This longitudinal section shows cardiac muscle cells of a cylindrical shape. Central parts of the cells contain one or more nuclei #1, #2 and organelles while the peripheral parts include transversely striated myofibrils #1, #2. Cardiac muscle cells are branched thereby forming anastomoses #1, #2. There are stripes of loose connective tissue between the cardiac muscle cells with a lot of blood capillaries containing red blood cells.

In hematoxylin-eosin stain, the striated nature of myofibrils and intercalated discs is not so marked, though transverse striation and intercalated discs #1, #2 are clearly pronounced in case of iron hematoxylin stain.

The transverse section reveals that cardiac muscle cells are of rounded or irregular polygonal shape. Myofibrils look like a cluster with oxyphilic granularity, while nuclei #1, #2 lie centrally; they are not detected in every cell.