How long does the nervous system develop in children? Nervous system of an infant

The nervous system coordinates and controls the physiological and metabolic parameters of the body's activity, depending on the factors of the external and internal environment.

In the child's body, the anatomical and functional maturation of those systems that are responsible for vital activity takes place. It is assumed that up to 4 years of age the mental development of the child occurs most intensively. Then the intensity decreases, and by the age of 17 the main indicators of neuropsychic development are finally formed.

By the time of birth, the baby's brain is underdeveloped. For example, a newborn has about 25% of the nerve cells of an adult, by 6 months of life their number increases to 66%, and by the year - up to 90-95%.

Different parts of the brain have their own pace of development. So, the inner layers grow more slowly than the cortical, due to which folds and furrows form in the latter. By the time of birth, the occipital lobe is better developed than others, and the frontal lobe is to a lesser extent. The cerebellum has small hemispheres and superficial grooves. The lateral ventricles are relatively large.

The younger the child, the worse the gray and white matter of the brain is differentiated, the nerve cells in the white matter are located quite close to each other. With the growth of the child, changes in the topic, shape, number and size of the furrows occur. The main structures of the brain are formed by the 5th year of life. But even later, the growth of convolutions and furrows continues, however, at a much slower pace. The final maturation of the central nervous system (CNS) occurs by the age of 30-40.

By the time of the birth of a child, in comparison with body weight, it has a relatively large size - 1/8 - 1/9, at 1 year this ratio is 1/11 - 1/12 to 5 years - 1/13-1/14 and in an adult - approximately 1/40. At the same time, with age, the mass of the brain increases.

The process of development of nerve cells consists in the growth of axons, an increase in dendrites, the formation of direct contacts between the processes of nerve cells. By the age of 3, a gradual differentiation of the white and gray matter of the brain occurs, and by the age of 8, its cortex approaches the adult state in structure.

Simultaneously with the development of nerve cells, the process of myelination of nerve conductors takes place. The child begins to acquire effective control over motor activity. The process of myelination as a whole ends by 3-5 years of a child's life. But the development of myelin sheaths of conductors responsible for fine coordinated movements and mental activity continues up to 30-40 years.

The blood supply to the brain in children is more abundant than in adults. The capillary network is much wider. The outflow of blood from the brain has its own characteristics. Diploetic foams are still poorly developed, therefore, in children with encephalitis and cerebral edema, more often than in adults, there is a difficulty in outflow of blood, which contributes to the development of toxic brain damage. On the other hand, children have a high permeability of the blood-brain barrier, which leads to the accumulation of toxic substances in the brain. The brain tissue in children is very sensitive to increased intracranial pressure, so factors contributing to this can cause atrophy and death of nerve cells.

They have structural features and membranes of the child's brain. The younger the child, the thinner the dura mater. It is fused with the bones of the base of the skull. The soft and arachnoid shells are also thin. Subdural and subarachnoid spaces in children are reduced. Tanks, on the other hand, are relatively large. The aqueduct of the brain (Sylvian aqueduct) is wider in children than in adults.

With age, a change in the composition of the brain occurs: the amount decreases, the dry residue increases, the brain cells are filled with a protein component.

The spinal cord in children is relatively better developed than the brain, and grows much more slowly, doubling its mass occurs by 10-12 months, tripling - by 3-5 years. In an adult, the length is 45 cm, which is 3.5 times longer than in a newborn.

The newborn has features of CSF formation and CSF composition, the total amount of which increases with age, resulting in increased pressure in the spinal canal. With spinal puncture, CSF in children flows out in rare drops at a rate of 20-40 drops per minute.

Of particular importance is the study of cerebrospinal fluid in diseases of the central nervous system.

Normal cerebrospinal fluid in a child is transparent. Turbidity indicates an increase in the number of leukocytes in it - pleocytosis. For example, cloudy cerebrospinal fluid is observed with meningitis. With a hemorrhage in the brain, the cerebrospinal fluid will be bloody, stratification does not occur, it will retain a uniform brown color.

Under laboratory conditions, a detailed microscopy of the cerebrospinal fluid is carried out, as well as its biochemical, virological and immunological examination.

Patterns of development of statomotor activity in children

A child is born with a number of unconditioned reflexes that help him adapt to his environment. First, these are transient rudimentary reflexes, reflecting the evolutionary path of development from animal to human. They usually disappear in the first months after birth. Secondly, these are unconditioned reflexes that appear from the birth of a child and persist for life. The third group includes mesencephalic established, or automatisms, for example, labyrinthine, cervical and trunk, which are acquired gradually.

Usually, the unconditioned reflex activity of the child is checked by a pediatrician or a neurologist. The presence or absence of reflexes, the time of their appearance and extinction, the strength of the response and the age of the child are assessed. If the reflex does not correspond to the age of the child, this is considered a pathology.

The health worker should be able to assess the motor and static skills of the child.

Due to the predominant influence of the extrapyramidal system of the newborn, they are chaotic, generalized, and inappropriate. There are no static functions. Muscular hypertension is observed with a predominance of flexor tone. But shortly after birth, the first static coordinated movements begin to form. At the 2-3rd week of life, the child begins to fix his gaze on a bright toy, and from 1-1.5 months he tries to follow moving objects. By the same time, children begin to hold their heads, and at 2 months and turn it. Then there are coordinated hand movements. At first, this is bringing hands to the eyes, examining them, and from 3-3.5 months - holding the toy with both hands, manipulating it. From the 5th month, one-handed grasping and manipulation of the toy gradually develops. From this age, reaching out and grasping objects resembles the movements of an adult. However, due to the immaturity of the centers responsible for these movements, in children of this age, movements of the second arm and legs occur simultaneously. By 7-8 months, there is a greater expediency of motor activity of the hands. From 9-10 months there is a finger retention of objects, which is improved by 12-13 months.

The acquisition of motor skills by the limbs occurs in parallel with the development of trunk coordination. Therefore, by 4-5 months, the child first rolls over from his back to his stomach, and from 5-6 months from his stomach to his back. In parallel, he masters the function of sitting. At the 6th month, the child sits on his own. This indicates the development of coordination of the muscles of the legs.

Then the child begins to crawl, and by 7-8 months already mature crawling is formed with a cross movement of the arms and legs. By 8-9 months, children try to stand and step over the bed, holding on to its edge. At 10-11 months they already stand well, and by 10-12 months they begin to walk independently, first with their arms extended forward, then their legs straighten and the child walks almost without bending them (by 2-3.5 years). By the age of 4-5, a mature gait with synchronous articulated hand movements is formed.

The formation of statomotor functions in children is a long process. The emotional tone of the child is important in the development of statics and motor skills. In acquiring these skills, a special role is assigned to the independent activity of the child.

The newborn has little physical activity, he mostly sleeps, and wakes up when he wants to eat. But even here there are principles of direct influence on neuropsychic development. From the first days, toys are hung over the crib, first at a distance of 40-50 cm from the child's eyes for the development of the visual analyzer. During the waking period, it is necessary to talk with the child.

At 2-3 months, sleep becomes less prolonged, the child is already awake for more time. The toys are attached at chest level so that after a thousand and one wrong moves, he finally grabs the toy and pulls it into his mouth. The conscious manipulation of toys begins. A mother or a person caring for a child during hygienic procedures begins to play with him, do massage, especially of the abdomen, gymnastics for the development of motor movements.

At 4-6 months, the child's communication with an adult becomes more diverse. At this time, the independent activity of the child is of great importance. A so-called rejection reaction develops. The child manipulates toys, is interested in the environment. There may be few toys, but they should be diverse in both color and functionality.

At 7-9 months, the movements of the child become more appropriate. Massage and gymnastics should be aimed at developing motor skills and statics. Sensory speech develops, the child begins to understand simple commands, pronounce simple words. The stimulus for the development of speech is the conversation of the surrounding people, songs and poems that the child hears during wakefulness.

At 10-12 months, the child gets on his feet, begins to walk, and at this time his safety becomes of great importance. During the wakefulness of the child, it is necessary to securely close all drawers, remove foreign objects. Toys become more complex (pyramids, balls, cubes). The child tries to independently manipulate the spoon and cup. Curiosity is already well developed.

Conditioned reflex activity of children, development of emotions and forms of communication

Conditioned reflex activity begins to form immediately after birth. A crying child is picked up, and he falls silent, makes exploring movements with his head, anticipating feeding. At first, reflexes are formed slowly, with difficulty. With age, the concentration of excitation develops, or the irradiation of reflexes begins. With growth and development, approximately from the 2-3rd week, differentiation of conditioned reflexes occurs. A 2-3-month-old child has a rather pronounced differentiation of conditioned reflex activity. And by 6 months in children, the formation of reflexes from all perceiving organs is possible. During the second year of life, the child's mechanisms for the formation of conditioned reflexes are further improved.

On the 2-3rd week during sucking, taking a break for rest, the child carefully examines the mother's face, feels the breast or the bottle from which he is fed. By the end of the 1st month of life, the child's interest in the mother increases even more and manifests itself outside the meal. At 6 weeks, the approach of the mother makes the baby smile. From the 9th to the 12th week of life, a rumor is formed, which is clearly manifested when the child communicates with the mother. General motor excitation is observed.

By 4-5 months, the approach of a stranger causes a cessation of cooing, the child carefully examines him. Then there is either a general excitement in the form of joyful emotions, or as a result of negative emotions - crying. At 5 months, the child already recognizes his mother among strangers, reacts differently to the disappearance or appearance of the mother. By 6-7 months, active cognitive activity begins to form in children. During wakefulness, the child manipulates toys, often a negative reaction to a stranger is suppressed by the manifestation of a new toy. Sensory speech is being formed, i.e. understanding of the words spoken by adults. After 9 months, there is a whole range of emotions. Contact with strangers usually causes a negative reaction, but it quickly becomes differentiated. The child has timidity, shyness. But contact with others is established due to interest in new people, objects, manipulations. After 9 months, the child's sensory speech develops even more, it is already used to organize his activities. The formation of motor speech is also referred to this time, i.e. pronunciation of individual words.

Speech development

The formation of speech is a stage in the formation of the human personality. Special brain structures are responsible for a person's ability to articulate. But the development of speech occurs only when the child communicates with another person, for example, with his mother.

There are several stages in the development of speech.

Preparatory stage. The development of cooing and babbling begins at 2-4 months.

Stage of occurrence of sensory speech. This concept means the child's ability to compare and associate a word with a specific object, image. At 7-8 months, the child, to the questions: “Where is mom?”, “Where is the kitty?”, - begins to look for an object with his eyes and fix his eyes on it. Intonations that have a certain color can be enriched: pleasure, displeasure, joy, fear. By the year there is already a vocabulary of 10-12 words. The child knows the names of many objects, knows the word "no", fulfills a number of requests.

Stage of occurrence of motor speech. The first words the child pronounces at 10-11 months. The first words are built from simple syllables (ma-ma, pa-pa, uncle-dya). A children's language is being formed: a dog - “av-av”, a cat - “kiss-kiss”, etc. In the second year of life, the child's vocabulary expands to 30-40 words. By the end of the second year, the child begins to speak in sentences. And by the age of three, the concept of “I” appears in speech. More often, girls master motor speech earlier than boys.

The role of imprinting and education in the neuropsychic development of children

In children from the period of the newborn, a mechanism of instant contact is formed - imprinting. This mechanism, in turn, is associated with the formation of the neuropsychic development of the child.

Maternal upbringing very quickly forms a sense of security in a child, and breastfeeding creates a feeling of security, comfort, warmth. The mother is an indispensable person for the child: she forms his ideas about the world around him, about the relationship between people. In turn, communication with peers (when the child begins to walk) forms the concept of social relations, camaraderie, inhibits or enhances the feeling of aggressiveness. The father plays a big role in the upbringing of the child. His participation is necessary for the normal building of relationships with peers and adults, the formation of independence and responsibility for a particular matter, a course of action.

Dream

For full development, the child needs proper sleep. In newborns, sleep is polyphasic. During the day, the child falls asleep from five to 11 times, not distinguishing day from night. By the end of the 1st month of life, the rhythm of sleep is established. Night sleep begins to prevail over daytime. Hidden polyphasic persist even in adults. On average, the need for nighttime sleep decreases over the years.

The decrease in the total duration of sleep in children occurs due to daytime sleep. By the end of the first year of life, children fall asleep once or twice. By 1-1.5 years, the duration of daytime sleep is 2.5 hours. After four years, not all children have daytime sleep, although it is desirable to keep it up to six years.

Sleep is organized cyclically, i.e., the phase of non-REM sleep ends with the phase of REM sleep. Sleep cycles change several times during the night.

In infancy, there are usually no problems with sleep. At the age of one and a half years, the child begins to fall asleep more slowly, so he himself chooses techniques that contribute to falling asleep. It is necessary to create a familiar environment and a stereotype of behavior before going to bed.

Vision

From birth to 3 - 5 years there is an intensive development of eye tissues. Then their growth slows down and, as a rule, ends in puberty. In a newborn, the mass of the lens is 66 mg, in a one-year-old child, 124 mg, and in an adult, 170 mg.

In the first months after birth, children have farsightedness (hypermetropia) and emmetropia develops only by the age of 9-12. The eyes of the newborn are almost constantly closed, the pupils are constricted. The corneal reflex is well expressed, the ability to converge is uncertain. There is nystagmus.

The lacrimal glands do not function. At about 2 weeks, fixation of the gaze on the object develops, usually monocular. From this time, the lacrimal glands begin to function. Usually, by 3 weeks, the child steadily fixes his gaze on the object, his vision is already binocular.

At 6 months, color vision appears, and by 6-9 months, stereoscopic vision is formed. The child sees small objects, distinguishes distance. The transverse size of the cornea is almost the same as in an adult - 12 mm. By the year, the perception of various geometric shapes is formed. After 3 years, all children already have a color perception of the environment.

The visual function of the newborn is checked by bringing a light source to his eyes. In bright and sudden lighting, he squints, turns away from the light.

In children after 2 years, visual acuity, visual field volume, color perception are checked using special tables.

Hearing

The ears of newborns are quite morphologically developed. The external auditory meatus is very short. The dimensions of the tympanic membrane are the same as those of an adult, but it is located in a horizontal plane. Auditory (Eustachian) tubes are short and wide. There is embryonic tissue in the middle ear, which is resorbed (resolved) by the end of the 1st month. The cavity of the tympanic membrane is airless before birth. With the first breath and swallowing movements, it is filled with air. From this moment, the newborn hears, which is expressed in a general motor reaction, a change in the frequency and rhythm of the heartbeat, breathing. From the first hours of life, a child is capable of perceiving sound, its differentiation in frequency, volume, and timbre.

The function of hearing in a newborn is checked by the response to a loud voice, clap, rattle noise. If the child hears, there is a general reaction to, he closes his eyelids, tends to turn towards the sound. From 7-8 weeks of life, the child turns his head towards the sound. Auditory response in older children, if necessary, is checked using an audiometer.

Smell

From birth, the perceiving and analyzing areas of the olfactory center have been formed in a child. The nervous mechanisms of smell begin to function from the 2nd to the 4th month of life. At this time, the child begins to differentiate smells: pleasant, unpleasant. Differentiation of complex odors up to 6-9 years occurs due to the development of cortical centers of smell.

The technique for studying the sense of smell in children is to bring various odorous substances to the nose. At the same time, the child's facial expressions in response to this substance are monitored. It can be pleasure, displeasure, screaming, sneezing. In an older child, the sense of smell is checked in the same way. According to his answer, the safety of the sense of smell is judged.

Touch

The sense of touch is provided by the function of skin receptors. In a newborn, pain, tactile sensitivity and thermoreception are not formed. The perception threshold is especially low in premature and immature children.

The reaction to pain stimulation in newborns is general, a local reaction appears with age. The newborn reacts to tactile stimulation with a motor and emotional reaction. Thermoreception in newborns is more developed for cooling than for overheating.

Taste

From birth, the child has a taste perception. Taste buds in a newborn occupy a relatively larger area than in an adult. The threshold of taste sensitivity in a newborn is higher than in an adult. Taste in children is examined by applying sweet, bitter, sour and salty solutions to the tongue. According to the reaction of the child, the presence and absence of taste sensitivity is judged.

During this period of development, the child is still not very independent, needs the guardianship and care of an adult. Only towards the end of this period does it become possible to move independently in space - the baby begins to crawl. Around the same moment, an elementary understanding of reversed speech appears - individual words. There is no own speech yet, but onomatopoeia is developing very actively. This is a necessary step in the transition to independent speech. The child learns to control not only speech movements, but also the movements of his hands. It grabs items and actively explores them. He really needs emotional contact with adults. At this age stage, the emergence of new opportunities for the child is strictly genetically determined and, accordingly, these new opportunities should appear in a timely manner. Parents need to be vigilant and not console themselves with thoughts that their child is “just lazy” or “fat” and therefore cannot begin to roll over and sit up.

Age tasks: implementation of genetic development programs (the emergence of new types of movements, cooing and babble) strictly within certain time limits.

The main motivation for cognitive development: the need for new experiences, emotional contact with an adult.

Leading activity: Emotional communication with an adult.

Acquisitions of this age: By the end of the period, the baby is developing selectivity in everything from movements and attention to relationships with others. The child begins to form his own interests and passions, he begins to be sensitive to the differences between the objects of the external world and people. He begins to use new skills for their intended purpose and reacts differently in different circumstances. For the first time, actions on his own inner impulse become available to him, he learns to control himself and influence others.

Development of mental functions

Perception: At the beginning of the period, it is still difficult to talk about perception as such. There are separate sensations and reactions to them.

A child, starting from the age of one month, is able to fix his gaze on an object, image. Already for a 2-month-old baby, a particularly important object of visual perception is human face, and on the face - eyes . The eyes are the only detail that babies can distinguish. In principle, due to the still weak development of visual functions (physiological myopia), children of this age are not able to distinguish their small features in objects, but only catch the general appearance. Apparently, the eyes are something so biologically significant that nature has provided a special mechanism for their perception. With the help of the eyes, we convey to each other some emotions and feelings, one of which is anxiety. This feeling allows you to activate the defense mechanisms, bring the body into a state of combat readiness for self-preservation.

The first six months of life is a sensitive (sensitive to certain influences) period during which the ability to perceive and recognize faces develops. People deprived of sight in the first 6 months of life lose their full ability to recognize people by sight and distinguish their states by facial expressions.

Gradually, the child's visual acuity increases, and systems mature in the brain that allow one to perceive objects of the outside world in more detail. As a result, by the end of the period, the ability to distinguish small objects improves.

By 6 months of a child's life, his brain learns to "filter" incoming information. The most active reaction of the brain is observed either to something new and unfamiliar, or to something that is familiar to the child and emotionally significant.

Until the very end of this age period, the infant does not have any hierarchy of significance of the various attributes of the object. The infant perceives the object as a whole, with all its features. One has only to change something in the object, as the baby begins to perceive it as something new. By the end of the period, a constancy of form perception is formed, which becomes the main feature on the basis of which the child recognizes objects. If earlier a change in individual details made the child think that he was dealing with a new object, now a change in individual details does not lead to the recognition of the object as new if its general shape remains intact. The exception is the mother's face, whose constancy is formed much earlier. Already 4-month-old babies distinguish the face of the mother from other faces, even if some details change.

In the first half of life, there is an active development of the ability to perceive speech sounds. If newborn children are able to distinguish different voiced consonants from each other, then from about 2 months of age it becomes possible to distinguish voiced and deaf consonants, which is much more difficult. This means that the child's brain can sense differences on such a subtle level and, for example, perceive sounds like "b" and "p" as different. This is a very important property that will help the assimilation of the native language. At the same time, such a distinction between sounds has nothing to do with phonemic hearing - the ability to distinguish those characteristics of the sounds of the native language that carry a semantic load. Phonemic hearing begins to form much later, when the words of native speech become meaningful for the child.

A 4-5 month old child, hearing a sound, is able to identify the facial expressions corresponding to the sounds - he will turn his head towards the face that makes the corresponding articulatory movements, and will not look at the face whose facial expressions do not match the sound.

Children who at the age of 6 months are better at distinguishing speech sounds that are close in sound, subsequently demonstrate better speech development.

Different types of perception in infancy are closely related to each other. This phenomenon is called "polymodal convergence". An 8-month-old child, having felt the object, but not being able to examine it, later recognizes it as a familiar one upon visual presentation. Due to the close interaction of different types of perception, the infant may feel the discrepancy between the image and sound and, for example, be surprised if a woman's face speaks in a man's voice.

The use of different types of perception in contact with the object is very important for the infant. He must feel any thing, put it in his mouth, turn it around before his eyes, he needs to shake it or knock on the table, and even more interesting - throw it with all his might on the floor. This is how the properties of things are known, and this is how their holistic perception is formed.

By 9 months, visual and auditory perception gradually becomes selective. This means that babies become more sensitive to certain, more important, characteristics of objects, and lose sensitivity to others, which are not significant.

Infants up to 9 months of age are able to distinguish not only human faces, but also the faces of animals of the same species (for example, monkeys). By the end of the period, they cease to distinguish representatives of the animal world from each other, but their sensitivity to the features of the human face, to his facial expressions intensifies. visual perception becomes electoral .

The same applies to auditory perception. Children aged 3-9 months distinguish the sounds of speech and intonation not only of their own, but also of foreign languages, melodies not only of their own, but also of other cultures. By the end of the period, infants no longer distinguish between speech and non-speech sounds of foreign cultures, but they begin to form clear ideas about the sounds of their native language. auditory perception becomes electoral . The brain forms a kind of "speech filter", due to which any audible sounds are "attracted" to certain samples ("prototypes"), firmly fixed in the mind of the baby. No matter how the sound “a” sounds in different cultures (and in some languages ​​different shades of this sound carry different semantic meanings), for a baby from a Russian-speaking family it will be the same sound “a” and the baby, without special training, will not be able to feel the differences between the sound "a", which is a little closer to "o", and the sound "a", which is a little closer to "e". But, it is thanks to such a filter that he will begin to understand the words, with whatever accent they may be pronounced.

Of course, it is possible to develop the ability to distinguish the sounds of a foreign language even after 9 months, but only through direct contact with a native speaker: the child must not only hear someone else's speech, but also see articulatory facial expressions.

Memory: In the first six months of life, memory is not yet a purposeful activity. The child is not yet able to consciously remember or recall. His genetic memory is actively working, thanks to which new, but programmed in a certain way, types of movements and reactions appear, which are based on instinctive urges. As soon as the child's motor system matures to the next level, the child begins to do something new. The second active type of memory is direct memorization. An adult person remembers intellectually processed information more often, while a child is not yet capable of this. Therefore, he remembers what comes to mind (especially emotional impressions) and what is often repeated in his experience (for example, the coincidence of certain types of hand movements and the sound of a rattle).

Speech comprehension: By the end of the period, the child begins to understand some words. However, even if in response to a word he looks at the corresponding correct object, this does not mean that he has a clear connection between the word and the object, and he now understands the meaning of this word. The word is perceived by the infant in the context of the whole situation, and if something in this situation changes (for example, the word is pronounced in an unfamiliar voice or with a new intonation), the child will be at a loss. Surprisingly, the understanding of a word at this age can be affected even by the position in which the child hears it.

Own speech activity: At the age of 2-3 months, cooing appears, and from 6-7 months - active babbling. Cooing is a child's experimentation with different kinds of sounds, and babble is an attempt to imitate the sounds of the language spoken by parents or guardians.

Intelligence: By the end of the period, the child becomes capable of a simple categorization (assignment to one group) of objects based on their shape. This means that he can already, at a rather primitive level, detect similarities and differences between different objects, phenomena, people.

Attention: During the entire period, the attention of the child is mainly external, involuntary. At the heart of this type of attention is the orienting reflex - our automatic reaction to changes in the environment. The child is not yet able to voluntarily concentrate on something. By the end of the period (about 7-8 months), internal, voluntary attention appears, regulated by the child's own impulses. So, for example, if a 6-month-old child is shown a toy, he will look at it with pleasure, but if he covers it with a towel, he will immediately lose interest in it. A child after 7-8 months remembers that under the towel there is an object that is not visible now, and will wait for it to appear in the same place where it disappeared. The longer a child of this age is able to wait for a toy, the more attentive he will be at school age.

Emotional development: At the age of 2 months, the child is already socially oriented, which manifests itself in the "revitalization complex". At 6 months, the child becomes able to distinguish between male and female faces, and by the end of the period (by 9 months) - different facial expressions, reflecting different emotional states.

By 9 months, the child develops emotional preferences. And this again shows selectivity. Up to 6 months, the baby easily accepts the “deputy” mother (grandmother or nanny). After 6-8 months, children begin to worry if they are weaned from their mother, there is a fear of strangers and strangers, and babies cry if a close adult leaves the room. This selective attachment to the mother arises because the baby becomes more active and begins to move independently. He is interested in exploring the world around him, but exploration is always a risk, so he needs a safe place where he can always return in case of danger. The absence of such a place causes great anxiety in the baby ().

Learning mechanism: One of the most common ways to learn something at this age is by imitation. An important role in the implementation of this mechanism is played by the so-called "mirror neurons", which are activated both at the moment when a person acts independently, and at the moment when he simply observes the actions of another. In order for a child to observe what an adult is doing, the so-called “attached attention” is necessary. This is one of the most important components of socio-emotional behavior, which underlies all productive social interactions. “Launching” of attached attention can only be carried out with the direct participation of an adult. If the adult does not look the child in the eye, address the child, or use pointing gestures, attached attention has little chance of developing.

The second learning option is trial and error, however, without imitation, the result of such learning can be very, very strange.

Motor functions: At this age, genetically determined motor skills develop rapidly. Development occurs from generalized movements with the whole body (in the structure of the revitalization complex) to electoral movements . The regulation of muscle tone, posture control, motor coordination are formed. By the end of the period, clear visual-motor coordinations appear (eye-hand interaction), thanks to which the child will subsequently be able to confidently manipulate objects, trying to act with them in different ways, depending on their properties. Details of the appearance of different motor skills during this period can be found in table . Movement during this period is one of the most important components of behavior that affect the cognitive development. Thanks to eye movements, viewing becomes possible, which greatly changes the entire system of visual perception. Thanks to groping movements, the child begins his acquaintance with the objective world, and he forms ideas about the properties of things. Thanks to the movements of the head, it becomes possible to develop ideas about the sources of sound. Due to the movements of the body, the vestibular apparatus develops, and ideas about space are formed. Finally, it is through movement that the child's brain learns to control behavior.

Activity indicators: The sleep duration of a healthy child from 1 to 9 months is gradually reduced from 18 to 15 hours a day. Accordingly, by the end of the period, the baby is awake for 9 hours. After 3 months, as a rule, a night sleep of 10-11 hours is established, during which the child sleeps with single awakenings. By 6 months, the baby should no longer wake up at night. During the day, a child under the age of 9 months can sleep 3-4 times. The quality of sleep at this age reflects the state of the central nervous system. It is shown that many children of preschool and primary school age, suffering from various behavioral disorders, unlike children without behavioral disorders, did not sleep well in infancy - they could not fall asleep, often woke up at night and, in general, slept little.

During the period of wakefulness, a healthy child enthusiastically engages in toys, communicates with adults with pleasure, actively coos and babbles, and eats well.

Major events in infant brain development from 1 to 9 months of age

By the first month of life, many events in the life of the brain are almost completed. New nerve cells are born in small numbers, and the vast majority of them have already found their permanent place in the structures of the brain. Now the main task is to get these cells to exchange information with each other. Without such an exchange, the child will never be able to understand what he sees, because each cell of the cerebral cortex that receives information from the organs of vision processes some one characteristic of the object, for example, a line located at an angle of 45 ° to the horizontal surface. In order for all perceived lines to form a single image of an object, brain cells must communicate with each other. That is why, in the first year of life, the most turbulent events concern the formation of connections between brain cells. Due to the emergence of new processes of nerve cells and the contacts that they establish with each other, the volume of gray matter increases intensively. A kind of "explosion" in the formation of new contacts between the cells of the visual areas of the cortex occurs in the region of 3-4 months of life, and then, the number of contacts continues to gradually increase, reaching a maximum between 4 and 12 months of life. This maximum is 140-150% of the number of contacts in the visual areas of the brain of an adult. In those areas of the brain that are associated with the processing of sensory impressions, the intensive development of intercellular interactions occurs earlier and ends faster than in areas associated with the control of behavior. The connections between the cells of the baby's brain are redundant, and this is what allows the brain to be plastic, ready for different scenarios.

No less important for this stage of development is the coating of nerve endings with myelin, a substance that promotes the rapid conduction of a nerve impulse along the nerve. As well as the development of contacts between cells, myelination begins in the posterior, "sensitive" areas of the cortex, and the anterior, frontal areas of the cortex, which are involved in controlling behavior, are myelinated later. The beginning of their myelination falls on the age of 7-11 months. It is during this period that the infant develops internal, voluntary attention. Myelin coverage of deep brain structures occurs earlier than myelination of cortical areas. This is important, since it is the deep structures of the brain that carry a greater functional load in the early stages of development.

By the end of the first year of life, a child's brain is 70% the size of an adult's.

What can an adult do to support a child's cognitive development?

It is important to try to eliminate obstacles that impede free development. So, if a child does not develop any of the skills in a timely manner, it is necessary to check whether everything is in order with his muscle tone, reflexes, etc. This can be done by a neurologist. If the interference becomes obvious, then it is important to eliminate it in a timely manner. In particular, when it comes to a violation of muscle tone (muscle dystonia), therapeutic massage, exercise therapy and swimming pools are of great help. In some cases, medical treatment is required.

It is very important to create conditions conducive to development. The creation of conditions means giving the child the opportunity to realize his genetic program without restrictions. So, for example, you can’t keep a child in an arena, not allowing him to move around the apartment, on the grounds that dogs live in the house and the floor is dirty. Conditioning also means providing the child with an enriched sensory environment. Cognition of the world in its diversity is what develops the child's brain and forms the backlog of sensory experience that can form the basis of all subsequent cognitive development. The main tool that we are used to using to help a child get to know this world is. A toy can be anything that can be grabbed, lifted, shaken, put in the mouth, thrown. The main thing is that it is safe for the baby. Toys should be varied, differing from each other in texture (soft, hard, smooth, rough), in shape, in color, in sound. The presence of small patterns or small elements in the toy does not play a role. The child is not yet able to see them. We should not forget that in addition to toys, there are other means that stimulate the development of perception. This is a different environment (walks in the forest and in the city), music and, of course, communication with the child of adults.

Manifestations that may indicate problems in the state and development of the central nervous system

The absence of a “revitalization complex”, a child’s interest in communicating with an adult, attached attention, interest in toys, and, on the contrary, heightened auditory, skin, and olfactory sensitivity may indicate a developmental disorder in the brain systems involved in the regulation of emotions and social behavior. This situation may be a harbinger of the formation of autistic traits in behavior.

Absence or late appearance of cooing and babbling. This situation may be a harbinger of delayed speech development. Too early appearance of speech (the first words) may be the result of cerebrovascular insufficiency. Early doesn't mean good.

Untimely appearance (too early or too late appearance, as well as a change in the sequence of appearance) of new types of movements can be the result of muscular dystonia, which, in turn, is a manifestation of suboptimal brain function.

Restless behavior of the child, frequent crying, screaming, restless, interrupted sleep. This behavior, in particular, is characteristic of children with increased intracranial pressure.

All of the above features should not go unnoticed, even if all relatives unanimously claim that one of them was exactly the same in infancy. Assurances that the child will “outgrow” himself, “will someday speak” should not serve as a guide to action. So you can lose precious time.

What should an adult do to prevent disorders of subsequent development if there are symptoms of trouble

Consult a doctor (pediatrician, pediatric neurologist). It is useful to do the following studies that can show the cause of the trouble: neurosonography (NSG), eoencephalography (EchoEG), Doppler ultrasound (USDG) of the vessels of the head and neck, electroencephalography (EEG). Contact an osteopath.

Not every doctor will prescribe these examinations and, as a result, the proposed therapy may not correspond to the true picture of the state of the brain. That is why some parents report the absence of the result of drug therapy prescribed by a pediatric neurologist.

Table. The main indicators of psychomotor development in the period from 1 to 9 months of life.

Age	Visual-orientational reactions	Auditory orienting responses	Emotions and social behavior	Hand movement / Actions with objects	General movements	Speech
2 months	Prolonged visual concentration on the face of an adult or a fixed object. A child follows a moving toy or an adult for a long time	Looking for head turns with a long sound (listens)	Quickly responds with a smile to a conversation with an adult. Prolonged visual focus on another child	Randomly swinging his arms and legs.	Turns the head to the side, turns and arches the body. Lying on his stomach, raises and briefly holds his head (at least 5 s)	Makes individual sounds
3 months	Visual concentration in a vertical position (in the hands of an adult) on the face of an adult speaking to him, on a toy. The child begins to consider his raised arms and legs.	“Revitalization complex”: in response to communication with him (shows joy with a smile, animated movements of arms, legs, sounds). Looking through the eyes of a child making sounds	Accidentally bumps into toys hanging low above the chest at a height of up to 10-15 cm	Tries to take the item given to him	Lies on his stomach for several minutes, leaning on his forearms and holding his head high. With support under the armpits, it rests firmly with the legs bent at the hip joint. Keeps head upright.	Actively hums when an adult appears
4 months	Recognizes mother (rejoices) Examines and grabs toys.	Locates sources of sound	Laughs out loud in response	Purposefully stretches the handles to the toy and tries to grab it. Supports the mother's breasts with her hands while feeding.	Rejoicing or angry, arches, makes a bridge and raises his head, lying on his back. It can turn from back to side, and when pulling up by the arms, raises the shoulders and head.	For a long time gurgles
5 months	Distinguishes loved ones from strangers		Rejoices, hums	Often takes toys from the hands of an adult. With two hands, he grabs objects that are above the chest, and then above the face and on the side, feels his head and legs. Grabbed objects can be held between the palms for several seconds. Squeezes the palm on the toy put into the hand, first grabs with the whole palm without abducting the thumb (“monkey grip”). Releases toys held with one hand when another object is placed in the other hand.	Lies on the stomach. Turns from back to stomach. Eating well from a spoon	Produces individual sounds
6 months		Reacts differently to his own and other people's names		Takes toys in any position. Begins to grab objects with one hand, and soon masters the skill of holding one object simultaneously in each hand and brings the held object to his mouth. This is the beginning of developing the skill of independent eating.	Rolls over from stomach to back. Grabbing the fingers of an adult or the bars of the crib, he sits down on his own, and for some time remains in this position, bending forward strongly. Some children, especially those who spend a lot of time on their stomach, before learning to sit down, begin to crawl on their stomach, moving with their hands around their axis, then back and a little later forward. They sit down generally later, and some of them first stand at the support and only then learn to sit down. This order of development of movements is useful for the formation of correct posture.	Pronounces individual syllables
Seven months				Waving a toy, knocking it. The “monkey grip” with the whole palm is replaced by a finger grip with opposition of the thumb.	Crawls well. Drinks from a cup. There is support for the legs. The baby, supported under the armpits in a vertical position, rests with his legs and makes stepping movements. Between the 7th and 9th months, the child learns to sit up from a side position, sits more and more on his own and straightens his back better. At this age, supported under the armpits, the child firmly rests his legs and makes bouncing movements.	To the question "Where?" locates an object. babbles for a long time
8 months			Looks at the actions of another child, laughs or babbles	Has been playing with toys for a long time. Can pick up one object with each hand, transfer an object from hand to hand, and purposefully throw. He eats crusts of bread, he holds the bread in his hand.	He sits down himself. Between the 8th and 9th months, the baby stands with a support, if he is placed, or is kept at the support on his knees. The next step in preparing for walking is to stand up on your own at the support, and soon steps along it.	To the question "Where?" finds several items. Pronounces various syllables loudly
9 months		Dance movements to a dance melody (if at home they sing to a child and dance with him)	Catches up with the child, crawls towards him. Imitates the actions of another child	Improving the movements of the fingers allows, by the end of the ninth month of life, to master the grip with two fingers. The child acts with objects in different ways depending on their properties (rolls, opens, rattles, etc.)	Usually begins to move, crawling on his knees in a horizontal position with the help of his hands (in a plastunsky way). Activation of crawling leads to a clear movement on all fours with the knees off the floor (variable crawling). Moves from object to object, lightly holding on to them with his hands. He drinks well from a cup, holding it lightly with his hands. Calmly refers to planting on a pot.	To the question "Where?" finds multiple items, regardless of their location. Knows his name, turns to the call. Imitates an adult, repeats after him the syllables that are already in his babbling

Bee H. Child development. SPb.: Peter. 2004. 768 p.

Pantyukhina G.V., Pechora K.L., Fruht E.L. Diagnosis of the neuropsychic development of children in the first three years of life. - M.: Medicine, 1983. - 67 p.

Mondloch C.J., Le Grand R., Maurer D. Early visual experience is necessary for the development of some – but not all – aspects of face processing. The development of face processing in infancy and early childhood. Ed. by O.Pascalis, A.Slater. N.Y., 2003: 99-117.

Samara branch of Moscow State Pedagogical University

Abstract on the topic:

Critical periods in the development of the central nervous system in a child

Completed by: 3rd year student

Faculty of Psychology and Education

Kazakova Elena Sergeevna

Checked:

Korovina Olga Evgenievna

Samara 2013

Development of the nervous system.

The nervous system of higher animals and humans is the result of a long development in the process of adaptive evolution of living beings. The development of the central nervous system took place primarily in connection with the improvement in the perception and analysis of influences from the external environment.

At the same time, the ability to respond to these influences with a coordinated, biologically expedient reaction was also improved. The development of the nervous system also proceeded in connection with the complication of the structure of organisms and the need to coordinate and regulate the work of internal organs. To understand the activity of the human nervous system, it is necessary to get acquainted with the main stages of its development in phylogenesis.

The emergence of the central nervous system.

The lowest organized animals, for example, the amoeba, still have neither special receptors, nor a special motor apparatus, nor anything resembling a nervous system. An amoeba can perceive irritation with any part of its body and react to it with a peculiar movement by the formation of an outgrowth of protoplasm, or pseudopodia. By releasing a pseudopodium, the amoeba moves towards a stimulus, such as food.

In multicellular organisms, in the process of adaptive evolution, specialization of various parts of the body arises. Cells appear, and then organs adapted for the perception of stimuli, for movement, and for the function of communication and coordination.

The appearance of nerve cells not only made it possible to transmit signals over a greater distance, but also became the morphological basis for the rudiments of coordination of elementary reactions, which leads to the formation of a holistic motor act.

In the future, as the evolution of the animal world, the development and improvement of the apparatus of reception, movement and coordination takes place. There are various sense organs adapted for the perception of mechanical, chemical, temperature, light and other stimuli. A complex motor apparatus appears, adapted, depending on the lifestyle of the animal, to swimming, crawling, walking, jumping, flying, etc. As a result of the concentration, or centralization, of scattered nerve cells into compact organs, a central nervous system and peripheral nervous systems arise. way. Nerve impulses are transmitted along one of these pathways from receptors to the central nervous system, along others - from centers to effectors.

General structure of the human body.

The human body is a complex system of numerous and closely interconnected elements, united in several structural levels. The concept of the growth and development of an organism is one of the fundamental concepts in biology. The term "growth" is currently understood as an increase in the length, volume and body weight of children and adolescents, associated with an increase in the number of cells and their number. Development is understood as qualitative changes in the child's body, consisting in the complication of its organization, i.e. in the complication of the structure and function of all tissues and organs, the complication of their relationships and the processes of their regulation. Growth and development of the child, i.e. Quantitative and qualitative changes are closely interconnected with each other. Gradual quantitative and qualitative changes that occur during the growth of the organism lead to the appearance of new qualitative features in the child.

The entire period of development of a living being, from the moment of fertilization to the natural end of an individual life, is called ontogeny (Greek ONTOS - being, and GINESIS - origin). In ontogenesis, two relative stages of development are distinguished:

1. Prenatal - begins from the moment of conception to the birth of a child.

2. Postnatal - from the moment of birth to the death of a person.

Along with the harmony of development, there are special stages of the most abrupt spasmodic atom-physiological transformations.

In postnatal development, there are three such "critical periods" or "age crisis":

	Changing Factors	Effects
from 2 to 4	Development of the sphere of communication with the outside world. The development of the form of speech. The development of a form of consciousness.	Increasing educational requirements. Increasing motor activity
from 6 to 8 years	New people. New friends. New responsibilities	Decreased motor activity
from 11 to 15 years old	Changes in hormonal balance with the maturation and restructuring of the endocrine glands. Expanding the circle of communication	Conflicts in the family and at school. Hot temper

An important biological feature in the development of a child is that the formation of their functional systems occurs much earlier than they need.

The principle of advanced development of organs and functional systems in children and adolescents is a kind of "insurance" that nature gives to a person in case of unforeseen circumstances.

A functional system is a temporary association of various organs of a child's body, aimed at achieving a result useful for the existence of the organism.

Purpose of the nervous system.

The nervous system is the leading physiological system of the body. Without it, it would be impossible to connect countless cells, tissues, organs into a single hormonal working whole.

The functional nervous system is divided "conditionally" into two types:

Thus, thanks to the activity of the nervous system, we are connected with the surrounding world, we are able to admire its perfection, to learn the secrets of its material phenomena. Finally, thanks to the activity of the nervous system, a person is able to actively influence the surrounding nature, transform it in the desired direction.

At the highest stage of its development, the central nervous system acquires another function: it becomes an organ of mental activity, in which, on the basis of physiological processes, sensations, perceptions arise, and thinking appears. The human brain is an organ that provides the possibility of social life, communication of people with each other, knowledge of the law of nature and society and their use in social practice.

Let us give some idea of ​​conditioned and unconditioned reflexes.

Features of unconditioned and conditioned reflexes.

The main form of activity of the nervous system is reflex. All reflexes are usually divided into unconditional and conditional.

Unconditioned reflexes- these are congenital, genetically programmed reactions of the body, characteristic of all animals and humans. The reflex arcs of these reflexes are formed in the process of prenatal development, and in some cases, in the process of postnatal development. For example, sexual innate reflexes are finally formed in a person only by the time of puberty in adolescence. Unconditioned reflexes have conservative, little-changing reflex arcs, passing mainly through the subcortical regions of the central nervous system. The participation of the cortex in the course of many unconditioned reflexes is not necessary.

Conditioned reflexes- individual, acquired reactions of higher animals and humans, developed as a result of learning (experience). Conditioned reflexes are always individually unique. Reflex arcs of conditioned reflexes are formed in the process of postnatal ontogenesis. They are characterized by high mobility, the ability to change under the influence of environmental factors. Reflex arcs of conditioned reflexes pass through the higher part of the brain - CGM.

Classification of unconditioned reflexes.

The question of classifying unconditioned reflexes is still open, although the main types of these reactions are well known. Let us dwell on some especially important unconditioned human reflexes.

1. Food reflexes. For example, salivation when food enters the oral cavity or the sucking reflex in a newborn baby.

2. Defensive reflexes. Reflexes that protect the body from various adverse effects, an example of which can be a hand withdrawal reflex during pain irritation of the finger.

3. Orienting reflexes. Any new unexpected stimulus draws the photograph of a person to itself.

4. Game reflexes. This type of unconditioned reflexes is widely found in various representatives of the animal kingdom and also has an adaptive value. Example: puppies, playing,. hunt each other, sneak up and attack their "opponent". Consequently, in the course of the game, the animal creates models of possible life situations and carries out a kind of "preparation" for various life surprises.

While retaining its biological foundations, children's play acquires new qualitative features - it becomes an active tool for understanding the world and, like any other human activity, acquires a social character. The game is the very first preparation for future work and creative activity.

The game activity of the child appears from 3-5 months of postnatal development and underlies the development of his ideas about the structure of the body and the subsequent isolation of himself from the surrounding reality. At 7-8 months, play activity acquires an "imitative or educational" character and contributes to the development of speech, the improvement of the emotional sphere of the child and the enrichment of his ideas about the surrounding reality. From the age of one and a half, the child's play becomes more and more complicated, the mother and other people close to the child are introduced into the game situations, and thus the foundations for the formation of interpersonal, social relations are created.

In conclusion, it should also be noted sexual and parental unconditioned reflexes associated with the birth and feeding of offspring, reflexes that ensure the movement and balance of the body in space, and reflexes that maintain the homeostasis of the body.

instincts. A more complex, unconditionally reflex activity is the instincts, the biological nature of which is still unclear in its details. In a simplified form, instincts can be represented as a complex interconnected series of simple innate reflexes.

Physiological mechanisms of formation of conditioned reflexes.

The following essential conditions are necessary for the formation of a conditioned reflex:

1) The presence of a conditioned stimulus

2) The presence of unconditional reinforcement

The conditioned stimulus should always somewhat precede the unconditioned reinforcement, i.e., serve as a biologically significant signal; the conditioned stimulus should be weaker than the unconditioned stimulus in terms of the strength of its effect; finally, for the formation of a conditioned reflex, a normal (active) functional state of the nervous system, especially its leading department - the brain, is necessary. Any change can be a conditioned stimulus! Powerful factors contributing to the formation of conditioned reflex activity are rewards and punishments. At the same time, we understand the words "encouragement" and "punishment" in a broader sense than simply "satisfaction of hunger" or "painful effect". It is in this sense that these factors are widely used in the process of teaching and raising a child, and every teacher and parent is well aware of their effective action. True, up to 3 years for the development of useful reflexes in a child, “food reinforcement” also has a leading role. However, then the leading role as a reinforcement in the development of useful conditioned reflexes acquires "verbal encouragement." Experiments show that in children older than 5 years, with the help of praise, you can develop any useful reflex in 100% of cases.

Thus, educational work, in its essence, is always associated with the development in children and adolescents of various conditioned reflex reactions or their complex interconnected systems.

Classification of conditioned reflexes.

The classification of conditioned reflexes is difficult due to their large number. There are exteroceptive conditioned reflexes that are formed when the exteroreceptors are stimulated; interoceptive reflexes, which are formed when receptors located in the internal organs are stimulated; and proprioceptive, arising from stimulation of muscle receptors.

There are natural and artificial conditioned reflexes. The first are formed under the action of natural unconditioned stimuli on the receptors, the second - under the action of indifferent stimuli. For example, salivation in a child at the sight of favorite sweets is a natural conditioned reflex, and salivation that occurs in a hungry child at the sight of dinner utensils is an artificial reflex.

The interaction of positive and negative conditioned reflexes is important for the adequate interaction of the organism with the external environment. Such an important feature of the child's behavior as discipline is associated precisely with the interaction of these reflexes. In physical education lessons, in order to suppress reactions of self-preservation and a sense of fear, for example, when performing gymnastic exercises on uneven bars, defensive negative conditioned reflexes are inhibited in students and positive motor reflexes are activated.

A special place is occupied by conditioned reflexes for time, the formation of which is associated with regularly repeated stimuli at the same time, for example, with food intake. That is why, by the time of eating, the functional activity of the digestive organs increases, which has a biological meaning. Such rhythmicity of physiological processes underlies the rational organization of the day regimen of preschool and school children and is a necessary factor in the highly productive activity of an adult. Reflexes for time, obviously, should be attributed to the group of so-called trace conditioned reflexes. These reflexes are developed if the unconditioned reinforcement is given 10-20 seconds after the final action of the conditioned stimulus. In some cases, it is possible to develop trace reflexes even after a 1-2 minute pause.

Important in the life of a child are imitation reflexes, which are also a kind of conditioned reflexes. To develop them, it is not necessary to take part in the experiment, it is enough to be its "spectator".

Higher nervous activity in the early and preschool periods of development (from birth to 7 years).

A child is born with a set of unconditioned reflexes. reflex arcs of which begin to form at the 3rd month of prenatal development. So, the first sucking and respiratory movements appear in the fetus precisely at this stage of ontogenesis, and the active movement of the fetus is observed at the 4-5th month of intrauterine development. By the time of birth, most of the innate unconditioned reflexes are formed in the child, providing him with the normal functioning of the vegetative sphere, his vegetative "comfort".

The possibility of simple food conditioned reactions, despite the morphological and functional immaturity of the brain, occurs already on the first or second day, and by the end of the first month of development, conditioned reflexes are formed from the motor analyzer and the vestibular apparatus: motor and temporal. All these reflexes are formed very slowly, they are extremely gentle and easily inhibited, which is apparently due to the immaturity of the cortical cells and the sharp predominance of excitatory processes over inhibitory ones and their wide irradiation.

From the second month of life, auditory, visual, and tactile reflexes are formed, and by the 5th month of development, the child develops all the main types of conditioned inhibition. The education of the child is of great importance in the improvement of conditioned reflex activity. The earlier training is started, i.e., the development of conditioned reflexes, the faster their formation subsequently proceeds.

By the end of the first year of development, the child relatively well distinguishes the taste of food, smells, the shape and color of objects, distinguishes voices and faces. Significantly improved movement, some children begin to walk. The child tries to pronounce individual words ("mom", "dad", "grandfather", "aunt", "uncle", etc.), and he develops conditioned reflexes to verbal stimuli. Consequently, already at the end of the first year, the development of the second signaling system is in full swing and its joint activity with the first is being formed.

The development of speech is a difficult task. It requires coordination of the respiratory muscles, muscles of the larynx, tongue, pharynx and lips. Until this coordination is developed, the child pronounces many sounds and words incorrectly.

It is possible to facilitate the formation of speech by the correct pronunciation of words and grammatical phrases so that the child constantly hears the patterns he needs. Adults, as a rule, when addressing a child, try to copy the sounds that the child utters, believing that in this way they will be able to find a "common language" with him. This is a profound delusion. There is a huge distance between a child's understanding of words and the ability to pronounce them. The lack of the right role models delays the development of the child's speech.

The child begins to understand words very early, and therefore, for the development of speech, it is important to "talk" with the child from the first days after his birth. When changing a vest or diaper, shifting a child or preparing him for feeding, it is advisable not to do this silently, but to address the child with the appropriate words, naming your actions.

The first signal system is the analysis and synthesis of direct, specific signals of objects and phenomena of the surrounding world, coming from visual, auditory and other receptors of the body and components

The second signaling system is (only in humans) the connection between verbal signals and speech, the perception of words - heard, spoken (aloud or to oneself) and visible (when reading).

In the second year of the child's development, all types of conditioned reflex activity are improved and the formation of the second signal system continues, the vocabulary increases significantly (250-300 words); direct stimuli or their complexes begin to cause verbal reactions. If in a one-year-old child conditioned reflexes to direct stimuli are formed 8-12 times faster than to a word, then at the age of two, words acquire a signal value.

Of decisive importance in the formation of the child's speech and the entire second signaling system as a whole is the communication of the child with adults, i.e. the surrounding social environment and learning processes. This fact is another proof of the decisive role of the environment in the unfolding of the potential possibilities of the genotype. Children deprived of a linguistic environment, communication with people, do not speak, moreover, their intellectual abilities remain at a primitive animal level. At the same time, the age from two to five is "critical" in mastering speech. There are cases that children abducted by wolves in early childhood and returned to human society after the age of five are able to learn to speak only to a limited extent, and those returned only after 10 years are not able to utter a single word.

The second and third years of life are distinguished by lively orientation and research activities. “At the same time,” writes M. M. Koltsova, “the essence of the orienting reflex of a child of this age can be more correctly characterized not by the question “what is it?”, but by the question “what can be done with it?”. The child reaches out to each object, touches it, feels it, pushes it, tries to lift it, etc."

Thus, the described age of the child is characterized by the "objective" nature of thinking, that is, by the decisive importance of muscular sensations. This feature is largely associated with the morphological maturation of the brain, since many motor cortical zones and zones of skin-muscle sensitivity already reach a sufficiently high functional usefulness by the age of 1-2 years. The main factor stimulating the maturation of these cortical zones are muscle contractions and high physical activity of the child. Limitation of its mobility at this stage of ontogenesis significantly slows down mental and physical development.

The period up to three years is also characterized by the extraordinary ease of formation of conditioned reflexes to a wide variety of stimuli, including the size, heaviness, distance and color of objects. Pavlov considered these types of conditioned reflexes to be prototypes of concepts developed without words ("grouped reflection of the phenomena of the external world in the brain").

A notable feature of a two-three-year-old child is the ease of developing dynamic stereotypes. Interestingly, each new stereotype is developed more easily. M. M. Koltsova writes: “Now not only the daily routine becomes important for the child: the hours of sleep, wakefulness, nutrition and walks, but also the sequence in putting on or taking off clothes or the order of words in a familiar fairy tale and song - everything becomes important. Obviously that with insufficiently strong and still mobile nervous processes, children need stereotypes that facilitate adaptation to the environment.

Conditional connections and dynamic stereotypes in children up to three years of age are distinguished by extraordinary strength, therefore their alteration for a child is always an unpleasant event. An important condition in educational work at this time is a careful attitude to all stereotypes developed.

The age from three to five years is characterized by the further development of speech and the improvement of nervous processes (their strength, mobility and balance increase), the processes of internal inhibition become dominant, but delayed inhibition and a conditioned brake are developed with difficulty. Dynamic stereotypes are developed just as easily. Their number increases every day, but their alteration no longer causes disturbances in higher nervous activity, which is due to the above functional changes. The orienting reflex to extraneous stimuli is longer and more intense than in schoolchildren, which can be used effectively to inhibit bad habits and skills in children.

Thus, truly inexhaustible possibilities open up before the creative initiative of the educator during this period. Many outstanding teachers (D. A. Ushinsky, A. S. Makarenko) empirically considered the age from two to five to be especially responsible for the harmonious formation of all the physical and mental capabilities of a person. Physiologically, this is based on the fact that the conditional connections and dynamic stereotypes that arise at this time are exceptionally strong and are carried by a person through his entire life. At the same time, their constant manifestation is not necessary, they can be inhibited for a long time, but under certain conditions they are easily restored, suppressing the conditional connections developed later.

By the age of five to seven, the role of the signaling system of words increases even more, and children begin to speak freely. "A word at this age already has the meaning of a "signal of signals", that is, it acquires a general meaning close to that which it has for an adult."

This is due to the fact that only by the age of seven postnatal development does the material substratum of the second signaling system mature functionally. In this regard, it is especially important for educators to remember that only by the age of seven can a word be effectively used to form conditional connections. Abuse of a word before this age without its sufficient connection with direct stimuli is not only ineffective, but also causes functional damage to the child, forcing the child's brain to work in non-physiological conditions.

Higher nervous activity of schoolchildren

The few existing data of physiology show that primary school age (from 7 to 12 years old) is a period of relatively "calm" development of higher nervous activity. The strength of the processes of inhibition and excitation, their mobility, balance, and mutual induction, as well as the reduction in the strength of external inhibition, provide opportunities for broad learning for the child. This is the transition "from reflex emotionality to the intellectualization of emotions"

However, only on the basis of teaching writing and reading does the word become an object of the child's consciousness, moving further and further away from the images of objects and actions associated with it. A slight deterioration in the processes of higher nervous activity is observed only in the 1st grade due to the processes of adaptation to school. It is interesting to note that at primary school age, on the basis of the development of the second signaling system, the conditioned reflex activity of the child acquires a specific character, characteristic only of man. For example, during the development of vegetative and somato-motor conditioned reflexes in children, in some cases, a response is observed only to an unconditioned stimulus, and the conditioned one does not cause a reaction. So, if the subject was given a verbal instruction that after the call he would receive cranberry juice, then salivation begins only upon presentation of an unconditioned stimulus. Such cases of "non-formation" of the conditioned reflex manifest themselves the more often, the older the subject is, and among children of the same age - among the more disciplined and capable.

Verbal instruction significantly accelerates the formation of conditioned reflexes and in some cases does not even require unconditional reinforcement: conditioned reflexes are formed in humans in the absence of direct stimuli. These features of conditioned reflex activity determine the enormous importance of verbal pedagogical influence in the process of educational work with younger schoolchildren.

Nervous system- this is a combination of cells and the structures of the body created by them in the process of evolution of living beings have reached a high specialization in the regulation of adequate vital activity of the body in constantly changing environmental conditions. The structures of the nervous system receive and analyze various information of external and internal origin, and also form the corresponding reactions of the body to this information. The nervous system also regulates and coordinates the mutual activity of various organs of the body in any conditions of life, provides physical and mental activity, and creates the phenomena of memory, behavior, perception of information, thinking, language, and so on.

In functional terms, the entire nervous system is divided into animal (somatic), autonomic and intramural. The animal nervous system, in turn, is divided into two parts: central and peripheral.

(CNS) is represented by the main and spinal cord. The Peripheral Nervous System (PNS) is the central part of the nervous system that combines receptors (sense organs), nerves, ganglia (plexuses) and ganglia located throughout the body. The central nervous system and the nerves of its peripheral part provide the perception of all information from external sense organs (exteroreceptors), as well as from receptors of internal organs (interoreceptors) and from muscle receptors (prorioreceptors). The information received in the CNS is analyzed and transmitted in the form of impulses of motor neurons to the executing organs or tissues, and, above all, to the skeletal motor muscles and glands. Nerves capable of transmitting excitation from the periphery (from receptors) to centers (in the spinal cord or brain) are called sensory, centripetal or afferent, and those that transmit excitation from the centers to the executing organs are called motor, centrifugal, motor, or efferent.

The autonomic nervous system (VIS) innervates the work of internal organs, the state of blood circulation and lymph flow, trophic (metabolic) processes in all tissues. This part of the nervous system includes two sections: sympathetic (accelerates life processes) and parasympathetic (mainly reduces the level of life processes), as well as a peripheral section in the form of nerves of the autonomic nervous system, which are often combined with nerves of the peripheral CNS into single structures.

The intramural nervous system (INS) is represented by individual connections of nerve cells in certain organs (for example, Auerbach cells in the walls of the intestines).

As you know, the structural unit of the nervous system is the nerve cell.- a neuron that has a body (soma), short (dendrites) and one long (axon) processes. Billions of body neurons (18-20 billion) form many neural circuits and centers. Between the neurons in the structure of the brain are also billions of macro- and microneuroglia cells that perform support and trophic functions for neurons. A newborn baby has the same number of neurons as an adult. The morphological development of the nervous system in children includes an increase in the number of dendrites and the length of axons, an increase in the number of terminal neural processes (transactions) and between neuronal connective structures - synapses. There is also an intensive covering of the processes of neurons with a myelin sheath, which is called the process of myelination of the Body, and all the processes of nerve cells are initially covered with a layer of small insulating cells, called Schwann cells, since they were first discovered by the physiologist I. Schwann. If the processes of neurons have only isolation from Schwann cells, then they are called silent ‘yakitnim and have a gray color. Such neurons are more common in the autonomic nervous system. The processes of neurons, especially axons, to the Schwann cells are covered with a myelin sheath, which is formed by thin hairs - neurolemamas that grow from the Schwann cells and are white. Neurons that have a myelin sheath are called neurons. Myakity neurons, unlike non-myakit neurons, not only have better isolation of the conduction of nerve impulses, but also significantly increase the speed of their conduction (up to 120-150 m per second, while for non-myakity neurons this speed does not exceed 1-2 m per second. ). The latter is due to the fact that the myelin sheath is not continuous, but every 0.5-15 mm it has the so-called intercepts of Ranvier, where myelin is absent and through which nerve impulses jump according to the principle of a capacitor discharge. The processes of myelination of neurons are most intense in the first 10-12 years of a child's life. The development between neural structures (dendrites, spines, synapses) contributes to the development of children's mental abilities: the amount of memory, the depth and comprehensiveness of information analysis grows, thinking arises, including abstract thinking. Myelination of nerve fibers (axons) increases the speed and accuracy (isolation) of the conduction of nerve impulses, improves coordination of movements, makes it possible to complicate labor and sports movements, and contributes to the formation of the final handwriting of the letter. Myelination of the nerve processes occurs in the following sequence: first, the processes of neurons that form the peripheral part of the nervous system are myelinated, then the processes of the own neurons of the spinal cord, medulla oblongata, cerebellum, and later all the processes of neurons of the cerebral hemispheres. The processes of motor (efferent) neurons are myelinated previously sensitive (afferent).

The nerve processes of many neurons are usually combined into special structures called nerves and which in structure resemble many leading wires (cables). More often, the nerves are mixed, that is, they contain processes of both sensory and motor neurons or processes of neurons of the central and autonomic parts of the nervous system. The processes of individual neurons of the central nervous system in the composition of the nerves of adults are isolated from each other by a myelin sheath, which causes isolated transmission of information. Nerves based on myelinated nerve processes, as well as the corresponding nerve processes, called myakitnims. Along with this, there are also non-myelinated nerves and mixed ones, when both myelinated and non-myelinated nerve processes pass as part of one nerve.

The most important properties and functions of nerve cells and the entire nervous system in general are ITS irritability and excitability. Irritability characterizes the ability of an element in the nervous system to perceive external or internal stimuli that can be created by stimuli of a mechanical, physical, chemical, biological and other nature. Excitability characterizes the ability of the elements of the nervous system to move from a state of rest to a state of activity, that is, to respond with excitation to the action of a stimulus of a threshold, or higher level).

Excitation is characterized by a complex of functional and physico-chemical changes occurring in the state of neurons or other excitable formations (muscles, secretory cells, etc.), namely: the permeability of the cell membrane for Na, K ions changes, the concentration of Na, K ions in the middle outside the cell, the charge of the membrane changes (if at rest it was negative inside the cell, then it becomes positive when excited, and on the contrary outside the cell). The resulting excitation is able to propagate along the neurons and their processes and even go beyond them to other structures (most often in the form of electrical biopotentials). The threshold of the stimulus is considered to be such a level of its action that is able to change the permeability of the cell membrane for Na * and K * ions with all subsequent manifestations of the excitation effect.

The next property of the nervous system- the ability to conduct excitation between neurons due to the elements that connect and are called synapses. Under an electron microscope, you can see the structure of the synapse (lynx), which consists of an expanded end of the nerve fiber, has the shape of a funnel, inside which there are oval or round bubbles that are capable of releasing a substance called a mediator. The thickened surface of the funnel has presynaptic membranes, while the postsynaptic membrane is contained on the surface of another cell and has many folds with receptors that are sensitive to the mediator. Between these membranes is the synoptic fissure. Depending on the functional orientation of the nerve fiber, the mediator can be excitatory (for example, acetylcholine) or inhibitory (for example, gamma-aminobutyric acid). Therefore, synapses are divided into excitatory and inhibitory. The physiology of the synapse is as follows: when the excitation of the 1st neuron reaches the presynaptic membrane, its permeability for synaptic vesicles increases significantly and they enter the synaptic cleft, burst and release a mediator that acts on the receptors of the postsynaptic membrane and causes excitation of the 2nd neuron, and the mediator itself quickly disintegrates. In this way, excitation is transferred from the processes of one neuron to the processes or body of another neuron or to cells of muscles, glands, etc. The speed of synapse response is very high and reaches 0.019 ms. Not only excitatory synapses, but also inhibitory synapses are always in contact with the bodies and processes of nerve cells, which creates conditions for differentiated responses to a perceived signal. The synaptic apparatus of the CIS is formed in children up to 15-18 years of age in the postnatal period of life. The most important influence on the formation of synaptic structures creates the level of external information. Exciting synapses are the first to mature in a child's ontogeny (the most intense in the period from 1 to 10 years), and later - inhibitory (at 12-15 years). This unevenness is manifested by the peculiarities of the external behavior of children; younger students are little able to restrain their actions, they are not satisfied, they are not capable of in-depth analysis of information, concentration of attention, increased emotional and so on.

The main form of nervous activity, the material basis of which is the reflex arc. The simplest double neuron, monosynaptic reflex arc consists of at least five elements: a receptor, an afferent neuron, the central nervous system, an efferent neuron, and an executing organ (effector). In the scheme of polysynaptic reflex arcs between afferent and efferent neurons there is one or more intercalary neurons. In many cases, the reflex arc closes into a reflex ring due to sensitive feedback neurons that start from the intero-or proprioreceptors of the working organs and signal the effect (result) of the action performed.

The central part of the reflex arcs is formed by the nerve centers, which are actually a collection of nerve cells that provide a certain reflex or regulation of a certain function, although the localization of the nerve centers is in many cases conditional. Nerve centers are characterized by a number of properties, among which the most important are: one-sided conduction of excitation; delay in the conduction of excitation (due to synapses, each of which delays the impulse by 1.5-2 ms, due to which the speed of movement of excitation everywhere in the synapse is 200 times lower than along the nerve fiber); summation of excitations; transformation of the rhythm of excitation (frequent irritations do not necessarily cause frequent states of excitation); tone of nerve centers (constant maintenance of a certain level of their excitation);

aftereffect of excitation, that is, the continuation of reflex acts after the cessation of the action of the pathogen, which is associated with the recirculation of impulses on closed reflex or neural circuits; rhythmic activity of nerve centers (ability to spontaneous excitations); fatigue; sensitivity to chemicals and lack of oxygen. A special property of the nerve centers is their plasticity (the genetically determined ability to compensate for the lost functions of some neurons and even nerve centers with other neurons). For example, after a surgical operation to remove a separate part of the brain, the innervation of parts of the body subsequently resumes due to the sprouting of new pathways, and the functions of the lost nerve centers can be taken over by neighboring nerve centers.

Nerve centers, and manifestations of excitation and inhibition processes on their basis, provide the most important functional quality of the nervous system - coordination of the functions of the activity of all body systems, including under changing environmental conditions. Coordination is achieved by the interaction of the processes of excitation and inhibition, which in children up to 13-15 years of age, as mentioned above, are not balanced with the predominance of excitatory reactions. The excitation of each nerve center almost always spreads to neighboring centers. This process is called irradiation and is caused by many neurons that connect separate parts of the brain. Irradiation in adults is limited by inhibition, while in children, especially at preschool and primary school age, irradiation is little limited, which is manifested by the intemperance of their behavior. For example, when a good toy appears, children can simultaneously open their mouths, scream, jump, laugh, etc.

Due to the following age differentiation and the gradual development of inhibitory qualities in children from 9-10 years old, mechanisms and the ability to concentrate excitation are formed, for example, the ability to concentrate, to adequately act on specific irritations, and so on. This phenomenon is called negative induction. Scattering of attention during the action of extraneous stimuli (noise, voices) should be considered as a weakening of induction and the spread of irradiation, or as a result of inductive inhibition due to the appearance of areas of excitation in new centers. In some neurons, after the cessation of excitation, inhibition occurs and vice versa. This phenomenon is called sequential induction, and it explains, for example, the increased motor activity of schoolchildren during breaks after motor inhibition during the previous lesson. Thus, the guarantee of high performance of children in the classroom is their active motor rest during breaks, as well as the alternation of theoretical and physically active classes.

A variety of external activities of the body, including reflex movements that change and appear in different connections, as well as the smallest muscular motor acts during work, writing, in sports, etc. Coordination in the central nervous system also ensures the implementation of all acts of behavior and mental activity. The ability to coordinate is an innate quality of the nerve centers, but to a large extent it can be trained, which is actually achieved by various forms of training, especially in childhood.

It is important to highlight the basic principles of coordination of functions in the human body:

The principle of a common final path is that at least 5 sensitive neurons from different reflexogenic zones are in contact with each effector neuron. Thus, different stimuli can cause the same appropriate response, for example, the withdrawal of the hand, and it all depends on which stimulus is stronger;

The principle of convergence (convergence of excitatory impulses) is similar to the previous principle and consists in the fact that impulses arriving in the CNS through different afferent fibers can converge (convert) in the same intermediate or effector neurons, which is due to the fact that on the body and the dendrites of most CNS neurons end with many processes of other neurons, which makes it possible to analyze impulses by value, to carry out the same type of reactions to various stimuli, etc.;

The principle of divergence is that the excitation that comes even to one neuron of the nerve center instantly spreads to all parts of this center, and is also transmitted to the central zones, or to other functionally dependent nerve centers, which is the basis for a comprehensive analysis of information.

The principle of reciprocal innervation of antagonist muscles is ensured by the fact that when the center of contraction of the flexor muscles of one limb is excited, the center of relaxation of the same muscles is inhibited and the center of the extensor muscles of the second limb is excited. This quality of the nerve centers determines cyclic movements during work, walking, running, etc.;

The principle of recoil is that with strong irritation of any nerve center, one reflex quickly changes to another, with the opposite meaning. For example, after a strong bending of the arm, it quickly and strongly extends it, and so on. The implementation of this principle lies at the basis of punches or kicks, at the basis of many labor acts;

The principle of irradiation lies in the fact that a strong excitation of any nerve center causes the spread of this excitation through intermediate neurons to neighboring, even non-specific centers, capable of covering the entire brain with excitation;

The principle of occlusion (blockage) is that with simultaneous stimulation of the nerve center of one muscle group from two or more receptors, a reflex effect occurs, which is less in strength than the arithmetic sum of the reflexes of these muscles from each receptor separately. This arises due to the presence of common neurons for both centers.

The dominant principle is that in the CNS there is always a dominant focus of excitation, which takes over and changes the work of other nerve centers and, above all, inhibits the activity of other centers. This principle determines the purposefulness of human actions;

The principle of sequential induction is due to the fact that the sites of excitation always have neuronal structures inhibition and vice versa. Due to this, after excitation, braking always occurs (negative or negative series induction), and after braking - excitation (positive series induction)

As stated earlier, the CNS consists of the spinal cord and the brain.

Which, during its length, is conditionally divided into 3 I segments, from each of which one pair of spinal nerves departs (31 pairs in total). In the center of the spinal cord there is the spinal canal and gray matter (accumulations of nerve cell bodies), and on the periphery - white matter, represented by processes of nerve cells (axons covered with myelin sheath), which form ascending and descending pathways of the spinal cord between the segments of the spinal cord itself. spinal cord, and between the spinal cord and the brain.

The main functions of the spinal cord are reflex and conduction. In the spinal cord there are reflex centers of the muscles of the trunk, limbs and neck (reflexes to muscle stretch, antagonist muscle reflexes, tendon reflexes), posture maintenance reflexes (rhythmic and tonic reflexes), and autonomic reflexes (urination and defecation, sexual behavior). The leading function carries out the relationship between the activity of the spinal cord and the brain and is provided by ascending (from the spinal cord to the brain) and descending (from the brain to the spinal cord) pathways of the spinal cord.

The spinal cord in a child develops earlier than the main one, but its growth and differentiation continue until adolescence. The spinal cord grows most intensively in children during the first 10 years. life. Motor (efferent) neurons develop earlier than afferent (sensory) ones throughout the entire period of ontogenesis. It is for this reason that it is much easier for children to copy the movements of others than to produce their own motor acts.

In the first months of development of the human embryo, the length of the spinal cord coincides with the length of the spine, but later the spinal cord lags behind the spine in growth and in the newborn the lower end of the spinal cord is at level III, and in adults it is at level 1 of the lumbar vertebra. At this level, the spinal cord passes into a cone and a final thread (consisting partly of nervous, but mainly of connective tissue), which stretches down and is fixed at the level of the JJ coccygeal vertebra). As a result of this, the roots of the lumbar, sacral, and coccygeal nerves have a long extension in the spinal canal around the final thread, thus forming the so-called cauda equina of the spinal cord. In the upper part (at the level of the base of the skull), the spinal cord connects to the brain.

The brain controls the entire vital activity of the whole organism, contains higher nervous analytical and synthetic structures that coordinate the vital functions of the body, provide adaptive behavior and mental activity of a person. The brain is conditionally divided into the following sections: the medulla oblongata (the place of attachment of the spinal cord); the hindbrain, which unites the pons and cerebellum, the midbrain (peduncles of the brain and the roof of the midbrain); the diencephalon, the main part of which is the optic tubercle or thalamus and under the tubercular formations (pituitary gland, gray tubercle, optic chiasm, epiphysis, etc.) the telencephalon (two large hemispheres covered with the cerebral cortex). The diencephalon and telencephalon are sometimes combined into the forebrain.

The medulla oblongata, the pons, the midbrain, and partially the diencephalon together form the brainstem, with which the cerebellum, telencephalon, and spinal cord are connected. In the middle of the brain there are cavities that are a continuation of the spinal canal and are called the ventricles. The fourth ventricle is located at the level of the medulla oblongata;

the cavity of the midbrain is the sylvian strait (aqueduct of the brain); The diencephalon contains the third ventricle, from which the ducts and lateral ventricles depart towards the right and left cerebral hemispheres.

Like the spinal cord, the brain consists of gray (the bodies of neurons and dendrites) and white (from the processes of neurons covered with a myelin sheath) matter, as well as neuroglia cells. In the brain stem, the gray matter is located in separate spots, thus forming nerve centers and nodes. In the telencephalon, gray matter predominates in the cerebral cortex, where the highest nerve centers of the body are located, and in some subcortical regions. The remaining tissues of the cerebral hemispheres and the brain stem are white, representing ascending (to the cortical zones), descending (from the cortical zones) and internal nerve pathways of the brain.

The brain has XII pairs of cranial nerves. At the bottom (base) of the IV-ro ventricle, there are centers (nuclei) of the IX-XII pair of nerves, at the level of the pons of the V-XIII pair; at the level of the midbrain of the III-IV pair of cranial nerves. The 1st pair of nerves is located in the region of the olfactory bulbs contained under the frontal lobes of the cerebral hemispheres, and the nuclei of the 2nd pair are located in the region of the diencephalon.

The individual parts of the brain have the following structure:

The medulla oblongata is in fact a continuation of the spinal cord, has a length of up to 28 mm and in front passes into the varolii of the brain cities. These structures are mainly composed of white matter, forming pathways. The gray matter (the bodies of neurons) of the medulla oblongata and the bridge is contained in the thickness of the white matter by separate islands, which are called nuclei. The central canal of the spinal cord, as indicated, expands in the region of the medulla oblongata and the pons, forming the fourth ventricle, the posterior side of which has a recess - a rhomboid fossa, which in turn passes in Silvio's aqueduct of the brain, connecting the fourth and third - and the ventricles. Most of the nuclei of the medulla oblongata and the bridge are located in the walls (at the bottom) of the IV-ro ventricle, which ensures their better supply of oxygen and consumer substances. At the level of the medulla oblongata and the bridge, the main centers of autonomic and, in part, somatic regulation are located, namely: the centers of innervation of the muscles of the tongue and neck (hyoid nerve, XII pairs of cranial nerves); centers of innervation of the muscles of the neck and shoulder girdle, muscles of the throat and larynx (accessory nerve, XI pair). Innervation of the organs of the neck. chest (heart, lungs), abdomen (stomach, intestines), endocrine glands carries out the vagus nerve (X pair),? main nerve of the parasympathetic division of the autonomic nervous system. The innervation of the tongue, taste buds, acts of swallowing, certain parts of the salivary glands is carried out by the glossopharyngeal nerve (IX pair). The perception of sounds and information about the position of the human body in space from the vestibular apparatus is carried out by the synco-coil nerve (VIII pair). The innervation of the lacrimal and part of the salivary glands, the facial muscles is provided by the facial nerve (VII pair). The innervation of the muscles of the eye and eyelids is carried out by the abducens nerve (VI pair). The innervation of the masticatory muscles, teeth, oral mucosa, gums, lips, some facial muscles and additional formations of the eye is carried out by the trigeminal nerve (V pair). Most nuclei of the medulla oblongata mature in children under 7-8 years of age. The cerebellum is a relatively separate part of the brain, it has two hemispheres connected by a worm. With the help of pathways in the form of lower, middle and upper legs, the cerebellum is connected to the medulla oblongata, the pons and the midbrain. The afferent pathways of the cerebellum come from various parts of the brain and from the vestibular apparatus. The efferent impulses of the cerebellum are directed to the motor parts of the midbrain, the visual tubercles, the cerebral cortex, and to the motor neurons of the spinal cord. The cerebellum is an important adaptive-trophic center of the body; it is involved in the regulation of cardiovascular activity, respiration, digestion, thermoregulation, innervates the smooth muscles of internal organs, and is also responsible for coordination of movements, maintaining posture, and tone of the muscles of the body. After the birth of a child, the cerebellum develops intensively, and already at the age of 1.5-2 years, its mass and size reach the size of an adult. The final differentiation of the cellular structures of the cerebellum is completed at the age of 14-15: the ability for arbitrary finely coordinated movements appears, the handwriting of the letter is fixed, and so on. and red core. The roof of the midbrain consists of two upper and two lower hillocks, the nuclei of which are associated with an orienting reflex to visual (upper hillocks) and auditory (lower hillocks) stimulation. The tubercles of the midbrain are called, respectively, the primary visual and auditory centers (at their level, there is a switch from the second to the third neurons in accordance with the visual and auditory tracts, through which visual information is then sent to the visual center, and auditory information to the auditory center of the cerebral cortex) . The centers of the midbrain are closely connected with the cerebellum and provide the emergence of "watchdog" reflexes (return of the head, orientation in the dark, in a new environment, etc.). The black substance and the red core involved in the regulation of posture and body movements, maintain muscle tone, coordinate movements during eating (chewing, swallowing). An important function of the red nucleus is the reciprocal (explained) regulation of the work of the antagonist muscles, which determines the coordinated action of the flexors and extensors of the musculoskeletal system. Thus, the midbrain, together with the cerebellum, is the main center for regulating movements and maintaining a normal body position. The cavity of the midbrain is the Sylvian Strait (aqueduct of the brain), at the bottom of which are the nuclei of the block (IV pair) and oculomotor (III pair) cranial nerves that innervate the muscles of the eye.

The diencephalon consists of the epithalamus (nadgirya), thalamus (hills), mesothalamus and hypothalamus (pidzhirya). Epitapamus is combined with the gland of internal secretion, which is called the pineal gland, or the pineal gland, which regulates the internal biorhythms of a person with the environment. This gland is also a kind of chronometer of the body, which determines the change of periods of life, activity during the day, during the seasons of the year, restrains such other things until a certain period of puberty. The thalamus, or visual tubercles, unites about 40 nuclei, which are conditionally divided into 3 groups: specific, non-specific and associative. Specific (or those that switch) nuclei are designed to transmit visual, auditory, skin-muscular-articular and other (except olfactory) information to the corresponding sensory zones of the cerebral cortex by ascending projection paths. Descending paths everywhere specific nuclei transmit information from the motor areas of the cortex to the underlying sections of the brain and spinal cord, for example, in the reflex arcs that control the work of skeletal muscles. Associative nuclei transmit information from specific nuclei of the diencephalon to the associative regions of the cerebral cortex. Nonspecific nuclei form the general background of the activity of the cerebral cortex, which maintains a vigorous state of a person. With a decrease in the electrical activity of nonspecific nuclei, a person falls asleep. In addition, it is believed that the nonspecific nuclei of the thalamus regulate the processes of non-voluntary attention and take part in the processes of consciousness formation. Afferent impulses from all receptors of the body (with the exception of olfactory ones), before reaching the cerebral cortex, enter the nuclei of the thalamus. Here, the information is primarily processed and encoded, gets an emotional coloring and then goes to the cerebral cortex. The thalamus also has a center of pain sensitivity and there are neurons that coordinate complex motor functions with autonomic reactions (for example, coordination of muscle activity with activation of the heart and respiratory system). At the level of the thalamus, a partial decussation of the optic and auditory nerves is carried out. The crossroads (chiasm) of healthy nerves is located in front of the pituitary gland and sensitive optic nerves (II pair of cranial nerves) come here from the eyes. The cross consists in the fact that the nerve processes of the photosensitive receptors of the left half of the right and left eyes are further combined into the left optic tract, which, at the level of the lateral geniculate bodies of the thalamus, switches to the second neuron, which is sent through the optic tubercles of the midbrain to the center of vision, located on the medial surface occipital lobe of the right cerebral cortex. At one time, neurons from receptors in the right halves of each eye create the right visual tract, which goes to the center of vision in the left hemisphere. Each optic tract contains up to 50% of the visual information of the corresponding side of the left and right eyes (for details, see Section 4.2).

The intersection of the auditory pathways is carried out similarly to the visual ones, but is realized on the basis of the medial geniculate bodies of the thalamus. Each auditory tract contains 75% of the information from the ear of the corresponding side (left or right) and 25% of the information from the ear of the opposite side.

Pidzgirya (hypothalamus) is part of the diencephalon, which controls autonomic reactions, i.e. carries out the coordinative-integrative activity of the sympathetic and parasympathetic divisions of the autonomic nervous system, and also ensures the interaction of the nervous and endocrine regulatory systems. Within the hypothalamus, 32 nerve nuclei are charged, most of which, using nervous and humoral mechanisms, carry out a kind of assessment of the nature and degree of homeostasis disturbances (the constancy of the internal environment) of the body, and also form “teams” that can influence the correction of possible homeostasis shifts both by changes in the autonomic nervous and endocrine systems, and (through the central nervous system) by changing the behavior of the body. Behavior, in turn, is based on sensations, of which those associated with biological needs are called motivations. Feelings of hunger, thirst, satiety, pain, physical condition, strength, sexual desire are associated with centers located in the anterior and posterior nuclei of the hypothalamus. One of the largest nuclei of the hypothalamus (gray tubercle) is involved in the regulation of the functions of many endocrine glands (through the pituitary gland), and in the regulation of metabolism, including the exchange of water, salts and carbohydrates. The hypothalamus is also the center of body temperature regulation.

The hypothalamus is closely related to the endocrine gland- the pituitary gland, forming the hypothalamic-pituitary pathway, due to which, as mentioned above, the interaction and coordination of the nervous and humoral systems of regulation of body functions is carried out.

At the time of birth, most of the diencephalon nuclei are well developed. In the future, the size of the thalamus grows due to the growth in the size of nerve cells and the development of nerve fibers. The development of the diencephalon also consists in the complication of its interaction with other brain formations, improves the overall coordination activity. The final differentiation of the nuclei of the thalamus and hypothalamus ends at puberty.

V of the central part of the brain stem (from oblong to intermediate) is a nerve formation - a mesh creation (reticular formation). This structure has 48 nuclei and a large number of neurons that form many contacts with each other (the phenomenon of the field of sensory convergence). Through the collateral pathway, all sensitive information from the receptors of the periphery enters the reticular formation. It has been established that the mesh creation takes part in the regulation of respiration, the activity of the heart, blood vessels, digestion processes, etc. The special role of the mesh formation is in the regulation of the functional activity of the higher parts of the cerebral cortex, which ensures wakefulness (together with impulses from nonspecific structures of the thalamus). In the network formation, the interaction of afferent and efferent impulses occurs, their circulation along the ring roads of neurons, which is necessary to maintain a certain tone or degree of readiness of all body systems for changes in the state or conditions of activity. The descending pathways of the reticular formation are capable of transmitting impulses from the higher parts of the central nervous system to the spinal cord, regulating the speed of the passage of reflex acts.

The telencephalon includes subcortical basal ganglia (nuclei) and two cerebral hemispheres covered by the cerebral cortex. Both hemispheres are connected by a bundle of nerve fibers that form the corpus callosum.

Among the basal nuclei, one should name the pale ball (palidum) where the centers of complex motor acts (writing, sports exercises) and facial movements are located, as well as the striatum that controls the pale ball and acts on it by slowing down. The striatum has the same effect on the cerebral cortex, causing sleep. It has also been established that the striatum takes part in the regulation of vegetative functions, such as metabolism, vascular reactions, and heat generation.

Above the brain stem in the thickness of the hemispheres there are structures that determine the emotional state, induce to action, take part in the processes of learning and memorization. These structures form the limbic system. These structures include areas of the brain such as the seahorse twist (hippocampus), cingulate twist, olfactory bulb, olfactory triangle, amygdala (amygdala), and anterior nuclei of the thalamus and hypothalamus. The cingulate twist, together with the seahorse twist and the olfactory bulb, form the limbic cortex, where acts of human behavior are formed under the influence of emotions. It has also been established that neurons located in the spin of the seahorse take part in the processes of learning, memory, cognition, emotions of anger and fear are immediately formed. The amygdala influences behavior and activity in meeting the needs of nutrition, sexual interest, etc. The limbic system is closely connected with the nuclei of the base of the hemispheres, as well as with the frontal and temporal lobes of the cerebral cortex. Nerve impulses that are transmitted along the descending paths of the limbic system coordinate the autonomic and somatic reflexes of a person according to the emotional state, and also link biologically significant signals from the external environment with the emotional reactions of the human body. The mechanism of this is that information from the external environment (from the temporal and other sensory areas of the cortex) and from the hypothalamus (about the state of the internal environment of the body) converts on the neurons of the amygdala (part of the limbic system), making synaptic connections. This forms imprints of short-term memory, which are compared with the information contained in the long-term memory and with the motivational tasks of behavior, which, finally, causes the emergence of emotions.

The cerebral cortex is represented by gray matter with a thickness of 1.3 to 4.5 mm. The area of ​​the bark reaches 2600 cm2 due to the large number of furrows and whorls. There are up to 18 billion nerve cells in the cortex, which form many mutual contacts.

Under the cortex is a white matter, in which there are associative, commissural and projection pathways. Associative pathways connect individual zones (nerve centers) within one hemisphere; commissural pathways connect symmetrical nerve centers and parts (twists and furrows) of both hemispheres, passing through the corpus callosum. The projection pathways are located outside the hemispheres and connect the lower located sections of the central nervous system with the cerebral cortex. These pathways are divided into descending (from the cortex to the periphery) and ascending (from the periphery to the centers of the cortex).

The entire surface of the cortex is conditionally divided into 3 types of cortex zones (areas): sensory, motor and associative.

Sensory zones are particles of the cortex in which afferent pathways from different receptors end. For example, 1 somato-sensory zone, which receives information from external receptors of all parts of the body, located in the region of the posterior-central twist of the cortex; the visual sensory zone is located on the medial surface of the occipital cortex; auditory - in the temporal lobes, etc. (for details, see subsection 4.2).

Motor zones provide efferent innervation of the working muscles. These zones are localized in the region of the anterocentral twist and have close connections with the sensory zones.

Associative zones are significant areas of the hemispheric cortex, which, using associative pathways, are connected with sensory and motor areas of other parts of the cortex. These zones consist mainly of polysensory neurons that are able to perceive information from different sensory areas of the cortex. Speech centers are located in these zones, they analyze all current information, and also form abstract representations, make decisions on what to perform intellectual tasks, create complex behavior programs based on previous experience and predictions for the future.

V children at the time of birth, the cerebral cortex has the same structure as in adults, however, ITS surface increases with the development of the child due to the formation of small twists and furrows, which lasts up to 14-15 years. In the first months of life, the cerebral cortex grows very rapidly, neurons mature, and intensive myelination of nerve processes takes place. Myelin performs an insulating role and contributes to an increase in the speed of nerve impulses, so myelination of the sheaths of nerve processes helps to increase the accuracy and localization of the conduction of those excitations that enter the brain, or commands that go to the periphery. Myelination processes most intensively occur in the first 2 years of life. Different cortical areas of the brain in children mature unevenly, namely: sensory and motor areas complete maturation at 3-4 years, while associative areas begin to develop intensively only from the age of 7 and this process continues up to 14-15 years. The frontal lobes of the cortex, responsible for the processes of thinking, intellect and mind, mature most late.

The peripheral part of the nervous system mainly innervates the separated muscles of the musculoskeletal system (with the exception of the heart muscle) and the skin, and is also responsible for the perception of external and internal information and for the formation of all acts of behavior and mental activity of a person. In contrast, the autonomic nervous system innervates all the smooth muscles of the internal organs, the muscles of the heart, blood vessels and glands. It should be remembered that this division is rather arbitrary, since the entire nervous system in the human body is not separate and whole.

Peripheral consists of spinal and cranial nerves, receptor endings of the sense organs, nerve plexuses (nodes) and ganglia. The nerve is a filamentous formation of predominantly white color in which the nerve processes (fibers) of many neurons are combined. Connective tissue and blood vessels are located between bundles of nerve fibers. If the nerve contains only fibers of afferent neurons, then it is called a sensory nerve; if the fibers are efferent neurons, then it is called the motor nerve; if it contains fibers of afferent and efferent neurons, then it is called a mixed nerve (there are most of them in the body). Nerve nodes and ganglia are located in different parts of the body of the organism (outside the CNS) and are places where one nerve process branches into many other neurons or places where one neuron switches to another in order to continue the nerve pathways. Data on the receptor endings of the sense organs, see section 4.2.

There are 31 pairs of spinal nerves: 8 pairs of cervical, 12 pairs of thoracic, 5 pairs of lumbar, 5 pairs of sacral and 1 pair of coccygeal. Each spinal nerve is formed by the anterior and posterior roots of the spinal cord, is very short (3-5 mm), occupies the gap between the intervertebral foramen and immediately branches outside the vertebra into two branches: the posterior and the anterior. The posterior branches of all spinal nerves metamerically (i.e., in small zones) innervate the muscles and skin of the back. The anterior branches of the spinal nerves have several ramifications (the outflow branch leading to the nodes of the sympathetic division of the autonomic nervous system; the sheath branch innervates the sheath of the spinal cord itself and the main anterior branch). The anterior branches of the spinal nerves are called nerve trunks and, with the exception of the nerves of the thoracic region, go to the nerve plexuses where they switch to second neurons sent to the muscles and skin of individual parts of the body. Allocate: cervical plexus (form 4 pairs of upper cervical spinal nerves, and from it comes the innervation of the muscles and skin of the neck, diaphragm, individual parts of the head, etc.); brachial plexus (form 4 pairs of lower cervical 1 pair of upper thoracic nerves innervating the muscles and skin of the shoulders and upper limbs); 2-11 pairs of thoracic spinal nerves innervate the respiratory intercostal muscles and the skin of the chest; lumbar plexus (form 12 pairs of thoracic and 4 pairs of upper lumbar spinal nerves that innervate the lower abdomen, thigh muscles and gluteal muscles); sacral plexus (form 4-5 pairs of sacral and 3 upper pairs of coccygeal spinal nerves that innervate the pelvic organs, muscles and skin of the lower limb; among the nerves of this plexus, the sciatic nerve is the largest in the body); shameful plexus (form 3-5 pairs of coccygeal spinal nerves that innervate the genitals, muscles of the small and large pelvis).

There are twelve pairs of cranial nerves, as mentioned earlier, and they are divided into three groups: sensory, motor and mixed. The sensory nerves include: I pair - olfactory nerve, II pair - optic nerve, VJIJ pair - cochlear nerve.

Motor nerves include: IV paratrochlear nerve, VI pair - abducens nerve, XI pair - accessory nerve, XII pair - hypoglossal nerve.

Mixed nerves include: III para-oculomotor nerve, V pair - trigeminal nerve, VII pair - facial nerve, IX pair - glossopharyngeal nerve, X pair - vagus nerve. The peripheral nervous system in children usually develops at the age of 14-16 (in parallel with the development of the central nervous system) and this consists in an increase in the length of nerve fibers and their myelination, as well as in the complication of interneuronal connections.

The vegetative (autonomous) nervous system (ANS) of a person regulates the functioning of internal organs, metabolism, adapts the level of the body's work to the current needs of existence. This system has two divisions: sympathetic and parasympathetic, which have parallel nerve paths to all organs and vessels of the body and often act on their work with the opposite effect. Sympathetic innervations habitually accelerate functional processes (increase the frequency and strength of heart contractions, expand the lumen of the bronchi of the lungs and all blood vessels, etc.), and parasympathetic innervations slow down (lower) the course of functional processes. An exception is the action of the ANS on the smooth muscles of the stomach and intestines and on the processes of urination: here, sympathetic innervations inhibit muscle contraction and urine formation, while parasympathetic ones, on the contrary, accelerate it. In some cases, both departments can reinforce each other in their regulatory effect on the body (for example, during physical exertion, both systems can increase the work of the heart). In the first periods of life (up to 7 years), the activity of the sympathetic part of the ANS in a child exceeds, which causes respiratory and cardiac arrhythmias, increased sweating, etc. The predominance of sympathetic regulation in childhood is due to the characteristics of the child's body, develops and requires increased activity of all life processes. The final development of the autonomic nervous system and the establishment of a balance in the activity of both departments of this system is completed at the age of 15-16. The centers of the sympathetic division of the ANS are located on both sides along the spinal cord at the level of the cervical, thoracic and lumbar regions. The parasympathetic division has centers in the medulla oblongata, midbrain and diencephalon, as well as in the sacral spinal cord. The highest center of autonomic regulation is located in the region of the hypothalamus of the diencephalon.

The peripheral part of the ANS is represented by nerves and nerve plexuses (nodes). The nerves of the autonomic nervous system are usually gray in color, since the processes of the neurons that form do not have a myelin sheath. Very often, the fibers of the neurons of the autonomic nervous system are included in the composition of the nerves of the somatic nervous system, forming mixed nerves.

The axons of the neurons of the central part of the sympathetic division of the ANS are first included in the roots of the spinal cord, and then, as a branch, go to the prevertebral nodes of the peripheral division, located in chains on both sides of the spinal cord. These are the so-called pre-bundles of the fiber. In the nodes, excitation switches to other neurons and goes after the nodal fibers to the working organs. A number of nodes of the sympathetic division of the ANS form the left and right sympathetic trunks along the spinal cord. Each trunk has three cervical sympathetic nodes, 10-12 thoracic, 5 lumbar, 4 sacral and 1 coccygeal. In the coccygeal region, both trunks are connected to each other. Paired cervical nodes are divided into upper (largest), middle and lower. From each of these nodes, cardiac branches branch off, reaching the cardiac plexus. From the cervical nodes there are also branches to the blood vessels of the head, neck, chest and upper limbs, forming around them the choroid plexuses. Along the vessels, the sympathetic nerves reach the organs (the salivary glands, pharynx, larynx, and pupils of the eyes). The lower cervical node is often combined with the first thoracic node, resulting in a large cervicothoracic node. The cervical sympathetic nodes are connected to the cervical spinal nerves, which form the cervical and brachial plexus.

Two nerves depart from the nodes of the thoracic region: a large gastrointestinal (from 6-9 nodes) and a small gastrointestinal (from 10-11 nodes). Both nerves pass through the diaphragm into the abdominal cavity and end in the abdominal (solar) plexus, from which numerous nerves depart to the abdominal organs. The right vagus nerve connects to the abdominal plexus. Branches also depart from the thoracic nodes to the organs of the posterior mediastinum, aortic, cardiac and pulmonary plexuses.

From the sacral section of the sympathetic trunk, which consists of 4 pairs of nodes, fibers depart to the crisis and coccygeal spinal nerves. In the pelvic area is the hypogastric plexus of the sympathetic trunk, from which the nerve fibers depart to the organs of the small pelvis *

The parasympathetic part of the autonomic nervous system is made up of neurons. located in the nuclei of the oculomotor, facial, glossopharyngeal and vagus nerves of the brain, as well as from nerve cells located in the II-IV sacral segments of the spinal cord. In the peripheral part of the parasympathetic division of the autonomic nervous system, the nerve ganglions are not very clearly defined, and therefore the innervation is mainly carried out due to the long processes of the central neurons. The schemes of parasympathetic innervation are mostly parallel to the same schemes from the sympathetic department, but there are some peculiarities. For example, parasympathetic innervation of the heart is carried out by a branch of the vagus nerve through the sinoatrial node (pacemaker) of the conduction system of the heart, and sympathetic innervation is carried out by many nerves coming from the thoracic nodes of the sympathetic division of the autonomic nervous system and go directly to the muscles of rage and ventricles of the heart.

The most important parasympathetic nerves are the right and left vagus nerves, numerous fibers of which innervate the organs of the neck, chest, and abdomen. In many cases, branches of the vagus nerves form plexuses with sympathetic nerves (cardiac, pulmonary, abdominal, and other plexuses). As part of the third pair of cranial nerves (oculomotor), there are parasympathetic fibers that go to the smooth muscles of the eyeball and, when excited, cause pupil constriction, while excitation of sympathetic fibers dilates the pupil. As part of the VII pair of cranial nerves (facial), parasympathetic fibers innervate the salivary glands (reduce saliva secretion). The fibers of the sacral part of the parasympathetic nervous system take part in the formation of the hypogastric plexus, from which branches go to the pelvic organs, which regulate the processes of urination, defecation, sexual administration, etc.

The nervous system is the leading physiological system of the body.

Neuropsychic development (NPD) is an improvement, a qualitative change in the intellectual and motor skills of the child. At the time of birth, the nervous system of children has this characteristic:

By the time of birth, a healthy full-term newborn has a well-developed spinal cord, medulla oblongata, trunk, and hypothalamus. Life support centers are connected with these formations. They provide vital activity, survival of the newborn, processes of adaptation to the environment.

At birth, the brain is the most developed organ. In a newborn, the mass of the brain is 1/8-1/9 of the body weight, by the end of the first year of life it doubles and is equal to 1/11 and 1/12 of the body weight, at 5 years it is 1/13-1/14, in 18-20 years - 1/40 of body weight. Large furrows and convolutions are very well expressed, but have a shallow depth. There are few small furrows, they appear only in the first years of life. The size of the frontal lobe is relatively smaller, and the occipital lobe is larger than in an adult. The lateral ventricles are relatively large and distended. The length of the spinal cord increases somewhat more slowly than the growth of the spine, so the lower end of the spinal cord moves upward with age. The cervical and dorsal thickenings begin to contour after 3 years of age.

The brain tissue of a child is characterized by significant vascularization, especially of the gray matter. At the same time, the outflow of blood from the brain tissue is weak, so toxic substances accumulate in it more often. Brain tissue is richer in proteins. With age, the amount of protein decreases from 46% to 27%. By birth, the number of mature neurocytes, which will then become part of the cerebral cortex, is 25% of the total number of cells. At the same time, there is a histological immaturity of nerve cells for the birth of a child: they are oval in shape, with one axon, there is granularity in the nuclei, there are no dendrites.

By the time of birth, the cerebral cortex is relatively immature, the subcortical motor centers are differentiated to varying degrees (with a sufficiently mature thalamo-pallidar system, the striatal nucleus is poorly developed), myelination of the pyramidal tracts is not completed. The cerebellum is poorly developed, characterized by small thickness, small hemispheres and superficial grooves.

Underdevelopment of the cortex and the prevailing influence of the subcortex affects the behavior of the child. Underdevelopment of the cortex, striatal nucleus, pyramidal tracts makes voluntary movements, auditory, visual concentration impossible. The dominant influence of the thalamo-pallidar system explains the nature of the movements of the newborn. In a newborn, involuntary slow movements are of a mass generalized nature with general muscle rigidity, which is manifested by physiological hypertension of the limb flexors. The movements of the newborn are limited, chaotic, erratic, athetosis-like. Tremor and physiological muscle hypertonicity gradually subside after the first month of life.

The prevailing activity of the subcortical centers with a weak influence of the cortex is manifested by a complex of congenital unconditioned reflexes (CBR) of the newborn, which are based on three: food, defensive, and orienting. These reflexes of oral and spinal automatism reflect the maturity of the nervous system of the newborn child.

The formation of conditioned reflexes occurs after birth and is associated with the food dominant.

The development of the nervous system continues after birth until puberty. The most intensive growth and development of the brain are observed in the first two years of life.
In the first half of the year, the differentiation of the striatal nucleus, pyramidal tracts ends. In this regard, muscle rigidity disappears, spontaneous movements are replaced by arbitrary ones. The cerebellum grows intensively and develops in the second half of the year, its development ends by the age of two. With the development of the cerebellum, coordination of movements is formed.

The first criterion for a child's NPR is the development of voluntary coordinated movements.

Levels of organization of movements according to N.A. Bernstein.

Spinal level - at the 7th week of intrauterine development, the formation of reflex arcs begins at the level of 1 segment of the spinal cord. It is manifested by muscle contraction in response to skin irritation.

Rubrospinal level - the red nucleus is included in the reflex arcs, due to which the regulation of muscle tone and trunk motility is ensured.

Talamopallidar level - from the second half of pregnancy, a number of subcortical structures of the motor analyzer are formed, integrating the activity of the extrapyramidal system. This level characterizes the motor arsenal of the child during the first 3-5 months of life. It includes rudimentary reflexes, emerging postural reflexes and chaotic movements of a newborn child.

The pyramidal-striatal level is determined by the inclusion in the regulation of the striatum with its various connections, including those with the cerebral cortex. Movements of this level are the main large voluntary movements, which are formed at 1–2 years of age.

Cortical, parieto-premotor level - the development of fine movements from 10-11 months, the improvement of motor skills throughout a person's life.

The growth of the cortex is carried out mainly due to the development of the frontal, parietal, temporal regions. Proliferation of neurons lasts up to a year. The most intensive development of neurons is observed at 2-3 months. This determines the psycho-emotional, sensory development of the child (smile, laughter, crying with tears, a complex of revival, cooing, recognition of one's own and others).

The second criterion of CPD is psycho-emotional and sensory development.

Different areas and fields of the cortex complete development at different times. The centers of movement, hearing, vision mature by 4-7 years. The frontal and parietal regions finally mature by the age of 12. Completion of the myelination of the pathways is achieved only by 3-5 years of postnatal development. The incompleteness of the process of myelination of nerve fibers determines the relatively low rate of conduction of excitation through them. The final maturation of conductivity is achieved at 10-12 years.

Development of the sensory sphere. Pain sensitivity - pain sensitivity receptors appear at 3 months of intrauterine life, however, the pain threshold of sensitivity in newborns is much higher than in adults and older children. The child's reactions to a painful stimulus are at first of a general generalized nature, and only after a few months do local reactions occur.

Tactile sensitivity - occurs at 5-6 weeks of intrauterine development exclusively in the perioral region and by 11-12 weeks it spreads to the entire surface of the skin of the fetus.

The thermoreception of a newborn child is morphologically and functionally mature. There are almost 10 times more cold receptors than thermal ones. The receptors are unevenly located. The sensitivity of the child to cooling is significantly higher than to overheating.

The eyes of a newborn child are relatively large, their ratio to body weight in a newborn is 3.5 times greater than in an adult. As the eye grows, refraction changes. In the first days after birth, the child opens his eyes for a short time, but by the time of birth, the system of synchronous opening of both eyes has not been formed. There is no reflex closing of the eyelids when any object approaches the eye. The asymmetry of eye movement disappears in the third week of a child's life.

In the first hours and days of life, children are characterized by hypermetropia (farsightedness), over the years its degree decreases. Also, a newborn child is characterized by moderate photophobia, physiological nystagmus. The pupillary reaction in a newborn is observed both direct and friendly, that is, when one eye is illuminated, the pupils of both eyes narrow. From 2 weeks, the secretion of the lacrimal glands appears, and from 12 weeks, the lacrimal apparatus is involved in the emotional reaction. At 2 weeks, transient gaze fixation occurs, usually monocular, it gradually develops, and at 3 months the child steadily binocularly fixes stationary objects with a glance and traces moving ones. By 6 months, visual acuity increases, the child sees well not only large, but also small objects.

At the eighth week of postnatal development, a blinking reaction appears to the approach of an object and to sound stimulation, which indicates the formation of protective conditioned reflexes. The formation of peripheral fields of vision is completed only by the 5th month of life. From 6 to 9 months, the ability of stereoscopic perception of space is established.

When a child is born, he perceives the surrounding objects as a lot of color spots, and sounds as noise. It takes the first two years of his life to learn to recognize patterns, or to link sounds into something meaningful. The infant's reaction to bright light and sound is defensive. In order for the baby to learn to distinguish the face of the mother (first of all) and then other people close to him from the foggy spots reflected in his eyes, conditional connections must be developed in the occipital cortex of his brain, and then stereotypes, which are complex systems such connections. So, for example, a child's perception of space is made up of the friendly work of many analyzers, primarily visual, auditory, and skin. Moreover, the connections in the cerebral cortex responsible for the complex structures that provide an idea of ​​the presence of the child himself in a confined space are formed rather late. Therefore, a child of the first years of life, being in a confined space, does not fix his gaze on individual objects and often simply does not notice them.

The presented facts are largely due to the relatively late development of the macular region of the eye in a child. So the development of the macula is largely completed 16-18 weeks after the birth of the child. A differentiated approach to the perception of color in a child begins only at 5-6 months of age. Only by the age of 2-3 years can children correctly assess the color of an object. But by this time, the morphological "maturation" of the retina does not end. The expansion of all its layers continues up to 10 - 12 years, and therefore, only by this age is the color perception finally formed.

The formation of the auditory system begins in the prenatal period at 4 weeks. Already by the 7th week, the first coil of the cochlea is formed. At 9-10 weeks of fetal development, the cochlea has 2.5 turns, i.e. its structure approaches that of an adult. The snail reaches the form characteristic of an adult at the 5th month of fetal development.

The ability to respond to sound appears in the fetus at prenatal age. A newborn child hears, but is able to differentiate the sound strength of only about 12 decibels (distinguishes sounds by one octave in height), by 7 months he begins to distinguish sounds that differ by only 0.5 tones.

At the age of 1 to 2 years, the auditory field of the cortex (field 41 according to Brodmann) of the brain is formed. However, its final "maturation" occurs by about 7 years. Therefore, even at this age, the child's auditory system is not functionally mature. Sensitivity to sound reaches a maximum only by adolescence.

With the development of the cortex, most of the innate unconditioned reflexes gradually fade away during the first year. Conditioned reflexes are formed under the influence of external stimuli.

On the basis of conditioned reflexes, speech develops - the third criterion of CPD. Up to 6 months, the preparatory stage of speech passes - the child communicates with others only with the help of emotions: a smile, a complex of animation when addressing him, cooing, differentiation of intonation. Cooing - the pronunciation of the first sounds (a, gu-u, uh-uh, etc.).

Direct speech develops after 6 months: the ability to understand the word (sensory speech) and speak (motor speech). Babble - the pronunciation of individual syllables (ba-ba-ba, ma-ma-ma, etc.).

By the end of 1 year of life, the child's vocabulary already has 8-12 words, the meaning of which he understands (give, mom, dad, etc.). Among them there are onomatopoeias (am-am - to eat, av-av - a dog, tick - so - a clock, etc.). At the age of 2, the vocabulary reaches 300, short sentences appear.

Due to the fact that sensory systems are actively functioning in a newborn child, he develops the simplest type of memory - a short-term sensory imprint. This type of memory is based on the property of the sensory system to preserve and lengthen the action of the stimulus (there is no object, but the person sees it, the sound has stopped, but we hear it). In an adult, this reaction lasts about 500 microseconds, in a child, due to insufficient myelination of nerve fibers and a lower speed of nerve impulse conduction, it takes a little longer.

In a newborn child, the functions of short-term and long-term memory are primarily associated with the activity of the auditory and sensory systems, and in later periods - with the locomotor function. From the second month of a child's life, other parts of the cortex are also included in the formation of memory. At the same time, the rate of formation of a temporary connection is individual and already at this age depends on the type of higher nervous activity.

In a newborn, due to the immaturity of the cerebral cortex, attention is carried out due to simple forms of orienting reactions (to sound, light). More complex (integrated) mechanisms of the attention process appear at the age of 3-4 months. During this period, the occipital -rhythm periodically begins to form on the electroencephalogram, but it is unstable in the projection zones of the cortex, which indicates the absence of conscious reactions in the child in the field of sensory modalities.

The child's NPD depends on environmental factors, upbringing, which can either stimulate the development of certain skills or slow them down.

Due to the peculiarities of the nervous system, the child cannot quickly switch from one type of activity to another, and quickly gets tired. A child is distinguished from an adult by high emotionality and imitative activity.

Evaluation of CPD is carried out in decreed (epicrisis) terms according to age-appropriate criteria

Unconditioned reflexes of the newborn

The main form of activity of the nervous system is reflex. All reflexes are usually divided into unconditional and conditional.

Unconditioned reflexes- these are congenital, genetically programmed reactions of the body, characteristic of all animals and humans.

Conditioned reflexes- individual, acquired reactions of higher animals and humans, developed as a result of learning (experience).

For a newborn child, unconditioned reflexes are characteristic: food, defensive and indicative.

Conditioned reflexes are formed after birth.

The main unconditioned reflexes of a newborn and infant are divided into two groups: segmental motor automatisms, provided by segments of the brain stem (oral automatisms) and the spinal cord (spinal automatisms).

VBR of a newborn baby

Reflexes in the position of the child on the back: Kussmaul-Genzler search reflex, sucking reflex, Babkin palmar-mouth reflex, grasping or hugging reflex (Moro), asymmetric neck-tonic reflex, grasping reflex (Robinson), plantar reflex, Babinsky reflex.

Reflexes in an upright position: the child is taken from the back by the armpits, the doctor's thumbs support the head. Support or straightening reflex; automatic gait or stepping reflex.

Reflexes in the position on the stomach: protective reflex, labyrinth tonic reflex, crawling reflex (Bauer), Galant reflex, Perez.

Oral segmental automatisms

Sucking reflex

With the introduction of the index finger into the mouth by 3-4 cm, the child makes rhythmic sucking movements. The reflex is absent in pareselic nerves, severe mental retardation, in severe somatic conditions.

Search reflex (Kussmaul reflex)

proboscis reflex

A quick tap of the finger on the lips causes the lips to stretch forward. This reflex persists up to 2-3 months.

Palmar-mouth reflex (Babkin reflex)

When pressing with the thumb on the area of ​​​​the palm of the newborn (both palms at the same time), closer to the tenar, the mouth opens and the head bends. The reflex is pronounced in newborns in the norm. Lethargy of the reflex, rapid exhaustion or absence indicate damage to the central nervous system. The reflex may be absent on the affected side with peripheral paresis. After 2 months it fades by 3 months. disappears

Spinal motor automatisms

Protective reflex of the newborn

If the newborn is placed on the stomach, then a reflex turn of the head to the side occurs.

Support reflex and automatic gait in newborns

The newborn does not have the readiness to stand, but he is capable of a support reaction. If you hold the child vertically in weight, then he bends his legs in all joints. The child placed on a support straightens the body and stands on half-bent legs on a full foot. The positive support reaction of the lower extremities is a preparation for stepping movements. If the newborn is slightly tilted forward, then he makes stepping movements (automatic gait of newborns). Sometimes, when walking, newborns cross their legs at the level of the lower third of the legs and feet. This is caused by a stronger contraction of the adductors, which is physiological for this age and outwardly resembles the gait in cerebral palsy.

Crawling reflex (Bauer) and spontaneous crawling

The newborn is placed on the stomach (head in the midline). In this position, he makes crawling movements - spontaneous crawling. If you put your palm on the soles, then the child reflexively pushes away from it with his feet and crawling intensifies. In the position on the side and on the back, these movements do not occur. Coordination of movements of arms and legs is not observed. Crawling movements in newborns become pronounced on the 3rd - 4th day of life. The reflex is physiological up to 4 months of life, then it fades away. Independent crawling is a precursor to future locomotor acts. The reflex is depressed or absent in children born in asphyxia, as well as in intracranial hemorrhages, spinal cord injuries. Pay attention to the asymmetry of the reflex. In diseases of the central nervous system, crawling movements persist for up to 6-12 months, like other unconditioned reflexes.

grasp reflex

Appears in a newborn with pressure on his palms. Sometimes a newborn wraps his fingers so tightly that he can be lifted up ( Robinson reflex). This reflex is phylogenetically ancient. Newborn monkeys are held on the mother's hairline by gripping the brushes. With paresis of the hand, the reflex is weakened or absent, in inhibited children the reaction is weakened, in excitable children it is strengthened. The reflex is physiological up to 3-4 months, later, on the basis of the grasping reflex, an arbitrary grasp of the object is gradually formed. The presence of a reflex after 4-5 months indicates damage to the nervous system.

The same grasping reflex can also be evoked from the lower extremities. Pressing the ball of the foot with the thumb causes plantar flexion of the toes. If you apply a dashed irritation to the sole of the foot with your finger, then there is a dorsiflexion of the foot and a fan-shaped divergence of the fingers (physiological Babinski reflex).

Reflex Galant

When the skin of the back is irritated paravertebral along the spine, the newborn bends the back, an arc is formed that is open towards the stimulus. The leg on the respective side often extends at the hip and knee joints. This reflex is well evoked from the 5th - 6th day of life. In children with damage to the nervous system, it may be weakened or completely absent during the 1st month of life. When the spinal cord is damaged, the reflex is absent for a long time. The reflex is physiological until the 3rd - 4th month of life. With damage to the nervous system, this reaction can be observed in the second half of the year and later.

Perez reflex

If you run your fingers, slightly pressing, along the spinous processes of the spine from the coccyx to the neck, the child screams, raises his head, unbends the torso, bends the upper and lower limbs. This reflex causes a negative emotional reaction in the newborn. The reflex is physiological until the 3rd - 4th month of life. Inhibition of the reflex during the neonatal period and a delay in its reverse development is observed in children with damage to the central nervous system.

Moro reflex

It is caused by various and not different methods: a blow to the surface on which the child lies, at a distance of 15 cm from his head, raising the extended legs and pelvis above the bed, sudden passive extension of the lower extremities. The newborn moves his arms to the sides and opens his fists - the 1st phase of the Moro reflex. After a few seconds, the hands return to their original position - phase II of the Moro reflex. The reflex is expressed immediately after birth, it can be observed during the manipulations of the obstetrician. In children with intracranial trauma, the reflex may be absent in the first days of life. With hemiparesis, as well as with obstetric paresis of the hand, an asymmetry of the Moro reflex is observed.

Assessment of the degree of maturity of the nervous system of a newborn child

The criteria for assessing CPD are:

motor skills (this is a purposeful, manipulative activity of the child.);

statics (this is the fixation and holding of certain parts of the body in the required position.);

conditioned reflex activity (1 signal system);

speech (2 signal system);

higher nervous activity.

The neuropsychic development of a child depends on biological and social factors, the conditions of the mode of life, upbringing and care, as well as the state of health of the child.

The delay in the pace of mental development may be due to the unfavorable course of the prenatal period, because. at the same time, brain damage associated with hypoxia is often noted, and the rate of maturation of individual complex structures is disrupted. The immaturity of certain parts of the brain in the postnatal period often leads to various disorders of neuropsychic development. Unfavorable biological factors include toxicosis of pregnancy, the threat of miscarriage, asphyxia, maternal illness during pregnancy, prematurity, etc. Bad habits of parents (smoking, alcohol abuse) matter.

Unfavorable family climate, incomplete family, low educational level of parents stand out among the unfavorable social factors.

The rate of development of the child is reduced due to frequent acute illnesses. Proper upbringing plays an important role in the development of a young child. Frequent systematic communication with him is necessary, the gradual formation of various skills and abilities in the child, the development of speech.

The child develops heterochronously, i.e. unevenly. When evaluating the CPD, the doctor looks at the epicrisis period for those lines (indicators) that by this moment are developing most intensively, i.e. leading lines.

Leading lines of CPD in a child at various epicrisis periods

FOR - visual analyzer

SA - auditory analyzer

E, SP - emotions and social behavior

DO - general movements

DP - movements with objects

PR - understood speech

AR - active speech

H - skills

DR - hand movements

SR - sensory development

ART - visual activity

G - grammar

B - questions

NDP for children of the first year

There are 4 main groups of NPR:

I group includes 4 subgroups:

- normal development, when all indicators correspond to age;

- accelerated, when there is an advance of 1 es;

- high, when there is an advance of 2 es;

- upper harmonic, when some of the indicators are ahead by 1 es, and some by 2 or more.

II group - these are children who have a delay in the NPR by 1 e.s. It includes 2 subgroups with a uniform delay of 1 es. along one or more lines:

a) 1–2 lines - 1 degree

b) 3-4 lines - 2nd degree

inharmonious - with uneven development, when some of the indicators have a delay of 1 es, and some are ahead.

III group - these are children with a 2 e.s. It includes 2 subgroups with a uniform delay of 2 es. along one or more lines:

a) 1–2 lines - 1 degree

b) 3-4 lines - 2nd degree

c) 5 or more lines - 3 degree

lower harmonic - with uneven development, when some of the indicators lag behind (or ahead of) by 2 es, and some by 1 es.

IV group- these are children with a delay in the NPR by 3 e.s. It includes 2 subgroups with a uniform delay of 3 es. along one or more lines:

a) 1–2 lines - 1 degree

b) 3-4 lines - 2nd degree

c) 5 or more lines - 3 degree

lower harmonic - with uneven development, when some of the indicators are behind (or ahead of) by 3 es, and some by 1 or 2 es.

A delay of 3 or more epicrisis periods indicates the presence of a borderline condition or pathology. These children need advice and treatment from specialist doctors.