MICRO- AND ULTRAMICROSCOPIC STRUCTURE OF THE LEFT ATRIA-VENTRICULAR VALVULAR APPARATUS IN HUMAN AT THE MATURE AGE IN NORM

This article presents the morphological characteristics of the mitral valve of a normal heart of an adult at a mature age.The purpose of our investigation is to find out the peculiarities of the morphology of the structural components of the mitral valve apparatus of the heart of a person of mature age in the norm.Material and methods. The study was performed on 32 preparations of mitral valves of adult human hearts. A complex of morphological research methods was used: methods of light and electron microscopy, histochemical method.Results. With the use of a complex of morphological research methods, a study of the structural components of the mitral valve apparatus of a normal mature person was carried out and their histoarchitectonics was established at the micro- and sub-microscopic levels.Conclusions. The leaflets of the mitral valve are connective tissue plates covered with a single-layer flat epithelium - endothelium. The leaflets are formed by fibrous connective tissue of different density, as a result of which three layers are identified: spongy, fibrous and ventricular. Typical chordae tendineae in the form of connective tissue threads extend from the papillary muscles to the leaflets of the mitral valve and attach to their ventricular surface. The skeleton of chordae tendinea is formed by dense fibrous connective tissue. Striated cardiac muscle tissue is found in some chordae tendinea in the areas on the side of the papillary muscles. The papillary muscles are formed by the working fibers of cardiomyocytes, which form a kind of network due to branches and anastomoses. The working fibers of cardiomyocytes are accompanied by layers of loose fibrous connective tissue, which includes a large number of blood vessels.