Senior school age(age from 12 to 17-18 years) - period of puberty. It is characterized by a sharp change in the functions of the endocrine glands. For girls, high school age is a period of rapid puberty; for boys, it is the beginning of puberty.
By the end of puberty, short stature and excessively tall stature can be clearly diagnosed. With the advent of menstruation, the increase in girls' body size slows down sharply. At this age, both girls and boys significantly increase lung capacity, muscle strength and performance.
Increasing motor and neuropsychic activity leads to significant stress on metabolism and the work of the endocrine glands, as well as the nervous system. The processes of general excitation intensify, stabilization becomes more difficult conditioned reflexes. The blood supply to the brain deteriorates somewhat, which causes increased fatigue, instability of autonomic regulation, and disorders of vascular tone.
Schoolchildren often experience disturbances in physical and sexual development. Eating disorders (obesity) and gastrointestinal diseases (gastritis, duodenitis, peptic ulcer) are also widespread. In girls, thermoregulation may be impaired.
High school age is divided into adolescence (girls 12-15 years old, boys 13-16 years old) and youth or juvenile (girls 16-20 years old, boys 17-21 years old).
Adolescence is a real period in a person’s life when he is no longer a child, but not yet an adult. Under the influence of sex hormones, the endocrine system is restructured and secondary sexual characteristics are formed. As a result of the implementation of the genetic program, the formation of the morphological and functional structures of the body is completed. The specifics of this stage of development are largely determined by the most important biological factor- puberty.
The following features of adolescence are distinguished.
Biological (functional and somatic, including
morphological and sexual).
Psychological.
Social.
Functional features are characterized by pronounced instability of endocrine and autonomic regulation, emotional lability, and reduced endurance to physical and mental stress. Adolescents are characterized by reduced endurance to physical activity, increased vulnerability to mental and physical factors, including environmental factors. Endogenous (focal infection) and exogenous (smoking, alcohol, toxic substances and drugs) cause more harm to the body than to the body of adults .
CENTRAL NERVOUS SYSTEM
The period of puberty is characterized by intense differentiation of the central nervous system. At this age, the formation of the cerebral cortex is completed, rapid restructuring occurs in the higher regulatory centers of autonomic functions, which causes their significant vulnerability in adolescents. The central nervous system in adolescence is characterized by a decrease in the threshold of excitability and lability of autonomic reactions. Electroencephalographic studies at this age often reveal a predominance of excitation over inhibition. A slow reaction to verbal and auditory information is possible, which is important to take into account when constructing educational programs and monitoring their adequacy to age-related developmental characteristics. Neurohumoral lability during puberty contributes to the development of pronounced changes in vital organs and systems, which makes it possible to consider adolescent children
age group at risk of developing functional and chronic pathologies.
At 13-14 years of age, the activity of the sympathoadrenal system increases, which ensures adequate energy supply and adaptation of the body to external influences. The influence of the sympathoadrenal system gradually decreases by the age of 17-18. The temporary predominance of sympathicotonia should be taken into account when assessing the health status and functions of the adolescent’s leading body systems, primarily the cardiovascular, respiratory and digestive.
ENDOCRINE SYSTEM
Changes in endocrine relationships in the period from 10 to 18 years lead to the completion of the ontogenetic stages of development: child - teenager - adult. The main feature of endocrine changes during puberty is the activation of the pituitary gland and the closely related hypothalamus. A sharp increase in the activity of the hypothalamus at the initial stage of puberty causes dramatic changes in the functioning of the body. The immaturity of the peripheral gonads and the lack of their inhibitory influence are considered the main factor determining the excessive activity of the hypothalamus.
The production of somatotropic hormone by the pituitary gland increases with
10 years of age, reaching a maximum at 12-14 years, and precisely at
At this age, a growth spurt is observed in adolescents.
Increasing production of adrenocotricotropic hormone method
stimulates the secretion of hormones by the adrenal glands, ensuring the growth of bone and
muscle tissue, formation of secondary sexual characteristics and sos
roaring of the reproductive system, facilitates the formation of conditioned
reflex activity, increases its stability, provides
biological foundations of knowledge acquisition, work skills, adaptation
onno-adaptive reactions.
High content of gonadotropins affects the formation of
fishing behavior.
Thyroid hormones affect all types of metabolism,
level of intelligence, physical development and puberty. You
High levels of these hormones promote proper maturation
teenagers who, due to accelerated development, sweat increased
the body's need for thyroid hormones, which often leads to "rare"
boch" hypertrophy of the thyroid gland. Girls have cabbage soup hyperplasia
thyroid gland is detected more often than in boys. Juvenile hype
Thyroid plasia can mask various diseases
of this organ, including autoimmune thyroiditis, nodular toxic goiter, cysts, thyroid cancer.
THE IMMUNE SYSTEM
According to modern concepts, in ontogenesis there are 5 critical periods of the state of the immune system, the last of which coincides with adolescence (for girls at 12-13 years old, and for boys at 14-15 years old). During the puberty period, a decrease in the mass of lymphoid tissue is observed, primarily the thymus gland and tonsils with the growth of connective tissue in them, which is accompanied by a decrease in cellular immunity and can lead to the occurrence of chronic inflammatory, autoimmune and lymphoproliferative diseases.
PHYSICAL DEVELOPMENT
Physical development is the main criterion for children's health. Individual assessment of the level of physical development is based on anthropometric data obtained from population studies, the results of which made it possible to reliably determine the indicators of physical development of adolescents aged 10-17 years. There is a certain connection between the hormonal activity of the gonads and the dynamics of physical development.
Pubertal growth acceleration in boys and girls begins at at different ages: in boys, the most intensive growth occurs at 13-15 years old, in girls 2 years earlier (at 11-13 years old). Girls begin to outstrip boys in height at the age of 10. After 13-14 years, with the onset of menarche, the rate of increase in girls' height decreases, and boys again begin to overtake them. Up to 11 years of age, the body weight of girls and boys is the same; from 11 to 14 years of age, the body weight of girls exceeds that of boys, and after 15 years of age, the opposite ratios are observed, and by the age of 16, the body weight of boys significantly exceeds the body weight of girls. IN last years Among adolescents, the number of people with a normal height-to-weight ratio and those with excess body weight has decreased, however, the number of adolescents with its deficiency has increased. A decrease in the number of adolescents with normal height-weight ratios, a decrease in the prevalence of overweight, and an increase in the frequency of low body weight indicate a tendency toward gracialization.
PUBERTY
Puberty occurs during adolescence. The maturation of the reproductive system ends only at 17-18 years of age.
During puberty, intensive sexual differentiation occurs. After 8 years, the growth of the uterus and ovaries increases significantly in girls, and in boys - the prostate gland and testicles. At the same time, a qualitative change in their structure occurs. The main sign of puberty in girls is menarche, in boys it is spermarche.
The first recorded indicator of puberty in girls is considered
initial enlargement of the mammary glands between the ages of 8.5 and 13 years. On
Initial pubic hair growth is noted 3-8 months later than the first signs
kov enlargement of the mammary glands, but hair growth in the pubic area
is formed faster than the mammary glands develop: complete ovo
pubic hair loss is recorded after 2.5-3 years, and full maturation can occur
mammary gland - almost 4 years later. Hair growth in the armpits
dinach appears on average 1.5-2 years after pubic, and reaches
peaks at 18-20 years of age. The age of menarche ranges from
from 12 to 14 years (the appearance of menarche at the age of 9.5-10 years, according to
frontier authors should be considered a variant of the norm). Correct
ovulatory cycles are established a year after the onset of menstruation
narhe, and 28-30 days is considered normal menstrual cycle. For
In girls, early puberty should be considered an increase in mo
mammary glands (or appearance of pubertal hair) up to 8 years or less
narche up to 9-10 years, and delayed puberty is the absence of
any secondary signs of puberty in girls in
growing up 13 years of age and older and lack of menstruation at 15 years of age and older.
All somatic changes that occur in boys and are designated
considered as puberty, lasts for 3-4 years.
The onset of noticeable enlargement of the testicles at the age of 11.5-12 years can be considered
be the first sign of the onset of puberty. Testicular growth has stopped
ends by the age of 17-18. Growth and external changes of the external genitalia
organs begin either immediately or 6-18 months after enlargement
testicles (on average from 12-12.5 years) and ends by 16 years. Hair growth
on the pubis occurs with the growth of the external genitalia on average
12-13 years and by 16-18 years reaches the expression characteristic of a husband
ranks Hair growth in the armpits was first noted in sulfur
mid-puberty (13-15 years old). Mustache and beard growth as of now
beginning of puberty, recorded at the end of puberty
(15 years). Wet dreams occur no earlier than 13 years of age, and by the age of 14.5-15 they
observed in most adolescents. Puberty of a boy
ov can be considered premature in the event of the appearance of secondary
sexual characteristics under the age of 10 years, and later - in their absence
at 13.5 years and older.
THE CARDIOVASCULAR SYSTEM
Great changes occur in the cardiovascular system, which in the pubertal period differs in significant anatomical, histological and functional features. During adolescence, the heart undergoes increased growth in all directions (length, thickness and width) and the size of the heart doubles. The left parts of the heart in early childhood exceed the right ones by 1.5 times, and in puberty by 3 times. Lagging growth rates of the right half of the heart during puberty with increased demands on the cardiovascular system can affect the mechanisms of circulatory compensation.
One of the features of the CVS of a teenager is the pronounced discrepancy between the volume of the heart cavities and the capacity of the great vessels, which is expressed in the fact that the diameter of the afferent vessels is larger than the outflow vessels, which creates conditions for increased resistance to blood flow and changes the nature of hemodynamics. Vascular development is largely complete by age 12.
Features of growth and development of the heart depend on the gender and age of adolescents. A rapid increase in heart volume in girls is noted at the age of 10-15 years, and after 16 years the size of the heart does not change. In young men, heart growth occurs less rapidly and continues until the age of 17-18. The increasing pumping force of the heart (stroke volume) and the relative narrowness of the vessels with their tendency to spasm can lead to an increase in peripheral resistance and the development of a hypertrophic variant of the heart in adolescence, as well as to youthful arterial hypertension.
During the entire period of childhood, a decrease occurs, and by the age of 14-15 it corresponds to that of adults (60-84 per minute). Sex differences are revealed already at the beginning of puberty (11-14 years). In boys, the pulse becomes slower than in girls. Rhythm and heart rate, like those, are subject to individual fluctuations during puberty.
The onset of puberty is a powerful factor that significantly influences the level. The age-related dynamics of average indicators is almost similar to the dynamics of growth: up to 10 years of age, blood pressure is higher in boys, from 10-12 years of age - in girls, and from 13-14 years of age, blood pressure in boys increases faster and remains higher throughout the entire adolescence period. In boys, a uniform increase in blood pressure values is noted with age, while in girls, maximum blood pressure is noted at the age of 13-14 years. By the age of 15-18, blood pressure in boys is higher than in girls. Adolescents with high blood pressure in the presence of hereditary disorders, excess body weight, physical inactivity or hyperkinesia, chronic
psychological psycho-emotional stress have a high risk of stabilization and progression of arterial hypertension. In adolescents with early puberty, accompanied by an intense increase in height and body weight, higher blood pressure is noted. In girls, with the onset of menstruation, the value of systolic blood pressure increases, and when a regular cycle is established, it approaches the original value.
Physiological hyperfunction of the hypothalamic-pituitary system causes a high level of production of catecholamines and their precursors, glucocorticoids, thyroidin, which have a sympathetic effect. The latter causes an uneconomical mode of functioning of the cardiovascular system and causes the occurrence of various deviations (“youthful heart”): changes in the configuration and size of the heart (youthful cardiac hypertrophy, small heart, mitral configuration of the heart during its normal sizes), disturbance of certain functions of the heart (automaticity, conductivity, excitability), the presence of functional noise over the area of the heart and large vessels.
Features of the function of cardiac automatism in adolescents are manifested in various nomotopic rhythm disturbances in the form of sinus tachycardia, tachyarrhythmia, bradycardia, bradyarrhythmia, sinus arrhythmia. More often among conduction disorders in adolescents, incomplete blockade of the right branch of the His bundle and disturbance of intraventricular conduction are noted. In adolescents, changes in the conduction of excitation through the atrioventricular system may occur. The syndrome of early ventricular repolarization in adolescence is also not uncommon, which is associated with imperfect neurovegetative control of electrical activation of the heart and the predominance of parasympathetic influences
Impaired myocardial excitability in adolescents manifests itself in the form of extrasystole. Extrasystoles occur at the end of diastole, are characterized by a large coupling interval and are assessed as late extrasystoles, which indicates their benign genesis
In adolescence, physiological hypertrophy of the myocardium of the left or right ventricles is possible. This ECG syndrome is considered a sign of a rapidly growing heart.
MUSCULOSCAL SYSTEM
The period of puberty is characterized by the completion of the formation skeletal system Calcium metabolism depends on the functional state of the digestive and urinary organs, which are associated with the intake and excretion of this element. Changes in hormonal
meostasis, the presence of pathology of the digestive organs, kidneys, insufficient consumption of high-calorie and protein foods, foods containing vitamin D, calcium, phosphorus leads to the development of osteopenia, osteoporosis and deterioration in the formation of bone and cartilage tissue, slowdown or early stopping of the growth of skeletal bones, and the occurrence of diseases bones, joints and spine.
During adolescence, it is often noted that growth and development chest ends by the age of 20 and occurs heterochronically; in adolescence, deformities of the spine, chest, and arthropathy often form. Due to pathology of bone tissue, social insufficiency is possible in the future (restrictions in choosing a profession, employment, etc.).
During adolescence, the most intensive increase in muscle mass is noted. In girls aged 14-15 years, muscle strength indicators reach the level of adult women. In boys, muscle strength increases significantly at the age of 14, but becomes the same as in adults much later. Against the background of pubertal growth acceleration, there may be a lag in the development of coordination of movements, which is accompanied by angularity of movements and clumsiness.
RESPIRATORY SYSTEM
In adolescence, the growth and formation of the accessory cavities of the nose and larynx ends, intensive development of the chest, respiratory muscles, growth of zones and segments of the lungs, proliferation of intercellular connective tissue, increase in the size of acini, elastic and muscle fibers occur, mainly in the walls of the alveoli and interalveolar spaces. During this period, the volume and surface of the lungs, vital capacity, and pulmonary ventilation increase significantly. Breathing becomes deeper and less frequent. The number of respirations at 17-18 years old corresponds to a similar figure in adults (16-20 per minute). By this time, gender differences are formed in the type of breathing (in boys the abdominal type is noted, in girls - the thoracic type) and in indicators of external respiration function, which is mainly due to the more developed muscular system in boys than in girls.
A teenager’s body often lacks oxygen, which is compensated by frequent deep breaths. Adolescents are less resistant to hypoxia and tolerate oxygen deprivation worse than adults and children. Girls adapt less well to a lack of oxygen than boys. A symptom of functional hypoxia can be fainting conditions that occur in adolescents when they are in a room with insufficient air exchange and during inadequate physical activity.
DIGESTIVE ORGANS
In adolescence, the structural and functional development of the digestive system is completed: by the age of 14-15, the formation of teeth (except for 3 molars) ends, by the age of 11-13 - the salivary glands and esophagus. By 10-11 years, the histological structure of the stomach, and by 11-13 years, the salivary glands and esophagus become the same as in an adult.
Adolescents are characterized by hypersecretion and hyperchlorhydria on an empty stomach and during the period of “sequential secretion” (increased amounts of total and free hydrochloric acid). Along with an increase in the evacuation activity of the stomach, spasm of the pyloric region is possible. These features of gastric secretion and motility create favorable preconditions for the formation of functional and pathological changes in the stomach.
An important practical feature is the weakness of the ligamentous apparatus of the abdominal organs characteristic of adolescents, which contributes to the development of ptosis of the organs (usually the stomach).
By the end of puberty, the morphofunctional transformation of the biliary system is completed. It is characterized by pronounced motor lability with the development of hyperkinesia or hypokinesia, depending on the predominance of the parasympathetic or sympathetic autonomic nervous system.
The peculiarities of the secretion of gastrointestinal glands in adolescents cause high vulnerability of the digestive system during prolonged emotional and physical stress, violation of diet, work and rest, and contribute to an increase in the frequency of gastroenterological pathologies in this area. age group with a tendency to progression in case of untimely diagnosis and treatment.
URINARY ORGANS
The urinary system undergoes significant anatomical and functional transformations during puberty. During this period, rapid growth and improvement of the kidney structure occurs. In adolescents by the age of 17-18 years, the mass of the kidney almost doubles compared to that in adolescents aged 10-11 years. At the same time, intensive growth and development are observed Bladder, ureters and urethra, which is especially important when assessing the results of functional studies.
Thus, the processes of growth and development constitute the main characteristic childhood. At the entire stage of maturation (from birth to puberty), the growth and development of the organism proceed in accordance with objectively existing laws of growth.
Growth is a reflection of the systemic development process. An increase in a child’s body length is an indicator of physical development child's body generally. Slowing skeletal growth simultaneously leads to slower growth and differentiation of the brain, skeletal muscles,
myocardium and others internal organs.
Slower growth rate with age. Maximum growth rate
that is noted during the period of intrauterine development, and in postnatal
period - in the first months of life, then in the first year of life, etc.
Uneven changes in growth rate. This law applies
to several periods of life: accelerated growth in children after 2-3 weeks
after birth and the so-called prepubertal growth acceleration
(after 11-12 years). In some children, the so-called “half-growth leap” is also observed between the ages of 5 and 8 years. Most tissues and organs grow according to the above age indicators or synchronously with skeletal growth. At the same time, special characteristics are distinguished for the brain, skull, lymphoid tissue and reproductive organs.
Craniocaudal growth gradient. After birth distal
segments are growing at a faster rate compared to the top or
proximal segments. Throughout postnatal growth
the foot increases relatively more than the lower leg, the lower leg increases relatively more than the thigh, and the neck grows the least
or head height. The presence of a craniocaudal growth gradient underlies the restructuring of body proportions occurring from the period
newborns to adulthood. Only during puberty
During maturation, the growth rate of the trunk is greater than the growth rate of the lower extremities.
Alternation of growth directions. Every single bone and skeleton
generally grow sequentially, alternating growth phases in length and width
well (in diameter) In this case, as in the growth of a child, alternating periods of stretching and rounding are noted.
Sex specificity of growth rate. There is a general trend towards faster skeletal growth in boys. Exception composition
There is only a short period of the 2nd stretch, which occurs at
girls earlier, and at this time they overtake boys in height. At the same time, the rate of skeletal maturation after 2-3 years is faster in girls.
During puberty, girls are superior to their boys in terms of height, body weight, and chest circumference. At the age of 15, the intensity of growth in boys increases, and they are again ahead of girls in their anthropometric indicators. At the same time, we observe an unequal rate of development of many functional systems, especially muscular, respiratory and cardiovascular. Differences are revealed not only in physical performance, but also in psychophysiological indicators.
Asymmetry of growth. With established right-handedness and left-handedness
In a child, the initiation of growth shifts and some advance of them always occurs on the side of the dominant hand.
The growth of the skeleton in length occurs solely as a result of processes occurring in the epiphyseal cartilages, which are the main “organs” of child growth. All complex influences on processes
growth as a result of skeletal extension are mediated through changes in the functional state of the epiphyseal cartilage.
A growing organism develops strictly individually, following its own unique life path. Often physical and mental maturation, functional organization of the motor system and internal organs, i.e. everything that characterizes the so-called biological age does not agree with calendar age, being ahead of it, or, conversely, lagging behind. The term “biological age” refers to the level of physical development and other life processes achieved by an individual. Exists a large number of data on the discrepancy between calendar and biological age, which is why children of the same calendar age react differently to physical and mental stress, and the influence of environmental factors.
Basic criteria of biological age
Maturity, assessed by the degree of development of secondary sexual organs
signs.
Skeletal maturity (order and timing of skeletal ossification).
Dental maturity (timing of eruption of primary and permanent teeth).
The rate of physical development of the child.
The pace of the child’s neuropsychic development.
Lesson No.__
Lesson topic: ANATOMICAL AND PHYSIOLOGICAL FEATURES OF A PERSON IN ADOLESCENCE.
Item: LIFE SAFETY FUNDAMENTALS.
Class: 7 "A", "B", "C"
Location: Municipal educational institution secondary school No. 1 of Yeisk
Quarter: 4
Teacher: Eremenko Marina Grigorievna
Target: consider the anatomical and physiological characteristics of a person in adolescence.
During the classes
Class organization.
Greetings. Checking the class roster.
State the topic and purpose of the lesson.
Updating knowledge.
What should we understand by stress?
Formulate a definition of general adaptation syndrome and name its stages.
Describe the effect of stress on human health.
Formulate the content general principles combat stress.
Checking homework.
Listening to several students' answers to homework (as chosen by the teacher).
Working on new material.
Teacher. Adolescence - period of human life from 12-13 to 18 years. This is the age when biological, mental and social restructuring of the body occurs, leading to maturity.
The boundaries of the transition from childhood to adulthood are relative. Thus, the Old Russian word “youth” meant a child, a teenager, and a young man. “Youth” literally meant “not having the right to speak.” In V. Dahl’s dictionary, a teenager is defined as “a child in his teens” - about 14-15 years old, and a youth is defined as “young”, “a guy from 15 to 20 years old or more.”
During adolescence, human puberty occurs, accompanied by accelerated physical development.
At this time it takes placerestructuring of the activities of all organs and systems.Rapid growth of the body, all organs and tissues occurs, which is mainly due to the influence of sex hormones and thyroid hormone. However, the growth rate different parts bodies are not the same. The most noticeable thing is the increase in the length of the arms and legs. Uneven growth of individual parts of the body causes a temporary loss of coordination of movements - clumsiness, clumsiness, and angularity appear. After 15-16 years, these phenomena gradually disappear.
The development of an organism is a complex biological process; it is characterized not only by a quantitative increase in body weight, but also by qualitative structural changes in many organs and tissues.
Main external indicators of physical developmentadolescent is length, body weight and chest circumference. The state of posture, the degree of muscle development, muscle tone, and the development of subcutaneous fatty tissue are also of great importance.
In adolescence, the individual characteristics of body proportions and appearance person. During this period, the contours of the muscles of the back and chest begin to appear in boys, the roundness of the contours characteristic of early age, the amount of subcutaneous fat layer decreases, at the same time muscle mass increases significantly due to the increased development of the muscles of the trunk and limbs.
In girls, along with the growth and development of the muscular system, the subcutaneous fat layer evenly increases with age, their upper body increases noticeably, their hips become wider, which makes the girl’s figure look more rounded.
The timing of the onset of puberty and its completion are different not only for children of different sexes, but also for children of the same sex.
As a rule, children with rapid growth enter puberty earlier and go through it faster. Children who are prone to excess body weight mature sexually earlier, but excessive body weight - true obesity - inhibits puberty.
During adolescence, various functionalorgan disorders.Often at this age there is an increase in blood pressure, palpitations, increased heart rate, sometimes shortness of breath, headache. More often, deviations in the functioning of the cardiovascular system are observed in adolescents with limited physical activity who do not exercise regularly. physical culture, or, conversely, with excessive physical activity that is not appropriate for age.
Often in adolescence, with intensive reading, computer work and mental stress, various visual impairments appear. When standing for a long time or sitting still for a long time, dizziness may occur, discomfort in the area of the heart, abdomen, legs. The cause of these disorders can be mental and physical stress.
It is known that the physical development of a person at this age is significantly influenced not only by hereditary, but also by many external factors, such as environmental conditions, diet, work and rest, alternation of mental and physical labor, physical activity, etc.
It is very important to complypersonal hygiene rulesin adolescence. Due to endocrine changes in the body, the function of the sebaceous glands increases, which leads to clogging of their ducts and the appearance of acne on the skin, which can become inflamed and suppurate. Therefore, it is necessary to wash regularly and shower daily.
We recommend that girls wash themselves with soap and water in the morning and evening. You should not take baths during menstruation; It’s better to wash yourself in the shower or pour warm water over your body. You cannot swim in open water during menstruation; you must refrain from walking, running and jumping for long periods of time.
So, knowledge of the patterns of one’s development in adolescence is the basis for the formation of a system healthy image life, maintaining and strengthening health, preparing for a full-fledged adult life. At the same time, a healthy lifestyle system must be built taking into account not only general physiological, but also individual characteristics. Thus, you will ensure the harmonious development of your body.
Work on the studied material.
Questions and tasks:
What are the features of human development during adolescence?
What is the importance of personal hygiene for maintaining and promoting health?
Lesson summary.
Teacher. Draw a conclusion from the lesson.
Students. Adolescence is the period of a person’s life from 12-13 to 18 years. This is the age when biological, mental and social restructuring of the body occurs, leading to maturity. During adolescence, human puberty occurs, accompanied by accelerated physical development.
End of lesson.
Homework. Prepare for retelling §6.3 “Anatomical and physiological characteristics of a person in adolescence.”
Giving and commenting on ratings.
Who do we call a teenager? This is the first question that arises when we start talking about the physiological characteristics of adolescence.
The answer to this question is simple at first glance, but in reality it is quite difficult. We have already written that a scientific symposium on age periodization, convened by the Institute of Physiology of Children and Adolescents of the Academy of Sciences of the USSR with the participation of representatives of various specialties, came to the conclusion that adolescents should be considered Girls aged 12 to 15 years and boys from 13 to 16 years .
Thus, adolescence for girls begins and ends one year earlier than for boys, but for both it lasts three years.
It must be emphasized that the boundaries of adolescence are quite arbitrary and in life there are significant individual variations in both the pace of development and the timing of the onset of certain characteristic features for this period.
Adolescence is a natural stage in the development of the body, but at the same time, in its originality and pace, it differs sharply from all other stages of human life. During this period, rapid changes occur in the activities of all physiological systems of the body. The child’s psyche and behavior changes. Moreover, all this receives a unique individual coloring depending on the inherited qualities and the influence of the social environment in which the child lived and developed.
The rapidity of age-related changes occurring in adolescents, significant differences in neuropsychic characteristics, the originality of the pace of qualitative changes in the activity of physiological systems - all these points taken together make educational work with adolescents quite complex and difficult.
The teacher has to deal with a group of students in which individual members are at different levels of development. This mosaic in age characteristics students, due to different rates of their development, requires the teacher to have a special, unconventional approach to solving educational problems.
Some foreign scientists even call this age a period of crises, catastrophes and cataclysms, and talk about the inferiority of the teenage period of development. These statements have no scientific basis and are incorrect.
The enormous factual material available to Soviet science gives grounds to assert that any period of development of a child’s body is complete. The child develops as a harmonious whole, but each stage of its development has its own characteristics.
What is most characteristic of adolescence? This is primarily emotional mobility, curiosity and the desire for new things. At this age, opportunities open up for a teenager to consciously master the knowledge and achievements of mankind accumulated in the process of its historical development, i.e., the experience of mankind. There is a sharp increase in the interest of teenagers in theater, painting, music, literature - in other words, in everything that we call a general word culture. An important feature of adolescence is also the opportunity for conscious and active participation in public life, involvement in work and the development of a creative attitude towards it. Sports and physical education begin to occupy a significant place in the interests and life of a teenager, which largely contribute to strengthening his health and overall development.
It is quite obvious that all of the above creates good preconditions for the creation of an appropriate educational process in adolescence, aimed at the formation of a healthy, comprehensively developed and deeply educated personality - a builder of a communist society. The successful solution of this task by the teacher will largely be facilitated by knowledge of the basic physiological characteristics of the teenage period of development, which determine the uniqueness of this age stage.
From a physiological point of view, adolescence is characterized by increased growth intensity, increased metabolism, increased oxygen consumption, a sharp increase in the activity of the endocrine glands, and, finally, this is the age of puberty.
Never, with the exception of the first two years of his life, does a person grow as intensely as in adolescence. Over the course of a year, growth increases by 6-7 and even 10 cm. Moreover, from the age of 11-12 years, girls are slightly ahead of boys in height; at 13-14 years old, they grow almost equally, and from 14-15 years old, boys are ahead of girls in height, and this excess of height in men over women persists throughout life. Perhaps the limbs elongate most intensively, so long, thin legs are a very characteristic feature of a teenager. Although the adolescent’s body weight also increases along with growth, the increase in weight lags somewhat behind the maximum increase in height. This is why teenagers usually have a thin and elongated appearance.
The cardiovascular system in adolescents develops as follows. The heart grows very intensively during this period, and its volume increases annually by approximately 25%. Thus, increased growth and increase in body weight, which require a greater supply of blood and greater oxygen delivery, are ensured by an increase in the volume of the heart and an increase in its functional activity. Blood pressure increases slightly and fluctuates between 110-115 mm. Hg Art. The heart rate slows down somewhat; if at 11 years old it is 85-90 beats per minute, then by 14-15 years it decreases to 70 beats per minute.
In parallel with the growth of the heart, the diameter of the blood vessels also increases. Although the growth of the circumference of blood vessels occurs slowly and lags somewhat behind the growth of the heart, this circumstance does not prevent the teenager from feeling good. Nevertheless, the rapid restructuring of the circulatory system and the instability of the regulatory mechanisms of the autonomic nervous system can lead to some circulatory disorders, in particular to transient (transient) hypertension, dizziness, etc. Changes in circulatory conditions are especially pronounced in girls, since an increase in weight their hearts begin earlier and end faster. The correct organization of the regime of adolescents is a decisive factor in preventing the development of these phenomena and their rapid elimination.
It is extremely important that in adolescence, due to increased tissue growth, the formation of new vessels and their collaterals occurs. Physical education and physical work are of great importance for the development of the vascular network.
Thus, at the teenage stage of life, there is a significant restructuring of the growth ratios of the heart and blood vessels. In this regard, there is a uniqueness of blood circulation conditions observed in boys and girls at different times due to different rates of puberty. Therefore, adolescence requires a careful and differentiated approach to the dosage of physical activity, so as not to cause overload phenomena, but at the same time provide the necessary training of the cardiovascular system.
The respiratory system also develops intensively during adolescence. The vital capacity of the lungs increases significantly. In boys it increases from 1900-2000 ml at 11 years old up to 2600-2700 ml at 15 years old, and for girls - from 1800-1900 ml at 11 years old up to 2500-2600 ml in 15 years. The number of breaths per minute decreases during this period by almost 2 times: from 20-25 to 14-16.
Breathing becomes less frequent and deeper.
The surface area of the lungs, which in newborns is 6 m 2, by the age of 16-17 it increases to 90 l 2, and the volume of the lungs increases 20 times.
The chest and respiratory muscles develop rapidly, and the pace of their development is most intense during puberty.
During adolescence, the type of breathing is finally formed: for boys - abdominal, and for girls - thoracic.
It is important to recall once again that during puberty, the body of adolescents is less resistant to hypoxia (oxygen starvation) than the body of an adult, although all age-related changes in the activity of the respiratory system are aimed at maximizing the oxygen needs of a rapidly growing organism.
Changes occur in the musculoskeletal system, characterized by a further increase in ossification and an increase in muscle mass. If at 8 years old muscle mass is approximately 27.2% of body weight, then at 15 years old it increases to 32.6%, and at 16 years old - to 44.2%.
The formation of the interventional apparatus of the muscles is completed, and their vascular network develops very intensively.
The ability to coordinate movements reaches a high level. In adolescence, any complexly coordinated movements are available - musical, choreographic, labor, sports, etc., but not associated with great muscle strength, range of motion and endurance. This is the age when a teenager can achieve virtuoso technique in playing musical instruments, extraordinary choreographic skill and great precision and coherence in a variety of work activities. It can be assumed that this is the optimal age period for mastering the technique of complex motor acts. In the vast majority of cases, people who did not engage in physical education in adolescence and did not develop many motor skills in themselves remain much more awkward and helpless in later life than they could have been.
The endocrine glands undergo exceptional restructuring during adolescence. By the age of 11-12 years, the activity of the pituitary gland, especially its anterior lobe, increases significantly. The hormone it secretes causes intensive growth of the human body. It is its influence that explains such a rapid increase in body length in adolescence.
A slight increase in the function of the middle lobe of the pituitary gland at this age can lead to darkening of hair color, since the hormone secreted by it affects pigment metabolism.
Simultaneously with the pituitary gland, the functions of the thyroid gland are enhanced. In the corresponding section, we have already written that the thyroid hormone thyroxine sharply increases metabolism and energy consumption in the body, and also changes the excitability of the central nervous system and causes pronounced emotionality. Increased activity of the thyroid gland leads to some thinness in adolescents, severe excitability, nervousness and relatively rapid fatigue.
If we add to this that in adolescents the inhibitory processes in the cerebral cortex are somewhat weakened, then the sometimes occurring breakdowns in their behavior and violent emotional experiences will become understandable. All this is a consequence of the unique neuro-hormonal background of the body during adolescence.
High school age partly covers adolescence and partly youth.
The specifics of this stage of development, in particular adolescence, are largely determined by the most important biological factor - puberty.
Due to significant changes at this stage of ontogenesis, changes in the body associated with puberty, the so-called transitional period or puberty is especially distinguished. It distinguishes the following stages:
1. Prepubertal period (12 - 13 years);
2. Actually - the puberty period, which occurs in two phases: the first phase - boys 13 - 15 years old, the second phase - boys 15 - 17 years old;
3. Post-pubertal period (adolescence).
At high school age, significant development is observed in all higher structures of the central nervous system. By the period of puberty, the weight of the brain compared to the weight of the brain of a newborn increases 3.5 times in young men. Until the age of 13–15 years, the development of the diencephalon continues. There is an increase in the volume and nerve fibers of the thalamus, differentiation of the hypothalamic nuclei. By the age of 15, the cerebellum reaches adult size.
In 13-year-old adolescents, the ability to process information, quickly make decisions, and increase the efficiency of tactical thinking significantly improves. The smooth improvement of brain processes in students is disrupted as they enter puberty
maturation - for girls at 11 - 13 years old, for boys at 13 - 15 years old. This period is characterized by a weakening of the inhibitory influences of the cortex on underlying structures and a “riot” of the subcortex, causing strong excitation throughout the cortex and increased emotional reactions in adolescents. The activity of the sympathetic nervous system and the concentration of adrenaline in the blood increases. Blood supply to the brain deteriorates. Such changes lead to disruption of the fine mosaic of excited and inhibited areas of the cortex, disrupt coordination of movements, and impair memory and sense of time. The behavior of adolescents becomes unstable, often unmotivated and aggressive. The role of the right hemisphere in behavioral reactions temporarily increases. In a teenager, the activity of the second signaling system (speech functions) worsens, and the significance of visual-spatial information increases. All types of internal inhibition are observed, the formation of conditioned reflexes, consolidation and alteration of dynamic stereotypes are difficult.
Hormonal and structural changes during the transition period slow down body length growth and reduce the rate of development of strength and endurance. With the end of this period of restructuring in the body (after 15 years in boys), the leading role of the left hemisphere of the brain increases again, and cortical-subcortical relationships with the leading role of the cortex are established. The transition from adolescence to adolescence is marked by an increased role of the anterior frontal tertiary fields and a transition of the dominant role from the right to the left hemisphere (in right-handed people). This leads to significant improvement in the abstract - logical thinking, development of the second signaling system and extrapolation processes. The activity of the central nervous system is very close to adult levels. However, it is also distinguished by smaller functional reserves and lower resistance to high mental and physical stress.
A teenager’s visual acuity noticeably increases, the field of vision expands, binocular vision improves, and the discrimination of color shades improves. Depth vision continues to develop until 16 - 17 years of age, when it reaches final values, and light sensitivity increases until 20 years of age.
At the age of 15 - 16, an insufficient ability to maintain balance on a movable support often manifests itself. After 16 years of age, the ability to maintain balance significantly improves and stabilizes.
In adolescence and young adulthood, vestibulovegetative reactions of the sympathetic type intensify, causing an increase in heart rate. As a result of vestibular loads, various emotional reactions arise, the flow of subjective time slows down, which disrupts the assessment of time intervals.
At the age of 16, the accuracy of distinguishing muscle tension is practically no different from the level of adults. Thanks to a clear perception of proprioceptive information, the ability to control not only individual muscles, but even individual motor units increases.
Significant changes occur in the length, weight, composition and proportions of the body, in the functioning of various organs and systems. Muscle mass reaches 32% of body weight by the age of 15, and by the age of 17-18 it reaches the adult level (44%). At the age of 8 - 18 years, the length and thickness of muscle fibers changes significantly. Maturation of fast, fatiguable glycolytic muscle fibers occurs, and with the end of the transition period, an individual type of ratio of slow and fast fibers in skeletal muscles is established.
The maturation of the musculoskeletal system and central regulatory mechanisms ensures the development of the most important qualitative characteristics of motor activity.
During high school age, changes occur in the blood, circulation, and breathing. The number of red blood cells and hemoglobin increases, the number of leukocytes decreases. At high school age, the circulatory system is fully formed. The mass and volume of the heart increase. The weight of the heart compared to the weight of the heart of a newborn increases by 16 years by 11 times. The minute volume of blood increases, the heart rate decreases.
The respiratory system is improved. The duration of the respiratory cycle and the rate of inhalation increase, and exhalation becomes longer. The tidal volume increases, the respiratory rate per minute decreases. By the age of 16 - 17 years, the development of respiratory functions is largely completed.
By high school age, the digestive system completes its development of all basic functions.
At high school age, skin temperature gradients from the trunk to the distal extremities increase. Daily fluctuations in body temperature become more pronounced. The importance of chemical thermoregulation decreases and the role of physical thermoregulation increases.
During high school age, changes occur in metabolism and energy. The predominance of assimilation processes over dissimilation processes decreases.
An increase in body weight and increased physical activity cause an increase in daily energy expenditure.
By adolescence, all the basic mechanisms of movement control characteristic of an adult body have been formed - reflex ring control with a feedback system and program control using the mechanism of central commands.
A high level of combination of motor and autonomic reactions is achieved.
Adolescents and young men more accurately assess interoceptive and proprioceptive information about the functional state of their own body in the process of work.
Conclusion on paragraph 1.2
Adolescence for both boys and girls can be characterized by the enhanced development and formation of all organs and systems, which is accompanied by an increase in physiological indicators that practically take on the values of an adult. With constant training, movement control reaches high level, allowing you to achieve high results in various types sports
The specifics of this stage of children's development are largely determined by the most important biological factor - puberty. The process of puberty, especially its initial period, is accompanied by significant changes in the activity of all physiological systems. The onset of puberty occurs at different calendar ages in girls and boys: for girls it is 11-12 years old, for most boys it is 12-13 years old.
At this time, the balance of nervous processes is disturbed, excitation becomes more powerful, the increase in the mobility of nervous processes slows down, and the differentiation of conditioned stimuli significantly worsens. The activity of the cortex is weakened, and at the same time the second signaling system. All functional changes lead to mental imbalance and conflict in the adolescent.
Adolescence (middle school) age (from 11-12 to 14-15 years). This age coincides in time with the second period of traction, the distinctive feature of which is the growth of the body in length due to the growth of the limbs. The development of the skeleton is uneven, and the body proportions established at the previous age change: while the bones of the spine and limbs grow at a rapid pace, there is a lag in the growth of the chest, which becomes very narrow. In his general appearance, the teenager becomes thin, “narrow-long.” There is a disproportion in the development of muscles and bones: in their development, muscles do not keep up with the growth of bones and only stretch due to their elasticity; this leads to a deterioration in the coordination of movements, which in a teenager become awkward and angular; Often teenagers do not know “where to put their hands.” At the same time, during this period (puberty), muscle strength increases, which, however, is not yet accompanied by the development of muscle endurance; this discrepancy is often the cause of muscle overstrain, since teenagers, experiencing a surge of strength, often take on muscular work, which in its intensity and duration far exceeds their capabilities. Increased growth of the bones of the spine, pelvis, and limbs may be accompanied by disruption of their structure and curvature as a result of heavy muscle work associated with excessive muscle tension. All this forces us to be very attentive to the organization of physical education for adolescents, to select and dose exercises in accordance with the specified characteristics of their age. This requirement is also dictated by the characteristics of the adolescent’s cardiovascular system: in terms of its rate, the growth of the heart surpasses the growth of the whole body at this age; While the weight of a teenager’s heart increases by more than 2 times, body weight increases by only 1.5 times. The increase in the power of the heart exceeds the possibilities for its work that are still provided by the relatively small lumens of the arteries, as a result of which blood pressure increases significantly during muscle work. Excessive strength exercises that require sudden strong movements or straining, as well as high-speed running competitions, are contraindicated for adolescents. The most suitable for this age are moderate-intensity physical exercises with relatively long muscular work (for example, cross-country skiing, ice skating, etc.).
Although the development of the anatomical structure of the brain is complete by this age, intensive functional development of the central nervous system, especially the cerebral cortex, continues. The number and complexity of associative pathways between different parts of the cortex are increasing, the physiological mechanisms of speech, reading and writing are further developing, and the role of the second signaling system in conditioned reflex processes is increasing. However, the characteristics of endocrine activity specific to a teenager leave their mark on the functioning of the brain: there is increased excitability, imbalance of nervous processes, rapid fatigue of nerve cells and, as a result, a sharp, seemingly unmotivated change in the mood and behavior of a teenager. All this is largely explained by the process of puberty occurring at this age, which for girls begins at 11-12, and for boys somewhat later, at 12-13 years old, and ends on average at 15 for girls, and at 16 for boys. -17 years old. During these years, girls overtake physical development boys: at the age of 11-15 they are superior to boys in both height and weight, although at the previous age boys had an advantage in this regard. But, starting from the age of 15, boys again overtake girls in physical development and maintain this advantage over subsequent years.
Puberty introduces drastic changes in the functioning of the body. The gonads are glands mixed type, performing a dual function related to both internal and external secretion: 1) in a mature state, they produce germ cells; 2) secrete sex hormones into the body, which have a very strong and varied effect on the activity of internal organs. Both of these functions of the sex glands are not activated simultaneously: endocrine activity is much faster than the production of germ cells. As a result, long before puberty, secondary sexual characteristics appear in adolescents - changes in general body shape (for example, enlargement of the mammary glands, intense deposition of fat in the subcutaneous tissue, rapid growth of the pelvic bones in girls, a breaking voice and the appearance of facial hair in boys and etc.). At the same time, adolescents develop sexual desires, become interested in sexual issues, etc. At the same time, since sexual desires and arousals occur before puberty, the internal balance of the body is sharply disturbed, which is reflected in the behavior of a teenager. In this transitional period, children need especially attentive pedagogical guidance, in switching their rapidly growing energy towards healthy manifestations - serious intellectual interests, art classes, active participation in public life and productive work, etc.
In the absence of such pedagogical influence and guidance, sexual desires in adolescents can take forms harmful to their health and psyche (masturbation). By the end of this age period Hormones of the sex glands inhibit the activity of the pituitary gland and thymus gland, which previously stimulated the growth of the body.
