PROLIFERATION (Latin proles posterity + ferre to carry, create) — a new growth of cells and intracellular structures (mitochondrions, a cytoplasmic reticulum, ribosomes, etc.).
The item — the phenomenon eurysynusic is normal also of pathology. It is the cornerstone of growth and a differentiation of fabrics in the course of an ontogeny, provides continuous cell renewal and intracellular structures, fluctuation funkts. activities of bodies, especially at their steady functional stress. The item of various cells of immunocompetent system (lymphocytes, plasmocytes, macrophages, etc.) and their organellas is a structural basis of an immunogenesis. At patol, the processes which are followed by damage of bodies and fabrics by means of P. the formed defect is liquidated and the broken function is normalized. The item can arise owing to disturbances of hormonal influences and leads to ugly increase in body, napr, at an acromegalia. As a result of proliferation of the cells which lost ability to be differentiated in cells of this or that body the tumor develops. The item is also the cornerstone metaplasias (see).
P.'s source are undifferentiated, so-called stem cells of this fabric which, periodically being exposed to division and the subsequent differentiation, gradually turn into the specific cells of this fabric performing function, characteristic of it. The item of cells is carried out by their direct or indirect division (see. Amitotic division , Mitosis ). The new growth of ultrastructures of cells occurs by means of their division, budding, etc.
A number of bodies and fabrics (the hemopoietic, fibrous connecting, bone tissue, epidermis, an epithelium of mucous membranes) has very high ability to P. of cells, others — more moderate (a skeletal muscle, pancreatic, salivary glands, etc.), the third — absolutely or are almost deprived of this ability (c. N of page, myocardium). In the last the reparation of damage and normalization of functions after the postponed diseases, and also steady functional stress are provided to hl. obr. at the expense of P. of intracellular structures in the remained cells which at the same time increase in volume hypertrophies are exposed. At the same time the hypertrophy of body can occur as as a result of P. of cells (see. Hyperplasia ), and only ultrastructures of the remained cellular elements.
Bibliography: Davydovsky I. V. General pathology of the person, page 376, M., 1969; Strukov A. I. and Serov V. V. Pathological anatomy, page 99, M., 1979.
D. S. Sarkisov.