared to chronological age. “Advanced” development is less common in student groups than “lagging” development. Accelerated development is observed more often in girls. Schoolchildren with an accelerated rate of individual development have lower performance capacity than children whose biological age corresponds to the calendar age. Among them there are more people suffering from hypertension and chronic tonsillitis, they have higher morbidity rates, and functional abnormalities are more common and more severe. The highest frequency of deviations from biological age is detected among adolescents.

Thus, individual deviations in the rate of growth and development of a child from the average age determine the discrepancy between the biological age and the chronological one, which, both in the case of advance and especially lag, requires attention from doctors and parents. Criteria for biological age: level of skeletal ossification, timing of teeth eruption and change, appearance of secondary sexual characteristics, onset of menstruation, as well as morphological indicators of physical development (body length and its annual increases). With age, the degree of information content of biological age indicators changes. From 6 to 12 years, the main indicators of development are the number of permanent teeth (“dental age”) and body length. Between 11 and 15 years, the most informative indicators are the annual increase in body length, as well as the degree of expression of secondary sexual characteristics and the age of menstruation in girls. At the age of 15 and later, the appearance of secondary sexual characteristics becomes a very important indicator of development, and indicators of body length and dental development lose their information content. The level of ossification of the skeleton is determined using radiographic studies only in the presence of special medical indications - with pronounced developmental disorders. Non-simultaneous growth and development of individual organs and systems (heterochrony). The processes of growth and development proceed unevenly. Each age is characterized by certain morphofunctional features. The child’s body is considered as a single whole, but the growth and development of its individual organs and systems occur non-simultaneously (heterochronously). Selective and accelerated maturation is ensured by those structural formations and functions that determine the survival of the organism. In the first years of a child’s life, the mass of the brain and spinal cord mainly increases, which cannot be considered accidental: there is an intensive formation of the functional systems of the body. Through the nervous system, the body communicates with the external environment: mechanisms of adaptation to constantly changing conditions are formed, optimal conditions are created for receiving information and performing integrative actions. In contrast, lymphatic tissue does not develop in the first years of life; its growth and formation occur at the age of 10-12 years. Only after 12 years do intensive development of the genital organs and the formation of reproductive function occur. The growth rates of individual parts of the body are also different. During the process of growth, the proportions of the body change, and the child from a relatively large head, short legs and long body gradually turns into a small head, long legs and short body. Thus, intensive development and final formation individual organs and systems do not occur in parallel. There is a certain order of growth and development of certain structural formations and functions. Moreover, during the period of intensive growth and development of the functional system, its increased sensitivity to the action of specific factors is observed. During the period of intensive brain development, there is an increased sensitivity of the body to the lack of squirrel in food; during the period of development of speech motor functions - to speech communication; during the development of motor skills - to motor activity. The child’s body’s ability to perform specific types of activities and its resistance to various environmental factors are determined by the level of maturation of the corresponding functional systems. Thus, the associative parts of the cerebral cortex, which ensure its integral function and readiness for learning at school, mature gradually during the individual development of the child by the age of 6-7 years. In this regard, forced education of children at an early age may affect their subsequent development. The system that transports oxygen to tissues also develops gradually and reaches maturity by 16-17 years. Taking this into account, hygienists prescribe limiting physical activity for children. Only in adolescence, upon reaching the morphofunctional maturity of the cardiovascular and respiratory systems, long-term performance of heavy physical activity and the development of endurance are allowed. Thus, functional readiness for certain types of educational, labor and sports activities is not formed simultaneously, therefore, both types of activity and the impact of environmental factors on various analyzers or functional systems should be differentiated. The hygienic norm throughout the entire stage of maturation of the body changes in accordance with changes in age-related sensitivity to the action of the factor. Heterochronicity of growth and development of individual organs and systems is the scientific basis for differentiated regulation of environmental factors and activities of children and adolescents.

Determination of growth and development by sex (sexual dimorphism).

Sexual dimorphism is manifested in the characteristics of the metabolic process, the rate of growth and development of individual functional systems and the organism as a whole. Thus, boys before the onset of puberty have higher anthropometric indicators. During puberty, this ratio changes: girls are superior to their peers in terms of body length, weight, and chest circumference. There is a crossover of the age curves of these indicators. At the age of 15, the intensity of growth in boys increases, and boys are again ahead of girls in their anthropometric indicators. A second intersection of curves is formed. This double cross of the curves of age-related changes in physical development indicators is characteristic of normal physical development. At the same time, there is an unequal rate of development of many functional systems, especially muscular, respiratory and cardiovascular. For example, the strength of the hand or back extensor muscles in boys of all ages is higher than that of their peers. There are differences not only in physical performance, but also in psychophysiological indicators. age physiology organism child

And so, along with those common to both sexes growth patterns of children and adolescents There are differences in the rates, timing and indicators of growth and development of boys and girls. Sexual dimorphism is taken into account when rationing physical activity, organizing educational process. Sex differences in the growth and development of the body are important in the vocational guidance of schoolchildren, sports selection and training of young athletes. Domestic hygienic science is developing the concept of compliance, first of all, study loads the functional capabilities of a growing organism and the advisability of its training in order to protect and promote health. In accordance with this, in our country, activity standards are being developed based on the age-sex principle and recommendations are given for the reasonable training of a growing organism in order to help increase its reserve abilities and more fully use the physical capabilities of the body inherent in nature.

Inside uterineuhstages of development.

In intrauterine development of a person, three periods are conventionally distinguished:

1 The implantation period lasts from the moment of fertilization to 2 weeks. This period is characterized by rapid systematic fragmentation of the fertilized egg, its movement along the fallopian tube to the uterine cavity; implantation (attachment of the embryo and penetration into the uterine mucosa) on the 6-7th day after fertilization and further formation of the membranes creating the necessary conditions for the development of the embryo. They provide nutrition (trophoblast), create a liquid habitat and mechanical protection (amniotic fluid).

2 The embryonic period lasts from the 3rd to the 10-12th weeks of pregnancy. During this period, the rudiments of all the most important organs and systems of the future baby are formed, the torso, head, and limbs are formed. The placenta is developing - the most important organ of pregnancy, separating two bloodstreams (mother and fetus) and ensuring metabolism between mother and fetus, protecting it from infectious and other harmful factors, from the mother’s immune system. At the end of this period, the embryo becomes a fetus with a child-like configuration.

3 The fetal period begins from the 3rd month of pregnancy and ends with the birth of a child. Nutrition and metabolism of the fetus is carried out through the placenta. There is rapid growth of the fetus, formation of tissues, development of organs and systems from their rudiments, formation and formation of new functional systems that ensure the life of the fetus in the womb and the child after birth.

After the 28th week of pregnancy, the fetus begins to form a supply of valuable substances necessary in the first time after birth - calcium salts, iron, copper, vitamin B12, etc. The surfactant matures, ensuring normal lung function. Intrauterine development is influenced by various environmental factors. They have the most significant effect on the organs that develop most intensively at the time of exposure.

Postnatal period

The postnatal period is a stage of ontogenesis, during which the growing organism begins to adapt to the influence of the external environment.

The postnatal period goes through three periods of development:

1. Juvenile (before puberty)

2. Mature (or pubertal, adult sexually mature state)

3. Hydrogen (old age) periods.

In humans, the postnatal period is conventionally divided into 12 periods (age periodization):

1. Newborns - from birth to 10 days

2. Infancy - from 10 days to 1 year

3. Early childhood - from 1 year to 3 years

4. First childhood - from 4 years to 7 years

5. Second childhood - 8 - 12 years (boys), 8 - 11 years (girls)

6. Adolescence - 13 - 16 years (boys), 12 - 15 years (girls)

7. Youth period - 17 - 18 years (boys), 16 - 18 years (girls)

8. Mature age, period I: 19 - 35 years (men), 19 - 35 years (women)

9. Mature age, period II: 36 - 60 years (men), 36 - 55 years (women)

10. Old age - 61 - 74 years (men), 56 - 74 years (women)

11. Old age 75 - 90 years (men and women)

12. Long-livers - 90 years and older.

Posted on Allbest.ru

THEORETICAL FOUNDATIONS OF AGE PHYSIOLOGY (DEVELOPMENTAL PHYSIOLOGY) OF A CHILD

Systemic principle of organization of physiological functions in ontogenesis

The importance of identifying the patterns of development of the child’s body and the peculiarities of the functioning of its physiological systems at different stages of ontogenesis for the protection of health and the development of age-appropriate pedagogical technologies determined the search for optimal ways to study the physiology of the child and those mechanisms that ensure the adaptive adaptive nature of development at each stage of ontogenesis.

According to modern ideas, which began with the works of A.N. Severtsov in 1939, all functions develop and undergo changes with close interaction between the organism and the environment. In accordance with this idea, the adaptive nature of the functioning of the body at different age periods is determined by two important factors: the morphofunctional maturity of physiological systems and the adequacy of the influencing environmental factors to the functional capabilities of the body.

Traditional for domestic physiology (I.M. Sechenov, I.P. Pavlov, A.A. Ukhtomsky, N.A. Bernstein. P.K. Anokhin, etc.) is the systemic principle of organizing an adaptive response to environmental factors. This principle, considered as the basic mechanism of the body’s vital activity, implies that all types of adaptive activity of physiological systems and the whole organism are carried out through hierarchically organized dynamic associations, including individual elements of one or different organs (physiological systems).

The most important contribution to the study of the principles of dynamic systemic organization of adaptive actions of the body was made by the research of A.A. Ukhtomsky, who put forward the principle of the dominant as a functional working organ that determines the adequate response of the body to external influences. Dominant, according to A.A. Ukhtomsky, is a constellation of nerve centers united by unity of action, the elements of which can be topographically sufficiently distant from each other and at the same time tuned to a single rhythm of work. Regarding the mechanism underlying the dominant, A.A. Ukhtomsky drew attention to the fact that normal activity is based “not on the once and for all defined and stage-by-stage functional statics of various foci as carriers of individual functions, but on the continuous intercentral dynamics of excitations at different levels: cortical, subcortical, medullary, spinal.” This emphasized plasticity and the importance of the spatiotemporal factor in the organization of functional associations that ensure adaptive reactions of the body. Ideas by A.A. Ukhtomsky’s ideas about functional-plastic systems for organizing activities were developed in the works of N.A. Bernstein. Studying the physiology of movements and the mechanisms of motor skill formation, N.A. Bernstein paid attention not only to the coordinated work of nerve centers, but also to phenomena occurring on the periphery of the body - at working points. This allowed him, back in 1935, to formulate the position that the adaptive effect of an action can be achieved only if the final result - a “model of the required future” - is present in the central nervous system in some encoded form. In the process of sensory correction, through feedback coming from working organs, it is possible to compare information about already carried out activities with this model.

Expressed by N.A. Bernstein's position on the importance of feedback in achieving adaptive reactions was of paramount importance in understanding the mechanisms of regulation of the adaptive functioning of the body and the organization of behavior.

The classical idea of an open reflex arc has given way to the idea of a closed control loop. A very important provision developed by N.A. Bernstein, is the high plasticity of the system he established - the possibility of achieving the same result in accordance with the “model of the required future” with an ambiguous path to achieving this result depending on specific conditions.

Developing the idea of a functional system as an association that ensures the organization of adaptive response, P.K. Anokhin considered the useful result of action as a system-forming factor that creates a certain ordered interaction of individual elements of the system. “It is the useful result that constitutes the operational factor, which contributes to the fact that the system... can completely reorganize the arrangement of its parts in space and time, which provides the adaptive result necessary in a given situation” (Anokhin).

Of primary importance for understanding the mechanisms that ensure the interaction of individual elements of the system is the position developed by N.P. Bekhtereva and her colleagues, about the presence of two systems of connections: rigid (innate) and flexible, plastic. The latter are most important for organizing dynamic functional associations and ensuring specific adaptive reactions in real operating conditions.

One of the main characteristics of the system support for adaptive reactions is the hierarchy of their organization (Wiener). Hierarchy combines the principle of autonomy with the principle of subordination. Along with flexibility and reliability, hierarchically organized systems are characterized by high energy structural and information efficiency. Individual levels may consist of blocks that carry out simple specialized operations and transmit processed information to higher levels of the system, which carry out more complex operations and at the same time have a regulatory influence on lower levels.

The hierarchy of the organization, based on the close interaction of elements both at the same level and at different levels of systems, determines the high stability and dynamism of the processes carried out.

In the course of evolution, the formation of hierarchically organized systems in ontogenesis is associated with progressive complication and layering of regulatory levels on top of each other, ensuring the improvement of adaptation processes (Vasilevsky). It can be assumed that the same patterns take place in ontogenesis.

The importance of a systematic approach to the study of the functional properties of a developing organism, its ability to form an optimal adaptive response for each age, self-regulation, the ability to actively search for information, formulate plans and programs of activity is obvious.

Patterns of ontogenetic development. The concept of age norm

Of utmost importance for understanding how functional systems are formed and organized in the process of individual development is the formulation formulated by A.N. Severtsov’s principle of heterochrony in the development of organs and systems, developed in detail by P.K. Anokhin in the theory of systemogenesis. This theory is based on experimental studies of early ontogenesis, which revealed the gradual and uneven maturation of individual elements of each structure or organ, which are consolidated with elements of other organs involved in the implementation of a given function, and, integrating into a single functional system, implement the principle of “minimum provision” of an integral function . Different functional systems depending on their importance in ensuring vital important functions mature at different times in postnatal life - this is heterochrony of development. It ensures high adaptability of the organism at each stage of ontogenesis, reflecting the reliability of the functioning of biological systems. Reliability of functioning of biological systems, according to the concept of A.A. Markosyan, is one of general principles individual development. It is based on such properties of a living system as the redundancy of its elements, their duplication and interchangeability, the speed of return to relative constancy and the dynamism of individual parts of the system. Research has shown (Farber) that during ontogenesis, the reliability of biological systems goes through certain stages of formation and formation. And if in the early stages of postnatal life it is ensured by the rigid, genetically determined interaction of individual elements of the functional system, ensuring the implementation of elementary reactions to external stimuli, and necessary vital functions (for example, sucking), then in the course of development plastic connections that create conditions for dynamic selective organization of system components. Using the example of the formation of an information perception system, a general pattern has been established to ensure the reliability of the adaptive functioning of the system. Three functionally different stages of its organization are identified: Stage 1 (newborn period) - the functioning of the earliest maturing block of the system, providing the ability to respond according to the “stimulus-response” principle; Stage 2 (first years of life) - generalized uniform involvement of elements of a higher level of the system, the reliability of the system is ensured by duplication of its elements; Stage 3 (observed from preschool age) - a hierarchically organized multi-level regulatory system provides the possibility of specialized involvement of elements of different levels in processing information and organizing activities. During ontogenesis, as the central mechanisms of regulation and control improve, the plasticity of the dynamic interaction of system elements increases; selective functional constellations are formed in accordance with specific situation and the task at hand (Farber, Dubrovinskaya). This determines the improvement of the adaptive reactions of the developing organism in the process of complication of its contacts with the external environment and the adaptive nature of functioning at each stage of ontogenesis.

From the above it is clear that individual stages of development are characterized both by the peculiarities of the morphofunctional maturity of individual organs and systems, and by the difference in mechanisms that determine the specifics of the interaction between the organism and the external environment.

The need for specific characteristics of individual stages of development, taking into account both of these factors, raises the question of what to consider as the age norm for each stage.

For a long time, the age norm was considered as a set of average statistical parameters characterizing the morphofunctional characteristics of the organism. This idea of the norm has its roots in those times when practical needs determined the need to identify certain average standards that make it possible to identify developmental deviations. There is no doubt that at a certain stage in the development of biology and medicine, such an approach played a progressive role, making it possible to determine the average statistical parameters of the morphofunctional characteristics of a developing organism; and even today it allows solving a number of practical problems (for example, when calculating standards of physical development, regulating the impact of environmental factors, etc.). However, this idea of the age norm, which absolutizes the quantitative assessment of the morphofunctional maturity of the organism at different stages of ontogenesis, does not reflect the essence of age-related transformations that determine the adaptive orientation of the development of the organism and its relationship with the external environment. It is quite obvious that if the qualitative specificity of the functioning of physiological systems at certain stages of development remains unaccounted for, then the concept of an age norm loses its content, it ceases to reflect the real functional capabilities of the body at certain age periods.

The idea of the adaptive nature of individual development has led to the need to revise the concept of age norm as a set of average morphological and physiological parameters. A position was put forward according to which the age norm should be considered as a biological optimum for the functioning of a living system, providing an adaptive response to environmental factors (Kozlov, Farber).

Age periodization

Differences in understanding the criteria for age norms also determine approaches to the periodization of age development. One of the most common is the approach, which is based on an analysis of the assessment of morphological characteristics (height, change of teeth, increase in body weight, etc.). The most complete age periodization, based on morphological and anthropological characteristics, was proposed by V.V. Bunak, according to whom changes in body size and associated structural and functional characteristics reflect transformations in the body’s metabolism with age. According to this periodization, the following periods are distinguished in postnatal ontogenesis: infantile, covering the first year of a child’s life and including the initial (1–3, 4–6 months), middle (7–9 months) and final (10–12 months) cycles; first childhood (initial cycle 1–4 years, final cycle - 5–7 years); second childhood (initial cycle: 8-10 years old - boys, 8-9 years old - girls; final cycle: 11-13 years old - boys, 10-12 years old - girls); teenage (14–17 years old - boys, 13–16 years old - girls); youth (18–21 years old - boys, 17–20 years old - girls); The adult period begins at the age of 21–22. This periodization is close to that accepted in pediatric practice (Tur, Maslov); Along with morphological factors, it also takes into account social ones. Infancy, according to this periodization, corresponds to younger toddler or infancy; the period of first childhood combines senior nursery or pre-preschool age and preschool age; the period of second childhood corresponds to primary school age and adolescence to senior preschool age. However, this classification of age periods, reflecting the existing system of education and training, cannot be considered acceptable, since, as is known, the issue of the beginning of systematic education has not yet been resolved; the border between preschool and school age requires clarification; the concepts of junior and senior school age are also quite amorphous.

According to the age periodization adopted at a special symposium in 1965, the following periods are distinguished in the human life cycle until reaching adulthood: newborn (1-10 days); infancy (10 days - 1 year); early childhood (1–3 years); first childhood (4–7 years); second childhood (8-12 years old - boys, 8-11 years old - girls); adolescence (13–16 years old - boys, 12–15 years old - girls) and adolescence(17–21 years old - boys, 16–20 years old - girls) (The problem of human age periodization). This periodization is somewhat different from that proposed by V.V. Bunak by highlighting the period of early childhood, some shifting of the boundaries of second childhood and adolescence. However, the problem of age periodization has not been completely resolved, primarily because all existing periodizations, including the latest generally accepted one, are not sufficiently physiologically substantiated. They do not take into account the adaptive nature of development and the mechanisms that ensure the reliable functioning of physiological systems and the entire organism at each stage of ontogenesis. This determines the need to select the most informative criteria for age periodization.

In the process of individual development, the child’s body changes as a whole. Its structural, functional and adaptive features are determined by the interaction of all organs and systems at different levels of integration - from intracellular to intersystem. In accordance with this, the key task of age periodization is the need to take into account the specific features of the functioning of the whole organism.

One of the attempts to search for an integral criterion characterizing the vital activity of an organism was the assessment of the energy capabilities of the organism proposed by Rubner, the so-called “energy surface rule”, reflecting the relationship between the level of metabolism and energy and the size of the body surface. This indicator, characterizing the energy capabilities of the body, reflects the activity of physiological systems associated with metabolism: blood circulation, respiration, digestion, excretion and the endocrine system. It was assumed that the ontogenetic features of the functioning of these systems should obey the “energy rule of the surface.”

However, the theoretical provisions discussed above about the adaptive adaptive nature of development give reason to believe that age periodization should be based not so much on criteria reflecting the stationary features of the organism’s life activity that have already been achieved at a certain moment of maturation, but rather on criteria for the interaction of the organism with the environment.

I.A. also spoke about the need for such an approach to the search for physiological criteria for age periodization. Arshavsky. According to his idea, age periodization should be based on criteria that reflect the specifics of the holistic functioning of the body. As such a criterion, a leading function is proposed for each stage of development.

In the detailed study by I.A. Arshavsky and his colleagues distinguished periods in early childhood in accordance with the nature of nutrition and characteristics of motor acts: neonatal, during which feeding with colostrum milk takes place (8 days), lactotrophic form of nutrition (5–6 months), lactotrophic form of nutrition with complementary foods and appearance of standing posture (7-12 months), toddler age (1-3 years) - mastering locomotor acts in the environment (walking, running). It should be noted that A. Arshavsky attached special importance to motor activity as a leading factor in development. Having criticized the “surface energy rule”, I.A. Arshavsky formulated the idea of the “energy rule of skeletal muscles,” according to which the intensity of the body’s vital activity, even at the level of individual tissues and organs, is determined by the peculiarities of the functioning of skeletal muscles, which ensure the interaction of the organism and the environment at each stage of development.

However, it must be borne in mind that in the process of ontogenesis the child’s active attitude to environmental factors increases, the role of the higher parts of the central nervous system in ensuring adaptive reactions to external environmental factors, including those reactions that are realized through motor activity, increases.

Therefore, criteria reflecting the level of development and qualitative changes in adaptive mechanisms associated with the maturation of various parts of the brain, including the regulatory structures of the central nervous system, which determine the activity of all physiological systems and the child’s behavior, acquire a special role in age periodization.

This brings together physiological and psychological approaches to the problem of age periodization and creates the basis for developing a unified concept of periodization of child development. L.S. Vygotsky considered mental neoplasms characteristic of specific stages of development as criteria for age periodization. Continuing this line, A.N. Leontyev and D.B. Elkonin attached special importance in age periodization to “leading activity” that determines the emergence of mental neoplasms. It was noted that the characteristics of mental, as well as the characteristics of physiological development, are determined by both internal (morphofunctional) factors and external conditions of individual development.

One of the goals of age periodization is to establish the boundaries of individual stages of development in accordance with the physiological norms of the growing organism’s response to the influence of environmental factors. The nature of the body's responses to the influences provided most directly depends on the age-related characteristics of the functioning of various physiological systems. According to S.M. Grombach, when developing the problem of age periodization, it is necessary to take into account the degree of maturity and functional readiness of various organs and systems. If certain physiological systems are not leading at a certain stage of development, they can ensure optimal functioning of the leading system in various environmental conditions, and therefore the level of maturity of these physiological systems cannot but affect the functional capabilities of the entire organism as a whole.

To judge which system is leading for a given stage of development and where the line of change from one leading system to another lies, it is necessary to assess the level of maturity and features of the functioning of various organs and physiological systems.

Thus, age periodization should be based on three levels of studying the child’s physiology:

1 - intra-system;

2 - intersystem;

3 - a whole organism in interaction with the environment.

The issue of periodization of development is inextricably linked with the choice of informative criteria that should be used as its basis. This brings us back to the idea of the age norm. One can completely agree with the statement of P.N. Vasilevsky that “the optimal modes of activity of the functional systems of the body are not statistically average, but by continuous dynamic processes occurring over time in a complex network of co-adapted regulatory mechanisms.” There is every reason to believe that the most informative criteria for age-related transformations are those that characterize the state of physiological systems in conditions of activity that are as close as possible to those that the object of study - the child - encounters in his life. Everyday life, i.e. indicators reflecting real adaptability to environmental conditions and adequacy of response to external influences.

Based on the concept of the systemic organization of adaptive reactions, it can be assumed that such indicators should first of all be considered those that reflect not so much the maturity of individual structures, but rather the possibility and specificity of their interaction with the environment. This applies both to indicators characterizing the age-related characteristics of each physiological system separately, and to indicators of the holistic functioning of the body. All of the above requires an integrated approach to the analysis of age-related transformations at the intrasystem and intersystem levels.

No less important when developing problems of age periodization is the question of the boundaries of functionally different stages. In other words, physiologically based periodization should be based on identifying the stages of “actual” physiological age.

Identification of functionally different stages of development is possible only if there is data on the characteristics of the adaptive functioning of various physiological systems within each year of a child’s life.

Long-term studies conducted at the Institute of Developmental Physiology of the Russian Academy of Education made it possible to establish that, despite the heterochrony of the development of organs and systems, within the periods considered as unified, key moments were identified, which are characterized by significant qualitative morphofunctional transformations leading to adaptive restructuring of the body. In preschool age this is from 3-4 to 5-6 years, in primary school age - from 7-8 to 9-10 years. In adolescence, qualitative changes in the activity of physiological systems are not associated with a certain passport age, but with the degree of biological maturity (certain stages of puberty - stages II–III).

Sensitive and critical periods of development

The adaptive nature of the development of the body determines the need to take into account in age periodization not only the features of the morphofunctional development of the physiological systems of the body, but also their specific sensitivity to various external influences. Physiological and psychological studies have shown that sensitivity to external influences is selective at different stages of ontogenesis. This formed the basis for the idea of sensitive periods as periods of greatest sensitivity to environmental factors.

Identifying and taking into account sensitive periods of development of body functions is an indispensable condition for creating favorable adequate conditions for effective learning and maintaining the health of the child. The high susceptibility of certain functions to the influence of environmental factors should, on the one hand, be used for effective targeted influence on these functions, promoting their progressive development, and on the other hand, the influence of negative external environmental factors should be controlled, because they can lead to disruption of the development of the organism.

It should be emphasized that ontogenetic development combines periods of evolutionary (gradual) morphofunctional maturation and periods of revolutionary, turning-point developmental leaps, which can be associated with both internal (biological) and external (social) development factors.

An important issue that requires special attention is the issue of critical periods of development . In evolutionary biology, it is generally accepted that the critical period is the stage of early postnatal development, characterized by the intensity of morphofunctional maturation, when, due to the lack of environmental influences, a function may not be formed. For example, in the absence of certain visual stimuli in early ontogenesis, their perception is not subsequently formed, the same applies to speech function.

In the process of further development, critical periods can arise as a result of a sharp change in social and environmental factors and their interaction with the process of internal morphofunctional development. Such a period is the age at which learning begins, when qualitative changes in the morphofunctional maturation of basic brain processes occur during a period of sharp changes in social conditions.

Puberty- the onset of puberty - is characterized by a sharp increase in the activity of the central link of the endocrine system (hypothalamus), which leads to a sharp change in the interaction of subcortical structures and the cerebral cortex, resulting in a significant decrease in the effectiveness of central regulatory mechanisms, including those determining voluntary regulation and self-regulation. In addition, social demands on adolescents increase, their self-esteem increases. This leads to a discrepancy between socio-psychological factors and the functional capabilities of the body, which can result in deviations in health and behavioral disadaptation.

Thus, it can be assumed that critical periods of development are caused by both intensive morphofunctional transformation of the main physiological systems and the whole organism, and the specifics of the increasingly complex interaction of internal (biological) and socio-psychological factors of development.

When considering issues of age periodization, it is necessary to keep in mind that the boundaries of development stages are very arbitrary. They depend on specific ethnic, climatic, social and other factors. In addition, the “actual” physiological age often does not coincide with the calendar (passport) age due to differences in the rates of maturation and development conditions of organisms different people. It follows that when studying the functional and adaptive capabilities of children of different ages, it is necessary to pay attention to the assessment of individual indicators of maturity. Only by combining an age-specific and individual approach to studying the characteristics of a child’s functioning can it be possible to develop adequate hygienic and pedagogical measures to ensure the preservation of health and the progressive development of the child’s body and personality.

Questions and tasks

1. Tell us about the systemic principle of organizing adaptive response.

2. What are the patterns of ontogenetic development? What is the age norm?

3. What is age periodization?

4. Talk about sensitive and critical periods of development.

Chapter 3. GENERAL PLAN OF THE STRUCTURE OF A CHILD’S BODY

Before we begin to study the most important patterns of age-related development of an organism, it is necessary to understand what an organism is, what principles are laid down by Nature in its general design and how it interacts with the outside world.

Almost 300 years ago it was proven that all living things consist of cells. The human body is made up of several billion tiny cells. These cells are far from identical in appearance, properties and functions. Cells that are similar to each other unite into fabrics. There are many types of tissue in the body, but they all belong to only 4 types: epithelial, connective, muscle and nervous. Epithelial tissues form the skin and mucous membranes, many internal organs- liver, spleen, etc. In epithelial tissues, cells are located closely to each other. Connective the tissue has very large intercellular spaces. This is how bones and cartilage are structured, this is how blood is structured - all these are types of connective tissue. Muscular And nervous tissues are excitable: they are able to perceive and conduct an excitation impulse. Moreover, for nervous tissue this is the main function, while muscle cells can still contract, significantly changing in size. This mechanical work can be transferred to the bones or fluids located inside the muscle bags.

Fabrics in various combinations form anatomical organs. Each organ consists of several tissues, and almost always, along with the main, functional tissue, which determines the specifics of the organ, there are elements of nervous tissue, epithelium and connective tissue. Muscle tissue may not be present in the organ (for example, in the kidneys, spleen, etc.).

Anatomical organs are formed into anatomical and physiological systems, which are united by the unity of the main function they perform. This is how the musculoskeletal, nervous, integumentary, excretory, digestive, respiratory, cardiovascular, reproductive, endocrine systems and blood are formed. All these systems together make up organism person.

The elementary unit of living things is the cell. The genetic apparatus is concentrated in the cell core, i.e. localized and protected from unexpected exposure to a potentially aggressive environment. Each cell is isolated from the rest of the world due to the presence of a complexly organized membrane - membranes. This shell consists of three layers of chemically and functionally different molecules, which, acting in concert, provide multiple functions: protective, contact, sensitive, absorbing and releasing. The main job of the cell membrane is to organize the flow of substances from the environment into the cell, and from the cell out. The cell membrane is the basis of all cell life, which dies when the membrane is destroyed. Any cell needs food and energy for its functioning - after all, the functioning of the cell membrane also largely involves the expenditure of energy. To organize the energy flow through the cell, there are special organelles in it that are responsible for energy production - mitochondria. It is believed that billions of years ago, mitochondria were independent living organisms that, during the course of evolution, learned to use certain chemical processes to generate energy. Then they entered into symbiosis with other single-celled organisms, which, thanks to this cohabitation, received a reliable source of energy, and the ancestors of mitochondria received reliable protection and a guarantee of reproduction.

The construction function in the cell is performed by ribosomes- factories for the production of protein based on matrices copied from genetic material stored in the nucleus. Acting through chemical stimuli, the nucleus controls all aspects of cell life. The transfer of information inside the cell is carried out due to the fact that it is filled with a jelly-like mass - cytoplasm, in which many biochemical reactions take place, and substances of informational value can easily penetrate into the farthest corners of the intracellular space due to diffusion.

Many cells also have one or another adaptation for movement in the surrounding space. It could be flagellum(like a sperm) villi(like intestinal epithelium) or the ability to transfuse cytoplasm in the form pseudopodium(like lymphocytes).

Thus, the most important structural elements of a cell are its shell (membrane), control organ (nucleus), energy supply system (mitochondrion), building block (ribosome), propulsion (cilia, pseudopodia, or flagellum) and internal environment (cytoplasm). Some single-celled organisms also have an impressive calcified skeleton that protects them from enemies and accidents.

Surprisingly, the human body, consisting of many billions of cells, has, in fact, the same important building blocks. A person is separated from the environment by his skin membrane. It has a mover (muscles), a skeleton, control organs (brain and spinal cord and endocrine system), an energy supply system (breathing and blood circulation), a primary food processing unit (gastrointestinal tract), as well as an internal environment (blood, lymph, intercellular fluid). This diagram does not exhaust all the structural components of the human body, but allows us to conclude that any living creature is built according to a fundamentally unified plan.

Of course, a multicellular organism has a number of features and, apparently, advantages - otherwise the process of evolution would not have been directed towards the emergence of multicellular organisms and the world would still be inhabited exclusively by those whom we call “protozoa”.

The main structural difference between a unicellular and a multicellular organism is that the organs of a multicellular organism are built from millions of individual cells, which, according to the principle of similarity and functional relationship, are combined into tissues, while the organelles of a unicellular organism are elements of one single cell.

What is the real advantage of a multicellular organism? The ability to separate functions in space and time, as well as the specialization of individual tissue and cellular structures to perform strictly defined functions. In essence, these differences are similar to the differences between medieval subsistence farming and modern industrial production. A cell, which is an independent organism, is forced to solve all the problems that confront it using the resources it has. To solve each functional problem, a multicellular organism allocates a special population of cells or a complex of such populations (tissue, organ, functional system) that are maximally adapted to solve this particular problem. It is clear that the efficiency of problem solving by a multicellular organism is much higher. More precisely, a multicellular organism is much more likely to adapt to a wide range of situations that it has to face. Hence the fundamental difference between a cell and a multicellular organism in the adaptation strategy follows: the first reacts holistically and generally to any environmental influence, the second is able to adapt to living conditions by restructuring the functions of only individual of its constituent parts - tissues and organs.

It is important to emphasize that the tissues of a multicellular organism are very diverse and each the best way adapted to perform a small number of functions necessary for the life and adaptation of the entire organism. At the same time, the cells of each tissue are able to perfectly perform only one single function, and the entire variety of functional capabilities of the body is provided by the diversity of the cells that make up its composition. For example, nerve cells are only capable of producing and conducting an excitation impulse, but are not able to change their size or destroy toxic substances. Muscle cells are capable of conducting an excitation impulse in the same way as nerve cells, but at the same time they themselves contract, ensuring the movement of body parts in space or changing the tension (tone) of the structures consisting of these cells. Liver cells are not able to conduct electrical impulses or contract, but their biochemical power ensures the neutralization of a huge number of harmful and poisonous molecules that enter the blood during the life of the body. Bone marrow cells are specifically designed to produce blood and cannot do anything else. This “division of labor” is a characteristic property of any complexly organized system; social structures also function according to the same rules. This must be taken into account when predicting the results of any reorganizations: no specialized subsystem is capable of changing the nature of its functioning if its own structure does not change.

The emergence of tissues with qualitative characteristics in the process of ontogenesis is a relatively slow process, and it does not occur due to the fact that existing cells acquire new functions: almost always new functions are provided by new generations of cellular structures, formed under the control of the genetic apparatus and under the influence of external requirements. or internal environment.

Ontogenesis is an amazing phenomenon during which a single-celled organism (zygote) turns into a multicellular one, maintaining integrity and viability at all stages of this remarkable transformation and gradually increasing the diversity and reliability of the functions performed.

Structural-functional and systems approach to the study of the body

Scientific physiology was born on the same day as anatomy - this happened in the middle of the 17th century, when the great English doctor William Harvey received permission from the church and the king and performed the first autopsy after a thousand-year interval on the corpse of a criminal sentenced to death in order to scientific study internal structure of the human body. Of course, even the ancient Egyptian priests, embalming the bodies of their pharaohs, knew perfectly well the structure of the human body from the inside - but this knowledge was not scientific, it was empirical, and, moreover, secret: the disclosure of any information about this was considered sacrilege and was punishable by death. The great Aristotle, teacher and mentor of Alexander the Great, who lived 3 centuries BC, had a very vague idea of how the body works and how it works, although he was encyclopedically educated and knew, it seems, everything that he had accumulated by that time European civilization. More knowledgeable were the ancient Roman doctors - students and followers of Galen (2nd century AD), who laid the foundations of descriptive anatomy. Medieval Arab doctors gained enormous fame, but even the greatest of them - Ali Abu ibn Sina (in European transcription - Avicenna, 11th century) - treated the human spirit rather than the body. And so W. Harvey, in front of a huge crowd of people, conducted the first study in the history of European science of the structure of the human body. But Harvey was most interested in HOW the body WORKS. Since ancient times, people have known that a heart beats in the chest of each of us. Doctors at all times measured the pulse and, based on its dynamics, assessed the state of health and the prospects for combating various diseases. Until now, one of the most important diagnostic techniques in the famous and mysterious Tibetan medicine is long-term continuous observation of the patient’s pulse: the doctor sits at his bedside and holds his hand on the pulse for hours, and then names the diagnosis and prescribes treatment. Everyone knew well: the heart stopped - life stopped. However, the Galenic school, traditional at that time, did not connect the movement of blood through the vessels with the activity of the heart.

But before Harvey’s eyes is a heart with tubes-vessels filled with blood. And Harvey understands: the heart is just a muscular sac that acts as a pump that pumps blood throughout the body, because there are vessels throughout the body that become more numerous and thinner as they move away from the pump. Through the same vessels, blood returns to the heart, making a full revolution and continuously flowing to all organs, to every cell, carrying with it nutrients. Nothing is known yet about the role of oxygen, hemoglobin has not been discovered, doctors are in no way able to distinguish between proteins, fats and carbohydrates - in general, knowledge of chemistry and physics is still extremely primitive. But various technologies have already begun to develop; the engineering mind of mankind has invented many devices that facilitate production or create completely new, previously unprecedented technical capabilities. It became clear to Harvey's contemporaries: certain things work in the body mechanisms , the structural basis of which is made up of individual organs, and each organ is designed to perform one or another specific function. The heart is a pump that pumps blood through the “veins,” just like those pumps that supply water from lowland lakes to a hilltop estate and feed fountains pleasing to the eye. The lungs are bellows through which air is pumped, as apprentices do in a forge, to make the iron hotter and make it easier to forge. Muscles are ropes attached to bones, and their tension causes these bones to move, which ensures the movement of the entire body, just as builders use hoists to lift huge stones to the upper floors of a temple under construction.

It is human nature to always compare new phenomena discovered by him with already known ones that have come into use. A person always builds analogies in order to more easily understand and explain to himself the essence of what is happening. High level The development of mechanics in the era when Harvey carried out his research inevitably led to a mechanical interpretation of the numerous discoveries made by doctors who followed Harvey. This is how structural-functional physiology was born with its slogan: one organ - one function.

However, as knowledge accumulated - and this largely depended on the development of physical and chemical sciences, since they provide the main methods for conducting scientific research in physiology, it became clear that many organs perform not one, but several functions. For example, the lungs not only ensure the exchange of gases between the blood and the environment, but also participate in the regulation of body temperature. The skin, primarily performing a protective function, is also both an organ of thermoregulation and an organ of excretion. Muscles are capable of not only actuating skeletal levers, but also, through their contractions, warming the blood flowing to them, maintaining temperature homeostasis. Examples of this kind can be given endlessly. The multifunctionality of organs and physiological systems has become especially clear in late XIX- early 20th century It is curious that at the same time, many different “universal” machines and tools appeared in technology, with a wide range of capabilities - sometimes to the detriment of simplicity and reliability. This is an illustration of the fact that the technical thought of mankind and the level of scientific understanding of the organization of processes in living nature are developing in close interaction with each other.

By the mid-30s of the XX century. It became clear that even the concept of multifunctionality of organs and systems is no longer able to explain the consistency of body functions in the process of adaptation to changing conditions or in the dynamics of age-related development. A new understanding of the meaning of the processes occurring in a living organism began to emerge, from which a systematic approach to the study of physiological processes gradually emerged. At the origins of this direction of physiological thought were outstanding Russian scientists - A.A. Ukhtomsky, N.A. Bernstein and P.K. Anokhin.

The most fundamental difference between the structural-functional and systems approaches is the understanding of what is a physiological function. For structural-functional approach Characteristic is the understanding of a physiological function as a certain process carried out by a certain (specific) set of organs and tissues, changing their activity in the course of functioning in accordance with the influence of control structures. In this interpretation, physiological mechanisms are those physical and chemical processes that underlie a physiological function and ensure the reliability of its implementation. The physiological process is the object that is the focus of the structural-functional approach.

Systems approach is based on the idea of expediency, i.e., a function within the framework of a systems approach is understood as the process of achieving a certain goal, result. At various stages of this process, the need for the involvement of certain structures can change quite significantly, therefore the constellation (composition and nature of interaction of elements) of the functional system is very flexible and corresponds to the particular task that is being solved at the current moment. The presence of a goal presupposes that there is some model of the state of the system before and after achieving this goal, an action program, and there is also a feedback mechanism that allows the system to control its current state (intermediate result) in comparison with the modeled one and, on this basis, make adjustments to the action program in order to achieve the final result.

From the standpoint of the structural-functional approach, the environment acts as a source of stimuli for certain physiological reactions. A stimulus arose and a reaction arose in response, which either fades away as one gets used to the stimulus, or stops when the stimulus stops working. In this sense, the structural-functional approach considers the body as a closed system that has only certain channels for exchanging information with the environment.

The systems approach considers the organism as an open system, the target function of which can be placed both inside and outside it. In accordance with this view, the body reacts to the influences of the external world as a whole, rebuilding the strategy and tactics of this response depending on the results achieved each time in such a way as to achieve model target results either faster or more reliably. From this point of view, the reaction to an external stimulus fades when the target function formed under its influence is realized. The stimulus can continue to act or, on the contrary, it can cease its effect long before the completion of functional rearrangements, but once started, these rearrangements must go through the entire programmed path, and the reaction will end only when the feedback mechanisms bring information about the complete balance of the organism with the environment at a new level of functional activity. A simple and clear illustration of this situation can be the reaction to any physical activity: to perform it, muscle contractions are activated, which necessitates the corresponding activation of blood circulation and respiration, and even when the load is already completed, physiological functions still retain their increased activity for quite a long time, since they ensure alignment of metabolic states and normalization of homeostasis parameters. The functional system that enables physical exercise to be performed includes not only the muscles and nerve structures that command the muscles to contract, but also the circulatory system, the respiratory system, the endocrine glands, and many other tissues and organs involved in this process of major changes. internal environment of the body.

The structural-functional view of the essence of physiological processes reflected the deterministic, mechanistic-materialistic approach, which was characteristic of all natural sciences of the 19th and early 20th centuries. The pinnacle of its development can probably be considered the theory of conditioned reflexes by I.P. Pavlov, with the help of which the great Russian physiologist tried to understand the mechanisms of brain activity using the same techniques with which he successfully studied the mechanisms of gastric secretion.

The systems approach takes a stochastic, probabilistic position and does not reject teleological (expedient) approaches characteristic of the development of physics and other natural sciences in the second half of the 20th century. It has already been said above that physiologists, simultaneously with mathematicians, precisely within the framework of this approach, came to the formulation of the most general cybernetic laws to which all living things obey. Equally important for understanding physiological processes at the modern level are ideas about the thermodynamics of open systems, the development of which is associated with the names of outstanding physicists of the 20th century. Ilya Prigogine, von Bertalanffy and others.

The body as an integral system

Modern understanding of complex self-organizing systems includes the idea that they have clearly defined channels and methods for transmitting information. In this sense, a living organism is a completely typical self-organizing system.

The body receives information about the state of the surrounding world and the internal environment using sensors-receptors that use a wide variety of physical and chemical design principles. Thus, for humans, the most important is the visual information that we receive with the help of our optical-chemical sensors - the eyes, which are both a complex optical device with an original and accurate guidance system (adaptation and accommodation), as well as a physical-chemical converter of photon energy into electrical impulse of the optic nerves. Acoustic information comes to us through a bizarre and finely tuned auditory mechanism that converts the mechanical energy of air vibrations into electrical impulses from the auditory nerve. Temperature sensors, tactile (tactile), and gravitational (sense of balance) are no less delicately designed. The most evolutionarily ancient are the olfactory and taste receptors, which have enormous selective sensitivity in relation to certain molecules. All this information about the state of the external environment and its changes enters the central nervous system, which performs several roles simultaneously - a database and knowledge, an expert system, a central processor, as well as the functions of RAM and long-term memory. Information from receptors located inside our body and transmitting information about the state of biochemical processes, about the tension in the work of certain physiological systems, about the current needs of individual groups of cells and tissues of the body also flows there. In particular, there are sensors for pressure, carbon dioxide and oxygen content, acidity of various biological fluids, tension of individual muscles and many others. Information from all these receptors is also sent to the center. Sorting of information coming from the periphery begins already at the stage of its reception - after all, the nerve endings of various receptors reach the central nervous system at its different levels, and accordingly the information enters various parts of the central nervous system. However, all of it can be used in the decision-making process.

A decision must be made when the situation has changed for some reason and requires appropriate reactions at the system level. For example, a person is hungry - this is reported to the “center” by sensors that record increased fasting secretion of gastric juice and gastrointestinal motility, as well as sensors that record a decrease in blood glucose levels. In response, the peristalsis of the gastrointestinal tract reflexively increases and the secretion of gastric juice increases. The stomach is ready to receive a new portion of food. At the same time, optical sensors allow you to see food on the table, and a comparison of these images with models stored in the long-term memory database suggests that it is possible to wonderfully satisfy your hunger, while enjoying the look and taste of the food you consume. In this case, the central nervous system orders the executive (effector) organs to carry out the necessary actions, which will ultimately lead to saturation and elimination of the original cause of all these events. Thus, the goal of the system is to eliminate the cause of the disturbance through its actions. In this case, this goal is achieved relatively easily: just reach out to the table, take the food lying there and eat it. However, it is clear that using the same scheme it is possible to construct an arbitrarily complex scenario of actions.

Hunger, love, family values, friendship, shelter, self-affirmation, craving for new things and love of beauty - this short list almost exhausts the motivations for action. Sometimes they become overgrown with a huge number of accompanying psychological and social complexities, closely intertwined with each other, but in their most basic form they remain the same, forcing a person to perform actions whether in the times of Apuleius, Shakespeare or in our time.

Act - what does this mean in terms of systems? This means that the central processor, obeying the program embedded in it, taking into account all possible circumstances, makes a decision, i.e., builds a model of the required future and develops an algorithm for achieving this future. Based on this algorithm, orders are given to individual effector (executive) structures, and almost always they contain muscles, and in the process of executing the order of the center, the body or its parts move in space.

And once movement occurs, it means that physical work is performed in the field of gravity, and therefore energy is consumed. Of course, the operation of the sensors and processor also requires energy, but the energy flow increases many times when muscle contractions are activated. Therefore, the system must take care of an adequate supply of energy, for which it is necessary to increase the activity of blood circulation, respiration and some other functions, as well as mobilize available reserves of nutrients.

Any increase in metabolic activity entails a violation of the constancy of the internal environment. This means that physiological mechanisms for maintaining homeostasis must be activated, which, by the way, also require significant amounts of energy for their activities.

Being a complexly organized system, the body has not one, but several regulatory circuits. The nervous system is probably the main, but by no means the only regulatory mechanism. Very important role performed by endocrine organs - endocrine glands, which chemically regulate the activity of almost all organs and tissues. Each cell of the body also has its own internal system of self-regulation.

It should be emphasized that the organism is an open system not only from a thermodynamic point of view, that is, it exchanges not only energy with the environment, but also matter and information. We consume the substance mainly in the form of oxygen, food and water, and excrete it in the form of carbon dioxide, feces and sweat. As for information, each person is a source of visual (gestures, postures, movements), acoustic (speech, noise from movement), tactile (touch) and chemical (numerous odors that are perfectly distinguished by our pets) information.

Another important feature of the system is the finiteness of its dimensions. The body is not smeared environment, but has a certain shape and is compact. The body is surrounded by a shell, a boundary separating the internal environment from the external one. The skin, which plays this role in the human body, is an important element of its design, since it is in it that many sensors are concentrated, carrying information about the state of the outside world, as well as ducts for removing metabolic products and information molecules from the body. The presence of clearly defined boundaries turns a person into an individual who feels his separation from the world around him, his uniqueness and uniqueness. This is a psychological effect that occurs on the basis of the anatomical and physiological structure of the body.

The main structural and functional blocks that make up the body

Thus, the main structural and functional blocks that make up the body include the following (each block includes several anatomical structures with multiple functions):

sensors (receptors) carrying information about the state of the external and internal environment;

central processor and control unit, including nervous and humoral regulation;

effector organs (primarily the musculoskeletal system), ensuring the execution of orders from the “center”;

an energy block that provides the effector and all other structural components with the necessary substrate and energy;

a homeostatic block that maintains the parameters of the internal environment at the level necessary for life;

a shell that performs the functions of a border zone, reconnaissance, protection and all types of exchange with the environment.