False-colour transmission electron micrograph of part of a striated muscle fibre (cell) from the human neck. Striated muscle cells are elongated, hence their description as fibres. Each cell has several nuclei (not visible) positioned just below the sarcolemma, the name given to the cell membrane of muscle cells. Running the length of each fibre are contractile protein filaments (actin and myosin myofilaments) arranged in bunches called myofibrils (20-30 myofibrils are visible here). The arrangement of the two types of myofilament causes the prominent transverse banding which gives striated muscle its name. Magnification: x1940 at 6x4.5cm size.