Development of the child's nervous system. Infant nervous system development
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The nervous system regulates the physiological functions of the body in accordance with changing external conditions and maintains a certain constancy of its internal environment at a level that ensures vital activity. And understanding the principles of its functioning is based on knowledge of the age-related development of the structures and functions of the brain. In the life of a child, the constant complication of the forms of nervous activity is aimed at the formation of an increasingly complex adaptive ability of the organism, corresponding to the conditions of the surrounding social and natural environment.
Thus, the adaptive capabilities of a growing human organism are determined by the level of age organization of its nervous system. The simpler it is, the more primitive its answers, which boil down to simple defensive reactions. But with the complication of the structure of the nervous system, when the analysis of environmental influences becomes more differentiated, the child's behavior also becomes more complicated, and the level of his adaptation increases.
How does the nervous system mature?
In the mother's womb, the embryo receives everything that it needs, is protected from any adversity. And during the period of maturation of the embryo, 25,000 nerve cells are born in its brain every minute (the mechanism of this amazing process is unclear, although it is clear that a genetic program is being implemented). Cells divide and form organs while the growing fetus floats in the amniotic fluid. And through the maternal placenta, he continuously, without any effort, receives food, oxygen, and toxins are removed from his body in the same way.
The nervous system of the fetus begins to develop from the outer germ layer, from which the neural plate, groove, and then the neural tube are first formed. In the third week, three primary cerebral vesicles form from it, two of which (anterior and posterior) divide again, resulting in the formation of five cerebral vesicles. From each cerebral bladder, various parts of the brain subsequently develop.
Further separation occurs during fetal development. The main parts of the central nervous system are formed: hemispheres, subcortical nuclei, trunk, cerebellum and spinal cord: the main furrows of the cerebral cortex are differentiated; the predominance of the higher parts of the nervous system over the lower ones becomes noticeable.
As the fetus develops, many of its organs and systems conduct a kind of “dress rehearsal” even before their functions become really necessary. So, for example, contractions of the heart muscle occur when there is still no blood and the need to pump it; peristalsis of the stomach and intestines appears, gastric juice is secreted, although there is still no food as such; eyes open and close in complete darkness; arms and legs move, which gives the mother indescribable joy from the sensation of life emerging in her; a few weeks before birth, the fetus even begins to breathe in the absence of air to breathe.
By the end of the prenatal period, the overall structure of the central nervous system is almost fully developed, but the adult brain is much more complex than the brain of a newborn.
Development of the human brain: A, B - at the stage of cerebral vesicles (1 - terminal; 2 intermediate; 3 - middle, 4 - isthmus; 5 - posterior; 6 - oblong); B - the brain of the embryo (4.5 months); G - newborn; D - adult
The brain of a newborn is approximately 1/8 of the body weight and weighs an average of about 400 grams (boys have a little more). By 9 months, the mass of the brain doubles, by the age of 3 it triples, and at the age of 5 the brain is 1/13 - 1/14 of the body weight, by the age of 20 - 1/40. The most pronounced topographic changes in various parts of the growing brain occur in the first 5-6 years of life and end only by the age of 15-16.
Previously, it was believed that by the time of birth, the child's nervous system has a complete set of neurons (nerve cells) and develops only by complicating the connections between them. It is now known that in some formations of the temporal lobe of the hemispheres and cerebellum, up to 80-90% of neurons are formed only after birth with an intensity that depends on the influx of sensory information (from the sense organs) from the external environment.
The activity of metabolic processes is very high in the brain. Up to 20% of all blood sent by the heart to the arteries of the systemic circulation flows through the brain, which consumes a fifth of the oxygen absorbed by the body. The high speed of blood flow in the cerebral vessels and its saturation with oxygen are necessary primarily for the vital activity of the cells of the nervous system. Unlike the cells of other tissues, the nerve cell does not contain any energy reserves: the oxygen and nutrition supplied with the blood are consumed almost instantly. And any delay in their delivery threatens with danger, when the oxygen supply is stopped for only 7-8 minutes, the nerve cells die. On average, an influx of 50-60 ml of blood is needed per 100 g of medulla in one minute.
The proportions of the bones of the skull of a newborn and an adult
Corresponding to an increase in the mass of the brain, significant changes occur in the proportions of the bones of the skull in the same way as the proportion of body parts changes in the process of growth. The skull of newborns is not completely formed, and its sutures and fontanelles may still be open. In most cases, by birth, a diamond-shaped opening at the junction of the frontal and parietal bones (large fontanelle) remains open, which usually closes only by the age of one, the child’s skull is actively growing, while the head is increasing in circumference.
This happens most intensively in the first three months of life: the head increases in circumference by 5-6 cm. Later, the pace slows down, and by the year it increases by a total of 10-12 cm. Usually in a newborn (weighing 3-3.5 kg ) head circumference is 35-36 cm, reaching 46-47 cm by one year. Further, head growth slows down even more (does not exceed 0.5 cm per year). Excessive growth of the head, as well as its noticeable lag, indicates the possibility of developing pathological phenomena (in particular, hydrocephalus or microcephaly).
With age, the spinal cord also undergoes changes, the length of which in a newborn is on average about 14 cm and doubles by 10 years. Unlike the brain, the spinal cord of a newborn has a functionally more perfect, complete morphological structure, almost completely occupying the space of the spinal canal. With the development of the vertebrae, the growth of the spinal cord slows down.
Thus, even with normal intrauterine development, normal childbirth, a child is born, albeit with a structurally formed, but immature nervous system.
What do reflexes give the body?
The activity of the nervous system is basically reflex. Under the reflex understand the response to the impact of an irritant from the external or internal environment of the body. To implement it, a receptor with a sensitive neuron that perceives irritation is needed. The response of the nervous system comes ultimately to the motor neuron, which reacts reflexively, prompting or “slowing down” the organ innervated by it, the muscle, to activity. Such a simple chain is called a reflex arc, and only if it is preserved can a reflex be realized.
An example is the reaction of a newborn to a slight dashed irritation of the corner of the mouth, in response to which the child turns his head towards the source of irritation and opens his mouth. The arc of this reflex, of course, is more complex than, for example, the knee reflex, but the essence is the same: in response to irritation of the reflexogenic zone, the child develops search head movements and readiness to suck.
There are simple reflexes and complex ones. As can be seen from the example, the search and sucking reflexes are complex, and the knee reflex is simple. At the same time, congenital (unconditioned) reflexes, especially during the neonatal period, are in the nature of automatisms, mainly in the form of food, protective and postural tonic reactions. Such reflexes in humans are provided on different "floors" of the nervous system, therefore, spinal, stem, cerebellar, subcortical and cortical reflexes are distinguished. In a newborn child, taking into account the unequal degree of maturity of the parts of the nervous system, reflexes of spinal and stem automatisms predominate.
In the course of individual development and the accumulation of new skills, conditioned reflexes are formed due to the development of new temporary connections with the obligatory participation of the higher parts of the nervous system. The large hemispheres of the brain play a special role in the formation of conditioned reflexes, which are formed on the basis of innate connections in the nervous system. Therefore, unconditioned reflexes exist not only on their own, but as a constant component they enter into all conditioned reflexes and the most complex acts of life.
If you look closely at the newborn, then the chaotic nature of the movements of his arms, legs, and head attracts attention. The perception of irritation, for example, on the leg, cold or pain, does not give an isolated withdrawal of the leg, but a general (generalized) motor reaction of excitation. The maturation of structure is always expressed in the improvement of function. This is most noticeable in the formation of movements.
It is noteworthy that the first movements in a fetus of three weeks of age (length 4 mm) are associated with heart contractions. A motor reaction in response to skin irritation appears from the second month of intrauterine life, when the nerve elements of the spinal cord are formed, which are necessary for reflex activity. At the age of three and a half months, the fetus can show most of the physiological reflexes observed in newborns, with the exception of screaming, grasping reflex and breathing. With the growth of the fetus and an increase in its mass, the volume of spontaneous movements also becomes large, which can be easily verified by causing the fetus to move by careful tapping on the mother's abdomen.
In the development of a child's motor activity, two interrelated patterns can be traced: the complication of functions and the extinction of a number of simple, unconditioned, innate reflexes, which, of course, do not disappear, but are used in new, more complex movements. The delay or late extinction of such reflexes indicates a lag in motor development.
The motor activity of a newborn and a child in the first months of life is characterized by automatisms (sets of automatic movements, unconditioned reflexes). With age, automatisms are replaced by more conscious movements or skills.
Why do we need motor automatisms?
The main reflexes of motor automatism are food, protective spinal, tonic position reflexes.
Food motor automatisms provide the child with the ability to suck and search for a source of food for him. The preservation of these reflexes in the newborn indicates the normal function of the nervous system. Their manifestation is as follows.
When pressing on the palm, the child opens his mouth, turns or bends his head. If you apply a light blow with your fingertips or a wooden stick on the lips, in response they are drawn into a tube (therefore, the reflex is called proboscis). When stroking in the corner of the mouth, the child has a search reflex: he turns his head in the same direction and opens his mouth. The sucking reflex is the main one in this group (characterized by sucking movements when a nipple, breast nipple, finger enters the mouth).
If the first three reflexes normally disappear by 3-4 months of life, then sucking - by one year. These reflexes are most actively expressed in a child before feeding, when he is hungry; after eating, they may fade somewhat, as a well-fed child calms down.
Spinal motor automatisms appear in a child from birth and persist for the first 3-4 months and then fade away.
The simplest of these reflexes is the defensive reflex: if the child is placed face down on his stomach, he will quickly turn his head to the side, facilitating his breathing through his nose and mouth. The essence of another reflex is that in the position on the stomach, the child makes crawling movements if a support (for example, a palm) is placed on the soles of the feet. Therefore, the inattentive attitude of parents to this automatism can end sadly, since a child left unattended by his mother on the table can, resting his feet on something, push himself to the floor.
Let's check the reflexes: 1 - palmar-mouth; 2 - proboscis; 3 - search; 4 - sucking
The tenderness of parents causes the ability of a tiny man to lean on his legs and even walk. These are support reflexes and automatic walking. To check them, you should lift the child, holding him under the arms, and put him on a support. Feeling the surface with the soles of the feet, the child will straighten the legs and rest against the table. If he is slightly tilted forward, he will take a reflex step with one and then the other foot.
From birth, a child has a well-defined grasping reflex: the ability to hold the fingers of an adult well placed in his palm. The force with which he grasps is sufficient to hold himself, and he can be lifted up. The grasping reflex in newborn monkeys allows the cubs to keep themselves on the mother's body when she moves.
Sometimes parental anxiety is caused by scattering of the child's arms during various manipulations with him. Such reactions are usually associated with the manifestation of an unconditioned grasping reflex. It can be caused by any stimulus of sufficient strength: by patting on the surface on which the child lies, by raising the extended legs above the table, or by quickly extending the legs. In response to this, the baby spreads the arms to the sides and opens the fists, and then returns them to their original position again. With increased excitability of the child, the reflex increases, being caused by stimuli such as sound, light, a simple touch or swaddling. The reflex fades after 4-5 months.
Tonic position reflexes. In newborns and children of the first months of life, reflex motor automatisms associated with a change in the position of the head appear.
For example, turning it to the side leads to a redistribution of muscle tone in the limbs so that the arm and leg, to which the face is turned, unbend, and the opposite ones bend. In this case, the movements in the arms and legs are asymmetrical. When the head is bent to the chest, the tone in the arms and legs increases symmetrically and leads them to flexion. If the child's head is straightened, then the arms and legs will also straighten due to an increase in tone in the extensors.
With age, at the 2nd month, the child develops the ability to hold his head, and after 5-6 months he can turn from his back to his stomach and vice versa, and also hold the “swallow” position if he is supported (under the stomach) by hand.
Let's check the reflexes: 1 - protective; 2 - crawling; 3 - support and automatic walking; 4 - grasping; 5 - hold; 6 - wraps
In the development of motor functions in a child, a descending type of formation of movement can be traced, that is, at the beginning of the movement of the head (in the form of its vertical setting), then the child forms the supporting function of the hands. When turning from back to stomach, the head first turns, then the shoulder girdle and then the torso and legs. Later, the child masters leg movements - support and walking.
Let's check the reflexes: 1 - asymmetric cervical tonic; 2 - symmetrical cervical tonic; 3 - holding the head and legs in the "swallow" position
When, at the age of 3-4 months, a child, who had previously been able to lean well on his legs and take steps with support, suddenly loses this ability, the anxiety of the parents makes them go to the doctor. Fears are often unfounded: at this age, the reflex reactions of support and the stepping reflex disappear and are replaced by the development of vertical standing and walking skills (by 4-5 months of life). This is how the “program” of mastering movements during the first year and a half of a child’s life looks like. Motor development provides the ability to hold the head by 1-1.5 months, purposeful hand movements - by 3-4 months. At about 5-6 months, the child grasps objects well in his hand and holds them, he can sit and he becomes ready to stand. At 9-10 months, he will already begin to stand with support, and at 11-12 months he can move with outside help and on his own. Uncertain at first, the gait becomes more and more stable, and by 15-16 months the child rarely falls while walking.
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 innate, 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, innate sexual 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 mouth 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 painful irritation of the finger.
3. Orienting reflexes. Every 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 of 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 school-age children, 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 durable 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 the child to learn widely. 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.
The nervous system integrates and regulates the vital activity of the whole organism. Its highest department - the brain is an organ of consciousness, thinking.
Mental activity takes place in the cerebral cortex. In the cerebral cortex, new neural connections acquired during life are established, new reflex arcs are closed, and conditioned reflexes are formed (the arcs of congenital, i.e., unconditioned reflexes, take place in the lower parts of the brain and in the spinal cord). In the cerebral cortex, concepts are formed and thinking occurs. Here is the activity of consciousness. The human psyche depends on the degree of development, condition and characteristics of the nervous system and primarily the cerebral cortex. The development of speech and labor activity of a person is closely connected with the complication and improvement of the activity of the cerebral cortex, and at the same time, mental activity.
The subcortical centers closest to the cerebral cortex and the centers of the brain stem carry out complex unconditioned reflex activity, the highest forms of which are instincts. All this activity is under the constant regulatory influences of the cerebral cortex.
Nervous tissue has the property of not only excitation, but also inhibition. Despite their opposites, they always accompany one another, constantly change and pass one into another, representing different phases of a single nervous process. Excitation and inhibition are in constant interaction and are the basis of all activity of the central nervous system. The occurrence of excitation and inhibition depends on the impact on the central nervous system and, above all, on the brain of the human environment and internal processes occurring in his body. Changes in the external environment or working conditions cause the emergence of new conditioned connections that are created on the basis of the unconditioned reflexes that a person has or old, strengthened previously acquired connections, and entail the inhibition of other conditioned connections that, in a new situation, have no data for their action. When a more or less significant excitation occurs in any part of the cerebral cortex, inhibition occurs in its other parts (negative induction). Excitation or inhibition, having arisen in one or another part of the cerebral cortex, is transmitted further, as if spreading in order to again concentrate in any one place (irradiation and concentration).
The processes of excitation and inhibition are of great importance in the matter of education and upbringing, since the understanding of these processes and the skillful use of them makes it possible to develop and improve new neural connections, new associations, skills, abilities, and knowledge. But the essence of education and training, of course, cannot be limited to the mere formation of conditioned reflexes, even if they are very subtle and complex. The human cerebral cortex has the properties of a versatile perception of the phenomena of the surrounding life, the formation of concepts, their consolidation in the mind (assimilation, memory, etc.) and complex mental functions (thinking). All these processes have the cortex of the cerebral hemispheres as their material substrate and are inextricably linked with all the functions of the nervous system.
In the knowledge of the laws of higher nervous activity (behavior) of animals and humans, the Russian physiological school, represented by its brilliant founders - I. M. Sechenov, N. E. Vvedensky, and especially I. P. Pavlov with their students, made a brilliant contribution. This made possible the materialistic study of psychology.
The development of the nervous system, and primarily the brain, in children and adolescents is of great interest, due to the fact that throughout childhood, adolescence and adolescence, the formation of the human psyche takes place. The formation and improvement of the psyche proceeds on the basis of the development of the cerebral cortex and with its direct participation. By the time of birth, the child's central and peripheral nervous system is far from being developed (especially the cerebral cortex and the subcortical nodes closest to it).
The weight of the brain of a newborn is relatively large, it is 1/9 of the weight of the entire body, while in an adult this ratio is only 1/40. The surface of the cerebral hemispheres in children in the first months of their life is relatively smooth. The main furrows, although outlined, are not deep, and furrows of the second and third categories have not yet formed. The convolutions are still poorly expressed. A newborn has as many nerve cells in the cerebral hemispheres as an adult, but they are still very primitive. Nerve cells in young children are simple spindle-shaped with very few nerve ramifications, and dendrites are just beginning to take shape.
The process of complicating the structure of nerve cells with their processes, that is, neurons, proceeds very slowly and does not end simultaneously with the completion of the development of other organs and systems of the body. This process continues until the age of 40 and even beyond. Nerve cells, unlike other cells of the body, are not able to multiply, regenerate, and their total number at the time of birth remains unchanged for the rest of life. But in the process of growth of the organism, as well as in subsequent years, nerve cells increase in size, gradually develop, neurites and dendrites lengthen, and the latter, in addition, form tree-like branches as they develop.
Most of the nerve fibers in young children are not yet covered with a white myelin sheath, as a result of which, when cut, the large hemispheres, as well as the cerebellum and medulla oblongata, do not sharply divide into gray and white matter, as occurs in subsequent years.
Functionally, of all parts of the brain in a newborn, the cerebral cortex is the least developed, as a result of which all life processes in young children are regulated mainly by subcortical centers. As the child's cerebral cortex develops, both perceptions and movements improve, which gradually become more differentiated and complex. At the same time, the cortical connections between perceptions and movements become more and more precise, and the cortical connections between perceptions and movements become more complicated, and the life experience acquired during development (knowledge, skills, motor skills, etc.) begins to show itself more and more.
The maturation of the cerebral cortex occurs most intensively in children during toddler age, that is, during the first 3 years of life. A 2-year-old child already has all the main features of the development of intracortical systems, and the overall picture of the structure of the brain differs relatively little from the brain of an adult. Its further development is expressed in the improvement of individual cortical fields and various layers of the cerebral cortex and an increase in the total number of myelin and intracortical fibers.
In the second half of the first year of life, the development of conditioned connections in children occurs from all perceiving organs (eyes, ears, skin, etc.) more and more intensively, but still more slowly than in subsequent years. With the development of the cerebral cortex at this age, the duration of periods of wakefulness increases, which favors the formation of new conditioned connections. In the same period, the foundation for future speech sounds is laid, which are associated with certain stimulations and are their external expression. All the formation of speech in children occurs according to the laws of the formation of conditioned reflex connections.
During the second year, simultaneously with the development of the cerebral cortex and the intensification of their activity, more and more new conditioned reflex systems and partly various forms of inhibition are formed in children. The cerebral cortex develops especially intensively in functional terms during the 3rd year of life. During this period, speech develops significantly in children, and by the end of this year, the child’s vocabulary reaches an average of 500.
In the subsequent years of preschool age (from 4 to 6 years old inclusive), children observe the consolidation and further development of the functions of the cerebral cortex. At this age, both analytical and synthetic activity of the cerebral cortex becomes much more complicated in children. Simultaneously, there is a differentiation of emotions. Due to the imitation and repetition inherent in children of this age, which contribute to the formation of new cortical connections, they quickly develop speech, which gradually becomes more complex and improves. By the end of this period, single abstract concepts appear in children.
At primary school age and during puberty, children continue to develop the brain, individual nerve cells are improved and new nerve pathways develop, and the entire nervous system develops functionally. At the same time, there is an increase in the growth of the frontal lobes. This entails an improvement in children's accuracy and coordination of movements. In the same period, regulatory control from the side of the cerebral cortex over instinctive and lower emotional reactions is noticeably revealed. In this regard, the systematic education of children's behavior, which diversifies the regulatory functions of the brain, is of particular importance.
During puberty, especially towards the end of it - in adolescence, an increase in brain mass is insignificant. At this time, there are mainly processes of complication of the internal structure of the brain. This internal development is characterized by the fact that the nerve cells of the cerebral cortex complete their formation, and a particularly vigorous structural development occurs, the final formation of convolutions and the development of associative fibers that connect individual areas of the cortex with each other. The number of associative fibers especially increases in boys and girls aged 16-18 years. All this creates a morphological basis for the processes of associative, logical, abstract and generalizing thinking.
The development and physiological activity of the brain during puberty is influenced by the profound changes that occur in the endocrine glands. Strengthening the activity of the thyroid gland, as well as the sex glands, greatly increases the excitability of the central nervous system and, first of all, the cerebral cortex. “Due to increased reactivity and the resulting instability, especially emotional processes, all adverse environmental conditions: mental trauma, heavy stress, and so on, easily lead to the development of cortical neuroses” (Krasnogorsky). This should be borne in mind by teachers conducting educational work among adolescents and young people.
During adolescence, by the age of 18-20, the functional organization of the brain is basically completed, and the most subtle and complex forms of its analytical and synthetic activity become possible. In subsequent mature years of life, the qualitative improvement of the brain and the further functional development of the cerebral cortex continue. However, the basis for the development and improvement of the functions of the cerebral cortex is laid in children in the preschool and school years.
The medulla oblongata in children is already fully developed and mature in functional terms by the time of birth. The cerebellum, on the contrary, is poorly developed in newborns, its furrows are shallow and the size of the hemispheres is small. From the first year of life, the cerebellum grows very rapidly. By the age of 3, the cerebellum in a child approaches the size of the cerebellum of an adult, and therefore the ability to maintain body balance and coordination of movements develops.
As for the spinal cord, it does not grow as fast as the brain. However, by the time of birth, the child has sufficiently developed pathways of the spinal cord. Myelination of intracranial and spinal nerves in children ends by 3 months, and peripheral - only by 3 years. The growth of myelin sheaths continues in subsequent years.
The development of the functions of the autonomic nervous system in children occurs simultaneously with the development of the central nervous system, although from the first year of life it has basically taken shape in terms of functionality.
As you know, the subcortical nodes are the highest centers that unite the autonomic nervous system and control its activity. When, for one reason or another, the controlling activity of the cerebral cortex is upset or weakened in children and adolescents, the activity of the subcortical nodes and, consequently, the autonomic nervous system becomes more pronounced.
As the researchers A. G. Ivanov-Smolensky, N. I. Krasnogorsky and others have shown, the higher nervous activity of children, with all the variety of individual characteristics, has some characteristic features. The cerebral cortex in children of preschool and primary school age is not functionally stable enough. The younger the child, the more pronounced is the predominance of excitation processes over the processes of internal active inhibition. Prolonged excitation of the cerebral cortex in children and adolescents can lead to overexcitation and to the development of phenomena of the so-called "outrageous" inhibition.
The processes of excitation and inhibition in children easily radiate, that is, they spread through the cerebral cortex, which disrupts the functioning of the brain, which requires a high concentration of these processes. Associated with this is the lesser stability of attention and the greater exhaustion of the nervous system in children and adolescents, especially in the case of improper organization of educational work, in which there is an excessively large load of mental work. If we take into account that children and adolescents in the process of learning have to significantly strain the activity of the central nervous system, then the need for a particularly attentive hygienic attitude to the nervous system of students becomes obvious.
brain blood circulation motor
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 it. 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, the 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.
CHAPTER 10. DEVELOPMENT OF THE NERVOUS SYSTEM IN NEWBORN AND CHILDREN OF EARLY AGE. RESEARCH METHOD. SYNDROMES OF DEFEATCHAPTER 10. DEVELOPMENT OF THE NERVOUS SYSTEM IN NEWBORN AND CHILDREN OF EARLY AGE. RESEARCH METHOD. SYNDROMES OF DEFEAT
In a newborn baby reflex acts are carried out at the level of the stem and subcortical parts of the brain. By the time of the birth of the child, the limbic system, the precentral region, especially field 4, which provides the early phases of motor reactions, the occipital lobe and field 17, are the most well-formed. The temporal lobe is less mature (especially the temporo-parietal-occipital region), as well as the lower parietal and frontal regions. However, field 41 of the temporal lobe (the projection field of the auditory analyzer) by the time of birth is more differentiated than field 22 (projection-associative).
10.1. Development of motor functions
Motor development in the first year of life is a clinical reflection of the most complex and currently insufficiently studied processes. These include:
The action of genetic factors - the composition of expressed genes that regulate the development, maturation and functioning of the nervous system, changing in spatio-temporal dependence; neurochemical composition of the CNS, including the formation and maturation of mediator systems (the first mediators are found in the spinal cord from 10 weeks of gestation);
myelination process;
Macro- and microstructural formation of the motor analyzer (including muscles) in early ontogenesis.
First spontaneous movements embryos appear on the 5-6th week of intrauterine development. During this period, motor activity is carried out without the participation of the cerebral cortex; segmentation of the spinal cord and differentiation of the musculoskeletal system occur. The formation of muscle tissue begins from the 4-6th week, when active proliferation occurs at the sites of muscle formation with the appearance of primary muscle fibers. The emerging muscle fiber is already capable of spontaneous rhythmic activity. Simultaneously, the formation of neuromuscular
synapses under the influence of neuron induction (i.e., the axons of the emerging motor neurons of the spinal cord grow into the muscles). In addition, each axon branches many times, forming synaptic contacts with dozens of muscle fibers. Activation of muscle receptors affects the establishment of intracerebral connections of the embryo, which provides tonic excitation of brain structures.
In the human fetus, reflexes develop from local to generalized and then to specialized reflex acts. The first reflex movements appear at 7.5 weeks of gestation - trigeminal reflexes that occur with tactile irritation of the face area; at 8.5 weeks, lateral flexion of the neck is noted for the first time. On the 10th week, a reflex movement of the lips is observed (a sucking reflex is formed). Later, as the reflexogenic zones in the lips and oral mucosa mature, complex components are added in the form of opening and closing the mouth, swallowing, stretching and squeezing the lips (22 weeks), sucking movements (24 weeks).
tendon reflexes appear on the 18th-23rd week of intrauterine life, at the same age the grasping reaction is formed, by the 25th week all unconditioned reflexes evoked from the upper limbs are distinct. From the 10.5-11th week, reflexes from the lower extremities, primarily plantar, and a reaction of the Babinski reflex type (12.5 weeks). First irregular respiratory movements of the chest (according to the Cheyne-Stokes type), arising on the 18.5-23rd week, pass into spontaneous breathing by the 25th week.
In postnatal life, the improvement of the motor analyzer occurs at the micro level. After birth, the thickening of the cerebral cortex in areas 6, 6a and the formation of neuronal groups continue. The first networks formed from 3-4 neurons appear at 3-4 months; after 4 years, the thickness of the cortex and the size of neurons (except for Betz cells growing until puberty) stabilize. The number of fibers and their thickness increase significantly. The differentiation of muscle fibers is associated with the development of motor neurons of the spinal cord. Only after the appearance of heterogeneity in the population of motor neurons of the anterior horns of the spinal cord does the division of muscles into motor units occur. Later, at the age of 1 to 2 years, not individual muscle fibers develop, but “superstructures” - motor units consisting of muscles and nerve fibers, and changes in the muscles are primarily associated with the development of the corresponding motor neurons.
After the birth of a child, as the controlling parts of the CNS mature, so do its pathways, in particular, myelination of peripheral nerves occurs. At the age of 1 to 3 months, the development of the frontal and temporal areas of the brain is especially intensive. The cerebellar cortex is still poorly developed, but the subcortical ganglia are clearly differentiated. Up to the midbrain region, myelination of fibers is well expressed; in the cerebral hemispheres, only sensory fibers are fully myelinated. From 6 to 9 months, long associative fibers are most intensively myelinated, the spinal cord is completely myelinated. By the age of 1 year, myelination processes covered long and short associative pathways of the temporal and frontal lobes and the spinal cord along its entire length.
There are two periods of intense myelination: the first of them lasts from 9-10 months of intrauterine life to 3 months of postnatal life, then from 3 to 8 months the rate of myelination slows down, and from 8 months the second period of active myelination begins, which lasts until the child learns to walk (t .e. on average up to 1 g 2 months). With age, both the number of myelinated fibers and their content in individual peripheral nerve bundles change. These processes, which are most intense in the first 2 years of life, are mostly completed by the age of 5.
An increase in the speed of impulse conduction along the nerves precedes the emergence of new motor skills. So, in the ulnar nerve, the peak of the increase in the impulse conduction velocity (SPI) falls on the 2nd month of life, when the child can briefly clasp his hands while lying on his back, and on the 3rd-4th month, when hypertonicity in the hands is replaced by hypotension, the volume of active movements increases (holds objects in the hand, brings them to the mouth, clings to clothes, plays with toys). In the tibial nerve, the greatest increase in SPI appears first at 3 months and precedes the disappearance of physiological hypertension in the lower extremities, which coincides with the disappearance of automatic gait and positive support reaction. For the ulnar nerve, the next rise in SPI is noted at 7 months with the onset of a jump preparation reaction and the extinction of the grasping reflex; in addition, there is an opposition of the thumb, an active force appears in the hands: the child shakes the bed and breaks toys. For the femoral nerve, the next increase in the conduction velocity corresponds to 10 months, for the ulnar nerve - 12 months.
At this age, free standing and walking appear, hands are freed: the child waves them, throws toys, claps his hands. Thus, there is a correlation between the increase in SPI in the fibers of the peripheral nerve and the development of the child's motor skills.
10.1.1. Reflexes of newborns
Reflexes of newborns - this is an involuntary muscular reaction to a sensitive stimulus, they are also called: primitive, unconditioned, innate reflexes.
Unconditioned reflexes according to the level at which they close can be:
1) segmental stem (Babkina, sucking, proboscis, search);
2) segmental spinal (grasping, crawling, support and automatic gait, Galant, Perez, Moro, etc.);
3) postural suprasegmental - levels of the brainstem and spinal cord (asymmetric and symmetrical tonic neck reflexes, labyrinth tonic reflex);
4) posotonic suprasegmental - the level of the midbrain (straightening reflexes from the head to the neck, from the trunk to the head, from the head to the trunk, start reflex, balance reaction).
The presence and severity of the reflex is an important indicator of psychomotor development. Many neonatal reflexes disappear as the child develops, but some of them can be found in adulthood, but they do not have topical significance.
The absence of reflexes or pathological reflexes in a child, a delay in the reduction of reflexes characteristic of an earlier age, or their appearance in an older child or adult indicate CNS damage.
Unconditioned reflexes are examined in the position on the back, stomach, vertically; it can reveal:
The presence or absence, inhibition or strengthening of the reflex;
The time of appearance from the moment of irritation (latent period of the reflex);
The severity of the reflex;
The speed of its extinction.
Unconditioned reflexes are influenced by factors such as the type of higher nervous activity, the time of day, and the general condition of the child.
The most constant unconditioned reflexes In the supine position:
search reflex- the child lies on his back, when stroking the corner of the mouth it lowers, and the head turns in the direction of irritation; options: opening the mouth, lowering the lower jaw; the reflex is especially well expressed before feeding;
defensive reaction- pain stimulation of the same area causes the head to turn in the opposite direction;
proboscis reflex- the child lies on his back, a light quick blow to the lips causes a contraction of the circular muscle of the mouth, while the lips are pulled out with a "proboscis";
sucking reflex- active sucking of the nipple inserted into the mouth;
palmar-mouth reflex (Babkina)- pressure on the thenar area of the palm causes the opening of the mouth, tilt of the head, flexion of the shoulders and forearms;
grasping reflex occurs when a finger is inserted into the child's open palm, while his hand covers the finger. An attempt to release the finger leads to an increase in grasping and suspension. In newborns, the grasp reflex is so strong that they can be lifted off the changing table if both hands are involved. The lower grasp reflex (Wercombe) can be induced by pressing on the pads under the toes at the base of the foot;
Robinson reflex- when you try to release the finger, suspension occurs; this is a logical continuation of the grasping reflex;
lower grasp reflex- plantar flexion of the fingers in response to touching the base of II-III toes;
Babinski reflex- with stroke stimulation of the sole of the foot, a fan-shaped divergence and extension of the fingers occur;
Moro reflex: I phase - breeding of hands, sometimes so pronounced that it occurs with a turn around the axis; Phase II - return to the starting position after a few seconds. This reflex is observed with a sudden shaking of the child, a loud sound; the spontaneous Moro reflex often causes a baby to fall off the changing table;
defensive reflex- when the sole is injected, the leg is triple flexed;
cross reflex extensors- a prick of the sole, fixed in the extended position of the leg, causes straightening and slight adduction of the other leg;
start reflex(extension of arms and legs in response to a loud sound).
Upright (normally, when the child is vertically suspended by the armpits, bending occurs in all joints of the legs):
support reflex- in the presence of a solid support under the feet, the body straightens and rests on a full foot;
automatic gait occurs if the child is slightly tilted forward;
rotational reflex- when rotating in vertical suspension by the armpits, the head turns in the direction of rotation; if at the same time the head is fixed by the doctor, then only the eyes turn; after the appearance of fixation (by the end of the neonatal period), the turn of the eyes is accompanied by nystagmus - assessment of the vestibular response.
In the prone position:
defensive reflex- when laying the child on the stomach, the head turns to the side;
crawl reflex (Bauer)- light pushing of the hand to the feet causes repulsion from it and movements resembling crawling;
Talent reflex- when the skin of the back near the spine is irritated, the body bends in an arc open towards the stimulus; the head turns in the same direction;
Perez reflex- when you run your finger along the spinous processes of the spine from the coccyx to the neck, a pain reaction, a cry occur.
Reflexes that persist in adults:
Corneal reflex (squinting the eye in response to touch or sudden exposure to bright light);
Sneezing reflex (sneezing when the nasal mucosa is irritated);
Gag reflex (vomiting when irritating the posterior pharyngeal wall or the root of the tongue);
Yawning reflex (yawning with a lack of oxygen);
Cough reflex.
Assessment of the motor development of the child of any age is carried out at the moment of maximum comfort (warmth, satiety, peace). It should be borne in mind that the development of the child occurs craniocaudally. This means that the upper parts of the body develop before the lower ones (for example,
manipulation precedes the ability to sit, which, in turn, precedes the appearance of walking). In the same direction, muscle tone also decreases - from physiological hypertonicity to hypotension by 5 months of age.
The components of the assessment of motor functions are:
muscle tone and postural reflexes(proprioceptive reflexes of the muscular-articular apparatus). There is a close relationship between muscle tone and postural reflexes: muscle tone affects posture in sleep and in a state of calm wakefulness, and posture, in turn, affects tone. Tone options: normal, high, low, dystonic;
tendon reflexes. Options: absence or decrease, increase, asymmetry, clonus;
volume of passive and active movements;
unconditioned reflexes;
pathological movements: tremor, hyperkinesis, convulsions.
At the same time, attention should be paid to the general condition of the child (somatic and social), the features of his emotional background, the function of analyzers (especially visual and auditory) and the ability to communicate.
10.1.2. Development of motor skills in the first year of life
Newborn. Muscle tone. Normally, the tone in the flexors predominates (flexor hypertension), and the tone in the arms is higher than in the legs. As a result of this, a “fetal position” arises: the arms are bent at all joints, brought to the body, pressed to the chest, the hands are clenched into fists, the thumbs are clamped by the rest; the legs are bent in all joints, slightly abducted at the hips, in the feet - dorsiflexion, the spine is curved. Muscle tone is increased symmetrically. To determine the degree of flexor hypertension, there are the following tests:
traction test- the child lies on his back, the researcher takes him by the wrists and pulls him towards himself, trying to seat him. At the same time, the arms are slightly unbent in the elbow joints, then the extension stops, and the child is pulled up to the hands. With an excessive increase in flexor tone, there is no extension phase, and the body immediately moves behind the hands, with insufficiency, the extension volume increases or there is no sipping behind the hands;
With normal muscle tone in a horizontal hanging posture behind the armpits, face down, the head is in line with the body. In this case, the arms are bent, and the legs are extended. With a decrease in muscle tone, the head and legs passively hang down, with an increase, a pronounced bending of the arms and, to a lesser extent, legs occurs. With the predominance of extensor tone, the head is thrown back;
labyrinthine tonic reflex (LTR) occurs when the position of the head in space changes as a result of stimulation of the labyrinths. This increases the tone in the extensors in the supine position and in the flexors in the prone position;
symmetrical neck tonic reflex (SNTR)- in the position on the back with a passive tilt of the head, the tone of the flexors in the arms and extensors in the legs increases, with the extension of the head - the opposite reaction;
asymmetric neck tonic reflex (ASTTR), Magnus-Klein reflex occurs when the head of a child lying on his back is turned to the side. At the same time, in the hand, to which the child's face is turned, the extensor tone increases, as a result of which it unbends and is retracted from the body, the hand opens. At the same time, the opposite arm is bent and her hand is clenched into a fist (swordsman's pose). As the head turns, the position changes accordingly.
Volume of passive and active movements
Flexor hypertension overcome, but limits the amount of passive movement in the joints. It is impossible to completely unbend the child's arms in the elbow joints, raise the arms above the horizontal level, spread the hips without causing pain.
Spontaneous (active) movements: periodic flexion and extension of the legs, cross, repulsion from the support in the position on the stomach and back. Movements in the hands are made in the elbow and wrist joints (hands clenched into fists move at chest level). Movements are accompanied by an athetoid component (a consequence of the immaturity of the striatum).
Tendon reflexes: the newborn can only cause knee jerks, which are usually elevated.
Unconditioned reflexes: all reflexes of newborns are caused, they are moderately expressed, slowly are exhausted.
Postural reactions: the newborn lies on his stomach, his head is turned to the side (protective reflex), the limbs are bent in
all joints and brought to the body (labyrinth tonic reflex). Direction of development: exercises for holding the head vertically, leaning on the hands.
Walking Ability: a newborn and a child of 1–2 months of age have a primitive reaction of support and automatic gait, which fades by 2–4 months of age.
Grasping and manipulation: in a newborn and a child of 1 month, the hands are clenched into a fist, he cannot open the hand on his own, a grasping reflex is caused.
Social contacts: The first impressions of the newborn about the world around are based on skin sensations: warm, cold, soft, hard. The child calms down when he is picked up, fed.
Child aged 1-3 months. When assessing the motor function, in addition to those listed earlier (muscle tone, postural reflexes, the volume of spontaneous movements, tendon reflexes, unconditioned reflexes), the initial elements of voluntary movements and coordination begin to be taken into account.
Skills:
Development of analyzer functions: fixation, tracking (visual), sound localization in space (auditory);
Integration of analyzers: sucking fingers (sucking reflex + influence of the kinesthetic analyzer), examining one's own hand (visual-kinesthetic analyzer);
The appearance of more expressive facial expressions, a smile, a complex of revival.
Muscle tone. Flexor hypertension gradually decreases. At the same time, the influence of postural reflexes increases - ASTR, LTE are more pronounced. The value of postural reflexes is to create a static posture, while the muscles are “trained” to actively (and not reflexively) hold this posture (for example, the upper and lower Landau reflex). As the muscles are trained, the reflex gradually fades away, since the processes of central (voluntary) regulation of the posture are turned on. By the end of the period, the flexion posture becomes less pronounced. During the traction test, the extension angle increases. By the end of 3 months, postural reflexes weaken, and they are replaced by straightening reflexes of the body:
labyrinth straightening (adjusting) reflex on the head- in the position on the stomach, the head of the child is located on the middle
line, a tonic contraction of the neck muscles occurs, the head rises and is held. Initially, this reflex ends with the fall of the head and turning it to the side (the influence of a protective reflex). Gradually, the head can be in a raised position for longer and longer, while the legs are tense at first, but over time they begin to actively move; arms are more and more unbent at the elbow joints. A labyrinthic installation reflex is formed in a vertical position (holding the head vertically);
straightening reflex from trunk to head- when the feet touch the support, the body straightens and the head rises;
cervical rectifying reaction - with a passive or active turn of the head, the body turns.
Unconditioned reflexes still well expressed; the exception is the reflexes of support and automatic gait, which gradually begin to fade. At 1.5-2 months, the child in an upright position, placed on a hard surface, rests on the outer edges of the feet, does not make step movements when leaning forward.
By the end of 3 months, all reflexes weaken, which is expressed in their inconstancy, lengthening of the latent period, rapid exhaustion, and fragmentation. The Robinson reflex disappears. Moro's reflexes, sucking and withdrawal reflexes are still well evoked.
Combined reflex reactions appear - a sucking reflex at the sight of the breast (kinesthetic food reaction).
The range of motion increases. The athetoid component disappears, the number of active movements increases. Arises recovery complex. The first becomes possible purposeful movement: straightening the arms up, bringing the hands to the face, sucking the fingers, rubbing the eyes and nose. At the 3rd month, the child begins to look at his hands, reach out with his hands to the object - visual blink reflex. Due to the weakening of the synergy of the flexors, flexion occurs in the elbow joints without bending the fingers, the ability to hold an enclosed object in the hand.
Tendon reflexes: in addition to the knee, Achilles, bicipital are called. Abdominal reflexes appear.
Postural reactions: during the 1st month, the child raises its head for a short time, then “drops” it. Arms bent under the chest (labyrinth straightening reflex on the head, tonic contraction of the neck muscles ends with the head falling and turning it to the side -
element of a protective reflex). Direction of development: exercise to increase the time of holding the head, extension of the arms in the elbow joint, opening of the hand. At the 2nd month, the child can hold his head at an angle of 45? for some time. to the surface, while the head is still swaying uncertainly. The angle of extension in the elbow joints increases. At the 3rd month, the child confidently holds his head, lying on his stomach. Forearm support. The pelvis is down.
Walking Ability: a child of 3-5 months holds his head well in an upright position, but if you try to put him, he draws his legs and hangs on the hands of an adult (physiological astasia-abasia).
Grasping and manipulation: on the 2nd month, the brushes are slightly ajar. At the 3rd month, a small light rattle can be put into the child's hand, he grabs it and holds it in his hand, but he himself is not yet able to open the brush and release the toy. Therefore, after playing for some time and listening with interest to the sounds of the rattle that are heard when it is shaken, the child begins to cry: he gets tired of holding the object in his hand, but cannot voluntarily release it.
Social contacts: at the 2nd month, a smile appears, which the child addresses to all living beings (as opposed to inanimate ones).
Child aged 3-6 months. At this stage, the assessment of motor functions consists of the previously listed components (muscle tone, range of motion, tendon reflexes, unconditioned reflexes, voluntary movements, their coordination) and newly emerged general motor skills, in particular manipulations (hand movements).
Skills:
Increase in the period of wakefulness;
Interest in toys, looking, grasping, bringing to the mouth;
The development of facial expressions;
The appearance of cooing;
Communication with an adult: the orienting reaction turns into a complex of revival or a reaction of fear, a reaction to the departure of an adult;
Further integration (sensory-motor behavior);
Auditory reactions;
Hearing-motor reactions (turning the head towards the call);
Visual-tactile-kinesthetic (examining one's own hands is replaced by examining toys, objects);
Visual-tactile-motor (grasping objects);
Hand-eye coordination - the ability to control with a glance the movements of a hand reaching for a closely located object (feeling one's hands, rubbing, joining hands, touching one's head, while sucking, holding a breast, a bottle);
The reaction of active touch - feeling the object with your feet and grasping with their help, stretching your arms in the direction of the object, feeling; this reaction disappears when the object capture function appears;
Skin concentration reaction;
Visual localization of an object in space based on a visual-tactile reflex;
Increasing visual acuity; the child can distinguish small objects against a solid background (for example, buttons on clothes of the same color).
Muscle tone. There is a synchronization of the tone of the flexors and extensors. Now the posture is determined by a group of reflexes that straighten the body and voluntary motor activity. In a dream, the hand is open; ASHTR, SSTR, LTR have faded. The tone is symmetrical. Physiological hypertension is replaced by normotonia.
There is further formation rectifying reflexes of the body. In the position on the stomach, a steady hold of the raised head is noted, reliance on a slightly extended arm, later - reliance on the outstretched arm. The upper Landau reflex appears in the position on the stomach ("swimmer's position", i.e. raising the head, shoulders and torso in the position on the stomach with straightened arms). Head control in a vertical position is stable, sufficient in the supine position. There is a straightening reflex from the body to the body, i.e. the ability to rotate the shoulder girdle relative to the pelvic.
tendon reflexes all are called.
Developing motor skills following.
Attempts to pull the body to the outstretched arms.
Ability to sit with support.
The appearance of a "bridge" - arching of the spine based on the buttocks (feet) and head while tracking the object. In the future, this movement is transformed into an element of a turn on the stomach - a “block” turn.
Turn from back to stomach; at the same time, the child can rest with his hands, raising his shoulders and head and looking around in search of objects.
Objects are captured by the palm (squeezing the object in the palm with the help of the flexor muscles of the hand). There is no opposition of the thumb yet.
The capture of an object is accompanied by a lot of unnecessary movements (both hands, mouth, legs move at the same time), there is still no clear coordination.
Gradually, the number of extra movements decreases. Grasping an attractive object with both hands appears.
The number of movements in the hands increases: lifting up, to the sides, clutching together, feeling, putting into the mouth.
Movements in large joints, fine motor skills are not developed.
Ability to sit independently (without support) for a few seconds/minutes.
Unconditioned reflexes fade away, except for the sucking and withdrawal reflexes. Elements of the Moro reflex are preserved. The appearance of a parachute reflex (in the position of hanging by the armpits horizontally face down, as in a fall, the arms are unbent and the fingers spread apart - as if in an attempt to protect themselves from a fall).
Postural reactions: at the 4th month, the child's head is stably raised; support on an outstretched arm. In the future, this posture becomes more complicated: the head, the shoulder girdle are raised, the arms are straightened and stretched forward, the legs are straight (swimmer's position, upper Landau reflection). Lifting up the legs (lower Landau reflex), the baby can rock on the stomach and turn around it. At the 5th month, the ability to turn from the position described above onto the back appears. First, a turn from the stomach to the back occurs by chance when the arm is thrown far forward and the balance on the stomach is disturbed. Direction of development: exercises for the purposefulness of turns. At the 6th month, the head and shoulder girdle were raised above the horizontal surface at an angle of 80–90°, the arms were straightened at the elbow joints, resting on fully open hands. Such a posture is already so stable that the child can follow the object of interest by turning his head, and also transfer the body weight to one hand, and with the other hand try to reach for the object and grab it.
Ability to sit - keeping the body in a static state - is a dynamic function and requires the work of many muscles and precise coordination. This posture allows you to free your hands for fine motor actions. To learn to sit, you need to master three fundamental functions: keep your head upright in any position of the body, bend your hips, and actively rotate your torso. At the 4-5th month, when sipping on the arms, the child, as it were, “sits down”: bends his head, arms and legs. At the 6th month, the child can be planted, while for some time he will hold his head and torso vertically.
Walking Ability: at the 5-6th month, the ability to stand with the support of an adult, leaning on a full foot, gradually appears. At the same time, the legs are straightened. Quite often, the hip joints remain slightly bent in an upright position, as a result of which the child does not stand on a full foot, but on his toes. This isolated phenomenon is not a manifestation of spastic hypertonicity, but a normal stage in the formation of gait. A "jump phase" appears. The child begins to bounce when placed on its feet: the adult holds the child under the armpits, he crouches and pushes off, straightening the hips, knees and ankle joints. This causes a lot of positive emotions and, as a rule, is accompanied by loud laughter.
Grasping and manipulation: at the 4th month, the range of motion in the hand increases significantly: the child brings his hands to his face, examines them, brings them and puts them in his mouth, rubs his hand in hand, touches the other with one hand. He may accidentally grab a toy that is within reach and also bring it to his face, to his mouth. Thus, he explores the toy - with his eyes, hands and mouth. At the 5th month, the child can voluntarily take an object lying in the field of vision. At the same time, he stretches out both hands and touches him.
Social contacts: from 3 months the child begins to laugh in response to communication with him, a complex of revival and cries of joy appear (until this time, a cry occurs only with unpleasant sensations).
Child aged 6-9 months. In this age period, the following functions are noted:
Development of integrative and sensory-situational connections;
Active cognitive activity based on visual-motor behavior;
Chain motor associative reflex - listening, observing one's own manipulations;
Development of emotions;
Games;
Variety of facial movements. Muscle tone - fine. Tendon reflexes are caused by everything. Motor skills:
Development of arbitrary purposeful movements;
Development of the rectifying reflex of the body;
Turns from stomach to back and from back to stomach;
Reliance on one hand;
Synchronization of the work of antagonist muscles;
Stable independent sitting for a long time;
Chain symmetrical reflex in the position on the stomach (the basis of crawling);
Crawling back, in a circle, with the help of pull-ups on the hands (legs do not participate in crawling);
Crawling on all fours with lifting the body above the support;
Attempts to take a vertical position - when sipping on the hands from a supine position, he immediately rises to straightened legs;
Attempts to get up, holding hands on a support;
The beginning of walking along the support (furniture);
Attempts to sit down independently from an upright position;
Attempts to walk while holding the hand of an adult;
Plays with toys, II and III fingers participate in manipulations. Coordination: coordinated clear hand movements; at
manipulations in the sitting position, a lot of unnecessary movements, instability (i.e. arbitrary actions with objects in the sitting position are a load test, as a result of which the position is not maintained and the child falls).
Unconditioned reflexes extinguished, except for the suckling.
Postural reactions: at the 7th month, the child is able to turn from his back to his stomach; for the first time, on the basis of the rectifying reflex of the body, the ability to sit down independently is realized. At the 8th month, turns are improved, and the phase of crawling on all fours develops. At the 9th month, the ability to purposefully crawl with support on the hands appears; leaning on the forearms, the child pulls the entire body.
Ability to sit: at the 7th month, the child lying on his back assumes a “sitting” position, bending his legs at the hip and knee joints. In this position, the child can play with his legs and pull them into his mouth. At 8 months, a seated baby can sit up on its own for a few seconds, and then “fall over” on its side, leaning with one hand on the surface to protect itself from falling. At the 9th month, the child sits for a longer time on his own with a “round back” (lumbar lordosis has not yet been formed), and when tired, he leans back.
Walking Ability: at the 7-8th month, a reaction of support on the hands appears if the child is sharply tilted forward. At the 9th month, a child placed on the surface and supported by the arms stands independently for several minutes.
Grasping and manipulation: on the 6-8th month, the accuracy of capturing the object improves. The child takes it with the entire surface of the palm. Can transfer an item from one hand to the other. At the 9th month, he voluntarily releases the toy from his hands, it falls, and the child carefully follows the trajectory of its fall. He likes it when an adult picks up a toy and gives it to a child. Releases the toy again and laughs. Such an activity, according to an adult, is a stupid and meaningless game, in fact it is a complex training of hand-eye coordination and a complex social act - a game with an adult.
Child aged 9-12 months. This age period includes:
Development and complication of emotions; the revitalization complex fades away;
Various facial expressions;
Sensory speech, understanding of simple commands;
The appearance of simple words;
Story games.
Muscle tone, tendon reflexes remain unchanged in comparison with the previous stage and throughout the rest of life.
Unconditioned reflexes everything faded away, the sucking reflex fades.
Motor skills:
Improvement of complex chain reflexes of verticalization and voluntary movements;
Ability to stand at a support; attempts to stand without support, on their own;
The appearance of several independent steps, the further development of walking;
Repeated actions with objects (“memorization” of motor patterns), which can be considered as the first step towards the formation of complex automated movements;
Purposeful actions with objects (inserting, putting on).
The formation of the gait children are very variable and individual. Manifestations of character and personality are clearly demonstrated in attempts to stand, walk and play with toys. In most children, by the beginning of walking, the Babinski reflex and the lower grasping reflex disappear.
Coordination: immaturity of coordination when taking an upright position, leading to falls.
Perfection fine motor skills: grasping small objects with two fingers; there is opposition between the thumb and little finger.
In the 1st year of a child's life, the main directions of motor development are distinguished: postural reactions, elementary movements, crawling on all fours, the ability to stand, walk, sit, grasping abilities, perception, social behavior, making sounds, understanding speech. Thus, there are several stages in development.
Postural reactions: at the 10th month, in the position on the stomach with a raised head and support on the hands, the child can simultaneously raise the pelvis. Thus, it rests only on the palms and feet and sways back and forth. At the 11th month, he begins to crawl with support on his hands and feet. Further, the child learns to crawl in a coordinated way, i.e. alternately extending the right arm - the left leg and the left arm - the right leg. At the 12th month, crawling on all fours becomes more and more rhythmic, smooth, and fast. From this moment, the child begins to actively explore and explore his home. Crawling on all fours is a primitive form of movement, atypical for adults, but at this stage the muscles are prepared for the following stages of motor development: muscle strength increases, coordination and balance are trained.
The ability to sit is formed individually from 6 to 10 months. This coincides with the development of a position on all fours (support on the palms and feet), from which the child easily sits down, turning the pelvis relative to the body (rectifying reflex from the pelvic girdle to the body). The child sits independently, stably with a straight back and legs straightened at the knee joints. In this position, the child can play for a long time without losing balance. Next, seat
becomes so stable that the child can perform extremely complex actions while sitting, requiring excellent coordination: for example, holding a spoon and eating with it, holding a cup with both hands and drinking from it, playing with small objects, etc.
Walking Ability: at the 10th month, the child crawls to the furniture and, holding on to it, gets up on its own. At the 11th month, the child can walk along the furniture, holding on to it. At the 12th month, it becomes possible to walk, holding on with one hand, and, finally, to take several independent steps. In the future, coordination and strength of the muscles involved in walking develop, and walking itself improves more and more, becoming faster, more purposeful.
Grasping and manipulation: on the 10th month, a “tweezer-like grip” appears with opposition of the thumb. The child can take small objects, while he stretches his thumb and forefinger and holds the object with them, like tweezers. At the 11th month, a “pincer grip” appears: the thumb and forefinger form a “claw” during grip. The difference between the pincer grip and the claw grip is that the former has straight fingers while the latter has bent fingers. At the 12th month, a child can accurately put an object into a large dish or an adult's hand.
Social contacts: by the 6th month, the child distinguishes "friends" from "strangers". At 8 months, the child begins to be afraid of strangers. He no longer allows everyone to take him in his arms, touch him, turns away from strangers. At 9 months, the child begins to play hide-and-seek - peek-a-boo.
10.2. Examination of a child from the neonatal period to six months
When examining a newborn baby, his gestational age should be taken into account, because even a slight immaturity or prematurity of less than 37 weeks can significantly affect the nature of spontaneous movements (movements are slow, generalized with tremor).
Muscle tone is changed, and the degree of hypotension is directly proportional to the degree of maturity, usually in the direction of its decrease. A full-term baby has a pronounced flexor posture (reminiscent of an embryonic one), and a premature baby has an extensor posture. A full-term baby and a child with prematurity of the 1st degree hold the head for a few seconds when pulling the handles, children with prematurity
a deeper degree and children with damaged central nervous system do not hold their heads. It is important to determine the severity of physiological reflexes in the neonatal period, especially grasping, suspension, as well as reflexes that provide sucking, swallowing. When examining the function of the cranial nerves, it is necessary to pay attention to the size of the pupils and their reaction to light, the symmetry of the face, and the position of the head. Most healthy newborns fix their eyes on the 2-3rd day after birth and try to follow the object. Symptoms such as Graefe's symptom, nystagmus in the extreme leads are physiological and are due to the immaturity of the posterior longitudinal bundle.
Severe edema in a child can cause depression of all neurological functions, but if it does not decrease and is combined with liver enlargement, a congenital form of hepatocerebral dystrophy (hepatolenticular degeneration) or lysosomal disease should be suspected.
Specific (pathognomonic) neurological symptoms characteristic of dysfunction of a particular area of the CNS are absent until 6 months of age. The main neurological symptoms are usually impaired muscle tone with or without motor deficits; communication disorders, which are determined by the ability to fix the gaze, follow objects, single out acquaintances, etc., and reactions to various stimuli: the more clearly visual control is expressed in a child, the more perfect his nervous system. Great importance is attached to the presence of paroxysmal epileptic phenomena or their absence.
The exact description of all paroxysmal phenomena is the more difficult, the younger the child. Convulsions that occur in this age period are often polymorphic.
The combination of altered muscle tone with movement disorders (hemiplegia, paraplegia, tetraplegia) indicates a gross focal lesion of the brain substance. In about 30% of cases of hypotension of central origin, no cause can be found.
History and somatic symptoms are of particular importance in newborns and children under 4 months of age due to the paucity of neurological examination data. For example, respiratory disorders at this age can often be the result of CNS damage and occur when
congenital forms of myatonia and spinal amyotrophy. Apnea and dysrhythmia may be due to abnormalities of the brainstem or cerebellum, Pierre Robin's anomaly, and metabolic disorders.
10.3. Examination of a child aged 6 months to 1 year
In children from 6 months to 1 year, both acute neurological disorders with a catastrophic course and slowly progressive ones often occur, so the doctor must immediately outline the range of diseases that can lead to these conditions.
The appearance of febrile and unprovoked convulsions such as infantile spasms is characteristic. Movement disorders are manifested by changes in muscle tone and its asymmetry. In this age period, such congenital diseases as spinal amyotrophy and myopathy clearly manifest themselves. The doctor must remember that the asymmetry of the muscle tone of a child of this age may be due to the position of the head in relation to the body. Lag in psychomotor development can be a consequence of metabolic and degenerative diseases. Emotional disorders - poor facial expressions, lack of a smile and loud laughter, as well as pre-speech development disorders (babbling formation) are caused by hearing impairment, brain underdevelopment, autism, degenerative diseases of the nervous system, and when combined with skin manifestations - tuberous sclerosis, for which motor stereotypes and convulsions are also characteristic.
10.4. Examination of a child after the 1st year of life
The progressive maturation of the central nervous system causes the appearance of specific neurological symptoms indicating a focal lesion, and it is possible to determine the dysfunction of a particular area of the central or peripheral nervous system.
The most common reasons for visiting a doctor are a delay in the development of gait, its violation (ataxia, spastic paraplegia, hemiplegia, diffuse hypotension), walking regression, hyperkinesis.
The combination of neurological symptoms with extraneural (somatic), their slow progression, the development of dysmorphia of the skull and face, mental retardation and emotional disturbance should lead the doctor to the idea of the presence of metabolic diseases - mucopolysaccharidosis and mucolipidosis.
The second most common reason for treatment is mental retardation. A gross lag is observed in 4 out of 1000 children, and in 10-15% this delay is the cause of learning difficulties. It is important to diagnose syndromic forms, in which oligophrenia is only a symptom of general underdevelopment of the brain against the background of dysmorphias and multiple developmental anomalies. Impairment of intelligence may be due to microcephaly, the cause of developmental delay is also progressive hydrocephalus.
Cognitive disorders in combination with chronic and progressive neurological symptoms in the form of ataxia, spasticity or hypotension with high reflexes should prompt the doctor to think about the onset of mitochondrial disease, subacute panencephalitis, HIV encephalitis (in combination with polyneuropathy), Creutzfeldt-Jakob disease. Impairment of emotions and behavior, combined with cognitive deficits, suggests the presence of Rett syndrome, Santavuori's disease.
Sensorineural disorders (visual, oculomotor, auditory) are very widely represented in childhood. There are many reasons for their appearance. They may be congenital, acquired, chronic or developing, isolated or associated with other neurological symptoms. They can be caused by embryofetal brain damage, an anomaly in the development of the eye or ear, or these are the consequences of previous meningitis, encephalitis, tumors, metabolic or degenerative diseases.
Oculomotor disorders in some cases are the result of damage to the oculomotor nerves, including the congenital Graefe-Mobius anomaly.
From 2 years oldthe frequency of occurrence of febrile convulsions sharply increases, which by the age of 5 should completely disappear. After 5 years, epileptic encephalopathy debuts - Lennox-Gastaut syndrome and most childhood idiopathic forms of epilepsy. The acute onset of neurological disorders with impaired consciousness, pyramidal and extrapyramidal neurological symptoms, debuting against the background of febrile condition, especially with concomitant purulent diseases in the face (sinusitis), should raise suspicion of bacterial meningitis, brain abscess. These conditions require urgent diagnosis and specific treatment.
At a younger age malignant tumors also develop, most often of the brainstem, cerebellum and its worm, the symptoms of which can develop acutely, subacutely, often after children stay in southern latitudes, and manifest not only headache, but also dizziness, ataxia due to occlusion of the CSF pathways.
It is not uncommon for blood diseases, in particular lymphomas, to debut with acute neurological symptoms in the form of opsomyoclonus, transverse myelitis.
In children after 5 years The most common reason for visiting a doctor is a headache. If it is of a particularly persistent chronic nature, accompanied by dizziness, neurological symptoms, especially cerebellar disorders (static and locomotor ataxia, intentional tremor), it is necessary first of all to exclude a brain tumor, mainly a tumor of the posterior cranial fossa. These complaints and the listed symptoms are an indication for CT and MRI studies of the brain.
Slowly progressive development of spastic paraplegia, sensory disorders in the presence of asymmetry and dysmorphias of the trunk may raise the suspicion of syringomyelia, and the acute development of symptoms - hemorrhagic myelopathy. Acute peripheral paralysis with radicular pain, sensory disturbance and pelvic disorders are characteristic of polyradiculoneuritis.
Delays in psychomotor development, especially in combination with the breakdown of intellectual functions and progressive neurological symptoms, occur against the background of metabolic and neurodegenerative diseases at any age and have different rates of development, but in this age period it is very important to know that impaired intellectual functions, motor skills and speech may be a consequence of epileptiform encephalopathy.
Progressive neuromuscular diseases debut at different times with gait disturbance, muscle atrophy, and changes in the shape of the feet and legs.
In older children, more often in girls, there may be episodic attacks of dizziness, ataxia with sudden visual impairment and the appearance of seizures, which at first
difficult to distinguish from epileptic. These symptoms are accompanied by changes in the affective sphere of the child, and observations of family members and assessment of their psychological profile make it possible to reject the organic nature of the disease, although in isolated cases additional research methods are required.
In this period, various forms of epilepsy, infections and autoimmune diseases of the nervous system often debut, less often - neurometabolic. Circulatory disorders may also occur.
10.5. Formation of pathological postural activity and movement disorders in early organic brain damage
Violation of the child's motor development is one of the most common consequences of damage to the nervous system in the ante- and perinatal period. The delay in the reduction of unconditioned reflexes leads to the formation of pathological postures and attitudes, inhibits and distorts further motor development.
As a result, all this is expressed in a violation of the motor function - the appearance of a complex of symptoms, which by the 1st year is clearly formed into the syndrome of cerebral palsy. Components of the clinical picture:
Damage to motor control systems;
Delayed reduction of primitive postural reflexes;
Delay in general development, including mental;
Violation of motor development, sharply enhanced tonic labyrinth reflexes, leading to the appearance of reflex-protective positions, in which the "embryonic" posture is maintained, a delay in the development of extensor movements, chain symmetrical and adjusting reflexes of the body;
