JUMP GROWTH at puberty.
Acceleration(from acceleratio - acceleration) - in anthropology and medicine, the acceleration of the growth and development of children and adolescents compared with previous generations.
The term "Acceleration"introduced the German scientist E. Koch (E. Koch) in 1935. Acceleration is part of a broader concept -" secular trend ", or" age-old tendency ", which also includes an increase in life expectancy, a later onset of menopause and more
In physiological terms, acceleration is manifested in the fact that at every age stage modern children are taller and larger than their peers of previous years. Acceleration can be traced from the prenatal period of development. Over the past 30–40 years, the body length of newborns has increased by 0.5–1 cm, and the body weight of the fetus has increased by 50–100 g. Doubling of the weight observed earlier by the 6th month now occurs between the 4th and 5th months, the chest circumference exceeds the head circumference not on the 6th, but between the 2nd and 3rd months. Baby teeth appear at an earlier age, on average one year earlier permanent teeth erupt, the skeleton ossification period has accelerated. With age, the acceleration rate increases, reaching a maximum during puberty (seePuberty).
The prepubertal increase in body length occurs earlier and therefore the so-called 1st and 2nd crosses of the curves of the length and weight dynamics of girls and boys are observed at an earlier age. Acceleration of physical development at school age is manifested both in basic morphological indicators and in functional signs of physiological maturity, one of the objective indicators of which is the beginning of puberty, in modern adolescents occurring much earlier. There was also an increase in other physiological indicators of the functional state of the body (muscle strength, lung capacity, etc.).
At an earlier age, higher final body sizes are achieved. However, acceleration is associated with the deterioration of some indicators of the functional state of the body, for example, with the increasing and "rejuvenation" of a number of diseases (hypertension, diabetes, leukemia, neurovascular dystonia, myopia, etc.).
There are a number of hypotheses explaining the causes of acceleration. One of the first was proposed heliogenic hypothesis,According to which, as the leading factor of acceleration, a more intense influence on solar radiation of modern children is recognized - one of the important conditions for the normal growth and development of the organism.
Acceleration is more pronounced among urban populations. This is explained in the hypothesis of urbanization, according to which the main factor of accelerated development is the influence of a big city (noise, traffic, changes in radiation levels, mental overstrain with insufficient exercise, etc.).
It is believed that the so-called damaging factors activate the body's defenses, causing compensatory reactions. The overall size of the body and the full maturity in humans are determined by heredity. At the same time (according to the genetic hypothesis) the length of the body of children as compared with that which would correspond to the height of the parents, can vary considerably depending on the socio-economic conditions of life.
Among the causes of acceleration, a certain importance is attached to the mixing of the population and the heterosis arising in this process, the general biological essence of which is that mixing different genotypes leads to an increase in viability, productivity, etc.
All existing acceleration hypotheses do not fully explain it. Obviously, the reason is in the complex of phenomena, and at different times different factors are put in the forefront. The most probable one should nevertheless be considered the social conditionality of acceleration.
During the existence of mankind, the cyclical nature of acceleration manifestation, more or less pronounced in time, has taken place. In the modern historical period, acceleration began about 150 years ago and covered the population of most countries of the world, especially industrialized ones. In our territory, as in some foreign countries, the acceleration rates began to slow down. Despite this, the phenomenon of acceleration puts forward a whole range of new biomedical, social, legal, and legal problems, the solution of which requires further in-depth research.