Modern ideas of intconnection of structure and function in terms of I.P. Pavlov's notions

In the paper there are presented modern ideas of interconnection of structure and function. These ideas are based on scientific notions, worked out by academician I.P. Pavlov's school. The literary data of methodological character served as a basis for distinguishing levels of biological substance organization. There are also given factors which have an objective influence on the correct evaluation of real interconnection of structure and function. These are the following factors: the norm of reaction, the level of research and adequacy of methods of research, the combination of different methods of research, retardation, the mosaic character of structural differences. There is emphasized a special role of the cell level of organization and methods of cytological research in investigating of the interconnection of structure and function of biological objects.