Colorized scanning electron micrograph of thigh muscle fibrils.

Figure 239 from Chapter 7 (Mitochondria) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. The cristae of mitochondria can take on zig-zag configuration (see arrows) which is particularly apparent in cel...

Transmission electron micrograph of a section of the right atrium of a guinea pig heart. A portion of nucleus is seen at far left, with two centrioles close to the nuclear envelope. A region of myofib...

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 ...