| Abstract: | The atrial walls in 10-13-day-old white rat embryos have been studied electron microscopically. The epimyocardium consists of 1-2 rows of cells and has an epitheliomorphic structure. At first the basal membrane is formed on the endocardial surface of cardiomyocytes; intercellular contacts in the lateral parts of the cells possess endo-epicardial polarity. The epicardial layer is formed on the 11th day of the prenatal development, the basal membrane begins to form at the same time on the epicardial surface of cardiomyocytes. Dynamics of differentiation of some cardiomyocytic organelles in cardiomyocytes is described. |
