1) a span from the moment of the birth of an organism to the present or any other moment;
2) the characteristic of life of an organism reflecting growth, development, maturing and aging, i.e. its biological evolution.
Distinguish V. chronological (passport, or calendar) — the period from the birth until its calculation and biological (anatomo-physiological), characterizing biol, a condition of an organism.
Chronological Century. has accurate gradation in time — day, month, year. Though this concept is also connected with idea of «average» signs biol, conditions of an organism, biol, features of a specific organism at the same time are not considered.
Biological Century., determined by set of exchange, structural, functional, regulatory features and adaptive opportunities of an organism, is obligatory function of time, but, unlike calendar, it is characterized by less accurate time slices, on an extent to-rykh there are irreversible age biol, shifts in an organism. The last are used as criteria of an age periodization of human life. Biological V. can not correspond to chronological — to advance or lag behind it.
Idea of the age periods is relative; the choice of criteria of the age periods, their durations depends from biol, features of an organism, social factors of the environment, level of scientific knowledge etc.
Age periods — these are these or those terms necessary for end of a certain stage morfol. and functional development of separate fabrics, bodies and organism in general. Division into the age periods reflects in the childhood, first of all, stages of maturing of a nervous system, internals and the chewing device, and also formation of century of N of; in each of stages rather homogeneous quantitative changes accrue.
The age periods at children
the Most dynamic and qualitatively new changes occur in the children's and youthful age periods. The natural continuity of developments is characteristic of the period of the childhood and growth (see). Bodies and functional systems of the child from the moment of his birth. change according to the known periods of children's Century.
Children's V. is preceded by the period of pre-natal development, in Krom distinguish a stage embryonal (the first 2 lunar months) and placental (from the 3rd on the 10th lunar month) development (A. F. Tour).
The extra uterine period of development is subdivided into the next periods:
I. A neonatality (to 4 weeks).
II. Chest, or younger yaselny, V. (first year of life).
III. The period of milk teeth (from 1 year to 6 — 7 years):
1. Prepreschool, or the senior yaselny, V. (from 1 year to 3 years).
2. Preschool V. (from 3 to 7 years).
IV. Younger school V. (7 — 12 — 13 years). Age stage from 10 to 12 — 13 years sometimes call the prepubertatny period; at girls it begins in 8 — 9 years.
V. The period of puberty (the senior school, teenage, pubertal V.) — at girls with 12 to 16, at boys — from 13 to 17 — 18 years.
Duration of the period of a neonatality, having individually various terms, reflects the period of adaptation to extra uterine living conditions (see. Newborn ). Changes morfol, and physical are characteristic of it. - chemical indicators of blood, natural fluctuation of activity of desmoenzymes and others biochemical, indicators. Owing to incompleteness morfol, structures of many bodies and their functional imperfection can be observed so-called fiziol, an albuminuria, urate heart attacks, tranzitorny fever, fiziol, transitional dyspepsia. The resistance to many infections (scarlet fever, measles, a rubella, diphtheria, typhus, smallpox, etc.) connected with the oroimmunity received from mother during pre-natal development or with breast milk is characteristic of the newborn. Hypersensitivity to pyogenic microbes and pathogenic strains of colibacillus is at the same time noted.
Chest V.'s duration is defined by the term of breastfeeding. By the end of the first year of life the organism of the full-term and normally developing child reaches the certain functional maturity allowing to pass to a so-called general diet. At the same time the main functions of the baby are not steady yet: there is no ability to restriction of pathological process within this or that body or fabric, there is a tendency to diffusion reactions and septic processes; c. by N of page of the child it is quickly exhausted therefore it needs a long dream (see. Baby ).
In the period of milk teeth all functions of the child are gradually improved. Its organism is very plastic and all influences of the environment, including and social very clearly affect in it. Initial oroimmunity weakens, tendency to diffusion reactions at diseases decreases, diseases of so-called children's infections, contamination of tuberculosis become frequent; anomalies of the constitution, in some cases — lymphatic are shown, is more rare — a neuroarthritic and hemorrhagic form of diathesis. Various forms of endocrine frustration become frequent.
In prepubertatny, younger school V. many bodies reach full development, comes to an end morfol. differentiation of a cerebral cortex and conduction paths.
The pubertal, senior school period (Latin of pubertas maturity) begins with formation of secondary sexual characteristics and comes to an end with achievement of biological puberty. The beginning and duration of the period depend on genetic features of the individual, climate, food etc. The pubertal period is not connected rigidly with calendar age, the end of the pubertal period merges with youthful V., in Krom development of the changes which began in the previous period comes to an end.
Due to acceleration age changes are displaced towards younger age periods (see. Acceleration ). There can be deviations in the form of delay or early approach of puberty, a precocity of mammary glands, a gynecomastia at boys etc.
In the pubertal period can take place of the phenomenon, boundary between norm and pathology. They are connected with constitutional variations of functions of hormonal glands and a number of the exogenous influences which are temporarily breaking harmonious development of an organism. Akromegaloidny changes of extremities, the increased growth, the weight loss or obesity similar to clinic of a pseudo-adiposagenital syndrome or an adipozogigantizm, neurovegetative dystonia, excessive mobility and instability of the autonomic nervous system, mentality and behavior, deviation from closed glands are observed — a pubertal craw, a tendency to spontaneous hypo - and a hyperglycemia, lability in mineral metabolism etc. Cases of disturbance of activity of cardiovascular system (a juvenile hypertension, a Crocq's disease, youthful heart etc.), changes are frequent from skin (eels, seborrhea, a hyperhidrosis), increase or falloff of appetite. Disturbances of a musculoskeletal system (scolioses, flat-footedness, H-shaped legs etc.) are possible.
Two groups of diseases are inherent in the pubertal period: 1) pathology of sexual and endocrine systems (abnormally early or late puberty, total or its partial absence, intersexuality, hermaphroditism, transvertizm, etc.); 2) the diseases which are found and in other age periods, but the having clinics, specific to this V., and the increased frequency of occurrence (a diabetes mellitus, tuberculosis, rheumatism, etc.).
In the pubertal period growth is accelerated — mean increment is equal to 10 cm a year that corresponds to intensity of growth of the 2-year-old child. The maximum increase of length of a body is the share of the beginning of emissions and periods. Girls have growth and weight in 11 — 15 years on average more, than at boys. Signs of sexual dimorphism, specific and typological features of appearance and a proportion of a body finally develop in this period. Limit increase of length of a trunk occurs for a year later, than the lower extremities. At girls after the intensive growth of the lower extremities increase in diameter of a basin and width of a thorax begins; boys have the maximum increase in diameter of a basin, then a final pulling of a trunk, increase in volume of a thorax.
The most important and characteristic indicator of development of various periods of children's V. is formation of c. N of page. After improvement of functions of analyzers there is a development difficult, inherent only in the person of mental and psychomotor activity. At the same time especially expressed changes happen over the first year of life when every month is followed by qualitatively new, notable indicators of development allowing to differentiate rather precisely and objectively these small stages of life that cannot be carried out in any other age periods. So, emergence of the first smile in response to a conversation of adults happens at the age of 1 month, in 4 months the child steadily gets up on legs with foreign support, emergence of babble (pronouncing separate syllables) — in 6 months, response to elementary questions with point at the same time on objects, about to-rykh ask — 9 months; an independent steady support on legs — in 11 months etc.
With age gradually (the first simple intelligent words in 11 months) informal conversation develops; by 3 years the speech stock reaches 1200 — 1500 words, the child begins to understand sense of the speech speaks about the events which are not connected with its personal experience difficult phrases.
A characteristic indicator of age dynamics of the child of the first year of life is disappearance at it specific reflexes, so-called reflexes of involution (primitive, fiziol, reflexes of newborns). They are caused by activity of preferential talamo-pallidarny system in view of immaturity of a cerebral cortex and in process of maturing of the last are exposed to involution. Each of reflexes (Robinson, Moro, Magnus — Klein, search, palmar and oral, «setting the sun», «doll eyes», hobotkovy, swimmings, crawlings, automatic walking, etc.) disappears in certain age intervals, and by the end of the first year of life the child acquires the neurologic status already almost identical to the adult.
In preschool V. there is a further complication and a differentiation of mental development. Influence of brake processes is more expressed. The child actively perceives the world around, acquires moral concepts and ideas of duties, shows great interest to children. Many children begin to read and write, easily seize elements of a foreign language.
In the school period development of irregular shapes of behavior continues, specific features form. At teenagers the features of behavior connected with hormonal reorganization come to light more and more. The thinking differs in tendency to abstraction and generalization.
During the age periods of the childhood it is natural, with rather certain quantitative indices functional characteristics of various bodies and systems change (e.g., the frequency and depth of breath, pulse, arterial pressure, electric activity of a brain, etc.), shifts in quantitative indices of a number of biochemical sizes of blood are noted (residual nitrogen, uric to - you, amino acids and proteins, sugar, enzymes, lipids, mucopolysaccharides, hormones, etc.) and releases of these substances with urine.
With age needs of the child for food change. The need for protein in view of intensive growth is much higher, than at adults. So, up to 3 years the child needs 2 — 4,0 g, and adult 1,1 — 1,3 g of protein on 1 kg of body weight. The need for early age for carbohydrates makes 12 — 14 g, and children of more advanced age have 10 — 12 g on 1 kg of body weight. Intensity of carbohydrate metabolism (at newborns the glycoclastic pathway of glucose prevails) is increased.
With age specific and nonspecific reactivity of an organism changes. It is established that unresponsiveness, i.e. inability of a fruit and the newborn to synthesis of immunoglobulins, is not considered indisputable any more. It is proved that the fruit synthesizes macroglobulins. In the course of immunological maturing at healthy newborns the sequence of synthesis of different classes changes immunoglobulins (see).
At the end of youthful and mature V. morfo-functional development of an organism comes to the end; expressiveness of indicators of morfo-functional development is influenced considerably by constitutional features of an organism (see. Constitution ), and in indicators extreme constitutional types can have quite sharp distinction. Depending on constitutional accessory considerably varies also V., in Krom morfo-functional signs receive expressiveness final, inherent in a mature state. It defines discrepancy of terms chronological and biol. B.
Increase in life expectancy of the person, achievement of gerontology, age physiology and other sciences about human biology brought essential changes in classification of the late age periods.
Age periods of the adult
I. Youthful V. (juventas) — from 17 to 21 years at men, from 16 to 20 years at women. It is characterized by delay of growth; length of a body in this period increases on average no more than by 1 — 2 cm
of II. Mature V. (maturitas) — from 21 to 60 years at men and from 20 to 55 at women; it is subdivided into two periods: the 1st period — from 21 to 35 years at men, from 20 to 35 at women. It is characterized by the termination of growth, blossoming and relative stability of functions of an organism; the 2nd period — from 35 to 60 years at men and to 55 at women. It is characterized by neuroendocrinal reorganization, considerable change fiziol, functions and emergence of the first clinical displays of the diseases inherent in more advanced ages.
III. Elderly V. (praesenium) — from 55 — 60 to 75 years at men and women. It is characterized by acceleration of aging since the existing reserves of adaptation hardly compensate the hardly noticeable, but accruing age changes; there are diseases inherent is preferential to this age period (atherosclerosis, a hypertension, etc.).
IV. Senile V. (senectus) — after 75 years at men and women (aged people are more senior than 90 years treat long-livers). The developed involution of an organism is characteristic: falloff of level of the main fiziol, functions, falling of reliability of adaptation, the increasing probability of death.
The evolution of an organism determined by influence of heredity and exogenous factors does not proceed harmoniously. During the separate periods of life there are significantly disproportional changes in different bodies and systems. So, on mature and elderly V.'s border allocate a special age interval, so-called. climacteric (see), characterized by rough shifts in neurohumoral regulation of exchange and functions.
In spite of the fact that criteria biol. Are constantly specified century, they are not always objective. In the choice of tests for definition biol. For century of the adult it is important to be guided by the main criteria: universality, endogennost, gradualness, destructiveness. Regardless of external conditions genetic conditionality of aging predetermines its universality and an endogennost. Aging is a gradual cumulation biol, changes; their accumulation, being destructive for an organism, inevitably lowers viability of an organism, increases probability of death.
All existing tests for definition biol. It is accepted to divide into three categories century: a) the «global» tests for aging reflecting degree of a degrowth of actively functioning protoplasm in an organism; b) tests of assessment of functional activity of bodies at rest; c) the tests for adaptation which are quantitatively characterizing limits of reliability of a number of functions (F. Burliyer, 1971).
During the definition biol. Century in days of a maturity consider: a condition of skin and its appendages (color, thickness of a skin fold on a shoulder, a stomach, the back of a brush, expressiveness and localization of wrinkles, a condition of a pilar cover), dental health, extent of ossification of a skeleton, morphology of capillaries of a nail bed, size of vital capacity of lungs, muscle strength, visual acuity, range of accommodation of a crystalline lens, rate of propagation of pulse wave, etc.
In definition biol. Century from elderly and old people the great value was gained by tests for adaptation, for fatigue, the standardized «ladder» test, for tolerance to glucose, etc. Aging is followed by accumulation of actually age and compensatory and adaptive (adaptive) changes (see the Old age, aging); their ratio substantially defines safety homeostasis (see) till an extreme old age.
In mature V. due to various reasons of involute character there are minimum microstructural changes testimonial of aging of various fabrics, systems which are followed by death of parenchymatous cells, substitution by their inactive fabric (fat, connective tissue elements) and excess accumulation in fabrics and cells of various substances and decomposition products of nek-ry structures, decrease of the activity of a number of enzymes and level of exchange processes in the beginning.
Accumulation of these changes leads to decrease in functional properties of bodies and systems. To a certain degree it smoothes out development of compensatory mechanisms (see. Compensatory processes ). The specified changes, their rate of development, time of the first externally visible changes and expressiveness are very variable and are defined considerably by heredity of this individual, and also extent of influence of environmental conditions (a condition of life, food, kind of work, professional harm, usual intoxications — nicotine, alcohol, etc.). The listed factors complicate the specific characteristic of the signs inherent in a certain passport age. In an average look the conventional indicators of senile changes give only an approximate idea of Century. Similarly told belongs also to functional and psychological indicators (blood pressure, reflexes, vibration sensitivity, amount of hemoglobin in blood, force of muscles, the increasing apathy, decrease in memory, emotional instability, a depression, etc.). Though the frequency of mental disorders does not increase with age, the possibility of increase of mental disorders at elderly and senile V.'s persons takes place in connection with a number of the factors inherent in this V. (the loss of relatives, forced retirement connected with age social isolation, etc.).
Medicolegal age determination it is carried out without fail: at survey of the defendant, suspect, victim, in particular at a minority (see. Minority ), when it matters for business, and documents are absent (Art. 79 of the Code of Criminal Procedure of RSFSR).
In practice V.'s definition is connected also with an identification of the identity of the unknown dismembered, the skeletirovanny, burned corpses etc. (see. Identification of the personality ). V.'s establishment is based on the indicators characterizing physical. and sexual development of the person, is also made with use of a complex of methods: anatomo-morfol., rentgenol., anthropometrical, microscopic, spectral, etc. At out-patient court. - medical surveys and at a research of corpses have the greatest value anatomo-morfol., anthropological and functional indicators.
V.'s definition a fruit is made on length of his body. With a length of body from 25 to 50 cm the received length of a body is divided on 5 (private from division specifies duration of gestation — V. of a fruit in lunar months); with a length of fruit less than 25 cm the square root is drawn; the received result means the same, as in the first case. It is also possible to determine century of a fruit and newborns by the sizes of long tubular bones. At newborns, besides, take the sizes of the head, a circle of a thorax, a kernel of ossification and some other signs into account (see. Donoshennost , Newborn ). To the signs characterizing physical. development of children, young men and girls, growth, weight, a circle of a thorax, extent of differentiation of a bone skeleton, terms of first dentition belong (see. Teeth ) and change by their constants, degree of a stertost of teeth, periods and emissions, the sizes of a basin, extent of development of mammary glands, a developmental character of vegetation on a face (boys), in axillary areas, on a pubis, etc. Average V. of emergence of periods — 13 — 14 years, emissions — apprx. 15 years. Development of mammary glands begins on average from 11 years and comes to an end by 16 — 18 years. By 17 — 18 years the basin at girls reaches the final sizes. Development of hair in axillary areas and on a pubis happens in limits And — 15 years at girls and 13 — 17 years at boys. The adult so accurate naturally proceeding processes have no age morphology. To the most expressed and about a nek-swarm the sequence to the proceeding age signs involute changes of bone system belong (see Age bone); changes from face skin, a neck, hands — loss of elasticity, discoloration, emergence of wrinkles (see. Skin ); degree of dental abrasion (see the tab.).
DEGREE of DENTAL ABRASION of the UPPER JAW DEPENDING ON AGE IN CONDITIONAL INDICATORS (according to M. M. Gerasimov, 19 55)
Note. Scale of indicators: 0 — there is no deleting, 1 — only enamel, 2 — deleting of hillocks is rubbed, 3 — deleting affected dentine, 4 — deleting touched a root canal, 5 — deleting reached bulk cross-section of a crown, 6 — full deleting of a crown.
Terms of emergence of wrinkles on face skin and a neck are individual and depend on a variety of reasons: development of a hypodermic fatty layer, profession, facial expression, and also climate, state of health etc. With age skin color of the person gradually turns pale, and at old people it can accept a yellowish shade. Approximately from 20 — 22 years wrinkles begin to develop frontal and nasolabial, in the beginning low-expressed. By 25 — 30 years they appear at outside corners of eyes. In more senior V. infraorbital and predkozelkovy wrinkles develop. By 50 years is also more senior along with sharply accruing development of the listed wrinkles of a wrinkle develop on a bridge of the nose, an upper lip, a chin (usually from top to bottom from corners of a mouth), on lobes of ears, on cheeks and on a neck; hair of the head turn gray. By 65 — 70 years usually all wrinkles become sharply expressed. Along with wrinkles, since 55 years, on face skin, hands and forearms there are small, and then gradually increasing pigmented sites. By this time skin loses elasticity and it is easy, especially on hands, gathers in folds. On a chin and a neck tendency of skin to an otvisaniye is observed.
Irrespective of reasons for V.'s examination always determine by set of signs with use of a complex of methods.
See also Age physiology .
Bibliography: Andronesku A. Anatomy of the child, the lane from Romanians., page 5, Bucharest, 1970; Arshavsky I. A. Problem of a periodization of ontogenesis of the person, Owls. pedagogics, No. 11, page 120, 1965; B at - N and to V. V. Allocation of stages of ontogenesis and chronological borders of the age periods, in the same place, page 105; Drill lyer F. Determination of biological age of the person, the lane with fr., M., 1971, bibliogr.; D and N and l to about in and the p H. M. Secondary dentition at children Vopr, antropol., century 27, page 61, 1967; Materials on physical development of children and teenagers of the cities and rural areas of the USSR, under the editorship of A. Ya. Goldfeld, etc., century 2, L., 1965; Pashkova V. I. About need of review of indicators of assessment of physical and sexual development of children and teenagers for problems of forensic medicine in connection with the phenomena of acceleration, Court. - medical examination, No. 1, page 13, 1973; Rapoport Zh. Zh. and P r and x and N of E. And. Physical development of children, Krasnoyarsk, 1970, bibliogr.; Salnikova G. P. Physical development of school students, M., 1968; Ageing of a cell, under the editorship of V. V. Frolkis, Kiev, 1971; Physiology and pathology of pubertal age, under the editorship of Br. Bratanova and K. Kubat, lane synonym, Sofia, 1965, bibliogr.; Physiology of the child of early age, under the editorship of 3. I. Kolarova and V. Gatev, lane with bolg., Sofia, 1970; Frolkis V. V. Regulation, adaptation and aging, L., 1970, bibliogr.
S. A. Zhdanova, E. G. Kalinovskaya, Yu. E.Lukoyanov; V. I. Pashkova (court.).