Transmission electron micrograph of longitudinal section of rat heart cardiac muscle from the atrium. A darkly stained intercalated disc runs from upper left to lower right. Also prominent are groups...

Transmission electron micrograph of longitudinal section of rat cardiac muscle from the heart atrium. Homogeneously staining spherical trial granules are present as well as mitochondria and myofibrils...

Transmission electron micrograph of longitudinal section of a a rat heart ventricle. Ordered arrays of myofibrils are interspersed with rows of mitochondria. Small, darkly staining glycogen granules a...

Transmission electron micrograph of mouse cardiac muscle. Transport is visible in the ventricle across a space from one muscle cell to the adjacent muscle cell.

Papillary muscle from cat heart shows a step-like end-to-end junction of two cardiac muscle cells. The longitudinally oriented lateral cell boundaries are straight and exhibit extensive gap junctions...

Gap junctions in papillary muscle from cat heart. These communicating junctions are responsible for the spreading wave of depolarization through the myocardium. Desmosomes can also be found on the l...

Lipid droplets partially enveloped by mitochondria in the interstices between cardiac myofibrils reveal a metabolic partnership that can serve as an alternative energy source for muscle. Figures 255 ...

In cardiac muscle, mitochondria are distributed uniformly in a near-continuous field of myofilaments, ensuring that ATP is readily available. This transverse section is of right ventricular papillary...

Figure 351 from Chapter 15 (Cytoplasmic Inclusions) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Glycogen in the ventricle papillary muscle of cat heart. In this tissue, the glycogen occurs as indi...

Transmission electron micrograph of rat heart cardiac muscle from the atrium showing the regular arrangement of the actin-myosin myofilaments in cross section and abundant mitochondria. This 1958 TE...