The dissertation stated the new data relative to mechanism of internal heart structure in the norm and under acquired combined mitral valvular disease, and investigation of currently controversial issue as for the mode of sanguimotion on the great vessels of the greater and lesser circulations. In normal condition there are two parts in the cavity of atriums proper: upper - a sine (of venae cavae - in the right and of pulmonary veins - in the left) and lower - a funnel-shaped, nose section of which is directed onto the relevant atrioventricular opening. In the interposition between them there are orifices of heart auricles. Internal surface of atriums is smooth. Longitudinal axes of both right and left heart auricles are located orthogonally to the axial blood flow from atriums into ventricles that to be considered as the special adaptation, which, under the auricles' systole, leads to formation of vortex flows, superimposed onto the main flow of blood from atriums into ventricles, making it somewhat turbulent. Internal surface of ventricles of heart is uneven due to presence of deep roughness, formed by muscular trabeculae that have ordered right-side spiral tract with high transconductance of turns from the apex of heart to its base, which causes the circus sanguimotion in the ventricles under systole. In the cavity of ventricle of heart there are endocardial and myoendocardial masses. Valvate and extravalvate tendinous cords are reffered to endocardial masses. Extravalvate cords are served as mechanical connection between existed adjacent various contractile masses, providing the strengthening of walls of ventricles during systole. At all characteristics, the extravalvate cords correspond to so-called "false" cords. Myoendocardial masses include generally known papillary muscles and muscular trabeculae, and constantly observable masses, which we called muscular reversing trabeculae that in the publication are mentioned as "anomalous" or "abnormally located" cords. In the right ventricle there are special muscular trabeculae - intermuscular trabecular intersections that connect opposite walls of pulmonary trunk cone. During the experimental tests it has been identified that in the cross-section of rabbit's abdominal aorta, in the solid erythrocytic mass, white blood cells and platelets are distributed evenly (white blood cells - one at a time, and platelets - in small group populations), in the cluster order. Such circumstances indirectly show that all blood corpuscles are in the aortic flow in the evenly mixed condition, which can be achieved only in the mode of turbulent motion. Under acquired combined mitral valvular disease the common principle of atriums' structure is preserved, but they undergo deformity, which is generally represented by the noticeable enlargement of sine parts of atriums proper, resulted in shortening and widening of its funnel-shaped parts in the area of left and right atrioventricular openings. The specific character of both forms of acquired combined mitral valvular disease is the deformation change of both valvate ("true") and extravalvate ("false") tendinous cords, which is evident by their shortening and thickening. Thus, in both forms of acquired combined mitral valvular disease endocardial and myoendocardial masses are subject to isometric deformity, due to which the internal relief of ventricles are becoming smoother, which can affect the mode of sanguimotion in the pulmonary trunk and aorta in the form of its turbulence decay, which in its turn, should result in disorder of even distribution of the other blood corpuscles in the erythrocytic flow.
