ПЕРИОДИЗАЦИЯ РАЗВИТИЯ КУРИНОГО ЭМБРИОНА

Abstract

Embryology (from the Greek embryon – embryo, logos – doctrine) is not just a biological discipline, but a science that studies the formation, development, and also the formation of embryos of living beings from the moment of the appearance of germ cells and their fusion until the birth of the world a new organism. One of the largest embryologists who studied the development of avian embryos, Hamilton, considering it amazing how the beginning of the functioning of one organ correlates with the functioning of other organs and systems of the body, writes: "It is not surprising that there are certain sensitive periods when the embryo is susceptible to disturbances both in the internal and and in the external environment". Quite a lot of literature is devoted to the issues of periods of hypersensitivity, or, as they are usually called, critical periods in the embryogenesis of various animals (invertebrates and vertebrates). The position of critical periods of development was first put forward by the English physician-scientist K. Stockard in the 20s. XX century And later it was deepened and expanded by the Soviet scientist-embryologist PG Svetlov. Periods of increased sensitivity to damaging influences in the embryonic development of fish are named. Omitting a large number of works, let us inform that Korovina, recognizing the stages of development and formation of a new quality at each stage, denies the existence of periods of increased sensitivity to the action of all environmental factors without exception. The author acknowledges that there are periods in embryonic development when embryos are equally sensitive to several influences, but considers it necessary to emphasize the specificity of the response to various environmental factors.