From Big Medical Encyclopedia

GRADIENT PHYSIOLOGICAL (Latin gradiens, gradient[is] walking) — the qualitative or quantitative characteristic of gradual change of any physiological indicator in time or space. A concept about G. f. it is formulated by Chayld (S. M. Child, 1914) for an explanation of patterns of formation of bonds in ontogenesis where G. f. acts as a factor of an ontogeny, according to the Crimea development of an organism is characterized by gradualny formation of functions. At the same time many processes in the developing organism (the direction of development of this or that body, behavior of a germ, etc.) cannot be understood from positions G. f., since G. f. is only a consequence of wider biol, patterns of development (see. Sistemogenez ).

See also Gradient .

Bibliography: Anokhin P. K. Physiological gradient, reflex and functional system as factors of embryonic development of unconditional reactions, Zhurn, general biol., t. 10, No. 5, page 361, 1949, bibliogr.; Chayld Ch. M. A role of organizers in developments, the lane with English, M., 1948, bibliogr.