Skeletal muscle. Scanning electron micrograph (SEM) of a transverse section through skeletal muscle. The many muscle fibres (red) are seen, along with the elastic sheath (epimysium, brown) which surrounds them. This tissue is under voluntary control and is responsible for the movement of long bones. It is also known as striated muscle, because the regular arrangement of its contractile proteins forms a pattern of alternating light and dark bands (striations, not seen) across each fibre. Magnification: x200 at 6x7cm size.