This semi-thin section (~1.0 µm thick) of skeletal muscle has excellent cellular definition compared to normal sections (4 to 6 µm thick). This longitudinal section allows the morphology of individual skeletal muscle cells (or fibers) to be examined.
The parallel arrangement of skeletal muscle cells is seen on the left of the specimen. Each cell is from 50 to 150 µm in diameter.
Some skeletal muscle cells can be followed for over 2.5 µm on the left side of the specimen.
Muscle Cell / Fibroblast Nuclei - muscle cell nuclei are mostly euchromatic and have a flattened, oval shape. Fibroblast nuclei are located between muscle cells and are more elongated and darker.
Sarcomere - cross-striations are evident in some areas.
A band - the main dark band
I band - the main light band
H band - thin light band in the middle of the A band
Z line - thin dark line in the middle of the I band