Individual development of organisms - a set of biological processes that lead to cell growth and change over the entire period of their existence.The generally accepted scientific name - ontogeny.Its main task is to observe, identifying the main stages and characteristics of each period, the identification of patterns, as well as analysis of the changes and identify the factors that may cause these changes.
individual development of the organism is inherent not only to man, but to all living creatures and plants.The main stages of development are:
- Predzarodyshevoe development (gametogenesis).
- prenatal development (property development of the embryo, embryogenesis).
- Postnatal (development from birth: growth, weight gain, recovery, modification).
- Gerontology period (aging).
- death of the body (as a separate stage in the ontogeny of death is not isolated, but any individual development it ends it).
consider individual development of the organism of plants in this small article we will not, and will focus on closer people-centered development of the animal world.The stages of development, as already mentioned, a person does not change and correspond to those that have been mentioned above.
Gametogenesis in humans consists of two components: spermatogenesis (maturation of male germ cells - sperm) and oogenesis (maturation of female gametes - eggs).Fertilization is possible only if mature sex cells in male and female mice.In the event of abnormalities in fertilization may be formed organisms - chimeras, some of which are quite viable.
human embryogenesis - one of the most important steps.It is divided into the initial stage (0 - 1 week after fertilization), the actual embryonic stage (2 - 8 weeks) and fetal or fetal stage (9 weeks - birth).It was during this period formed the vital organs, the body is made, can manifest themselves or other genetic diseases.
individual development of the organism in the postnatal period is to further the development of organs, increase in size and weight, the acquisition of new mental functions, changes in motor activity and its development of new species.Postnatal - the most important in the development of the new man.Its length is about 17 years (from birth to adolescence).On the individual development of the organism during this period affect not only features due to heredity, but also psychological, social factors.Formed conscience, speech, thinking and other processes of higher nervous activity.By the end of this period, new individuals tend to come with a complete gametogenesis.
of aging - the stage of decay, depletion of resources of the body.Irreversible disturbances in nerve cells, the myelin sheath is reduced quality of vision and hearing, "wear" vital organs, skin changes, lost the function of reproduction and dramatically slows tissue regeneration, etc.
