EntranceDevelopmental physiology as a science and educational subject. 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 ensuring normal physical and mental development of the younger generation.
The main questions that should arise from parents, teachers and psychologists in the process of raising and educating a child at home, in kindergarten or at school, at a counseling session, or individual lessons, - this is what it is like, what its features are, what option of training with it will be 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, and 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 formation age 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.
In the same time pedagogical effectiveness the learning process largely depends on how the forms and methods of pedagogical influence are adequate to the age-related physiological and psychophysiological characteristics of schoolchildren, whether the conditions of the organization correspond educational process 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 are taken into account 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 body and the mechanisms of its adaptation to 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 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, 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 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 environmental factors on a living organism and the ways in which the organism adapts 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 the problems of developmental psychology and the physiology of development: only in this case his activities will bring real benefits to his students.
Current page: 1 (book has 12 pages total) [available reading passage: 8 pages]
Yuri Savchenkov, Olga Soldatova, Sergei Shilov
Age-related physiology (physiological characteristics of children and adolescents). Textbook for universities
Reviewers:
Kovalevsky V. A. , Doctor of Medical Sciences, Professor, Head of the Department of Childhood Psychology, Krasnoyarsk State pedagogical university them. V. P. Astafieva,
Manchuk V. T. , Doctor of Medical Sciences, Corresponding Member. RAMS, Professor of the Department of Outpatient Pediatrics of Krasnoyarsk State Medical University, Director of the Research Institute of Medical Problems of the North of the Siberian Branch of the Russian Academy of Medical Sciences
© VLADOS Humanitarian Publishing Center LLC, 2013
Introduction
The child’s body is an extremely complex and at the same time very vulnerable socio-biological system. Exactly at childhood The foundations for the health of the future adult are laid. Adequate assessment physical development child is possible only by taking into account the characteristics of the corresponding age period, comparing the vital signs of a given child with the standards of his age group.
Developmental physiology studies the functional characteristics of the individual development of an organism throughout its life. Based on the data of this science, methods of teaching, raising and protecting the health of children are being developed. If the methods of education and training do not correspond to the capabilities of the body at any stage of development, the recommendations may be ineffective, cause a child’s negative attitude towards learning and even provoke various diseases.
As the child grows and develops, almost all physiological parameters undergo significant changes: blood counts, activity of the cardiovascular system, breathing, digestion, etc. change. Knowledge of the various physiological parameters characteristic of each age period is necessary to assess the development of a healthy child.
This publication summarizes and classifies by system the features of the age-related dynamics of the main physiological parameters of healthy children of all age groups.
A manual on age-related physiology is an additional educational material according to the physiological characteristics of children of different ages, necessary for mastering by students who study at pedagogical higher and secondary specialized educational institutions and are already familiar with general course human physiology and anatomy.
Each section of the book gives short description the main directions of ontogenesis of indicators of a specific physiological system. In this version of the manual, the sections “Age characteristics of higher education” have been significantly expanded nervous activity and mental functions”, “Age-related characteristics of endocrine functions”, “Age-related characteristics of thermoregulation and metabolism”.
This book contains descriptions of numerous physiological and biochemical parameters and will be useful in practical work not only future teachers, speech pathologists, child psychologists, but also future pediatricians, as well as already working young professionals and high school students who want to expand their knowledge about the physiological characteristics of the child’s body.
Chapter 1
Age periodization
Patterns of growth and development of the child’s body. Age periods of child development
A child is not a miniature adult, but an organism, relatively perfect for each age, with its own morphological and functional characteristics, for which the dynamics of their course from birth to puberty are natural.
The child’s body is an extremely complex and at the same time very vulnerable socio-biological system. It is in childhood that the foundations for the health of the future adult are laid. An adequate assessment of a child’s physical development is possible only by taking into account the characteristics of the corresponding age period and comparing the vital signs of a particular child with the standards of his age group.
Growth and development are often used as identical concepts. Meanwhile their biological nature(mechanism and consequences) is different.
Development is a process of quantitative and qualitative changes in the human body, accompanied by an increase in its level of complexity. Development includes three main interrelated factors: growth, differentiation of organs and tissues, and morphogenesis.
Growth is a quantitative process characterized by an increase in body mass due to changes in the number of cells and their sizes.
Differentiation is the emergence of specialized structures of a new quality from poorly specialized precursor cells. For example, a nerve cell that is formed as part of the neural tube of an embryo (fetus) can potentially perform any nervous function. If a neuron migrating to the visual area of the brain is transplanted into the area responsible for hearing, it will turn into an auditory neuron rather than a visual one.
Shape formation is the acquisition by an organism of its inherent forms. For example, the auricle takes on the shape characteristic of an adult by the age of 12.
In cases where intensive growth processes simultaneously occur in many different tissues of the body, so-called growth spurts are noted. This manifests itself in a sharp increase in the longitudinal dimensions of the body due to an increase in the length of the torso and limbs. In the postnatal period of human ontogenesis, such “jumps” are most pronounced:
in the first year of life, when there is a one and a half times increase in length and a three to four times increase in body weight;
at the age of 5–6 years, when, mainly due to the growth of the limbs, the child reaches approximately 70% of the body length of an adult;
13–15 years – pubertal growth spurt due to an increase in the length of the body and limbs.
The development of the body from birth to adulthood occurs in constantly changing environmental conditions. Therefore, the development of the organism is adaptive, or adaptive, in nature.
To ensure an adaptive result, various functional systems mature non-simultaneously and unevenly, turning on and replacing each other at different periods of ontogenesis. This is the essence of one of the defining principles of individual development of an organism - the principle of heterochrony, or non-simultaneous maturation of organs and systems and even parts of the same organ.
The timing of maturation of various organs and systems depends on their significance for the life of the organism. Those organs and functional systems that are most vital at this stage of development grow and develop faster. By combining individual elements of one or another organ with the earliest maturing elements of another organ that takes part in the implementation of the same function, a minimum provision of vital functions is provided, sufficient for a certain stage of development. For example, to ensure food intake at the time of birth, the first to mature from the facial muscles is the orbicularis oris muscle; from the cervical - muscles responsible for turning the head; of the receptors of the tongue - receptors located at its root. By this time, the mechanisms responsible for coordinating respiratory and swallowing movements and ensuring that milk does not enter the respiratory tract mature. This ensures the necessary actions related to the feeding of the newborn: grasping and holding the nipple, sucking movements, directing food along the appropriate paths. Taste sensations are transmitted through the receptors of the tongue.
The adaptive nature of the heterochronic development of body systems reflects another of the general principles of development - the reliability of the functioning of biological systems. The reliability of a biological system is understood as such a level of organization and regulation of processes that is capable of ensuring the vital activity of the organism in extreme conditions. It is based on such properties of a living system as redundancy of elements, their duplication and interchangeability, the speed of return to relative constancy and the dynamism of individual parts of the system. An example of the redundancy of elements is the fact that during the period of intrauterine development, from 4,000 to 200,000 primary follicles are formed in the ovaries, from which eggs are subsequently formed, and during the entire reproductive period, only 500–600 follicles mature.
The mechanisms for ensuring biological reliability change significantly during ontogenesis. In the early stages of postnatal life, reliability is ensured by a genetically programmed combination of links functional systems. During development, as the cerebral cortex, which provides the highest level of regulation and control of functions, matures, the plasticity of connections increases. Thanks to this, the selective formation of functional systems occurs in accordance with a specific situation.
Another important feature The individual development of a child’s body is the presence of periods of high sensitivity of individual organs and systems to the effects of environmental factors - sensitive periods. These are periods when the system is rapidly developing and needs an influx of adequate information. For example, for the visual system, adequate information is light quanta, for the auditory system - sound waves. The absence or deficiency of such information leads to negative consequences, up to the immaturity of a particular function.
It should be noted that ontogenetic development combines periods of evolutionary, or gradual, morphofunctional maturation and periods of revolutionary, turning-point developmental leaps associated with both internal (biological) and external (social) factors. These are the so-called critical periods. The discrepancy between environmental influences and the characteristics and functional capabilities of the organism at these stages of development can have detrimental consequences.
The first critical period is considered to be the stage of early postnatal development (up to 3 years), when the most intense morphofunctional maturation occurs. In the process of further development, critical periods arise as a result of a sharp change in social and environmental factors and their interaction with the processes of morphofunctional maturation. Such periods are:
age of beginning of education (6–8 years), when a qualitative restructuring of the morphofunctional organization of the brain occurs during a period of sharp change in social conditions;
the beginning of puberty is the pubertal period (in girls – 11–12 years, in boys – 13–14 years), which is characterized by a sharp increase in the activity of the central link of the endocrine system – the hypothalamus. As a result, there is a significant decrease in the efficiency of cortical regulation, which determines voluntary regulation and self-regulation. Meanwhile, it is at this time that social demands on a teenager increase, which sometimes leads to a discrepancy between the requirements and the functional capabilities of the body, which can result in a violation of the child’s physical and mental health.
Age periodization of ontogenesis of a growing organism. There are two main periods of ontogenesis: antenatal and postnatal. The antenatal period is represented by the embryonic period (from conception to the eighth week of the intrauterine period) and the fetal period (from the ninth to the fortieth week). Typically pregnancy lasts 38–42 weeks. The postnatal period covers the period from birth to the natural death of a person. According to the age periodization adopted at a special symposium in 1965, the following periods are distinguished in the postnatal development of the child’s body:
newborn (1–30 days);
infant (30 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);
teenage (13–16 years old – boys, 12–15 years old – girls);
youth (boys 17–21 years old, girls 16–20 years old).
When considering issues of age periodization, it is necessary to keep in mind that the boundaries of development stages are very arbitrary. All age-related structural and functional changes in the human body occur under the influence of heredity and environmental conditions, that is, they depend on specific ethnic, climatic, social and other factors.
Heredity determines the potential for physical and mental development of an individual. For example, the short stature of African pygmies (125–150 cm) and the tallness of representatives of the Watussi tribe are associated with the characteristics of the genotype. However, in each group there are individuals for whom this indicator may differ significantly from the average age norm. Deviations may occur due to effects on the body various factors external environment, such as nutrition, emotional and socio-economic factors, the child’s position in the family, relationships with parents and peers, the level of culture of society. These factors can disrupt the growth and development of the child, or, on the contrary, stimulate them. Therefore, the growth and development indicators of children of the same calendar age may vary significantly. It is generally accepted to form groups of children in preschool institutions and classes in secondary schools by calendar age. In this regard, the educator and teacher must take into account individual psychophysiological characteristics of development.
Delayed growth and development, called retardation, or advanced development - acceleration - indicate the need to determine the biological age of the child. Biological age, or developmental age, reflects the growth, development, maturation, and aging of the organism and is determined by the totality of the structural, functional and adaptive characteristics of the organism.
Biological age is determined by a number of indicators of morphological and physiological maturity:
by body proportions (the ratio of the length of the torso and limbs);
degree of development of secondary sexual characteristics;
skeletal maturity (order and timing of skeletal ossification);
dental maturity (timing of eruption of baby and molar teeth);
metabolic level;
features of the cardiovascular, respiratory, neuroendocrine and other systems.
When determining biological age, the level of mental development individual. All indicators are compared with standard indicators typical for a given age, gender and ethnic group. At the same time, for each age period it is important to take into account the most informative indicators. For example, in the puberty period - neuroendocrine changes and the development of secondary sexual characteristics.
To simplify and standardize the average age of an organized group of children, it is customary to consider the child’s age to be 1 month if his calendar age is in the range from 16 days to 1 month 15 days; equal to 2 months - if his age is from 1 month 16 days to 2 months 15 days, etc. After the first year of life and up to 3 years: 1.5 years includes a child with an age from 1 year 3 months to 1 year 8 months and 29 days, by the second years - from 1 year 9 months to 2 years 2 months 29 days, etc. After 3 years at annual intervals: 4 years include children aged 3 years 6 months to 4 years 5 months 29 days, etc.
Chapter 2
Excitable tissues
Age-related changes in the structure of the neuron, nerve fiber and neuromuscular synapse
Various types of nerve cells mature heterochronically during ontogenesis. Large afferent and efferent neurons mature most early, even in the embryonic period. Small cells (interneurons) mature gradually during postnatal ontogenesis under the influence of environmental factors.
Individual parts of a neuron also do not mature at the same time. Dendrites grow much later than the axon. Their development occurs only after the birth of a child and largely depends on the influx of external information. The number of dendrite branches and the number of spines increases in proportion to the number of functional connections. The neurons of the cerebral cortex have the most extensive network of dendrites with a large number of spines.
Myelination of axons begins during fetal development and occurs in the following order. The peripheral fibers are first covered with the myelin sheath, then the fibers of the spinal cord, brainstem (medulla oblongata and midbrain), cerebellum, and lastly the fibers of the cerebral cortex. In the spinal cord, motor fibers myelinate earlier (by 3–6 months of life) than sensory fibers (by 1.5–2 years). Myelination of brain fibers occurs in a different sequence. Here, sensory fibers and sensory areas are myelinated earlier than others, while motor areas are myelinated only 6 months after birth, or even later. Most myelination is complete by age 3, although growth of the myelin sheath continues until approximately 9–10 years.
Age-related changes also affect the synaptic apparatus. With age, the intensity of the formation of mediators in synapses increases, and the number of receptors on the postsynaptic membrane that respond to these mediators increases. Accordingly, as development progresses, the speed of impulse transmission through synapses increases. The influx of external information determines the number of synapses. First, synapses are formed in the spinal cord, and then in other parts of the nervous system. Moreover, excitatory synapses mature first, then inhibitory ones. It is with the maturation of inhibitory synapses that the complication of information processing processes is associated.
Chapter 3
Physiology of the central nervous system
Anatomical and physiological features of maturation of the spinal cord and brain
The spinal cord fills the cavity of the spinal canal and has a corresponding segmental structure. In the center of the spinal cord is gray matter (a collection of nerve cell bodies) surrounded by white matter (a collection of nerve fibers). The spinal cord provides motor reactions of the trunk and limbs, some autonomic reflexes (vascular tone, urination, etc.) and conductive function, since all sensory (ascending) and motor (descending) pathways pass through it, along which communication between various parts CNS.
The spinal cord develops earlier than the brain. In the early stages of fetal development, the spinal cord fills the entire cavity of the spinal canal, and then begins to lag in growth and, by the time of birth, ends at the level of the third lumbar vertebra.
By the end of the first year of life, the spinal cord occupies the same position in the spinal canal as in adults (at the level of the first lumbar vertebra). In this case, the segments of the thoracic spinal cord grow faster than the segments of the lumbar and sacral regions. The spinal cord grows slowly in thickness. The most intensive increase in the mass of the spinal cord occurs by the age of 3 (4 times), and by the age of 20 its mass becomes like that of an adult (8 times more than that of a newborn). Myelination of spinal cord nerve fibers begins with motor nerves.
By the time of birth, the medulla oblongata and the pons are already formed. Although the maturation of the nuclei of the medulla oblongata continues up to 7 years. The location of the bridge also differs from adults. In newborns, the bridge is slightly higher than in adults. This difference disappears by 5 years.
The cerebellum in newborns is still underdeveloped. Increased growth and development of the cerebellum is observed in the first year of life and during puberty. Myelination of its fibers ends at approximately 6 months of life. The complete formation of the cellular structures of the cerebellum occurs by 7–8 years, and by 15–16 years its size corresponds to the level of an adult.
The shape and structure of the midbrain in a newborn is almost no different from that of an adult. The postnatal period of maturation of midbrain structures is accompanied mainly by pigmentation of the red nucleus and substantia nigra. Pigmentation of neurons in the red nucleus begins at the age of two and ends by the age of 4. Pigmentation of neurons in the substantia nigra begins from the sixth month of life and reaches a maximum by 16 years.
The diencephalon includes two important structures: the thalamus, or thalamus optic, and the subthalamic region, the hypothalamus. Morphological differentiation of these structures occurs in the third month of intrauterine development.
The thalamus is a multinucleated formation associated with the cortex cerebral hemispheres. Through its nuclei, visual, auditory and somatosensory information is transmitted to the corresponding associative and sensory zones of the cerebral cortex. The nuclei of the reticular formation of the diencephalon activate cortical neurons that perceive this information. By the time of birth, most of its nuclei are well developed. Increased growth of the thalamus occurs at the age of four. The thalamus reaches adult size by age 13.
The hypothalamus, despite its small size, contains dozens of highly differentiated nuclei and regulates most autonomic functions, such as maintaining body temperature and water balance. The nuclei of the hypothalamus are involved in many complex behavioral reactions: sexual desire, feelings of hunger, satiety, thirst, fear and rage. In addition, through the pituitary gland, the hypothalamus controls the functioning of the endocrine glands, and substances formed in the neurosecretory cells of the hypothalamus itself are involved in the regulation of the sleep-wake cycle. The nuclei of the hypothalamus mature mainly by 2–3 years, although the differentiation of cells of some of its structures continues until 15–17 years.
The most intense myelination of fibers, an increase in the thickness of the cerebral cortex and its layers occurs in the first year of life, gradually slowing down and stopping by 3 years in projection and by 7 years in projection associative areas. The lower layers of the bark ripen first, then the upper ones. By the end of the first year of life, ensembles of neurons, or columns, are distinguished as a structural unit of the cerebral cortex, the complication of which continues until the age of 18. The most intense differentiation of cortical interneurons occurs between the ages of 3 and 6 years, reaching a maximum by 14 years. The cerebral cortex reaches full structural and functional maturation at about 20 years of age.
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
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 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, 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.
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.
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 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.
In development modern science Two main trends are clearly expressed. On the one hand, there is a specialization of a particular science, its deepening in its inherent sphere. On the other hand, between different branches of knowledge there is close connection, integration is constantly happening scientific knowledge. These trends are clearly manifested in the biological sciences, among which age-related physiology occupies a significant place. There are a number of basic integration connections of age-related physiology in the system of modern science.
Age-related physiology is associated with a number of related sciences and its successes reflect the achievements of anatomy (the science of the structure of the human body), histology (the science that studies the structure and function of tissues), cytology (the science that studies the structure, chemical composition, processes of vital activity and cell reproduction), embryology (the science that studies the patterns of development of cells, tissues and organs of the embryo), biochemistry (the science that studies the chemical patterns of physiological processes), etc. She widely uses their methods and achievements in the process of studying the functions of the body. Age-related physiology is based on data from sciences that study the structure of the body, since structure and function are closely related. It is impossible to deeply understand the functions without knowledge of the structure of the body, its organs, tissues and cells, as well as those structural and histochemical changes that occur during their activity. With the development of science and technology, methods that are used for physiological research are being developed and improved. Without knowledge of genetics (the science of the patterns of heredity and variability of organisms), it is impossible to understand the laws of evolutionary and individual development of the human body). General laws, namely the laws of heredity, also apply to human body. Studying them is necessary to identify specific features of the functioning of the organism at different stages of ontogenesis. Multifaceted and numerous connections have long existed between physiology and medicine. According to I.P. Pavlova “Physiology and medicine are inseparable.” Based on the knowledge gained about physiological mechanisms and their characteristics in ontogenesis, the doctor detects their deviations from the norm, finds out the nature and extent of these violations, and determines ways to improve the health of the sick organism. With the aim of clinical diagnostics Physiological methods for studying the human body are widely used.
Knowledge of physiological phenomena is based on an understanding of the laws of chemistry and physics, because all life activity is determined by the transformation of substances and energy, that is, by chemical and physical processes. Age-related physiology, based on the general laws of chemistry and physics, gives them new qualitative features and raises them to higher levels. high level, which is inherent in living organisms.
Fruitful and promising connections with mathematics - the most schematized of all sciences, which significantly changed physics, chemistry, genetics and other fields scientific knowledge. The importance of mathematical principles for processing the results of physiological experiments and establishing their scientific reliability is well known. These are, for example, the methods of variation statistics in the process of comparative study of wave electrical phenomena in the brain and other physiological processes in the body.
In physiology, holography methods are being introduced - obtaining a three-dimensional image of an effective object, based on the mathematical superposition of wave-like processes associated with it. Holographic methods make it possible to replace a flat two-dimensional image with a three-dimensional one and thus reveal the subtle mechanisms of operation sensory system- from its receptive field to the final neural projections in the cerebral cortex.
Physiology has common tasks with technical sciences, namely: it opens up promising methodological opportunities in the study of physiological phenomena. On this path, a related direction has achieved great development - electrophysiology, which studies electrical phenomena living organism. Modern age-related physiology includes new generations of electronic amplifiers, microelectronic technology, telemetry, computer equipment, etc.
The interaction of age-related physiology with cybernetics, the science of general principles control and communication in machines, mechanisms and living organisms. A type of cybernetics is physiological cybernetics, which studies the general patterns of perception, transformation and coding of information and its use for the purpose of controlling physiological processes and self-regulation of living systems.
Various connections between age-related physiology and pedagogy. There is no doubt that understanding the physiological patterns of growth and development of children, taking into account the peculiarities of the functioning of the body in various age groups is based on the natural scientific basis of teacher training and the entire system school education. So, the teacher must know the structural features and vital functions of the child’s body. Intertwined with the problems of age-related physiology are numerous issues of physiological and hygienic support of the educational process at school, the formation of the student’s personality, his hardening, and the prevention of diseases, which are studied by school hygiene.
A special place is occupied by the connections between age-related physiology and philosophy. Like other branches of natural science, age-related physiology is one of the natural science foundations of philosophical knowledge. It is natural that many concepts and theoretical generalizations that were formed within the framework of age-related physiology went beyond its boundaries and acquired general scientific and philosophical significance. Such a general theoretical meaning has, for example, the idea of the growth and development of an organism, its integrity and systematic functioning, adaptation to changing environmental conditions, and the neurophysiological mechanisms of complex forms of behavior and psyche.
School hygiene as a science develops on the basis of age-related physiology and anatomy. As a field of science, it also widely uses methods and data from related disciplines: age-related physiology, bacteriology, toxicology, biochemistry, biophysics, and the like. It widely uses general biological laws of development. School hygiene is closely related to all medical disciplines, as well as technical and pedagogical sciences. Correct regulation of the activities of children and adolescents is impossible without understanding the basic principles of pedagogy and psychology. School hygiene is closely related to biology, physiological data is considered and at the same time expands the understanding of the characteristics of the body's reaction in children and adolescents to loading and environmental influences.
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
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 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, 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 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.
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 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.
Basic concepts of age-related physiology:
Organism - a complex, hierarchically (subordinately) organized system of organs and structures that ensure life activity and interaction with the environment. The elementary unit of an organism is cell . A collection of cells similar in origin, structure and function forms textile . Tissues form organs that perform specific functions. Function - specific activity of an organ or system.
Physiological system - a set of organs and tissues connected by a common function.
Functional system - a dynamic association of various organs or their elements, the activities of which are aimed at achieving a specific goal (useful result).
Regarding the structure of the proposed teaching aid, then 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 the characteristic features of the 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 morphophysiological 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 characteristics 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 independent work students, which allow them to refresh their memory of the main provisions of the material being studied that require special attention.
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.