How the proportions of the body are changed with age. Growth and proportions of the body at different stages of the development of the body. Cell structure and function
| Content |
|---|
| Age periods of human development |
| The main stages of individual human development |
| Prenatal ontogenesis |
| Fifth-eighth week |
| Third-ninth months |
| Critical periods of Ontogenesis |
| Postnatal ontogenesis. Period of newborn |
| Breeding |
| Early childhood period |
| Period of the first childhood |
| The period of the second childhood |
| Teenage years |
| Youth age |
| Mature, elderly, senile age |
| Individual differences in the process of growth and development |
| Factors affecting individual development |
| Sizes and proportions, body weight |
| Acceleration |
| Conclusion |
| Literature |
| All pages |
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Sizes and proportions, body weight
Among the sizes of the body are allocated total (from FR. Total - entirely) and partial (from lat. Pars - part). Total (general) body sizes are the main indicators of human physical development. These include the length and weight of the body, as well as chest girth. Partial (partial) body sizes are the terms of the total size and characterize the value of individual parts of the body.
Body sizes are determined by anthropometric examinations of various contingents of the population.
Most anthropometric indicators have significant individual fluctuations. Table 2 shows some averaged anthropometric indicators in postnatal ontogenesis.
The proportions of the body depend on the age and gender of the person (Fig. 4). The length of the body and its age changes are usually individual. So, for example, differences in the length of the body of newborns with normal in pregnancy periods lie within 49-54 cm. The greatest increase in the length of the body of children is observed in the first year of life and averages 23.5 cm. In the period from 1 to 10 years, this indicator Gradually decreases by an average of 10.5 - 5 cm per year. From the 9th year of age, sex differences are beginning to appear in growth rates. Body mass from the first days of life and about 25 years old in most people gradually increases, and then remains unchanged.
Fig.4 Changes in the proportions of body departments in the process of human growth.
Km - middle line. The numbers on the right show the ratios of body parts in children and adults, the numbers below are age.
table 2
Length, weight and surface area of \u200b\u200bthe body in posttyatal orthogynes
After 60 years of body weight, as a rule, begins to gradually decrease, mainly as a result of atrophic changes in tissues and reduce the content of water in them. The total body mass consists of a number of components: the masses of the skeleton, muscles, fatty fiber, internal organs And skin. In men, the middle mass of the body is 52-75 kg, in women - 47-70 kg.
In the elderly and old age, characteristic changes are traced not only the sizes and mass of the body, but also its structure; These changes are exploring a special science of gerontology (Gerontos - old man).
It should be emphasized that the active lifestyle, regular classes physical culture Slow aging processes.
boys 8-12 years old
girls 8-11 years old
boys 13-16 years old
girls 12-15 years old
boys 17-23 years old
girls 16-21 year
men 24-35 years old
women 22-35 years old
men 36-60 years old
women 36-55 years old
men 61-74 years
women 56-74 years
Newborn period (neonatal period) - the first 4 weeks
Breeding - 1 month - 1 year
Early childhood - 1-3 years
First childhood - 4-7 years
Second childhood
Teenage years
Youth period
Mature age (1 period)
Mature age (2 periods)
Old age
Senile age - 75-90 years old
Long-livers - 90 years and more
Development -it is a potential and qualitative change, incl. 3 main factors:
The growth process is continuous and is wearing a wave-like character.
Changing the proportions of the body is an external development indicator.
Factors affecting growth and development:
Food
Muscular activity
Season
Psychological stress
Socio-economic situation, etc.
3. Higher nervous activity, its age characteristics. Types of GNI in children, value in the learning process and education.
The bark and the nearest subcortical structures are the highest department of the CNS - the substrate of the implementation of complex reflex reactions underlying the highest nervous activity. The idea of \u200b\u200bthe reflex nature of the activities of the High Departments of the Central CNS was first put forward by I. M. Sechenov. Before I. M. Sechenov dominated the idea of \u200b\u200bthe separation of body and "soul" and the question of the possibility of an objective study of mental activity was not even put.
Ingenious ideas I. M. Sechenov were confirmed experimentally I. P. Pavlov. I. M. Sechenov and I. P. Pavlov are the founders of a reflex theory, materialistically explaining the principles of reflection by man of the surrounding material world. I. P. Pavlov developed a reflex theory and created the doctrine of the highest nervous activity. He managed to open a nervous mechanism, providing complex forms of human response and higher animals on the impact of the external environment. This mechanism is a conditional reflex.
The combination of complex forms of the activities of the bark of large hemispheres and the subcortical formations closest to it, which ensures the interaction of a holistic organism with an external environment, is called higher nervous activity.
In the teaching about the highest nervous activity, the physiological mechanisms of the most complex processes of reflection by the person of the external objective world are opened, which gave a brilliant natural score substantiation of the Leninsky theory of reflection.
Reflex is a response of the body to irritating receptors carried out with the participation of the nervous system.
Let's give some idea of \u200b\u200bconditional and unconditional reflexes. Features of unconditional I. conditional reflexes. The main form of activity of the nervous system is reflex. All reflexes are customary to divide the unconditional and conditional. Unconditional reflexes are congenital, genetically programmed organism reactions peculiar to all animals and man. 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, genital congenital reflexes are finally formed in humans only by the time of puberty in adolescence. Unconditional reflexes have conservative, little changing reflex arcs passing mainly through the subcortex departments of the central nervous system. The participation of the cortex in the flow of many unconditional reflexes is optional.
Conditional reflexes are individual adaptive reactions arising based on the formation of a temporary connection between the conditional irritant (signal) and the undisporaneflex actual act. Conditional reflexes are always individually peculiar.
Reflex arcs of conditional reflexes are formed in the process of postnatal ontogenesis. They are characterized by high mobility, the ability to change under the action of environmental factors. Reflex arcs of conditional reflexes through the highest department of the brain of KGM.
For the formation of conditional reflex, the following major conditions are needed: the presence of a conditional stimulus, the presence of unconditional reinforcement. The conditional stimulus should always be somewhat preceded by an unconditional reinforcement, that is, to serve as a biologically significant signal, the conditional stimulus according to its exposure should be weaker than the unconditional stimulus; Finally, to form a conditional reflex, a normal (active) functional state of the nervous system is necessary, primarily its leading brain department. The conditional stimulus can be any change! Powerful factors contributing to the formation of convention and reflex activity are encouraging and punishment. At the same time, the words "promotion" and "punishment" we understand in a broader sense than just "satisfaction of hunger" or "painful impact."
Thus, educational work, in its essence, is always associated with the development of children and adolescents, various conditionally reflex reactions or their complex interconnected systems.
Age Features of the GNP
The child is born with a set of unconditional reflexes of reflex arcs of which begin to form in the 3rd month of prenatal development. Thus, the first sucks and respiratory movements appear in the fetus at this stage of ontogenesis, and the active movement of the fetus is observed on the 4-5th month of intrauterine development.
Simple food conditional reactions, despite the morphological and functional immaturity of the brain, arises for the first second day, and by the end of the first month of development, conditional reflexes from the motor analyzer and the vestibular apparatus are formed: Motor and temporary. All these reflexes are very slowly formed, they are extremely gentle and easily braked. Since the second month of life, hearing, visual and tactile reflexes are formed, and by the 5th month of development, the child is produced by all major types of conditional braking.
By the end of the first year of development, the child distinguishes the taste of food and odors, the shape and color of objects, distinguishes the voices and faces. Movement is greatly improved, some children start walking. The child is trying to pronounce separate words ("Mom", "Pope", "grandfather", "Aunt", "Uncle", etc.), and he has conditional reflexes for verbal irritants. Consequently, at the end of the first year, the second signal system is being developed in full swing and its joint activity is formed.
In the second year, the development of the child is improved by all types of conditionally reflex activities and the formation of the second signal system continues, vocabulary (250-300 words) is significantly increased; Direct stimuli or their complexes begin to cause verbal reactions. If a one-year-old child has conditional reflexes on direct stimuli, they are 8-12 times faster than the word, then in two years the words acquire alarm value.
Decisive in the formation of a child's speech and the entire second signaling system as a whole has a child communication with adults, i.e. the surrounding social environment and training processes. Children, deprived of the language environment, communicating with people, do not speak speech, moreover, their intellectual abilities remain at a primitive animal level. 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 five years are able to learn to speak only in limited limits, and not the words have already been returned only after 10 years.
The second and third year of life are distinguished by lively indicative and research activities. The child stretches to each subject, touches it, feeling, pushes, tries to raise, etc. This feature is largely due to the morphological ripening of the brain, since many motor cortical zones and skin-muscle sensitivity zones are already reaching for 1-2 years. sufficiently high functional fullness. The main factor stimulating the ripening of these cortical zones is muscle contraction and high motor activity of the child. The restriction of its mobility at this stage of ontogenesis significantly slows mental and physical development.
A period of up to three years is also characterized by the extraordinary ease of formation of conditional reflexes on a variety of stimuli, including size, heaviness, remoteness and painting of objects. A feature of a two-year-old child is also the ease of developing dynamic stereotypes. Conditional connections and dynamic stereotypes in children under three years are distinguished by extraordinary strength, so their alteration for a child is always an unpleasant event.
Age from three to five years is characterized by the further development of speech and improving the nerve processes (their strength, mobility and balance increases), the processes of internal braking acquire the dominant value, but the delayed braking and the conditional brake are worked out with difficulty. Dynamic stereotypes are still produced as easy. Their number increases every day, but their alteration no longer causes violations of the highest nervous activity.
By five to seven years, the role of the word signal system and children begin to speak fluently. This is due to the fact that only for seven years of postnatal development, the material substrate of the second signal system is functionally matured.
From 7 to 12 years old (younger school age) -ceiod about the "calm" development of the highest nervous activity. The strength of the processes of braking and excitation, their mobility, balance and mutual induction, as well as a decrease in external braking force ensure the possibilities of widely learning the child. This is the transition "from reflex emotionality to intellectualization of emotions." However, only on the basis of learning a letter and reading the word becomes the subject of the child's consciousness, which is more than moving away from related images of objects and actions. A minor deterioration in the processes of higher nervous activity is observed only in the 1st grade in connection with the adaptation processes to school.
Of particular importance for the teacher and the educator has the next age period - adolescent (from II - 12 to 15-17 years). This is the time of large endocrine transformations in the body of adolescents and the formation of the secondary sexual signs, which in turn affects the properties of the highest nervous activity. The equilibiousness of nerve processes is violated, the excitement becomes greater force, the growth of the mobility of nerve processes is slowed down, the differentiation of conditional stimuli is significantly deteriorated. The activity of the cortex is weakened, and at the same time the second signal system. All functional changes lead to mental impassable teenager (hot temper, "explosive" response even for minor irritation) and frequent conflicts with parents and teachers. The position of the teenager, as a rule, is aggravated by increasingly complicated requirements for him from adults and primarily schools.
Only the right healthy regime, a calm atmosphere, a firm program of classes, physical culture and sports, interesting extracurricular work, goodwill and understanding from adults are the main conditions so that the transition period has passed without the development of functional disorders and related complications in the child's life.
Senior school age (15-18 years) coincides with the final morphofunctional ripening of all physiological systems of the human body. The role of cortical processes increases in the regulation of mental activity and physiological functions of the body, the leading value is obtained by cortical processes that ensure the functioning of the second signal system. All properties of major nerve processes reach the level of an adult.
4. General patterns of the development of the skeleton: the functions of the musculoskeletal system. Chemical composition and growth of children's bones. Flatfoot. Prevention.
Movement, moving in space is one of the most important functions of living beings, including a person. The function of movements in person performs musculoskeletal system,unifying bones, their compounds and skeletal muscles. The musculoskeletal system is divided into passive and active part. TO passive partbelieve the bones and their compounds, on which the nature of the movements of body parts depends, but they themselves cannot perform movements. Active partcome on skeletal muscles that have ability to reduce and lead in the movement of the skeleton bone (bone levers).
The specifics of the support apparatus and human movements are associated with the vertical position of its body, straightening and work. The adaptations to the vertical position of the body are in the structure of all skeletal departments: spine, skulls and limbs. The closer to the sacrum, the more massive vertebra (lumbar), which is caused by a large load on them. In the place where the spine, which takes over the severity of the head, all the body and the upper limbs, relies on the pelvic bones, the vertebra (sacral) has grown into one massive bone - the crushes. The bends create the most favorable conditions for maintaining the vertical position of the body, as well as to perform springs, spring functions when walking and running.
The lower limbs of a person withstand a large load and the functions of movement are fully assumed. They have a more massive skeleton, large and sustainable joints and vaulted foot. Developed longitudinal and transverse stops are available only in humans. Points of foot support are the heads of tie bones in front and the heel hill at the back. Spring foot arches distribute the severity per stop, reduce shock and shock when walking, inform smoothness. The muscles of the lower limb possess more power, but at the same time less diversity in their structure than the muscles of the upper limb.
The release of the upper limbs from the functions of the support, adapting them to work led to the relief of the skeleton, the presence of more muscles and the mobility of the joints. A person's hand acquired a special mobility, which is provided by long clavies, the position of the blades, the shape of the chest, the structure of the shoulder and other top limbs. Thanks to the leading the upper limb set up from the chest, with the result that the hand acquired significant freedom in his movements.
The blades are located on the back surface of the chest, which is flattened in the front-crisp (sagittal) direction. The articular surfaces of the blade and shoulder bones provide greater freedom and a variety of movements of the upper limbs, their big scope.
In connection with the adaptation of the upper limbs to labor operations, their muscles are functionally more developed. The mobile human brush is of particular importance for labor functions. A large role in this belongs to the first finger of the brush due to its big mobility and the ability to oppose the rest of the fingers. The functions of the first finger are so great that when it loss, the brush almost loses the ability to capture and hold objects.
Significant changes in the structure of the skull are also associated with the vertical position of the body, with labor activity and speech functions. The brain department of the skull clearly dominates the facial. The facial department is less developed and is located under the brain. Reducing the size of the facial skull is associated with relatively small sizes of the lower jaw and its other bones.
The person with the functions of the musculoskeletal system is associated with the advantage of the remaining representatives of the organic world: purely human qualities - work and speech, which were the most important driving forces of anthropogenesis.
Improving polytechnic training, physical education and military-patriotic student training requires knowledge of the knowledge of the anatomy-physiological characteristics of the musculoskeletal system of children and adolescents, the physiological foundations of exercise and physical labor. The reasons for such close attention to the development of the physical abilities of the child are quite understandable. The human body on any age stage is a single integer. All its physiological systems: nervous, musculoskeletal, cardiovascular, etc., are closely interrelated, the functional changes in one physiological system lead to a change in the activity of the other.
Special importance muscular activity has a child for a developing body. Limiting mobility or muscle overload violates harmonicity of development and are an important pathogenetic factor in the development of many diseases. That is why training and education involve not only the development of the mental abilities of schoolchildren, but also their physical improvement. It is quite natural that this task lies not only on the shoulders of teachers of physical education and labor, but also is a paramount task for every teacher and educator.
Chemical composition bone tissue and its age-related changes
The bone consists of two types of chemicals: inorganic and organic. Inorganic substances include water and salts (mainly calcium salts). The organic substance of the bone is called Ossein. In the fresh bone of about 50% of water, 22% of salts, 12% ossein and 16% fat. Dehydrated, skimmed and bleached bone contains approximately 1/3 osseyn and 2/3 inorganic substances.
Special specific physico-chemical combination of organic and inorganic substances in the bones and determines their basic properties - elasticity, elasticity, strength and hardness. This is easy to make sure. If the bone is put in hydrochloric acid, the salts will dissolve, ossein will remain, the bone will save the form, but it will become very soft (it can be tied to the node). If the bone is combustion, then organic substances burned, and the salts will remain (ash), the bone will also retain its shape, but it will be very fragile. Thus, the elasticity of the bone is associated with organic substances, and the hardness and the fortress - with inorganic. The human bone withstands the pressure of 1 mm 2 15 kg, and the brick is only 0.5 kg.
The chemical composition of the bones is inconsistent, it changes with age, depends on the functional loads, nutrition and other factors. Children's bones are relatively more than in the bones of adults, Ossein, they are more elastic, less susceptible to fractures, but under the influence of excessive loads, the bones that carry out a large load, richer than bones, are less damaged than bones. Power supply only vegetable or animal food can also cause changes in the chemical composition of bones. With a shortage of vitamin D food in the bones of the child, lime salts are poorly postponed, the dates of the ossification are broken, and the lack of vitamin. And can lead to thickening bones, launching channels in bone tissue.
In the old age, the amount of Osein decreases, and the number of inorganic salts, on the contrary, increases, which reduces its strength properties, creating prerequisites for more frequent bone fractures. To the old age in the region of the edges of the articular surfaces of the bones, the bridges of bone tissue may appear in the form of spikes, increased, which can limit mobility in the joints and cause painful sensations when driving. On the mechanical properties of the bone can be judged on the basis of their fortress for compression, stretching, breaking, breaking, etc. on the compression of the bone is ten times tightly cartilage, five times more fixed reinforced concrete, twice as many lead strength. On the stretching compact substance of the bone withstands the load to 10-12 kg per 1 mm 2, and 12-16 kg on compression is 12-16 kg. According to the resistance to the break, the bone in the longitudinal direction exceeds the resistance of the oak and is equal to the resistance of the cast iron. For example, it takes approximately 3 thousand kg for the fragmentation of the femoral bone of pressure, for the fragmentation of the tibial bone of at least 4 thousand kg. The organic substance of the bone - ossein can withstand the stretching load of 1.5 kg per 1 mm 2, for compression - 2.5 kg, the fortress of tendons is 7 kg per 1 mm 2, despite the significant fortress and durability of the bone of a very plastic organ and can be rebuilt Throughout the human life.
A child is not a miniature of an adult, his body has its anatomy - physiological features that are constantly changing throughout the entire childhood period. Anthropometric research methods are used to study physical development that allow quantitative and qualitative development indicators, develop standards of physical development of children and adolescents for each age, gender and region of residence:
Somatometric - measurement of growth, mass, thoracic circumference;
Somatoscopic - determination of the development of the skeleton, the forms of the spine, chest, legs and feet, posture, the development of musculatures and subcutaneous - fatty fiber, the degree of sexual development, the appearance and change of teeth;
Physiometric - determination of the life capacity of the lungs, the strength of the hand of hand, the frequency of respiration and heart abbreviations, blood pressure, etc.). The growth of the child is a direct reflection of the process of its development. If the baby does not grow - it does not develop! An increase in body length is a very important and subtle indicator of the child's development as a whole. After birth, a particularly intensive child grows in the first year of life, adding in growth by 10-11 centimeters. After a year to 3-5 years, the growth rate is reduced. There is the so-called first rounding period, or the first completeness. At this age, the children have a truly "angel" view: the body, the handles and legs are reminded in the form of a cylinder, a good pronounced subcutaneous fat gives the kid a chubby look, on the handles and legs - threads, the tumors, the tummy looks always full and lightly outward. At this time, all the kids are similar to each other with their puppet crop. At the end of this period, the child begins to declare himself and disintegrated his own "I".
In 5-6 years, Angelsky look gradually disappears, the child is drawn up, his "plump" as it may be "dries", becoming visible muscle contours and bone landmarks, the baby very quickly grows out of his clothes.
In the end elementary school, about 8-10 years old, the period of prepubertate rounding occurs when the growth rates are somewhat slow compared to the accumulation rate of subcutaneous fat. As a rule, since this age, the appetite is sharply intensified and the question "what to feed the child?" Replaced by the concern "how to feed it." As mentioned above, during this period, the girls overtake boys and in growth, and in mass, and in relation to sexual development. After 2-3 years, everything becomes in its place, the boys again turn out to be ahead of girls in all respects. BODY MASS.
When body weight from 3500 to 4000 g, they talk about a big child. Children born with a body weight of more than 4,200 g are considered "children-giants". The mass of the body of the premature child is 2500 g and below. During the first days of life, the labored body mass is reduced by 150-300 g (transient (physiological) mass loss) and is about 5 - 9% of the mass at birth. Reducing it by more than 9 -10% (more than 300 g) is considered a pathological loss of mass.
The physiological loss of mass is due to the following factors: evaporation of moisture from the skin and when breathing; mummification of the umbilical residue; insufficient nutrition and drinking in the first days of life; vomiting of swallowed births by the accumulative liquid; relative starvation; Departure of meconia, urine. The body weight of children over 1 year is calculated by formulas:
For children from 2 to 10 years M (kg) \u003d 10 + 2n, where N is the age of the child in years. Over 10 years old: m \u003d 30 + 4 (N-10), where N is the age of the child in the years. Changing the proportions of the body in the process of child development
The growth of various parts of the body during the life of the child also occurs unevenly. So, from the moment of birth to an adult condition, the height of the head is doubled, the length of the body is three times, the length of the hands is four times, five times. That is, human growth occurs to a greater extent due to the elongation of the legs. Due to the uneven growth of the skeleton in length throughout the childhood, the body proportions are changed. We would be very much upset if in an adult condition retained the proportions of the newborn period! The newborn has a relatively big head - it accounts for the fourth part of all its growth, short handles and legs. In an adult, the height of the head is only a tenth of the body's length. The median point in the newborn corresponds to the navel, and in an adult it is in the design of the pubis. It is noted that a large activation of growth, like everyone in wildlife, occurs in the spring-summer period, in the fall and in winter the child is not so intense. In the cold climate and in the conditions of high mountains, people's growth are usually lower. The growth rates of the system of organs and tissues of the child are different. The growth of all major internal organs, bones and muscles have a fairly unique aspantage, corresponding to periods of accelerated growth. The brain is accelerated only in the first years of life and by five years almost reaches the size of an adult. The growth of immune lymphoid tissue, its relative mass reaches 200% aged 3 to 6-7 years. This is a normal age physiological response of lymphoid tissue hypertrophy, when the child can be forgiven increased lymph nodes, to identify the increasing adenoids, see huge little almonds. If they are not inflamed and "do not interfere with living", they do not need to touch them, but you should wait patiently when they themselves begin to decrease. Such a reverse development process begins with the advent of the signs of puberty. The development of the organs of the sexual system: until time, this system is in the "dormant" state, AC 11-12 years old in girls, and from 12-13 years old, boys begins to "wake up" At the same time, the boys increase the scrotum and testicles, the genital member, the prostate gland, and the girls begin to develop dairy glands, uterus, pipes, ovaries, external genital organs.
Parents are very important to know and take into account such asyinchrony of the growth of various organs and systems of the child. This can protect the family from unnecessary unrest and adopting ill-conceived decisions, especially related to the possibility of removal of adenoids and almonds.
Cell structure and function
The human body has a cellular structure. Cells are in the intercellular substance, which provides them with mechanical strength, nutrition and breathing. The lowest unit is the smallest unit of building all living restrictions, with the exception of viruses capable of metabolism and self-reproduction.
The cytoplasm is an internal semi-winged medium in which the kernel and all organides of the cell are located. It has a fine-grained structure, penetrated by numerous thin threads. It contains water dissolved salts and organic matter. The main function of the cytoplasm is to combine into one integer and ensure the interaction of the core and all organides of the cell.
The outer membrane surrounds the cell with a thin film consisting of two layers of the protein, between which the fat layer is located. It is permeated with numerous small pores through which the exchange of ions and molecules between the cell and the medium is carried out. The endoplasmic network (EPS) is a complex system of channels and cavities membranes that permeate the entire cytoplasm. Epsows there are two types - granulated (rough) and smooth. On the membranes of the granular network there are many smallest television - ribosomes; There are no them in the smooth network. The main function of EPS is to participate in the synthesis, accumulation and transportation of the main organic substances produced by the cell. The protein is synthesized into granular, and carbohydrates and fats - in smooth EPS.
Ribosomes are small tales, a diameter of 15-20 nm, consisting of two particles. In each cell their hundreds of thousands. Most ribosomes are located on the membranes of granular EPS, and part in the cytoplasm. They include proteins and r-RNA. The main function of ribosomes - protein synthesis.
Mitochondria is small tales, 0.2-0.7 microns. Their amount in the cell reaches several thousand. They often change the shape, sizes and location in the cytoplasm, moving into the most active part of them. The outer cover of mitochondria consists of two three-layer membranes. The outer membrane is smooth, internal - forms numerous growths, on which respiratory enzymes are located. The internal cavity of mitochondria is filled with a liquid in which ribosomes, DNA and RNA are placed. New mitochondria are formed when dividing old. The main function of mitochondria - synthesis ATF.. They are synthesized a small amount of proteins, DNA and RNA.
Plasts are characteristic of only plant cells. There are three kinds of plastic - chloroplasts, chromoplasts and leucoplasts. They are capable of mutual transition to each other. Plasts are multiplied by division.
Chloroplasts have green, oval shape. The size of them is 4-6 microns. From the surface, each chloroplast is limited to two three-layer membranes - outer and internal. Inside it is filled with a liquid, in which several dozen special, interconnected cylindrical structures are located - Grand, as well as ribosomes, DNA and RNA. Each grana consists of several dozen plane flat bags from membranes. In cross-section, it has a rounded shape, the diameter of its 1 μm. All chlorophyll focuses in the grams, the process of photosynthesis occurs in them. The carbohydrates formed at the same time are accumulated in chloroplast, then enter the cytoplasm, and from it to other parts of the plant.
Chromoplasts define red, orange and yellow color painting, fruits and autumn leaves. They have the form of multifaceted crystals located in cytoplasm cells.
The leukoplasts are colorless. They are contained in unpainted parts of plants (stems, tubers, roots), have a rounded or row shape (5-6 microns size). They are postponed spare substances. The Golgji complex was called by the name of the Italian scientist who first discovered him in nerve cells. It has a diverse shape and consists of cavity-bounded membranes, which are bubbles located on their ends. The main function is the accumulation and removal of organic substances synthesized in the endoplasmic network, the formation of lysosomes.
Lizosomes - rounded calves with a diameter of about 1 μm. From the surface of the lysosome, a three-layer membrane is limited, inside it is a complex of enzymes capable of splitting carbohydrates, fats and proteins. The cell has several dozen lysosomes. New lysosomes are formed in the Golgjie Complex. Their main function is to digest food in the cell by phagocytosis, and removing dead organoids.
Motion organides - Tiki and Cilia - are the cells of the cells and have the same type in animals and plants (the community of their origin). Motion of multicellular animals is provided by muscle abbreviations. The main structural unit of the muscular cell is the myofibrillas - thin threads with a length of more than 1 cm, with a diameter of 1 μm, located beams along the muscle fiber.
Cellular inclusions - carbohydrates, fats and proteins - relate to non-permanent cell components. They periodically synthesize, accumulate in the cytoplasm as spares and are used in the course of the life of the body. The kernel is one of the most important organoid cells. From the cytoplasm, it separates it a nuclear sheath consisting of two three-layer membranes, between which the narrow strip from the semi-liquid substance is located. Through the pores of the nuclear shell, the metabolism between the core and the cytoplasm is carried out. The core cavity is filled with nuclear juice. It contains nucleolus (one or more), chromosome, DNA, RNA, proteins and carbohydrates. Yardshko - a rounded caller in size from 1 to 10 microns and more; RNA is synthesized in it. Chromosome are visible only in dividing cells.
Cell function
The kernel stores genetic information.
Mitochondria produce energy.
Machine Gopji - "Transport" Cell System.
Lizosomes remove waste and split protein.
Dosemomomomas communicate with other cells.
Organoishads take part in the exchange of cell substances.
The cell membrane maintains the shape of the cell.
Depending on the function performed, all cells are divided into certain types. The most important cells in their own appearance and "performed tasks" are divided into: bone, cartilage cells (type of connective tissue), connective, muscular, nervous, coating fabrics, as well as cells of glands and blood. Various cells even "share work" among themselves, and each is responsible for its. For example, muscle tissue cells do not produce glucose, and it is obtained from other cells that perform this function.
Chemical composition of cells
The cell consists of the same chemical elements as non-fat nature: it has most elements of the periodic system of Mendeleev. In the cells of living organisms, the content of four elements - oxygen (O), carbon (C), hydrogen (H), nitrogen (N), called macroelements, is particularly great. In sum, they constitute about 98% of the entire contents of the cell. Together with gray and phosphorus, these elements are part of biopolymers -belkov, fats, carbohydrates and nucleic acids.
Microelements: sulfur (S), phosphorus (P), potassium (k), sodium (mA), calcium (CA), magnesium (MD), iron (Fe), chlorine (CI), in sum amounting to about 1.9% Cell content.
Ultramic-elements: zinc (Zn), copper (C), iodine (j), fluorine (F), etc., are less than 0.1% of the cell content. All elements play an important role in the cell and are necessary in a strictly defined quantity, their disadvantage or excess leads to various exchange violations in the body.
Organic cells cells:
Proteins are macromolecules, or biopolymers. Monomers of proteins of living cells are 20 different amino acids. Between the carboxyl group, the coxy (acid) and the amine group H - N - N (basic) two adjacent amino acids are formed by peptide (covalent) communication. Various combinations of amino acids in protein molecules give proteins specificity. A sequential compound of amino acids in protein forms its primary structure - polypeptide. In most cases, the polypeptide is twisted into the helix - the secondary structure of the protein. Protein functions:
Construction: Proteins are part of cellular structures.
Transport: the ability of proteins to bind and transfer many chemical compounds with a blood flow (for example, transport of hemoglobin oxygen).
Receptor function: Provides cellular interoperability, as well as various protein macromolecules to the reversible change in the structure in response to the effect of physical and chemical factors underlies irritability.
The contractile function is provided by special contractile proteins, due to which the movement of flagellas, cilia, muscle contraction, etc. occurs.
Energy function: Proteins are a spare source of energy.
Catalytic function: Proteins-enzymes accelerate chemical reactions.
Protective function: proteins-antibodies (immunoglobulins) neutralize antigens (foreign substances) causeing diseases of the body.
The regulatory function is provided by hormones proteins that regulate the metabolism.
Carbohydrates are divided into simple - monosaccharides (ribose, deoxyribosis, glucose, fructose, etc.) and complex - disaccharides (sucrose, lactose, maltose) and polysaccharides (starch, glycogen, cellulose, chitin, etc.).
Functions of carbohydrates: Particularly included in nucleic acids and ATPs are a universal source of energy in the body, participate in the neutralization and removal of poisonous substances from the body, polysaccharides play the role of spare products.
Lipids are neutral fats, waxes, phospholipids and steroid hormones. They are insoluble in water, but are well soluble in organic solvents (gasoline, ether, benzene, etc.). Their composition, as a rule, includes glycerin and fatty acids.
Lipid functions: used as a spare energy source; included in cell membranes; Perform protective functions (thermal insulation).
Nucleonic acids are DNA molecules (deoxyribonucleic acid) and RNA (ribonucleic acid). DNA - biopolymer, its monomers - nucleo-tids consist of a nitrogen base (adenine, guanine, cytosine, thymine), monosaccharide (deoxyribosis) and phosphoric acid residue. The DNA molecule itself is 2 spiral polynucleotide chains combined with hydrogen bonds.
DNA function: recording, storage and reproduction of hereditary information.
Ribonucleic acid (RNA) One-chain biopolymer consisting of nucleotides in which a nitrogen base of Timin is replaced by uracil, and carbohydrate deoxyribosis - ribose. There are 3 types of RNA: information (and-RNA), transport (T-RNA) and ribosomal (P-RNA).
RNA functions: participation in reproduction of hereditary information (in protein synthesis).
Adenosyntrifosphoric acid (ATP) is a mononucleotide, consisting of Ri-bose, adenine and three phosphoric acid residues.
Function: ATP - universal energy source in a cell.
Body proportions
Body type - dimensions, shapes, proportions and peculiarities of body parts, as well as the features of the development of bone, fat and muscle tissues.
The sizes and shapes of the body of each person are genetically programmed. This hereditary program is implemented during ontogenesis, that is, in the course of consecutive morphological, physiological and biochemical transformations of the body from its origin until the end of life.
Somatotype (Somatic Constitution) This is, in fact, the constitutional type of human body (see the human constitution), but this is not only a physique actually, but also the program of its future physical development. The physique of a person varies throughout his life, while somatotype is due to genetically and is constant its characteristic from birth to death. Age changes, various diseases, reinforced physical exertion change the size, body shape, but not somatotype. Somatotype - the type of physique - determined on the basis of anthropometric measurements (somatotype), genotypically determined, constitutional type characterized by the level and feature of metabolism (preemptive development of muscle, fatty or bone tissue), a tendency to certain diseases, as well as psychophysiological differences.
Body sizes
Among the sizes of the body are isolated by total (from FR. Total - whole) and partial (from lat. Pars - part). Total (general) body sizes are the main indicators of human physical development. These include the length and weight of the body, as well as chest girth. Partial (partial) body sizes are the terms of the total size and characterize the value of individual parts of the body. Body sizes are determined by anthropometric examinations of various contingents of the population. Most anthropometric indicators have significant individual fluctuations. Total body sizes depend on its length and mass, the circumference of the chest. Body proportions are determined by the ratio of the size of the body, limbs and their segments. For example, to achieve high sports results in basketball great importance Has high growth and long limbs. However, those athletes, somatotype of which differ from the best for this sport, are also reached. In such cases, the influence of many factors affects, and first of all, such as the level of physical, technical, tactical and volitional preparation of athletes. Body sizes are important indicators (along with other parameters characterizing physical development) are important parameters of sports selection and sports orientation. As you know, the task of sports selection is to select the children most suitable in connection with the requirements of the sport. The problem of sports orientation and sports selection is a comprehensive, requiring use of pedagogical, psychological and medical and biological methods.
Body proportions
With the same length of the body of the size of its individual parts, different individuals may be different. These differences are expressed both in absolute sizes and in co-values. Under the proportions of the body, the ratios of the sizes of individual parts of the body (torso, limbs and their segments) are meant. Typically, the sizes of individual parts of the body are considered in the ratio with the length of the body or are expressed as a percentage of the length of the body or the length of the housing. To characterize the proportions of the body, the relative values \u200b\u200bof the length of the legs and the widths of the shoulders have the most important.
Canons
A long time was made to establish patterns in the ratio of parts of the human body, that is, to find the dependence of various parts of the body from one size adopted for the original. These attempts found their expression in the creation of the canons of the proportions of the body, the authors of which were sculptors and artists who sought to reproduce the perfect type of human body. Known canons belonging to the greatest masters of classical antiquity and later eras. So, according to the canon of the polyclet (Greek sculptor V c. BC) The head is 1/8 of the length of the body, the face is 1/10, etc. According to Canon, who was based on the creations of the masters of ancient Egypt, was taken for the initial magnitude The dimensions of the middle finger of the left hand; This value should be 1/19 of the body length, 1/11 height to the navel, etc., the greatest fame enjoys the Canon Friccha, which for the source value took the length of the spinal column. Canon Frich was somewhat modified and supplemented by an anthropologist. Canon Fricha Stand, like all other canons, is only an abstract conditional scheme that does not provide for normal variability, according to their authors, should be perceived as a single perfect, normal type of structure of the human body. But the idea of \u200b\u200bbeauty to a certain extent subjectively and conventionally reflects not only individual tastes, but also national ideas, era, fashion, etc. The idea of \u200b\u200bthe "norm" is also conditionally. For different groups, it is different. If you understand under the "norm" the average type most common in this group, then such "norms" as much as we consider groups.
Indices and types of body proportions
Since the proportions of the body indicate the ratio of the sizes of various parts, then not absolute, and the relative sizes of the body, limbs, etc. are important for their characteristics, but the most old, but the common reception to establish the size of the sizes is the method of indexes that consists The fact that one size (smaller) is determined in the percentages of another (greater) size. The most common method of body proportions characteristic is to calculate the length of the length of the limbs and the width of the shoulders to total length Body. According to the ratios of these sizes, three main types of body proportions are usually distinguished: 1) brahimorphic, which is characterized by a wide torso and short limbs, 2) a dehomorphic, characterized in reverse relations (narrow torso and long limbs) in h) mesomorphic, which occupies an intermediate position between Brahi- and Dolichomorphic types. The differences between these types are usually expressed using the index system; For example, in percent of the body length determine the width of the shoulders, the width of the pelvis, the length of the body, the length of the legs. These indexes can be used as means of direct form expression and for this purpose are quite suitable.
Body proportions and human age
Age changes in body proportions. Km - middle line. Figures on the right show the ratios of body parts in children and adults, the numbers below - age
Age differences in the proportions of the body are well known: the child differs from an adult with a relatively short legs, a long torso, a big head (rice). For the characterization of age-related changes of the proportions of the body, you can express the sizes in children in the shares of the magnitude of these sizes in adults, the prize unit. Below are the data of age-related changes in the body proportions in boys (Bunaku):
| Dimensions | Newborn | 1 year | 4 years | 7 years | 13 years | 17 years | 20 years |
|---|---|---|---|---|---|---|---|
| Leg length | 0,24 | 0,36 | 0,56 | 0,68 | 0,85 | 0,98 | 1,00 |
| Length hand | 0,32 | 0,44 | 0,54 | 0,67 | 0,81 | 0,97 | 1,00 |
| Torch length | 0,36 | 0,46 | 0,6 | 0,68 | 0,82 | 0,92 | 1,00 |
| Width shoulder | 0,32 | 0,44 | 0,58 | 0,68 | 0,83 | 0,93 | 1,00 |
| Width pelvis | 0,28 | 0,44 | 0,6 | 0,68 | 0,83 | 0,93 | 1,00 |
Table 2. Body size in men and women with the same source size (Bunaku)
Body proportions and sexual differences
Sexual differences are partly associated with the difference in the length of the body of men and women, but mainly they are a specific manifestation of sexual dimorphism. Women differ from men with greater width of the pelvis and a smaller shoulder width (in% body length). The length of the arms and the length of the leg in the percentage of the body length is about the same in both floors. If you consider the proportion of the body in men who do not differ on average in their growth from women, the results will be different, namely: such men, on average, will certainly be longer-legged (by index) than the other men. This long-beability is a consequence of the fact that the correlation of the length of the legs and the length of the housing is small and therefore there will be subjects among selected men with a small case with both short and long legs. Studies have shown that women on the relative length of the legs are distinguished both from men of small growth and from men with a small case. Woman is longer than the first, and shorter than the second. Similar results are obtained in the case of bringing the size of women to the length of the body and the length of the men's housing (Table 2). With all calculations, men have a relatively narrower pelvis and wider shoulders than women.
Body proportions and constitutional type
The harmony of the proportions of the body is one of the criteria in assessing the state of human health. In disproportion in the structure of the body, you can think about the violation of the growth processes and the resulting causes (endocrine, chromosomal, etc.). Based on the calculation of the proportions of the body in anatomy, three main types of human buildings are distinguished: mesomorphic, brahimorphic, dollyomorphic. People, the anatomical features of which are approaching the averaged parameters of the norm (taking into account age, gender, etc.) to the mesomorphic type of physique (normostics). People brahimorphic type of physique (hyperstoles) are dominated by the transverse dimensions, muscles are well developed, they are not very high growth. The heart is located transversely due to the highly standing diaphragm. The brahimorphic lungs are shorter and wide, the loops of the small intestine are predominantly horizontally. The faces of the deathomorphic type of physique (aesthenics) are distinguished by the predominance of longitudinal sizes, have relatively longer limbs, weakly developed muscles and a thin layer of subcutaneous fat, narrow bones. The diaphragm is below them below, so the lungs are longer, and the heart is almost vertically. In tab. 3 shows the relative sizes of body parts in people of different types of physique.
Table 3. Body proportions (according to P. N. Bashkirov)
| Type of physique | Sizes of body parts relative to body length,% | ||||
| Length | Width | ||||
| torch | hands | legs | shoulder | pelvis | |
| Dolichomorphic (asthenic) | 29,5 | 55,0 | 46,5 | 21,5 | 16,0 |
| Mesomorphic (normostic) | 31,0 | 53,0 | 44,5 | 23,0 | 16,5 |
| Brahimorphic (hypersthenic) | 33,5 | 51,0 | 42,5 | 24,5 | 17,5 |
Group differences in bodies
Somatotyping
Typology of man Krechmera
The specificity of metabolic processes and endocrine reactions is the essence of the functional constitution. The Constitution in a broad sense (including genetic, morphological and functional) is of interest because it is considered responsible for the originality of the reactivity of the body. The unequal susceptibility of people of various constitutional types and the action of external and internal factors is considered proven. Currently, there are more than a hundred classifications of the human constitution based on various signs. Therefore, there are constitutional schemes that are based on morphological, physiological, embryological, histological, neuropsychiatric, and a degree, strong physique, high or medium height, wide shoulder belt and narrow thighs, convex facial bones. In addition to these types, E. Krechmer highlighted a dysplastic type characterized by a formless structure and various deformations of the physique.
Ecto-, Meso and Endomorphia
Stages of the intrauterine development of man. Formation of 3 germ sheets: ECTODERM, MEZODERM AND ENDERM
In the West distinguish three main types of physique: Ee face shifted back chin, high forehead, narrow chest and belly, narrow heart, thin and long arms and legs. The subcutaneous fat layer is almost absent, musculature of underdeveloped. Explicit ectomorph completely does not face obesity.
Most people do not apply to extreme versions of the physique (endomorph, mesomorph, ektomorph), all three components are expressed in their physique, and the most common somatotypes will be 3-4-4, 4-3-3, 3-5- 2. In addition, individual parts of the body of one person can explicitly refer to different somatotypes - such a discrepancy is called dysplasia, but its accounting remained a weak place of Sheldon. Sheldon considered the human somatotype as constant during life - the appearance and size of the body are changing, but not somatotype. For example, various diseases, improper nutrition or muscle hypertrophy, associated with enhanced physical activity, change only the outlines of the body, but not somatotype itself. The studies of Sheldon and his students are great interest, which were devoted to the study of the change in the body weight (growth-weight index) of a person throughout his life depending on the somatotype. A huge number of anthropological measurements have been conducted for decades, and the results obtained were summarized in the table. Based on these tables, the weight forecast is the weight of the male or female individual in various life periods Depending on its growth and somatotype.
Forecasting physical development
For example, when studying a group of sports students, about one age (from 18 to 21 years), their growth-weight and somatotypes are identified.
Prediction of maximum weight depending on the somatotype (on Sheldon). Explanation in the text)
Student A. has somatotype 5-2-2 and weight 72 kg. When height 166 cm. This is a preferential endomorph. If we, on the basis of these Sheldon tables, we construct a graph of the dependence of the hypothetical body weight for this somatotype in different periods of his life, we will see that its real weight exceeds the calculated and will probably be taken with age up to 84 kg to 60 years. Student B. - Preferential Mesomorph and its predicted weight will probably be in the older age group of 83 kg. Anything, student V., with a height of 185 cm he weighs 67 kg. This is a normal weight for its constitutional type and we see that with age, its weight will change little. Thus, when determining the somatotype, it is necessary to take into account age, the presence or absence of pathological processes and the degree of physical activity, that is, it is necessary to have a certain experience, which allows you to see the "skinny endomorph" or "fatty mesomorph". In the practice of somatotypes it is believed that this somatotype should be taken for the final assessment, which consists of 20-25 years in normal nutrition. The concept of the constant sovedon somatotypes was convenient for both theoretical anthropometry, and to study the natural types of physique. However, the rapid development of bodybuilding in the 60s led to the emergence of such muscular-developed bodies whose parameters did not climb in any framework. The training system developed in bodybuilding and the emergence of special food products (proteins, energy, free amino acids) actually allowed changing somatotype and maintain it in a changed form how long.
Somatezrezon Hit Carter
In 1968, American physiologists B. Hit and L. Carter finalized the Sheldon system, eliminating the upper limit for estimated points, representing the formula for the numerical, and not visual determination of the components of the somatype and the formula for the calculation X-y coordinates The resulting point on the plane with three axes. Thus, the calculation of the components of the somatotype to properly performed the measurements made it possible to obtain a completely objective and adequately changing assessment of the physique in the form of a single visual point on the plane. The English anthropologists are widely used by Parnell (Parnell, 1958), based on the use of the table, driven in the work of Hit (1968). It takes into account three combination of measuring signs for representatives of different age groups: Rosto-weight ratios, bone diameters and clasped sizes, as well as leather-fat folds. The resulting is a scoring assessment of somatotype. Despite the fact that Parnell criticized the same scheme, mainly for the incorrectness of the photographing methodology and subjectivism in assessing the development of components of the composition of the body and satellite points, which is based on this method, of course, Sheldon's approach. In particular, an arbitrary seven-ball scale is preserved, the distribution intervals of the fat component scale are provided in accordance with the average values \u200b\u200bof Sheldon. A graphically somatese is expressed by a point on a plane with three coordinate axes, located at an angle of 120 ° to each other.
Somatezrezon Hit Carter. Explanation in the text
The axis - endomorphia ("fat" - left-down), mesomorphia ("muscles" - up) and ectomorphia ("bones" - right-down). For example, more tightened, slender people are "located" on the plane of the somatosrea in the zero area somewhat to the top of the coordinates, the mannequins, - more to the right; Bodybuilders are located along the axis of mesomorphia at the top of the plane with the value of Y more than ten, and overweight drives the point to the left from zero. When the muscle mass change and the amount of fat in the somatonoscience, it will change, and in comparison with the points of previous measurements you can observe the flowing point drift, showing the direction of changes occurring in your body. The advantage of the scheme
Literature
Links
- New method of somatotyping B. A. Nikityuk, A. I. Kozlov
Wikimedia Foundation. 2010.
Watch what is "body proportions" in other dictionaries:
- (in humans). The study of P. body in humans turned primarily the attention of artists. Already in the ancient Hindus and the Egyptians were canons with the definition of P. different parts of the body, and the length of the length was taken, for example, a hand, or length ... ... encyclopedic Dictionary F. Brockhaus and I.A. Efron
The growth and development of a person, beginning with the fertilization of the egg, is a continuous progressive process flowing throughout his life. The process of development proceeds by jumpingly, and the difference between individual stages, or periods, life is reduced not only to quantitative, but also qualitative changes.
The presence of age features in the structure or activities of certain physiological systems in no way can be evidence of the inferiority of the child's body in separate age-related stages. It is a complex of such features, one or another age is characterized.
Under development In the broad sense of the word, it is necessary to understand the process of quantitative and qualitative changes occurring in the human body leading to an increase in the levels of complexity of the organization and the interaction of all its systems. Development includes three main factor: growth, differentiation organs and tissues, formation (acquisition by the body of characteristic forms inherent in it). They are among themselves in close relationships and interdependence.
An important patterns of growth and development of children include unevenness and continuity of growth and development, heterochrony with the phenomena of the ripening of vital functional systems and acceleration. Functional systems ripen unevenly, turn on phasately, change, ensuring the body to the body in different periods of ontogenetic development.
For example, accelerated development undergo the circular muscle of the mouth, other muscles of the person and the structures of the central nervous system that provide an act of sucking. Of all the nerves, the hands are primarily developed by those that ensure the reduction of blow muscles involved in grateful reflex. Such a selective and accelerated development of morphological formations that are full-fledged functional systemproviding newborn survival, received the name of system genesis.
The characteristic feature of the growth process of the children's body is its unevenness, or heterochronism, and wave-likeness. Periods of reinforced growth are replaced by some slowdown. This pattern is particularly brightly traced in graphic expression of the growth rate of the child's body (Fig. 1).
It can be seen from the figure that the greatest intensity of the child's growth is different in the first year of life and during puberty, i.e. in 11-15 years. If at birth, the child's growth is on average 50 cm, then by the end of the first year of life it reaches 75-80 cm, i.e. it increases by more than 50%; Body mass for the year triples: at the birth of a child, it is equal to an average of 3.0 ... 3.2 kg, and by the end of the year - 9.5 ... 10 kg. In subsequent years, the growth rate decreases to the period of puberty, and the annual weight gain is 1.5 ... 2 kg, and an increase in body length is 4-5 cm.
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The second rising leap is associated with the onset of puberty. During the year the length of the body increases by 7-8 and even 10 cm. Moreover, from 11-12 years, girls are somewhat ahead of the growth of boys, at 13-14 years old girls and boys grow almost the same, and from 14-15 years old, young people overtake in growth Girls, and this is the excess of growth in men over women persists throughout life.
From the period of newborn, before reaching mature age, the body length increases 3.5 times, the length of the body is 3 times, the length of the hand is 4 times, the length of the leg is 5 times.
The proportions of the body with age are also strongly changing (Fig. 2). The newborn is different from an adult with relatively short limbs, a large torso and a big head. The height of the newborn head is 1/4 of the length of the body, the child has 2 years - 1/5, 6 years old - 1/6, 12 years old - 1/7 and in adults - 1/8. With age, the growth of the head slows down, and the growth of the limbs is accelerated.
Prior to the beginning of the period of sexual ripening (pre-period), sex differences are absent in the proportions of the body, and during the period of puberty (puberty) in the young men, the young men becomes longer, and the body is shorter and the pelvis already than the girls. It can be noted three periods of the difference in proportions between the length and width of the body: from 4 to 6 years, from 6 to 15 years and from 15 years before an adult state. If in the pre-period period, the overall growth increases due to the growth of the legs, then in the pubertal period - due to the growth of the body. The growth curves of individual parts of the body, as well as many organs, mainly coincide with the body length growth curve.
However, some organs and parts of the body have a different type of growth. For example, the growth of genital organs occurs strongly during puberty, the growth of lymphatic tissue ends to this period. The sizes of the head in children are 4 years old reach 75-90% of the magnitude of the adult head. Other parts of the skeleton and after 4 years continue to grow intensively. During puberty, not only intensive growth occurs, but also the formation of secondary sexual signs.
Growth unevenness is a device produced by evolution. The rapid growth of the body in length in the first year of life is associated with an increase in body weight, and growth slowdown in subsequent years is due to the manifestation of active processes of differentiation of organs, tissues, cells.
Development leads to morphological and functional changes, and growth - to an increase in the mass of tissues, organs and the whole body. With the normal development of the child both of these processes are closely interrelated. However, periods of intensive growth may not coincide with periods of intensive differentiation. The increase in the mass of the head and spinal cord is mainly ends to 8-10 years, almost reaching the masses of an adult, but the functional improvement of the nervous system occurs for a long time.
Along with typical of each age period, individuals have individual development features. They vary and depend on the state of health, living conditions, degree of development of the nervous system. Consistent individual deviations in development are manifested mainly in the first year of life when they are associated with congenital characteristics and cultivation conditions.
Acceleration
Under acceleration, an increase in body size and maturation occurs in earlier time. The term "acceleration" is used mainly in two values: acceleration Epochal and acceleration of intragroup.
Epochkal accelerationindicates the acceleration of the physical development of modern children and adolescents in comparison with the preceding generations. Body length of newborns for 60-80 years XX century. increased by 2 ... 2.5 cm, and their weight is 0.5 kg. The length of the body in the fifteen years increased by 6-10 cm, and the mass of 3-10 kg (in comparison with the teenagers of the beginning of the XX century). Significantly faster the development and growth of some sections of the skeleton and the endocrine system, providing and more previously puberty (two years earlier than was at the beginning of the XX century). Growth duration reduced: at the end of the XX century. The growth of girls and young men on average ended in 16-19 years old, and at the beginning of the XX century. People reached maximum growth by 25-26 years.
Under the intragroup accelerationunderstand the acceleration of the growth and development of individual children and adolescents in certain age groups. On average, such children make up 15-20% of the total number of children of this age. They are characterized by higher growth, large muscular power, great respiratory ability. They have much faster than sexual ripening occurs, earlier growth ends in length (usually by 15-17 years) and somewhat faster, as the majority of scientists believes, mental development is carried out.
So close attention to the problem of acceleration is explained simply: its solution is of great practical importance. Earlier growth and development of children and adolescents require a revision of training methods, changes in the forms of sexual, physical and aesthetic education of young people, revising the age-related possibilities of man, physical education planning and sports.
Unfortunately, the phenomenon of acceleration is not always positive manner It affects the functional capabilities of the children's body. There is evidence that acceleted children, the growth and development of the heart are lagging behind the body growth. As a result, its normal activity is violated, the prerequisites for the development of cardiovascular diseases are created.
The biological mechanisms of acceleration are not yet clarified. It can be assumed that the reasons for the acceleration of physical development are different and the most significant are the following.
1. The effect of heterosis associated with the wide migration of the modern population and an increase in the number of mixed marriages. At the same time, the offspring of the first generation has a temporary advantage in physical development.
2. Urbanization of the population (increasing urban population) and the stimulating influence of city life conditions on the pace of physical development.
3. Moderate deterioration in the environmental situation (an increase in industrial radiation, accumulation of exhaust products and smoke from pipes of industrial enterprises, dusting, etc.).
It should be noted that if changes in the growth rates and body sizes retained a constant direction, even a low increase in indicators during the transition from one generation to another caused an increase in body modern man to gigantic sizes.
Therefore, acceleration is only a link in the history of the conversion of Homo Sapiens, and not the main factor of this process.
Age periodization
The child's body is continuously growing and developing. In the process of ontogenesis, specific anatomical and functional features that have received the name of age arise. Accordingly, this person's life cycle can be divided into periods, or steps. There are no clearly defined borders between these periods, and they are largely conditional. However, the exhaustion of such periods is necessary, since the children of the same calendar (passport), but different biological age react differently to sports and labor loads; At the same time, their performance may be greater or less, which is important for solving a number of practical issues of organizing an educational process in a school surrounding the child.
What criteria to take the basis of age periodization? Some researchers as the basis of periodization take the ripening of the genital glands, the rate of growth and differentiation of tissues and organs; Others propose to be guided by the so-called skeletal maturity (bone age) when radiographically in the skeleton determine the time of the appearance of points of ossification and the onset of the fixed bonding connection.
IN modern science There is no generally accepted classification periods of growth and development and their age borders. The symposium on the problem of age periodization in Moscow (1965), convened by the Institute of Children's Physiology and Adolescents of the USSR, recommended the following age-periodization scheme, which has a significant distribution.
Newborn: 1-10 days.
Breast age: 10 days - 1 year.
Early childhood: 1-3 years.
First childhood: 4-7 years.
Second Childhood: Boys 8-12 years old,
girls 8-11 years old.
Teenage age: boys 13-16 years old,
girls 12-15 years old.
Youth age: young men 17-21 years old
girls for 16-20 years.
Mature age I period: Men 22-35 years old
women 22-35 years old.
II period: Men 36-60 years old,
women 36-55 years old.
Elderly Age: Men 61-74,
women 56-74 years.
Old age: 75-90 years.
Long-livers: 90 years and above.
The criteria for such periodization included a complex of signs: the size of the body and organs, the mass, the osenation of the skeleton, the teething, the development of the glands of the internal secretion, the degree of puberty, muscular strength. This scheme takes into account the features of boys and girls. Each age period is characterized by its specific features. The transition from one age period to the next one is referred to as the turning stage of individual development, or a critical period. According to our data, the critical period in the development of the cardiovascular system is the age of 7-9 years, when the strengthening of the central influences on the heart is revealed, which creates less favorable conditions for its functioning. Therefore, with extreme caution, children 7-9 years should be prescribed exercise.
Questions for self-control
1. What does the subject "age physiology" study?
2. Name the binding components of age physiology with other disciplines.
3. Call the basic value of age physiology for pedagogy.
4. What is the value of age physiology for medicine?
5. To define and characterize the concepts of "growth" and "development".
6. How do body proportions change at different stages of development?
7. Reveal the concept of "acceleration".
8. Give the definition and call the periodization criteria.
Age peculiarities
Musculoskeletal
The system of motion organs includes bones (skeleton), ligaments, joints and muscles. Bones, ligaments and joints are passive elements of the organs of movement. The active part of the movement apparatus is muscles.
Recently it was believed that the role of a skeleton in the human body is limited by the function of body support and participation in motion. Hence the term "musculoskeletal system" occurred. Currently it has been established that the functions of the skeleton are significantly wider. Skeleton is actively involved in metabolism, in particular in maintaining at a certain level mineral Makeup blood. In addition, a number of substances that are part of the bones (calcium, phosphorus, citric acid, etc.), if necessary, easily comes into exchange reactions.
The skeleton forms the structural base of the body and determines to a large extent its size and shape. Parts of the skeleton, like a skull, chest and pelvis, vertebral pole, serve as container and protecting vital organs: brain, lungs, heart, intestines, etc.
Growing bones
In the embryonic period of development, the skeleton is laid as a coupon education. Even before the birth of the child, the connecting tissue is replaced by cartilage, after which the gradual destruction of cartilage and education instead of bone tissue occurs. The process of ossification is very long, flows over the entire period of the development of the body. In the growing body, the ends of the long bones are epiphysis - long remain cartilage.
Young bones grow long due to cartilages located between their ends and body. By the time the growth of bones, cartilage is replaced by bone tissue. During the period of growth in the bones of the child, the amount of water is reduced, and the amount of mineral substances increases. The content of organic substances is reduced.
The development of the skeleton in men ends to 20-24 years. At the same time, the growth of bones is stopped, and their cartilage parts are replaced with bone tissue. The development of the skeleton in women ends 2-3 years earlier.
Skeleton torso
The skeleton of the body consists of a spinal column and chest. Vertebral pillar (Fig. 3) The person consists of 33-34 vertebrae. It distinguishes departments: cervical, consisting of 7 vertebrae, chest - out of 12 vertebrae, an explanatory - out of 5 vertebrae, sacral - out of 5 vertebrae and smoking - from 4-5 vertebrae. In an adult, sacral vertebrae is growing into one bone - the crushes, and the spheroids - in the tailbone. The vertebral pillar takes about 40% of the body length and is its main rod, support. The vertebral holes of all vertebrae form a vertebrate channel in which it is placed spinal cord. Muscles are attached to vertebral processing.
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Fig. 3. Human skeleton in front (a) and rear (b): 1 - skull; 2 - vertebral pole; 3 - clavicle; 4 - blade; 5 - Greet; 6 - ribs; 7 - shoulder bone; 8 - elbow bone; 9 - Cresan; 10 - radiation bone; 11 - wrist; 12 - plump; 13 - dice of the fingers of the brush; 14 - iliac bone; 15 - Lobc bone; 16 - Sedal Bone; 17 - femur; 18 - patella; 19 - large ber bone; 20 - small ber bone; 21 - replous; 22 - plus; 23 - dice of the fingers of the foot
There are intervertebral discs from fibrous cartilage between the vertebra; They contribute to the mobility of the spinal column. With age, the height of the disks is changing.
The process of ossification of the spinal column begins in the intrauterine period. After birth, new points of ossification appear. Up to 14 years old are the average parts of the vertebral bodies. The complete ossification of individual vertebrae ends to 21-23 years.
Up to 1.5 years, the vertebral pillar grows evenly, from 1.5 to 3 years, the growth of cervical and upper breast vertices is relatively slowed down, and lumbar and lower breast vertebrae are vigorously growing vigorously.
In a newborn baby, a vertebral pillar is almost direct, characteristic of an adult bends only outlined and develop gradually.
The first cervical lordosis appears (bending directed by convexing ahead) at the age of 6-7 weeks, when the child begins to hold the head. By six months, when the child begins to sit, breast kyphosis is formed (bending directed by convexing back). When a child begins to stand and walk, a lumbar lordosis is formed (see Fig. 4). With the formation of the lumbar lordosis, the center of gravity moves the stop, preventing the body drop in the vertical position. By the year there are already all the bends of the spine. But the resulting bends are not fixed and disappeared when muscle relaxation. To seven years, there are already clearly pronounced cervical and cheerful bends, the fixation of the lumbar bending occurs later (in 12-14 years).
The bends of the spinal column make up a specific feature of a person and arose due to the vertical position of the body. Thanks to the bends, the vertebral pillar springs. Boots and shocks when walking, run, jumps weakened and fucked that it protects the brain from concussions. With the right, or slim, posture of the spinal column bends moderate, the shoulders are deployed, the legs are straight with normal foot flashes.
Fig. 4. The appearance of spinal bends due to the seat
(explanation in the text)
People with a good posture are slight, their head holds right or slightly thrown back, the chest somewhat stands out above the belly. Elastic muscles, movements collected, clear. Proper posture (Fig. 5) is most favorable for the functioning of the system of movement organs and internal human internal organs, which ultimately contributes to improving performance.
With incorrect posture, the head is extended forward, the chest is flattened, the shoulders are switched out, the stomach is sucked, and the chest places, the legs are dispersed in the knee joints. Lumbar lordosis and chest kyphosis are stronger than ("Round spin"). Often incorrect posture accompanies scoliosis, that is, the side curvature of the spinal column. With scoliosis, shoulders, blades and pelvis asymmetric.
Incorrect posture makes it difficult to work the heart, light, gastrointestinal tract; It decreases the life capacity of the lungs, the metabolism is reduced, headaches appear, increased fatigue.
The posture does not apply to the number of inherited features. It begins to form from an early age and may change during life. Basically, the formation of posture occurs in 6-7 years. To form a correct posture, the development of muscles of the body is of great importance. The voltage of these muscles forms and holds the posture, and the decrease in their voltage disrupts it. In children, the muscles of the torso are still weakly developed, so their posture is unstable.
The curvature of the spinal column to the side (scoliosis) (Fig. 5) is often developing in children with a weak physical development, as a result of a long-term seat at the table or a desk, with an incorrect landing, especially with a letter, in the inconsistency of the furniture sizes to the proportions of schoolchildren. If there is a side curvature of the spine, it also arises to rotate it around the vertical axis (twisting). Following the curvature of the thoracic spine, twisting the ribs connected to the spine. This leads to the deformation of the chest.
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It should be borne in mind that at first scoliosis is the nature of the unstable defect of posture, and if you pay attention to the child in time, then this defect is easily corrected by the child himself. If you do not pay attention to this defect in time, then the posture defect is kept by a child constantly, which leads to changes in the muscles and bundles of the body, and then the bone of the spinal column.
Rib cage Forms the bone base of the thoracic cavity. It consists of sternum, 12 pairs of ribs connected from behind with a vertebral pillar. The chest protects the heart, lungs, liver and serves as a place to attach the respiratory muscles and muscles of the upper extremities.
Greet is a flat unpaired bone, consisting of a handle (upper part), the body (middle part) and a sword-shaped process. Between these parts there are cartilaginous interlayers, which by 30 years old are soldered. The fire of segments of the sternum goes gradually: the lower segments of the sternum grow up in 15-16 years, and the upper - only by 21-25 years. The oake of the sword-shaped process ends to 30 years.
In the first years of life, the chest is compressed from the sides and has a cone shape, its front-facing size is more transverse. Due to the enhanced increasing ribs, the development of the lungs, the chest gradually expands and by 12-13 years old, it acquires the same form as an adult person. In an adult, the chest is wide, with a predominant transverse size, which is associated with the vertical position of the body, in which the insides are pressured by their weight in the direction parallel to the breast.
Skeleton upper limbs.The belt of the upper limbs consists of two blades and two clavies. They form a rigid frame that shape the upper border of the body. The blades of free extremities (right and left) are movably attached to the shovels, which include the shoulder bone, the forearm (radiation and elbow bones) and the brush (small dice of the wrist, five long faded bones and dice of the fingers).
The ossification of the free extremities continues until 18-20 years, and the clavicle (almost still intrauterine), then the blades and the latter - the bones of the brush are also soldered. In the newborn on the radiograph, they only outlined; Gradually developing, they become clearly visible only by 7 years. By 10-12 years, sexual differences are revealed, which are in a more rapid oake of girls in comparison with the boys (the difference is about 1 year). Ocanification The phalange of the fingers is completed mainly by 11 years, and wrists in 12 years, although individual zones continue to be left not by chanting until 20-24 years. In this regard, the rapid (running) letter to children of junior classes is unable.
Of particular importance in person has I finger due to the labor function. It has great mobility and is opposed to all other fingers. Permanent physiological loads or a game on musical instruments from an early age delay the process of filling the phalanx of the fingers, which leads to their elongation ("Musician's fingers").
Belt lower extremities It consists of a sacrum and still connected to it two pelvic bones. The pelvic bones in the newborn consist of each of the three bones, the battle of which begins in children from 5-6 years, and about 17-18 years old they are already fighting. In adolescence, there is a gradual fire of sacral vertebrae into a single bone - the crushes. In girls with sharp jumps from a high height, when wearing high-heeled shoes, nonsense pelvic bones can shift, which will lead to the wrong combustion of them and, as a result, narrowing the exit of the cavity of the small pelvis, which may further make the fetal passage in childbirth.
After 9 years, differences in the shape of the pelvis in boys and girls are noted: boys the pelvis is higher and narrow than girls. Pelvic bones have round depressions, which includes the heads of the femur bones of the legs.
The skeleton of the free lower limb consists of a femoral bone, two bones of the leg (tibial, small-terber) and feet bones. The stop is formed by the bones, plus, plus and phalanges of the fingers of the foot.
The foot of a person forms a set, which relies on the heel bone and on the front ends of the bones of the plus. The arch of the foot is the exclusive privilege of a person associated with straightening. In terms of the foot, the severity of the body is evenly distributed, which is of great importance when transferring weights. The arch acts as a spring, softening the impetus of the body when walking. The newborn baby has no vaobility of the foot, it is formed later when the child begins to walk.
The vaulted location of the bones of the foot is maintained by a large number of strong articular ligaments. With long standing and seat, transferring large weights, when wearing narrow shoes, the ligaments are stretched, which leads to a flattening of the foot. And then they say that developed flatfoot (Fig. 6). Rickets may also contribute to the development of flatfoot.
It adversely affects the state of the foot. Permanent stay of children in the room in insulated and felted shoes (i.e. soft), as it relaxes the muscles of the foot.
In flatopyopic, the posture is disturbed, due to the deterioration of blood supply, the fatal of the lower extremities will quickly occur, often accompanied by fragmentation, pains, and sometimes cramps. For prevention, flatfoot recommend walking barefoot on the uneven surface, in the sand, which helps to strengthen the foot of the foot. Exercises for leg muscles, especially for foot muscles, walking on tiptoe, jumping long and height, running, soccer game, volleyball and basketball, swimming warn the development of flatfoot.
Skull - Skeleton head. There are two skull departments: a brain (cranial box) and facial (bones of the face). In the brain department is a brain.
The composition of the brain department of the skull includes unpaired bones (occipital, wedge-shaped, frontal, lattice) and paired (dark and temporal). All bones of the brain skull are connected motionless. Inside the temporal bone is a hearing body, a wide auditory is leading to it. Through a large opening of the occipital bone, the skull cavity is connected to the spinal canal. In children at an early age, the brain part of the skull is more developed than the facial. The most strongly bones of the skull grow during the first year of life. With age, especially from 13-14 years old, the facial department grows more vigorously and begins to prevail over the brain. In a newborn, the volume of the brain skull is 8 times more facial, and in an adult 2 ... 2.5 times.
The newborn cranial bones are connected to each other soft connective tissue. In those places where 3-4 bones are converged, this membrane is especially large, such zones are called spring (Fig. 7).
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Thanks to the skin of the bones of the skull, we retain mobility, which is essential in childbirth, since the head of the fetus in the process of childbirth must pass through very narrow generic paths of the woman.
After the birth of Springs, they will overtake mainly by 2-3 months, but the biggest - frontal - only for age is 1.5 years old.
General About muscles
There are about 600 skeletal muscles in the human body. The development of muscles and the growth of their mass in postnatal ontogenesis is unevenly. The muscular system is a significant part of the total mass of the human body. If the newborn mass of all muscles is 23% of the body weight, and at 8 years old - 27%, then in 17-18 it reaches 43-44%, and athletes with well-developed muscles are even 50%. The growth of muscle mass occurs, mainly due to an increase in the longitudinal and transverse dimensions of muscle fiber (90%); While the total number increases slightly (10%). The growth of minions in length is carried out due to the growth points at the ends of the fibers adjacent to the tendons. Mion's growth in thickness occurs due to an increase in the amount of myofibrils in it. As a result, the muscle mass first increases gradually (up to 15 years each year by 0.7 ... 0.8%), and then very quickly (from 15 to 17 years by 5-6% per year) and in young men 17-18 Muscular weight is 44% of the body weight, like adults. The development of muscles, vascular system and innervation lasts up to 25-30 years.
In infants, first of all, the abdominal muscles are developing, later - chewable. By the end of the first year of life, the muscles of the back and limbs are noticeably growing with a walking and starting. For the whole period of the growth of the child, the mass of muscles increases 35 times. In the period of puberty (12-16 years), along with the elongation of tubular bones, intensively and muscle tendons are extended. Muscles at this time become long and thin, and teenagers look long-legged and long. In 15-18 years continued further growth of muscle transience. Music development continues up to 25-30 years.
The muscles of the child paler, gentle and more elastic than the muscles of an adult.
The muscles of the person even at rest are somewhat shortened. This state of a long-held voltage is called muscle tone. During sleep, with anesthesia, the muscle tone decreases somewhat, the body relaxes. Muscle tone completely disappears only after death. The magnitude of the muscle tone is depending on the functional state of the central nervous system.
The muscle tone plays an important role in the implementation of coordination of movements. The newborn children predominate the tone of the arm's flexors, the tone of muscle extensors prevails in children, in children is 3-5 months old - the equilibrium of the tone of muscle antagonists. The increased tone of muscles in newborns and in the first months of their lives is associated with the increased excitability of the red cores of the midbrain. As the functional ripening of the pyramid system and the cortex of large hemispheres of the brain, the muscle tone is reduced.
Increased tone of the muscles of the newborn in the second half of the life of the child gradually decreases, which is a necessary prerequisite for the development of walking.
Muscular abbreviation poweras a result of the increase in the total cross section, myofibrils increases due to the growth of mions in thickness as a result of an increase in the number of myofibrils and partially (by 10%) by the appearance of new muscle fibers. The differences between the muscular strength indicators in boys and girls become more pronounced as growth and development. In the younger school age (7-8 years) Boys and girls have the same force of most muscle groups, after which the growing process is uneven. In girls by 10-12 years, muscle strength increases so intensively that they become relatively and absolutely stronger than boys. In the future, there is a predominant development of muscle strength in boys. Especially intensively there is an increase in muscle strength in boys at the end of the period of puberty, however, young men in 18 years old are only approaching the lower boundary of adults.
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